TABULARUM EXPLICATIO.
[Tabula Septima.]
Fig. I. Exhibet corallinæ plantam, quæ corallina muscosa, sive muscus marinus tenui capillo spermophorus vocatur.
Fig. II. Corallina ramulis dichotomis teneris capillaribus rubentibus.
Fig. III. Junior planta corallinæ tubulariæ laryngi similis.
Fig. IV. Duæ species a, b, fig. I. et. II. et c eschara papyracea utrinque cellulifera, uni basi adnatæ, quod sæpius in doliis marinis coniformibius contigit.
Fig. V. Corallinæ rubræ ramulus, quem per aliquot hebdomadas in aqua marina sæpius renovata servavi, quo tempore parvi ramuli a, a, multum creverunt, et alii b, b, pullulaverunt.
Fig. VI. Pars conchæ ostrei, in qua, præter filamenta quædam viridia, duo polypi a a conspiciendi.
Fig. VII. Cancer arachnoideus, cui duæ polyporum species insidebant. Singulus in a, et multi cellulas habitantes in b.
Fig. VIII. Animal, quod aarsgat vocatur, et januis emissasiorum veterioribus et navibus accrescit: huic parva corallinæ planta erat innata, in qua nullos detegere poteram polypos; plurimos vero b. b. ipsi animali insidentes.
N.B. Caudas horum et præcedentis figuræ polyporum nimis longas delineavit pictor, ut eo melius in conspectum venirent.
[Tabula Octava.]
Fig. I. Ramus corallinæ rubentis magnitudine naturali.
Fig. II. Idem microscopio visus, et tres polyporum species in eo conspiciendæ.
a. b. Duæ diversæ species caudâ vel corporis parte posteriore corallinæ affixæ.
c. Tertia species in cellulis habitans.
d. Polypus mortuus.
e. Polyporum cellulæ.
Fig. III. Planta corallinæ tubulariæ laryngi similis magnitudine naturali.
Fig. IV. Hujus plantæ ramus maximus, microscopio visus, in quo quinque diversos polypos inveni.
a. Prima et maxima species polypi, quem coccineum voco, et [tab. IX.] fig. II. fortiore adhuc microscopio visum exhibet.
b. Eadem sed minor species.
c. Tertia, quæ eadem ut hujus tabulæ fig. II. litt. b.
d. Quarta, quæ eadem ut hujus tabulæ fig. II. litt. c.
e. Quinta et minima polyporum species, maxime aucta magnitudine adhuc delineata fig. 1. [tab. IX.]
f. Cellulæ, quas quarta species habitat.
Fig. V. Corallina erecta pennata denticulis alternis caule appressis: in hac nulli erant polypi nisi in cellulis circumcirca truncam affixis a a.
b. Cochleæ magnitudine auctæ in B.
c. Eschara millepora minima crustacea cellulis tubiformibus, animalculis domicilio inserviens, et magnitudinæ auctæ in C.
Fig. VI. Corallina abietis forma, quam mense Decembri accepi: ejus rami vesiculis vel ovulis a, a, per paria ordine quadam positis, erant obsessi.
A. Talis vesicula vel ovum microscopio visum.
b. Cochleæ, & c. Eschara minima, ut in præcedente figura magnitudine aucta in B et C.
d. d. Dua corpuscula fusca, quæ microscopio visa nidum vermium referunt in D.
Fig. VII. Corallina pennata et siliquata, ab ostreo abstracta: in hac præter tres polyporum species
a A, b B. (quæ cædem ac in fig. II.) c C, sex alia insecta reperire contigit, quæ delineata sunt in [tab. X.] fig. 1, 6, 8.
Philos. Trans. Vol. L. Tab. VIII. p. 276.
I. Rhodius ad vivum pinxit.
J. Mynde sc.
[Tabula Nona.]
Fig. I. Minimorum polyporum marinorum genus, cum polypis ramosis (polypes à bouquet) aquæ dulcis conveniens.
A. talis polypus conservæ marinæ viridi insidens vix oculo nudo conspicuus.
B. idem lente oculari, et in C fortiore visus microscopio.
Fig. II. Polypus coccineus, quem tabulæ secundæ
Fig. III. & IV. naturali et aucta magnitudine exhibent, hic fortissimo microscopio visus.
A. hic polypus expansis brachiis, prædam expectans.
B. idem brachia contrahendo, prædam arripiens.
a. Brachia majora inferiora numero 16, 18, vel 20.
b. Brachia superiora breviora numero 12, 14, vel 16.
c. Corporis pars superior pyriformis, inferiori infixa.
d. Corporis pars inferior compressa.
e. Locus, ubi polypus corallinæ inhæret.
C. idem polypus a parte anteriore visus, cum corporis partem superiorem pyriformem in globulum contraxerat, quod in majoribus polypis (vide infra fig. IV, V, VI.) magis visibile.
Fig. III. Similis polypus coccineus, cæteris major, ex cujus corpore (ubi partes c et d conjunguntur) octo ramuli enascebantur, qui in summitatibus duos vel tres gerebant globulos, punctum rubrum in medio habentes, et quos in polypos juniores excreturos fore speraveram frustra.
a. Hujus polypi brachia longiora inferiora.
b. Brachia breviora superiora.
c. In medio corporis pyriformis os polypi esse videtur.
Fig. IV. Majus, ut videtur, genus polyporum, quos klapkonten vocant, ostreorum conchis insidentium, quorum hic, rudius attractum, brachia penitus in corpus suum abscondit.
Fig. V. Idem polypus corpore extenso brachia expandens.
Fig. VI. Idem capta præda se contrahens.
Philos. Trans. Vol. L. Tab. IX. p. 278.
I. Rhodius ad vivum pinxit.
J. Mynde sc.
Philos. Trans. Vol. L. Tab. X. p. 279.
I. Rhodius ad vivum pinxit.
J. Mynde sc.
[Tabula Decima.]
Fig. I. Tres species animalculorum lucentium in guttula aquæ marinæ fortiore microscopio visorum.
Fig. II. Mirum animalculum in corallinis a doliis marinis coniformibus abrasis repertum.
A. tales minores erant centeni.
B. decem vel duodecim erant hac magnitudine naturali.
C. idem animal microscopio visum.
a. Antennæ.
b. Primum par pedum vel brachiorum.
c. Secundum par.
d. Tertium et maximum par.
e, e, e, e. Quatuor corpuscula oviformia, quæ animal ut movebat natando.
f, f, f, f, f, f. Sex pedes posteriores, quibus simul corallinæ ramum arripiens, quaquaversum se flectore poterat.
g. Cauda in cujus extrema parte anus.
h. Oculi.
Fig. III. Aliud animal in iisdem corallinis repertum.
A. illud animal pronum.
B. supinum.
C. fortiore microscopio visum.
Fig. 1, 2, 3, 4, 5, 6, 7, 8. exhibent quasdam noctilucas, et alia animalcula in diversis corallinis reperta, ea magnitudine, qua tertia et quarta lens microscopii à Dº. Cuff in Anglia fabrefacti illa ostendit.
Animalculum c, fig. 8. mirabilissimæ erant structuræ, et plurima habebat membra.
XXXIII. Remarks on Dr. Job Baster's Observationes de Corallinis, &c. printed above, p. 258. In a Letter to the Right Honourable George Earl of Macclesfield, President of the R. S. from Mr. John Ellis, F.R.S.
My Lord,
Read June 9, 1757.
I Have read Dr. Job Baster's letter to the Royal Society; wherein he endeavours to prove, that corallines are not of an animal, but a vegetable nature; and has brought many arguments to support his system; which, to gentlemen not well acquainted with the subject, may appear plausible.
I could have wished the Doctor had read and examined thoroughly what has been lately written on the subject: I then should not have had occasion to trouble your Lordship with the following remarks, which I find necessary to support what I have already advanced on that head.
His first argument is, That because he does not find as many polypes in the corallines adhering to ships, flood-gates, and buoys, as in deep water on oysters, muscles, and rocks, therefore he concludes, that corallines are not formed by polypes.
In answer to this, let us examine the pliable structure of these bodies, and how wisely nature has defended such tender substances with a tough thin membranaceous covering, and we shall find, that the sea is calm enough often near the surface to give them time to grow, even in the strongest currents: but, without doubt, they are more liable to be destroyed in such agitated situations, than in the calm depths of the sea.
His second argument is, That finding polypes are not equally dispersed over the whole plant, how can they form it? and gives us an example, [Tab. VIII.] fig. 5. of a coralline, that is incrusted with many other corallines or polypes on the stem, but has none on the branches.
Here we plainly see the mistake: the Doctor looks for the tender part of the polype on the surface of the coralline, considering it as a plant; and indeed, if this was the case, he ought so to do; but he never once takes notice of the internal hollow structure of the stem, branches, and denticles of those bodies, to inform us whether he found an animal in those parts or no. This material point he seems not to have thought on; which is really the true point in controversy at present among gentlemen, who have not examined these bodies recent in sea-water.
His third argument is, That almost always one and the same coralline plant cherishes polypes of different kinds; and refers us to [Tab. VIII.] fig. 2. and 4.
In fig. 2. he gives us an elegant painting of a geniculated red conserva for a coralline, surrounded, as is very common, by many species of small corallines and escharas. And in fig. 4. he gives us a drawing of one of the tubular corallines, with the head of the animal at the top of it; the stem of this is incrusted with four different corallines and escharas, like the conserva fig 2.; and then he asks, which of these five polypes made the tubular coralline?
To give him some proof of the animal nature of this coralline, let him consult Ray's Synopsis, ed. 3. p. 34. n. 4. and there he will find one of his species, called adianti aurei minimi facie planta marina, taken notice of so long ago as the year 1713. by Dr. Lloyd, as a zoophyte, from its stem or tube's being full of a thick reddish liquor, rather resembling blood than the juice of a plant; which, upon pressing the stem, communicated with the little head at top.
His fourth argument is, That as upon one and the same coralline plant you shall find different kind of polypes; so, in different species of coralline, the same polypes; and, to confirm this, he quotes my Essay on Corallines; where I have remarked, that the polypes in the denticles of the setaceous or bristly coralline, Nº. 16. appear to be like those, that are on the lobster's horn coralline, Nº. 19. And to illustrate this, he observes, that bees and wasps always build their cells invariably the same; and that therefore these two corallines should be the same.
But herein he takes this matter wrong: he has considered, in all his observations, the heads of those parts of the polype, in which are the mouths, arms, or tentacula, which appear coming out of the cups, denticles, and at the ends of the tubes of the corallines, as so many whole and intire animals, without every observing, that the body of the animal is contained in the tubular part of the root, stem, and branches; and that these differ from one another widely both in size and shape, as he may plainly see in the two corallines he has instanced: for the more exact drawings of which, I shall refer him, viz. for the setaceous or bristly coralline, to my Plate, Nº. 38. the natural size of which is at fig. 4. and the magnified one at fig. D: this he will observe to have a small stem, and its branches disposed in a pinnated form: and for the lobster's-horn coralline, I shall refer him to Tab. xxii. of Vol. xlviii. of the Philosophical Transactions; where, at Nº. 3. the natural size is expressed, and at C the upper part of this coralline is drawn in proportion to the bristly coralline from the same magnifying glass; which shews the stem to be much larger, and surrounded by its branches growing in whorles at equal distances, not unlike the equisetum, or horse-tail plant; and yet the heads of this animal nearly resemble the other, only a little larger. Further, his comparison to bees and wasps, and their cells, is not conclusive: for these ramified, hollow, and denticulated bodies, called corallines, which we so frequently find dead on our shores, are properly skins of certain marine polypes, and not nests, as those constructed by these little winged animals are. And yet we find as great a regularity in the same species of these corallines, as when we compare two oak trees to one another, or two of Mr. Trembley's branched fresh-water polypes to one another.
He then proceeds to his fifth argument, That if corallines were formed by polypes, neither the polypes, nor even their cells, would ever fix on living animals, or any other bodies.
Here we may observe, that the consequence he draws doth not follow; for corallines may be formed or produced by certain species of polypes, and yet polypes of another species may be found adhering to other bodies, and even to animal bodies.
By his sixth argument he endeavours to prove, That the vesicles, which are found in regular rows on the sea-fir coralline in winter, [Tab. VIII.] fig. 6. do not belong to it; and are no more than the eggs of some sea insect deposited on it, of which there may be a great variety.
But to convince him of his mistake, let him take off one of the vesicles, and apply a large magnifier to the place, and he will discover a hole, by which this vesicle or ovary has had a communication thro' the skin with the parent polype. For a further illustration of the manner in which these vesiculated polypes breed, let him consult the 38th Plate of my Essay, where he will find several accurate figures (drawn by Mr. Ehret from the life) of these vesicles, with the spawn of the polypes coming out of them; some of which spawn we evidently discovered to be young polypes with their arms formed; and, as they fell from the vesicle, extending themselves in the watch-glass of sea-water.
In examining the drawings for his plates, I have observed, that [Tab. VII.] fig. 2. is evidently a red conserva, which he calls a coralline. We have no corallines, but many conservas, of this form and bright red colour on our coasts; and these shores, I believe, are allowed to have similar marine productions with those of Holland.
[Tab. VII.] fig. 5. he calls a branch of red coralline, which he says he kept several weeks in sea-water, and that often changed; during which time it sprouted and grew very much. This experiment, I am persuaded, is very true; because it is plainly a vegetable, as appears from his own exact drawing of it; and seems to be the fucus teres rubens minus in longnum protensus of Ray's Synopsis, ed. 3. p. 91. N. 53. This is one of his principal arguments to prove the vegetation of corallines.
[Tab. VIII.] fig. 1. he calls a branch of red coralline; and at fig. 2. he has it magnified, where it appears to be a geniculated red conserva, drawn and painted with great exactness.
These arguments, my Lord, and these figures of real vegetables, which the Doctor has given us for corallines, shew, how much he is willing to support the old opinion of the botanists: but I am satisfied he will soon alter his opinion, when he observes the remarkable difference of the texture of vegetable and coralline bodies, when viewed in sea-water thro' a good aquatic microscope. And to convince him more fully, that corallines are an animal substance, let him burn them, and he will perceive the same pungent volatile alkaline smell, which he finds in burning horn, hair, or oysters; whereas burnt fucus's and conservas yield a smell not much unlike that of common land vegetables. Even the stony corallines, when their cretaceous covering has been dissolved in vinegar, the membranous part, that remains of them, put into the fire, yields the same animal smell with other corallines.
Further, since I find the Doctor has promised the Royal Society to continue his researches at the seaside, the following hints may be of use to him. And, first, he will find, that those he seems to think naked polypes, which he found adhering to corallines and other bodies, are really small corallines and escharas, with their proper skins and cells; all which I have particularly described already. I would then recommend him to examine such corallines as are taken out of the deepest water, which are found adhering to shells and fucus's. He will find Mr. Cuff's aquatic microscope, or one of that form, the most commodious for observing these animals alive.
The most transparent ones he will find the best to discover their gelatinous inside, which runs thro' the stem and ramifications, and ends in the heads, where the claws are. Some of the best kinds to observe are as follows: The sea-oak coralline, the lily-flowering coralline, the great tooth coralline, the sea-thread coralline, and the branched tubular coralline. Pieces of these should be cut off while they are in the sea water, and placed in watch-glasses full of the same: in these they should remain a while, till they recover themselves; and when they are placed on the stage of the microscope, the motion of the internal part communicating with the heads will be easily discovered.
If the Doctor will immerse some of these corallines, when they are extended, in two thirds of spirit of wine and one third of clear sea-water, it will preserve them many years, as I have experienced. He may then put the different sorts into distinct phials, and view them at pleasure with a lens of about one inch and half focus.
In fine, my Lord, opportunities so seldom offer at the sea-side to make these experiments with accuracy; and likewise to this, the strong lines of vegetation that these bodies carry in their appearance, and your Lordship will not be surprised, that there are so many gentlemen, even of the Royal Society, that totally disbelieve them to be animals.
Many there are in the Society, that are wavering between both opinions. If then, my Lord, you think, that any specimens which I have, or any demonstrations tending to clear up this point, that lie in my power, will be acceptable to your Lordship and the Society, your Lordship may freely command them, whenever you think proper, from
Your Lordship's
Much obliged and most obedient Servant,
John Ellis.
London, June 9. 1757.
XXXIV. An Account of an extraordinary Operation performed in the Dock-Yard at Portsmouth: Drawn up by Mr. John Robertson, F.R.S.
Read May 26, 1757.
THE Royal William, a first rate man of war, built about 40 years ago, having, upon examination, been judged in so good a state, as to be worthy of repairing for sea service, was ordered into dock, and brought thither on the 29th of June 1756. On these occasions it is usual to lay across the middle line of the bottom of the dock, at distances of about five feet from one another, thick pieces of oak timber of about four feet long; their upper surfaces lying in the same plane, or so posited, that a line stretched from the two extreme blocks will touch all the intermediate ones; and on the middle of these blocks the keel of the ship is to rest. On the said day the tide did not rise so high as was expected; and there was not quite depth enough of water to float the ship in, and set her on the blocks, notwithstanding the assistance of an empty lighter, which, being fixed to the stern, lifted the ship at the end six inches: and as the officers knew they should not have so much water again before the next spring-tides, they were determined to heave her in; which is a very common operation in most dock-yards. Now it so happened, thro' the great weight of the head and stern, that the ship cambered very much; that is, her keel, from being straight, was become much curved, the two extremities hanging lower than the middle part by many inches; and consequently the foremost part of the keel, instead of sliding over the blocks, forced all the foremost ones away, for above 60 feet; whereby that part of the keel rested on the bottom or floor of the dock, and the aftermost part rested on such of the blocks, as had escaped the violence, which had displaced the others. In this situation the keel was very far from being strait; and so it was resolved to lift by main force the head of the ship, until the keel should be strait; and in that position to support it by the blocks, which had been forced away from their places.
For this purpose there were set up, under the wales and other parts of the ship, to the length of near 80 feet of the stem, as many shoars, as were judged necessary; and also nine pair of bed-screws, three pair under each bow, and three pair under the knee of the head. At each shoar a workman was appointed, to drive wedges between the heels of the shoars and the parts of the dock whereon they rested; whereby the shoars were raised end-wise, and consequently the body of the ship lifted at the same time. While this was doing, the 18 screws were also at work: and between these efforts the fore part of the ship was raised upwards of 19 inches, so much being necessary to bring the fore part of the keel in a right line with the hinder part.
In this service were employed about 270 men; whereof about 144 worked at the screws, and the others worked at the shoars with their mawls and wedges; and the whole operation was performed in about seven hours.
My curiosity leading me to inquire what was the weight of the ship, in the condition she was at the time of bringing her into the dock; for this purpose I procured draughts of the elevation and section, and of the plans at the line of floating, and at the parallel sections of every foot distance down to the keel. Then, by finding the mean area between every two sections, I was thereby enabled to come at the magnitude of a solid, that would nearly fill the trough the ship made in the water; and, by increasing this magnitude by that of the keel, and so much of the stern-post and stem, as were under water, the cubic feet of the fluid displaced by the ship were obtained, being 54869; and consequently her weight was 3532091 pounds, or 1576 tons, 16 C. 2 qrs. 3 ℔. These numbers were not altogether so easily come at, as they would have been, had the ship swam on an even keel, her draught of water before being 13 feet 2 inches, and abast 16 feet 6 inches. However, the computation may be esteemed as correct as the nature of the subject would admit; because I found pretty near the same solidity by another method.
I got a block or model made, by a scale of a quarter of an inch to a foot, of so much of the Royal William's body, as was immerged, when she was brought into dock; and this block I immersed in a trough of sea-water, and found its weight in the following manner.
The length of the trough was 46 inches, breadth 14 inches, and depth 8 inches: at each corner was a graduated scale of inches, and pencil-lines drawn round the inside of the trough at every inch. Sea-water was poured into the trough to the height of 5 inches; and the trough was exactly levelled, by means of the pencil-line, at 5 inches: then the block being forced under the water's surface, the fluid, when still, was risen to 6⅓ inches; consequently the magnitude of the block was equal to a parallelopipedon of 46 inches long, 14 inches broad, and 1⅓ inches deep, or to 858⅔ cubic inches.
Now 858⅔ cubic inches are equal to 0.4969 cubic feet.
And a cubic foot of sea-water weighs 64.373² pounds avoirdupoize.
Then 64.373² × 0.4969 = 31.987 pounds.
So that by a quarter inch scale, a model similar to the Royal William weighs near 32 ℔.
But a quarter inch scale is 1/48 of a foot scale.
And the model is to the ship as 1³ is to 48³, or as 1 is to 110592.
Then 3537506 ℔. (= 110592 × 31.987), or 1579 tons, 4 C. 3 qrs. 14 ℔. is the weight sought.
The difference by the two methods amounts to 5415 ℔. or to 2 tons, 8 C. 1 qr. 11 ℔.
Some of the persons present at this experiment read the height of the water at 6⅜ inches: the difference between 6⅜ and 6⅓ inches is 1/24 of an inch; a difference easily to be made by different persons in an experiment of this kind. But observing, that the computation made on 6⅜ inches amounted to near 50 tons more than on 6⅓ inches, I caused the trough to be diminished in its depth to 6½ inches, had one of the ends cut off, and a board fixed on the open side, being desirous of making the experiment with the trough standing on one end: and indeed, in this situation, an error of ⅒ of an inch in the height of the water makes a difference of about 16½ tons in the weight of the ship. Into this upright trough water was poured to the height of 36 inches; and the block being immerged, the water was raised 9⅓ inches: so that the block was equal in magnitude to a parallelopipedon of 14 inches long, 6½ inches wide, and 9⅓ inches deep, or to 849⅓ cubic inches: from whence I find the weight of the ship to be 1562 tons, 1 C. 2 qrs. 16 ℔. And altho' I take this number to be nearest the truth, yet it may be observed, that it is no easy matter to come at accuracy in this subject by any of the methods in common use.
My next inquiry was, to find how much of this weight was lifted, and how to proportion it among the screws and mawl-men: but in this, less accuracy must be expected than in the preceding inquiry; for the exact number of men employed is not known; neither can it be told, how many worked at the screws, and how many with the mawls; and only a guess can be made at the part lifted. However, something may be gathered, which may, perhaps, be worth the knowing.
Let the weight raised be taken at half the weight of the ship; for 64 feet, the length of the keel raised, is not far from half the whole length: add to this the sally of the head, the weight of the forecastle, the friction of the timber, and the resistance of the parts bent by the cambering: beside, the mawls worked at several shoars set up abast the said 64 feet.
Now the weight by the last experiment was 3499064 pounds: one half, or 1749532 ℔. I take to be the weight raised between the screws and mawls.
The distance between two contiguous threads of each screw was 1⅓ inches; the length of the two opposite levers was 12 feet 8 inches, or 152 inches, and described a circumference of 477½ inches: each screw was worked by 8 men: their force, reckoned at 30 ℔. each, makes the power working on each screw equal to 240 ℔.
Hence, from the known property, each screw could raise 65485 ℔.
And the 18 screws raised 1178730 ℔.
Then there remained 570802 ℔. to be raised among about 126 mawls:
Which gives 4530 ℔, or a little more than two tons, to be raised by each man with his mawl and wedges; which is considerably less than what I have seen raised by way of experiment.
XXXV. Observations on an Evening, or rather Nocturnal, Solar Iris. By Mr. George Edwards, Librarian of the College of Physicians.
To the Reverend Dr. Birch.
SIR,
Read June 16, 1757.
ON Sunday evening the 5th of June 1757, being walking in the fields near Islington, about half a mile north of the upper reservoir or bason of the New River, I observed the sun to sink beneath the visible horizon to the north-west, it being very clear in that quarter, except some thin clouds a little above the horizon, which were painted of fine red and golden colours, as is usual when the sun sets in a calm clear evening. But about 20 minutes after sun-set, as near as I could judge, it then being darkish, I was greatly surprised to see an Iris in the dusky air, at a height greater than is seen at any time in the rainbow. It was in the contrary quarter of the heavens to the setting sun, and fell on the smoke, mists, and evening vapours arising from the city of London and its neighbourhood. The arch seemed to be a full half circle, tho' its lower parts fell some degrees short of the horizon. It was very distinctly seen for about 15 minutes. Its colours the same as in the rainbow, but fainter. The lower ends of the bow arose gradually higher from the earth, as the sun declined beneath the horizon, until the whole arch disappeared. The center of the arch was above the horizon at its first appearance. What most perplexed me, was, to find the cause of this painted arch. I could not believe, that it proceeded from the sun-beams falling on rain; for there had been none that afternoon; nor was there any sort of signs of rain or rainy clouds to be seen; the wind being northerly, and the air cool, and somewhat hazy in the quarter where the bow appeared; which was not near so bright as the rainbow appears to be in the day-time; and I believe, that it would not have been visible at all in the presence of the sun. I imagine it was formed on the gross particles of the evening vapours, mixed with those of the smoke arising from the town; for had the sun-beams shot from beneath the horizon on falling rain at a considerable height above the earth, I believe the darkness would have rendered the appearance of such a bow far brighter than it appears to the sight in the presence of the sun: but this night or evening arch being reflected, as I suppose, from particles so minute as those of floating vapours, gave but little light and colour to the sight, and what would not have been visible, had the sun been above the horizon. For the same reason, the moon and stars are visible in the absence of the sun, and, on the contrary, are unseen when the sun is present: and if we light a candle, and set it in the sun-beams, the flame is lost to our sight, tho' the same candle will give us a considerable share of light in the night. As I have never before seen or heard of such an arch, I thought this account of it (imperfect as it is) might not be disagreeable to the Royal Society.
It could not be a lunar arch, the moon being then many degrees below the horizon, and the arch in a place, where it could not be affected by the moon's rays. The consciousness of my inability to give a proper account of such an uncommon appearance could not deter me from the attempt.
I think I have said all that is necessary on this subject; yet am ready to answer any question for the farther illustrating of it. I am,
Reverend Sir,
Your most humble Servant,
Geo. Edwards.
College of Physicians, London, June 6th, 1757.
XXXVI. The Effects of the Opuntia, or Prickly Pear, and of the Indigo Plant, in colouring the Juices of living Animals. Communicated by H. Baker, F.R.S.
June 23d, 1757.
Read June 23, 1757.
MR. Baker received a letter yesterday from Dr. Alexander Garden, of Charles Town in South Carolina, part of which he hopes he shall be excused for laying before the Royal Society.
The Doctor writes thus:——“As you desired, I tried the effects of the prickly pear in colouring the urine. A few days after your letter, I went down to one of the islands, and gathered some of the fruit, and gave four of the pears to a child of three years of age, and six pears to one of five. The next morning I examined the urine of both, and it appeared of a very lively red colour, as if tent-wine had been mixed with clear water. The urine of the eldest was deeper coloured, and of a darker look: the youngest (who always naturally made clear urine) was of a more lively and beautiful red. Next day I gave six pears to a Negroe wench, who gave suck, and strictly forbad her suckling her child for six or eight hours; and then taking some of her milk in a tea-cup, and setting it by for some hours, the cream had a reddish lustre, tho' it was very faint.
I was led to this last experiment by an observation, which I made on the milk of cows, who had fed in an indigo-field; the indigo had not only tinged their urine blue, but the cream of the milk was of a most beautiful blue colour, and had a radiated appearance from the centre (Is it not hence probable, that the dye is the oily part of the plant?). The milk underneath was clear and white as usual.”
Dr. Garden wrote, a year ago, that the prickly pear grows in great abundance about Carolina; and also that the cochineal insects are found upon it; but hitherto no attempts have been made to cure them as the Spaniards do. In hope, that some rich dye may be produced from the plant itself, Mr. Baker proposed some experiments to Dr. Garden, which he intends to prosecute this summer.
XXXVII. Account of an extraordinary Shower of black Dust, that fell in the Island of Zetland 20th October 1755[194]. In a Letter from Sir Andrew Mitchell, of Westshore, Bart. to John Pringle, M.D. F.R.S.
Pall-Mall, June 9th, 1757.
SIR,
Read June 23, 1757.
IN compliance with your desire, I made particular inquiry, whether at or about the time the earthquake happened at Lisbon the 1st of November 1755. any uncommon phænomena were observed to appear in the islands of Orkney or Zetland, as such had happened about that time in other parts of Scotland. From Orkney I was informed, that nothing particular had happened; only, that about the time mentioned the tides were observed to be much higher than ordinary. I received from Zetland a letter, dated 28th May 1756. from Mr. William Brown, Master of the grammar-school at Scalloway in that country, a sensible and observing man; wherein he writes verbatim as follows. “Blessed be God, notwithstanding the great devastations, that have been made in other parts of the world by earthquakes, we have been intirely free from any disaster of that nature: nor has any thing extraordinary happened in this country since you left it; only on Monday the 20th October last, betwixt the hours of three and four in the afternoon, the sky being very hazy, as it uses to be before a storm of thunder and lightning, there fell a black dust over all the country, tho' in greater quantities in some places than in others. It was very much like lampblack; but smelled strongly of sulphur. People in the fields had their faces, hands, and linen, blackened by it. It was followed by rain.——Some people assign the cause of it to some extraordinary eruption of Hecla. But I shall trouble you no more about it, as no doubt some of your friends have written to you of it some time ago.”——
In June 1756. I returned to Zetland; and, upon further inquiry, found what Mr. Brown had written me was attested by Mr. Mitchell, parson of the parish of Tengwall, and by several Gentlemen of credit and reputation, who had seen and observed the same phænomenon in different parts of the country at the time above-mentioned.
Mr. Brown having omitted to mention, how the wind did blow at the time the black dust was observed, I made particular inquiry about that circumstance, and found it was from the S.W. which does not seem to favour the opinion, that the dust proceeded from an eruption of mount Hecla, which lies about N. W. from Zetland; unless it may be supposed, that a north wind happening just before had carried this dust to the southward, and the south-west wind immediately following had brought it back to the northward. But, in this case, would not this black dust have been observed in Zetland at its first travelling to the southward? Upon inquiry, I did not hear it was.
Thus far I have obeyed your commands, which I will always do with pleasure; and if you think it worth while to lay this letter before the Royal Society, I leave you at full liberty to do so, or not, as you think proper: but what it contains may be relied on as truth. I am, with great regard,
Dear Sir,
Your most obedient humble Servant,
And. Mitchell.
P.S. I may add, that the distance from mount Hecla to Zetland is between 500 and 600 miles.
XXXVIII. A Description of some Thermometers for particular Uses. By the Right Honourable the Lord Charles Cavendish, V.P.R.S.
Read June 30, 1757.
THE thermometer ([Tab. XI.] fig. 1.) is designed for shewing the greatest degree of heat, which happens in any place during the absence of the observer. It consists of a cylinder of glass joined to a tube, and differs from common thermometers only in having the top of the stem drawn out into a capillary tube, which enters into a glass ball C, joined on to the stem at the place where it begins to be contracted. The cylinder, and part of the tube, are filled with mercury; the top of which shews the common degrees of heat as usual. The upper part of the tube above the mercury is filled with spirit of wine, and some of the same liquor is left in the ball C, so as to fill it almost up to the top of the capillary tube.
Now when the thermometer rises, the spirit of wine will be driven out of the tube, and will fall into the ball C. When the thermometer sinks again, as the spirit cannot return back from the ball, the top of the tube will remain empty, and the length of the empty part will be proportional to the fall of the thermometer. Therefore, by means of a proper scale, the top of the spirit of wine will shew how many degrees it has been higher than when observed; which being added to the present height, will give the greatest degree of heat it has been at.
Philos. Trans. Vol. L. Tab. XI. p. 300.
J. Mynde sc.
To fit this thermometer for a new observation, it is necessary to fill the upper part of the tube with spirits; which may be done, by inclining the instrument till the spirits in the ball C cover the end of the capillary tube. For if the cylinder is then heated, by applying the hand to it, or by the flame of a lamp held at some distance, till the spirits rise to the top of the tube and run over into the ball C, and is then suffered to cool in the same position, the tube will remain full of spirits, and the thermometer will be fitted for a new experiment.
The top of the capillary tube is made to stand pretty near to one side of the ball, and also to the top of it, that a less inclination of the instrument may be sufficient to make the spirit of wine in the ball cover the end of the tube.
The ball C is joined on as high as possible, so as to hide no part of the tube, except that, where the bore is contracted. By this means, the top of the spirit of wine begins to appear before the thermometer has sunk one degree.
It will be convenient to leave some mercury in the ball C, which may be made to cover the end of the capillary tube, by inclining the thermometer more than what is necessary to make the spirit of wine cover it. By this means some mercury may be got back into the tube, in case any of it should happen to be driven into the ball by the thermometer's being exposed to too great a heat.
The scale of degrees at top, which shews the descent of the thermometer from the highest point it has arrived at, ought not, in strictness, to be the same at all times of the year; for those degrees exceed the common degrees of heat pointed out by the top of the mercury, as much as the column of spirit of wine expands, and therefore are greatest when that column is so; that is to say, when the greatest heat to which the instrument has been exposed is least. A difference of 30 degrees of Fahrenheit's scale, in the greatest rise of the thermometer, would require the scale to be altered one sixtieth part: and the error arising from making use of the same scale will be about one sixth of a degree, if the thermometer is observed when it has fallen ten degrees.
In the instrument here described, the bore of the tube is about 0.027 inches; and one inch of it contains two grains of mercury, and answers to about ten degrees, the cylinder containing about 2280 grains. If a much shorter tube was made use of, a considerable error might arise from too great a quantity of spirits adhering to the sides of the tube, in that part, which is filled with mercury; especially when the thermometer rises fast. This makes it necessary to employ a cylinder of a considerable bigness, if it is desired to have the scale of degrees pretty large.
If the weight of the mercury is thought inconvenient, it may be avoided by the construction described in [fig. 2.] where the bottom of the tube is bent so as to point upwards, and is joined to a ball A, which communicates with a cylinder placed above it. In all other respects it is the same as the instrument before described.
It is filled with spirit of wine and mercury; the quantity of the latter being sufficient to fill the whole tube and the ball A.
No part of the spirit, with which the cylinder is filled, can get into the tube, as long as the instrument is kept in an erect position, or even if it is carefully laid down flat on a table. For tho' in this last case some of the spirits may get into the ball A, it will rise to that part of the ball, which is then uppermost, and will not touch the orifice of the tube n; which was the reason for adding this ball, which would be unnecessary, if the instrument was kept constantly erect, or nearly so. If the spirit should come to touch the orifice of the tube n, it would work up between the mercury and the glass; which would put the instrument out of order.
The thermometer [fig. 3.] is designed for shewing the greatest cold, which happens in any place during the time the instrument is left in it. The tube is bent into the shape of a syphon of unequal legs standing parallel to one another, the bend being at the bottom. The top of the shorter leg is bent to a right angle, and immediately opens into a ball A, which, by means of a short bent tube on the opposite side, communicates with a cylinder standing parallel to the legs of the syphon, and pointing downwards. This cylinder contains the greatest part of the fluid; and is added only to make the thermometer more sensible than it would be, if the ball A was made of a sufficient bigness to contain the proper quantity of fluid. This instrument is filled with spirit of wine, with the addition of as much mercury as is sufficient to fill both legs of the syphon, and about a fourth or fifth part of the ball A.
The common degrees of heat are shown by the top of the mercury in the longest leg, or by the top of the spirit, in case any of it is left above the mercury.
When the mercury in the longest leg sinks by cold, that in the shorter leg will rise, and will run over into the ball A; from whence it cannot return back when the thermometer rises again, as the surface of the mercury in the ball is below the orifice of the tube n. Therefore the upper part of the shorter leg will be filled with a column of spirits of a length proportional to the increase of heat; the bottom of which, by means of a proper scale, will show how much the thermometer has been lower than it then is; which being subtracted from the present height, will give the lowest point that it has been at.
If no further contrivance was used, the mercury would fall into the ball A in large drops; which would make the instrument less accurate. For the thermometer's beginning to rise immediately after a drop is fallen, or just as it is going to fall (in which case it will return back into the tube), will make a difference of such part of a degree nearly as that drop answers to. To prevent this inconvenience, the top of the shorter leg, close to the ball, is contracted, by being held in the flame of a lamp; and the passage is further streightened by a solid thread of glass placed within the tube, and extending from the bottom of the shorter leg to the part near the ball A, where it is most contracted. By this means, as soon as any small portion of mercury is got beyond the end of the thread of glass, it breaks off, and falls into the ball in very small drops. This thread of glass is fastened by the heat given to the tube in making the bend next to the ball. In order to fill the shorter leg with mercury, to fit the instrument for a new experiment, it must be inclined till the mercury in the ball covers the orifice of the tube n. The cylinder being then heated, the mercury will be forced into the shorter leg, and will run down the thread of glass in drops, which will soon unite. By this means, such a quantity of mercury must be got into the shorter leg, as, upon the cooling of the instrument, will be sufficient to drive all the spirit of wine into the ball with a less degree of cold than what the thermometer is likely to be exposed to.
The ball A must always have some mercury in it, but never enough to fill it up to the orifice of the tube n. It must therefore be made of such a size, as to contain all the mercury, which can come into it from the tube without being too full. If it should happen to be made too small, so as to be too full in cold weather, any part of the mercury may easily be driven into the cylinder, and got back again into the ball when wanted in warmer weather.
It will be better to leave a little of the spirit above the mercury in the longest leg; in which case the top of the spirit will shew the common degrees of heat. For the filling the tube, so as to leave none, is attended with some trouble; and more of it will be apt to get up there, if the instrument should happen to be held in an improper situation, or if it be kept in too warm a place without filling the shorter leg with mercury by the method above described. If too great a quantity should get up, tho' it would not affect the scale for the common degrees of heat, it would however cause some error in the degrees on the shorter leg; inasmuch as the expansion of that portion of spirits, which has got up into the longer leg, exceeds the expansion of the mercury, which must supply its place. It may be got back at pleasure, by exposing the thermometer to such a degree of cold as will make the spirit get beyond the bend of the syphon; for then it will run up along the thread of glass in the shorter leg till it gets above the mercury there. For this purpose the point of 0 degrees of Fahrenheit's scale should be near the bend; by which means, any part of the spirit of wine may be got beyond it by an artificial cold; and there will be no danger of the whole getting beyond it by any natural cold; in which case the air would get up into the ball.
The scale of degrees on the shorter leg will, in different seasons, be liable to an error of the same kind as that, which was explained in the first-mentioned thermometer; but in this it will be less considerable, as the space between the two scales is filled with mercury, whose expansion is about six times less than that of spirit of wine.
In the thermometer, which I have, the bore of the tube is about 0.054 inches; and one inch of it contains eight grains of mercury, and answers to seven degrees of Fahrenheit's scale. The drops of mercury, which fall into the ball A, answer to about one eighth of a degree.
If instruments of the nature of those above described, were to be used for finding the temper of the sea at great depths, some alteration would be necessary in the construction of them, principally upon account of the great pressure of the water; the ill effect of which can, I believe, be prevented no other way, than by leaving the tube open. For if the thermometer was made strong enough to resist the pressure without breaking, yet it would be impossible to be sure, that the figure of the glass would not thereby be altered, which should make the experiment uncertain.
The instrument for finding the greatest heat might be made just like that of [fig. 1.] only leaving the top open. It is to be filled with mercury only, as is also the lower part of the ball at top, but not near so high as the end of the capillary tube. The upper part of that ball, being left open, will in a great measure be filled with the sea-water, which will be forced into it by the pressure.
If this instrument (the tube being quite full of mercury) is plunged into any part of the sea, where the heat is greater than that of the air above, part of the mercury will be driven out of the tube; and, upon bringing it into a colder place, the sea-water or air in the ball will enter into the tube, and will fill the space left by the mercury.
As this thermometer does not show the common degrees of heat, it must be placed in a vessel of water with another thermometer, and the scale of degrees at top will shew how much the heat it has been exposed to is greater than that of the water in the vessel.
The sea-water getting into the glass will corrode the mercury, and thereby foul the glass; which will make the experiment less exact: and therefore it would be much more convenient, if the sea-water could intirely be kept out; which probably may be done by tying a bladder full of air to the neck of the ball C, which will contract by the pressure of the water, without letting any of it get in.
If this can be done, the instrument may be filled with mercury and spirits, just like that at [fig. 1.] But it would be more convenient to fill it with mercury only: in which case it may be made with as small a tube and ball as common mercurial thermometers: or it may be filled with spirits only. The instrument will thereby become much less bulky; which will compensate the want of the common scale of heat.
It is better to put but little mercury into the ball at top, for fear of its getting into the capillary tube by the motion of the instrument.
The thermometer for finding the greatest cold, if applied to this purpose, must also be left open at top. There is another inconvenience to be avoided; which is, that the mercury in the ball A, by the tossing of the instrument, might sometimes get into the shorter leg of the syphon; which would spoil the experiment. To prevent such an accident, the most convenient construction, which occurs to me, is that of [fig. 4.] which differs from [fig. 3.] in having the ball A omitted; so that the mercury running out of the shorter leg will fall to the bottom of the cylinder, and will not be so liable to get back into the tube by motion. The cylinder is made to stand not quite parallel to the legs of the syphon, that the mercury contained therein may more easily be brought to touch the end of the tube, in order to fit the instrument for a new experiment.
If, by means of a bladder, the sea-water can be kept out of the glass, this instrument may be made to shew the common degrees of heat; but even then, in order to render it less bulky, it may be better to supply the want of them as in the last instrument. The longer leg of the syphon may in that case be made as short as you please; only making the ball B big enough to receive all the mercury, which may be driven into it by heat.
If thermometers of this kind were to be sent up into the air by means of a kite, they might be made like those proposed for the sea; but it would not be necessary to leave them open.
As it would be desirable to make them as small as possible, they should be made so as not to shew the common degrees of heat: and it would also, on that account, be convenient to omit the thread of glass placed within the shorter leg of the syphon in [fig. 3.] and [4.] This thread of glass is placed there in order to make the mercury fall into the ball A. [fig. 3.] or cylinder C. [fig. 4.] in smaller drops, and also to facilitate the filling the shorter leg with mercury. The latter purpose may be answered by having a ball blown towards the bottom of the shorter leg, as marked in [fig. 4.] at M: for as soon as the mercury driven out of the cylinder by heat gets to that ball, it will pass by the spirit of wine. The other purpose may probably be answered by having the tube contracted as much as possible at n.
In the foregoing instruments the tubes made use of were of a large bore, as most of the errors in them would increase by making use of smaller ones. Possibly less ones might be used without much inconvenience. The chief advantage will be, the making these thermometers more sensible of the changes of heat, than when large cylinders are used. This will be of service when the greatest degree of heat or cold continues but a short time.
It is better to use plain spirit of wine, than what is tinged, which seems more apt to cause a foulness in the tube, and thereby makes the surface of the mercury less well defined. I am induced to believe so, from observing, that the portion of spirits above the mercury in the tube [fig. 3.] which at first was strongly tinged with cochineal, in some months became perfectly colourless, the tinging particles being deposited in different parts of the tube, and causing a foulness there. The colour of the spirits in the cylinder does not appear to be altered.
The dark-shaded part in the several figures represents mercury, the dotted part spirit of wine.
Philos. Trans. Vol. L. Tab. XII. p. 311.
J. Mynde sc.
XXXIX. Observationes Anatomico-Medicæ, de Monstro bicorporeo Virgineo A. 1701. die 26 Oct. in Pannonia, infra Comaromium, in Possessione Szony, quondam Quiritum Bregetione, in lucem edito, atque A. 1723. die 23 Febr. Posonii in Cœnobio Monialium S. Ursulæ morte functo ibidemque sepulto. Authore Justo Johanne Torkos, M.D. Soc. Regalis Socio.
[See [Tab. XII.]]
Read May 23. 1751.
I. PARTUS hic bicorporeus singulare exemplum exhibet admirandarum virium imaginationis maternæ in fœtum utero contentum. Mater enim hujus bicorporis, primis graviditatis suæ mensibus vel potius hebdomadis, attentius contemplabatur canes coëuntes, arctius cohærentes, et capitibus erga se invicem quodammodo conversos, eosque sibi crebrius præfigurabat.
II. In partu, primum prodiit umbilicotenus Helenæ corpus; post tres demum horas editi sunt ejus pedes, cum adnexo corpore altero Judithæ. Helenæ corporis statura erat altior et rectior, Judithæ brevior et obliquior; et quamvis infra lumbos, a tergo, in unum corpus concretæ fuissent, attamen vultu et corporibus, semilateraliter, erga se fuerant conversæ, ut commode sedere, lentoque gradu procedere et recedere potuerint. Unus communi ipsis erat alvi exitus, intra duas nates, seu Helenæ dextrum et Judithæ sinistrum femur, situatus. Unam quoque habebant vulvam, intra quatuor pedes reconitam, ut dum erectis starent corporibus, ne vestigium ejus conspicuum esset. Quoad duos istos excretionum meatus, observatum est, quod, una excretionem alvi moliente, altera quoque nisum egerendi senserit; in reddenda vero urina, quælibet, diverso tempore, stimulos habuerit: quamobrem altera ad urinæ missionem solicitata, altera subinde recessum negavit. Unde in juventute, utut alias semper semet tenerrime amarent et amplexarentur, sæpius altercationes inter ipsas exortæ, et alterutra aliam vel dorso injectam abripuit, vel colluctando eo, quo vellet, protraxit.
III. Anno ætatis sexto, Judithæ paralysis totius partis sinistræ; obtigit ex qua affectione, utut convaluisset, per totam vitam suam debilior, tardior, et stupidior perstitit; e contra Helena semper agilior, docilior, et formosior suit.
IV. Prout diversa erant corpora, ita functionum vitalium, animalium, et naturalium, magna in utroque corpore, tam in sano quam ægroto statu, observata est differentia. Et quamvis variolas et morbillos uno eodemque tempore habuissent, reliqui tamen morbi eis non erant communes. Cum Judith sæpius convelleretur, Helena nec alterata nec debilitata fuit. Helena erat pleuritica. Judith benigniore febre laboravit: alterâ tussi, catarrho, colicâ afflictâ, altera sana exstitit. Hinc etiam quælibet, pro suo diverso statu, diversis medicamentis tractabatur: phlebotomia autem semper in saniore et vegetiore celebrabatur.
V. Anno ætatis decimo sexto, menstrua comparuerunt, quæ deinde per totam vitam, non tamen æquali tempore, modo, et quantitate successere. Subinde alterutra majores hinc sensit molestias; Judith vero crebrius convellebatur, variisque hystericis et pectoris affectionibus obnoxia fuit.
VI. Anno ætatis vicesimo secundo, seu A. C. 1723. die 8 Febr. Judith fortiter convulsa est, postea comatosa, usque ad mortem, quæ die 23 Febr. mane contigit, perstitit. Intra hos dies Helena febricula laboravit, eique accesserunt crebriores lipothymiæ, quibus tandem ita debilitata est, ut integra quamvis mente et loquela, subito, tribusque horæ minutis prius quam Judith, in agonem inciderit: postea vero ambæ, post brevem agonem, uno ferme momento expiraverint.
VII. Corporibus post mortem dissectis, reperta sunt in quolibet corpore viscera singula: In Helena omnia sana; in Judithæ thorace vero cor nimis magnum, fortissimo pericardio velatum, et pulmonum dexter lobus putridus: Arteria aorta et vena cava ex utroque corde descendentes, antequam arteriæ et venæ iliacæ ex iisdem emergerent, inflexæ coadunabantur, et unam arteriam aortam, unamque venam cavam, e corde uno ad aliud procedentes seu reflexas, præsentarunt. In abdomine utrinque viscera omnia sana et integra. Quodlibet corpus suum habuit hepar, splenem, pancreas, renes, vesicam, uterum cum ovariis, tubis Fallopianis, et portione vaginæ, quæ utrinque concurrentes unam communem vaginam efformarunt. Partes genitalium externorum, præter commune orificium vaginæ, cuilibet erant propriæ, velut clitoris, nymphæ, orificium urethræ; alæ seu labia utrinque ad perinæum concurrentia fossulam navicularem densiorem constituerant. Ventriculus cum intestinis, in utrâque, naturaliter erant situata; intestina recta autem utrinque ad os sacrum reflexa et coalita, unum satis amplum et communem canalem constituerunt: os sacrum ad secundam divisionem concretum erat, et unum corpus efformando, in uno utrique ossi sacro communi, osse coccygis, terminabatur.
Ex prærecensitis, sicut causa diversitaris actionum et functionum patet, ita etiam ex arteriarum aortarum, et venarum cavarum, intestinorum quoque rectorum et vaginarum uteri, compagine, coadunatione et harmonia, apparet ratio conformitatis et disparitatis morborum, synthanasiæ, communis nisus egerendæ alvi, possibilis imprægnationis alterutrius, vel fors utriusque virginis, uno eodemque coitu.
Hæc omnia conquisivi et retexui, partim e relationibus fide dignis autoptarum; partim ex ephemeridibus B. Caroli Raygeri, soceri mei, qui, dum viveret, medicum cœnobii dicti ordinarium agebat; partim ex libro cœnobiali, cui B. Vir formulas medicamentorum inscripserat. Dab. Posonii die 3 Julii 1757.
Justus Joannes Torkos,
Eques Pannonius, Medic. Doct. et
Liberæ Regiæ Civitatis Posoniensis
Physicus ordinarius.
The interval between the reading of this paper before the Royal Society and the present publication, was occasioned by the long indisposition, and afterwards death, of their late President Martin Folkes, Esq; who having taken it to his house, with a view of collecting and adding to it some further particulars, it could not be found after his decease. But Dr. Torkos, the writer, being again applied to, immediately transmitted the copy of it printed above: and, in order to supply in some measure the want of what Mr. Folkes's extensive reading and industry might have furnished the public with, in relation to so very remarkable a fact, the following accounts, printed and manuscript, are subjoined as a supplement to the preceding article.
Extract of a Letter of William Burnet, Esq; F.R.S. eldest Son of Dr. Gilbert Burnet, Lord Bishop of Salisbury, to Dr. (afterwards Sir) Hans Sloane, dated at Leyden, May 9. 1708. N. S.[195]
“SIR,
I Send you inclosed the print of a wonderful union of two twin sisters, who are at this time to be seen at the Hague. I saw them, and observed all, that I could think tended to explain the appearance. They are Hungarians, as the lines under the print will shew you. There is there an exact enough description of their condition; only I may add, that in [fig. 1.] the urinal passage is between the two foremost thighs, as they are in the print. The same is true of the anus in the 2d figure, in such manner, that the situation of these parts is the same to outward appearance as naturally, with this difference, that they are between two different bodies here, whereas in the course of nature they are between the two parts of the same body. It seems probable, that their parts are distinct; but that the most remote labia of each are outwardly visible, and the two contiguous ones are within. There seems to be no cheat in the thing; and the skin, where they are joined, is perfectly smooth, without any scar. They are now about six years old. They speak French and High German. They are very full of action, and talk one more than the other. When one stoops to take up any thing, she carries the other quite from the ground; and that one of them often does, being stronger as well as more lively than the other. They have not their feeling common any where but in the place of their conjunction. This is all I can say about it. If you think it worth while, you will do me an honour in giving the print, and the substance of this account, to the Society; to which, tho' an unworthy member, I would be proud to be capable of any service.”
This letter was read to the Royal Society on the 12th of May 1708[196]; and the print mentioned in it produced; which, being now become extremely difficult to be met with, is thought proper to be engraved again, and inserted here. See [Tab. XIII.]
Soon after the date of Mr. Burnet's letter the twin sisters were brought to England, and publicly shewn in London, as appears from the following MS. note in a copy of the print bound up by the writer with Fortunius Licetus de Monstris[197], edit. Amstelod. 1665. 4to. in the possession of Thomas Wilbraham, M.D. F.R.S. “Londini 14 Junii 1708. has vidi gemellas (plus annis sex natas) quarum forma et vivacitas elegantior et vegetior quam pictura et descriptio.”
Philos. Trans. Vol. L. Tab. XIII. p. 316.
Corpora Binarum sic concrevere Sororum,
Non nisi Divina dissocianda manu.
SZÖNY Patria est, vicus COMORÆ co terminus Arci,
Qvæ nunquam Lunæ paruit Imperio.
Amplexa est ulnis HELENAM Lucina priorem,
Horis deinde tribus JUDITHA fuit.
Exitus Urinæ patet unicus, unicus alvo,
Observant numerum cætera membra suum.
Misit ad Ignotos tenuis Fortuna Parentum,
Neu pereat tantæ Fama stupenda rei.
InterIora Latent, neqVeVnt abstrVsa VIDerI:
eXIgVo totVM CorpVs In ære patet.
J. Mynde sc.
Another account of them by an eye-witness in London is in a manuscript volume among those of Sir Hans Sloane, Bart. in the British Museum, intituled, A short History of human Prodigies and monstrous Births, of Dwarfs, Sleepers, Giants, strong Men, Hermaphrodites, numerous Births, and extreme old Age, &c. The name of the writer was James Paris du Plessis. In p. 39. under the Title Two Sisters conjoined, he gives a drawing of them, and the following description: “These two monstrous girls were born at Szony in Hungary in the year 1701. They were born conjoined together at the small of the back. I asked the father and mother, if they could not be separated one from the other? but they answered, No; because the urinary and fœcal vessels and passages were so united, as to have but one issue for the urine, and another for the excrements, betwixt both. They were brisk, merry, and well-bred: they could read, write, and sing very prettily: they could speak three different languages, as Hungarian or High Dutch, Low Dutch, and French, and were learning English. They were very handsome, very well shaped in all parts, and beautiful faces. Helen was born three hours before her sister Judith. When one stooped, she lifted the other from the ground, and carried the other upon her back; neither could they walk side by side. They loved one another very tenderly. Their clothes were fine and neat. They had two bodies, four sleeves; and one petticoat served to the bodies, and their shifts the same. When one went forward, the other was forced to go backward.”
A later and more particular account is contained in p. 41, & seqq. of a book very seldom met with in this country, being printed at Vienna in 1729. intituled, Gerardi Cornelii Drieschii Historia magnæ Legationis Cæsareæ, quam Caroli VI. auspiciis suscepit Damianus Hugo Virmondtius, &c. The following extract, tho' long, will not probably be thought unentertaining.
“Sunt in comitatu Commaroniensi in terris illustrissimi Zichii (pagus Hungaris Szony dicitur) à parentibus colonis, quibus sua vita constat, dum hæc scribo, anno 1701. vii calendas Novembreis procreatæ in lucem duæ filiæ gemellæ, posticâ parte, quâ spina dorsi definit, concretæ, sic ut altera alteram sequi, quo se cunque vertat, cogatur: cætera haud deformes aspectu, nisi concretio illa corporum prodigium efficeret. Binæ singulis manus, totidem pedes, et capita, necnon corpora: suus membris omnibus usus; rationis multò etiam, quod mirere, certior; ut, si sedentes solum videris, neque sciveris, hic monstri notare nihil valeas. Majori natu, quæ lucem citius aspexit tribus horis, Helenæ, minori Judithæ nomen est. Hæc ante annos circiter tres stupore apoplectico tacta linguæ modicum ex eo ac bonæ mentis officium impeditum habuit, simplicitatem quandam ingenii modo ut redoleat. Illa animo semper integro atque spiritu prædita eodem, pudicâ facie, non inconcinnis motibus, intuentium in se oculos ad misericordiam commovet, utpote quæ rationis planè compos, sororis tenerrimè amans, nec status ignara sui, duplicem miseriam tolerat, suam et istius. Ductæ sunt olim infantes per varias regiones ac provincias, Germaniam, Angliam, Galliam, Italiam, Poloniam, Bataviam, Austriam, Moraviam, Hungariam, à medico Hungarico nomine Csuszio, qui easdem certâ pecuniâ ad tempus sibi a parentibus concreditas et elocatas, bonâ eorundem veniâ, paterno à solo âbduxit; unde trium gentium linguis, Germanicâ, Gallicâ, Hungaricâ, hodiedum etiam loquuntur; alias desuetudine usuque interrupto, ætate præsertim nondum satis confirmatâ, omnino dedidicere.
Dux Augustus Saxo Cizius inter purpuratos LXXII patres à constantia religionis, timore erga Deum et caritate in proximum notissimus, archiepiscopus Strigoniensis, veritus, ne frequentes hæ perignationes puellarum adhuc infantium innocentiæ officerent, ac mores denique illarum, ut fieri non raro assolet, planè depavarent, pacto persolutoque pretio à medico redemit, et revocatas domum ad suos virginibus à divâ Ursulâ nuncupatis intra Posonium deinceps educandas commisit, necessariis ad hoc sumptibus benignè subministratis. Ingressæ non diu puerilem ætatem suerant, nonusque illis annus agi cœptus currebat, quando harum in disciplinam virginum tradebantur. Hic legere primum ac scribere, ea, quæ ad fidem necessaria sunt, mente atque animo comprehendere; operas manuum exercere varias, acu præcipuè phrygionicâ pingere, denticulatas affabre fimbrias conficere, et cætera quæ sunt ejusdem generis, edoctæ fuerunt. Vidi ego ex illarum operibus aliqua, quæ magistras hâc in arte fecisse non pudeat. Receptæ autem sunt sacrum hoc in collegium anno secul ix. die XII. kalendas Aprilis, ibi XI mansionis, vitæ XIX jam planè complerunt. Istuc divarum contubernium, quod adhuc constanter incolunt, nunquam postea deseruere. Addita illis e prudentioribus virago, quæ indefinentur adsit, quo velint, ducat, actonibus invigilet, de quibus respondere, ad aliosque referre, si necessum fuerit, aliquando possit. Ex hâc scire quæ cupiebam, remotis arbitris, nullo negotio percepi. Crediderat namque, quod res quoque erat, non curiositatis gratiâ, sed officii, ac boni publici causâ ista à me rogari: quare alios omnes secedere jussi, solus cum eadem remanens, ut quæ, junioribus præsertim aliquot præsentibus, accuratius explicare verecundia illam antea prohibuerat, majori mecum libertate communicaret. Partes, quas vel nominare pudor honestasque vetuit, per quas potus ciborumque fæces et reliqua corporis excrementa (sit verbo venia) ejicimus, non illis his, quibus nobis, constitutæ locis. Illis quidem, ubi nos eas habemus, occlusa sunt omnia; at infernè, quâ parte concretio illa corporum incipit, easdem obtinent utrique communes. Neque tamen cum necessitas alterutram premit ad exonerandum, exempli gratiâ, ventrem, altera se quoque sentit tam inutili pondere gravatam, at satisfaciendum necessario naturæ sit: sed jam huic, jam isti istud imbecillitatis humanæ incommodum perferendum est, sitque etiam, ut cum alvum purgat altera, alteri meatus sit urinarius aperiendus. Muliebria, quæ statis fœminas vicibus incommodant, non uno ambabus tempore veniunt. Octidui quandoque intervallo ac longiori disjuncta sunt. Dum dormit hæc, sæpe vigilat illa, et in alterius labore altera nonnunquam quiescit. Visa una potare est, aut cibo corpus reficere, cum aliud alii agebatur. Sedent, stant, ambulant, jacent semper unà, nec sine incommodo. Non permittit conglutinatio ista corporum, hæ uti actiones separentur. Si colloquuntur, obtortis faciem collis obvertunt. Suavia dant sibi, cum amant, et pugnis impetunt, cum furunt. Donec suæ utrique vires adhuc constabant, si sorte exortæ inter illas aliquando discordiæ essent, hæc, quæ se læsam magis credebat aut fortem, sublatam in humeros aliam alio asportabat. Veruntamen ingenio miti magis ac placido sunt quam incenso aut iracundo, et in communibus malis communem fidem, commune robur adhibent, immissam sibi à Deo miseriam fortitèr sustinentes. Ante triennium in gravi secundò genitæ morbo, de quo nonnulla superiùs facta est mentio est, prior nata sacris omnibus munita ad mortem quoque feliciter obeundam disposita ab sacerdote fuit, quia medicorum pars potior credit aliâ extinctâ aliam haud posse longùm amplius superesse. Id quod probare ex hoc etiam laborant, quod quoties male uni sit, quamvis altera non eadem continuo ægrotatione teneatur, angustias tamen animi certas, hebetationem sensuum, et commotionem quandam viscerum in seipsa experiatur. Equidem dubitandum minimè reor, quin monstrosa hæc bina corpora duplici mente ac spiritu regantur. Nam sive cor faciamus, sive cerebrum statuamus animi sedem, ex utrolibet idem nullo negotio evincitur. Adde tot actiones multiplices, cogitationes rerum diversas, sensa animi varia, quæ, ut aliud nihil sit, isthuc pariter nos docent. Unum præcipue hic admirandum venit, quod commemorare superius memoria excidit; post prodigiosum videlicet hunc difficilemque partum natos esse matri alios liberos, ex eodem patre procreatos, sanos et valentes, corpore, specie ac forma integros, qui monstri nihil admixtum habeant.”
XL. Observations on the Origin and Use of the Lymphatic Vessels of Animals: being an Extract from the Gulstonian Lectures, read in the Theatre of the College of Physicians of London, in June 1755. By Mark Akenside, M.D. Fellow of the College of Physicians, and of the Royal Society.
Read Nov. 30, 1757.
IT is proved, by a multitude of experiments, that the lymphatics communicate with the blood-vessels. They may be distended by blowing air, or by injecting water or mercury, into an artery: and the lymph, which they carry, is frequently, in a morbid state, found tinged with a mixture of the red globules or crassamentum of the blood. Upon this foundation two different theories have been raised, concerning the connection of the lymphatics with the arteries.
Of these, we shall first consider that of the late famous professor Boerhaave. He observed, that every artery of the body is greater, in its diameter, than any of its branches: and this observation being found true, as far as our eye and the microscope can inform us, he inferred, by analogy, that it held good even thro' the most minute subdivisions of the arterial system. But, says he, proportionable to the diameter of the canal is the size of the particles moving thro' it: therefore, if an ultimate capillary artery, admitting only one red globule at once to pass thro' it, send off lateral branches, these branches will be capable of receiving such particles only as are smaller than a red globule. But the particles next in magnitude below the red globules are the yellow serous ones; and the lateral vessel, thus receiving them, is a serous artery, and the trunk of a second order of vessels. In like manner, this trunk, being continued on thro' many lessening branches, will at last grow so minute, as to admit only one serous globule: its lateral branches, therefore, will receive only such particles as are smaller than the serous ones: but these are the particles of the lymph; and this lateral branch is a lymphatic artery, and the trunk of a third order of vessels. Thus, in the red arteries are contained all the circulated fluids of the body; in the serous arteries, all except the red blood; in the lymphatics, all except the red blood and serum: and this subordination is, according to the same laws, continued down thro' fluids more subtile than the lymph, to the smallest vessel, which is propagated from the aorta. Such was Boerhaave's doctrine concerning the vascular system of animal bodies; like many of his other notions, ingenious, plausible, and recommending itself, at first sight, by an appearance of geometrical and mechanical accuracy: but founded upon insufficient data, and by no means to be reconciled to appearances.
For, in the first place, should we admit his hypothesis, it is certain, that the conical or converging form of the aorta, and the change of direction in its branches, must, in the distant blood-vessels, occasion a great resistance to the moving blood, and a great diminution of its velocity. Suppose that this resistance be, in any capillary red artery, to the resistance in the trunk of the aorta, as any larger assignable number is to unit: the resistance, then, in a capillary serous artery will, to that in the aorta, be as the square of that number is to unit; in the capillary lymphatic, as the cube; and so in progression: that is, the velocity of the fluids, in the remoter series of vessels, will be, physically, nothing. But we know, on the contrary, that some very remote series of vessels have their contents moved with a very considerable velocity; particularly the vessels of the insensible perspiration: and in anatomical injections, the liquor thrown into an artery scarce returns more easily or speedily by the corresponding vein, than by the most subtile excretory ducts. Moreover, there are an infinite number of observations of morbid cases, in which the red blood itself has been evacuated thro' some of the most remote series of vessels, merely from an occasional temporary obstruction in one part, or a præternatural laxity in another; and without any lasting detriment to the structure and subordination of the vessels; which yet, upon this hypothesis, must have been utterly destroyed before such an irregularity could have happened.
The other theory concerning the origin of the lymphatics has been maintained by some very eminent physiologists later than Boerhaave; and supposes, that these vessels receive their lymph from the blood-vessels, or from the excretories of the larger glands, by the intermediation of only one small vessel, which these authors term a lymphatic artery, invisible in its natural state, nor yet rendered subject to the senses by experiments. But to this it may be answered, that the lymphatics are traced into many parts of the body, and lost there; and therefore most probably have their origin there, where no large gland nor blood-vessel is to be found in their neighbourhood: that it contradicts the whole analogy of nature, to suppose the motion of an animal fluid more discernible in the veins than in the arteries: and, finally, that it seems rather an instance of want of thought, and of being imposed upon by words, to call the lymphatic vessels veins, because they are furnished with valves; and then, because they are called veins, to take for granted, that of course they must be the continuation of arteries.
In attempting to investigate matters too subtile for the cognizance of our senses, the only method, in which we can reasonably proceed, is by inferring from what we know in subjects of the same nature: and our conclusion thus inferred, concerning the subject sought, will be firmer and more unquestionable, in proportion as it resembles the subject known. But if the subjects be really of the same kind; if no difference can be shewn between them, in any respect material to the inquiry, in which we are engaged; in this case our inference from analogy becomes the very next thing to a physical certainty: and this I apprehend to be true in relation to the problem before us, concerning the origin of the lymphatic vessels. Tho' in general we cannot, by experiments, arrive at the extremities of those tubes, nor satisfy ourselves, by inspection, in what manner they receive their fluid; yet in a very considerable number of them we can do both. There is a certain part of the human body very abundantly provided with lymphatics; in which part we can actually force injections thro' those vessels into a cavity, where their extremities open: and from this cavity, on the other hand, we can at pleasure introduce a coloured liquor into their extremities, and trace it from smaller into wider canals; from capillary tubes, without valves, into large lymphatic trunks copiously furnished with them. We know likewise, that into this cavity are continually exhaling an infinite number of watery and mucous vessels, both arterial tubes and excretory ducts: that these keep it moist with a perpetual vapour, which the extremities of those lymphatics are, in the mean time, perpetually imbibing. Does it not seem strange, while these particulars are known and acknowledged by all the world, that the great authors of anatomy and physiology should never have reasoned from them; but should run into complex and obscure suppositions, in order to explain a process, which they may at any time examine with their own eyes? But perhaps this inadvertency may be accounted for, if we recollect, that at the time when these vessels, and the structure of this part, were discovered, the lymph, and every thing belonging to it, was utterly unknown; and that the vessels in question were first seen and considered as performing another and more remarkable office: which circumstance, it should seem, has prevented succeeding authors from being duly attentive to them in the capacity of lymphatics. However this be, it is certain, that the lymphatics of the mesentery, commonly called the lacteals, differ from those of the other parts in no one particular, save that occasionally they carry chyle instead of lymph; or rather carry lymph mixed, at stated times (that is, for two or three hours after the creature has taken food) with an emulsion of vegetable and animal substances, and coloured white by that mixture. At other times, (that is, during sixteen of eighteen hours out of the twenty-four) they contain nothing but lymph; and are, in every respect, mere lymphatic vessels, not to be distinguished from those in any other part of the body. Their structure is the same; the membrane of which they are formed, their valves, the lymph which they contain, the glands thro' which they pass, their direction from smaller tubes to larger, and from these to the blood, differ in nothing from what we observe of the other lymphatics. Their lymph, in the mean time, is without doubt or controversy supplied from the cavity of the intestines; being the watery moisture continually exhaled there for the purposes of digestion, and for the preservation of the alimentary canal, and as continually taken up by the roots or extremities of these vessels, in order to be carried back to the blood, after it has performed its office in the bowels. Let it also be remembered, that these vessels, in other places of the body, are generally, when we trace them, lost in muscular, tendinous, or membranous parts: and then, I should presume, it may fairly, and with a good degree of evidence, be concluded, that the lymphatics of the body, in general, have their origin among the little cavities of the cellular substance of the muscles, among the mucous folliculi of the tendons, or the membranous receptacles and ducts of the larger glands: that their extremities or roots do, from these cavities, imbibe the moisture exhaled there from the ultimate arterial tubes, just as the lacteals (the lymphatics of the mesentery) do on the concave surface of the intestines: and that the minute imbibing vessels, by gradually opening one into another, form at length a lymphatic trunk, furnished with valves to prevent the return of its fluid, and tending uniformly, from the extremities and from the viscera, to reconvey to the blood that lymph, or that fine steam, with which they are kept in perpetual moisture; a circumstance indispensibly necessary to life and motion: while, at the same time, the continual re-absorption of that moisture by the lymphatics is no less necessary, in order to preserve the blood properly fluid, and to prevent the putrefaction, which would inevitably follow, if this animal vapour were suffered to stagnate in the cavities where it is discharged.
XLI. A Letter to the Right Honourable the Earl of Macclesfield, President, the Council, and Fellows, of the Royal Society, concerning the Variation of the Magnetic Needle; with a Sett of Tables annexed, which exhibit the Result of upwards of Fifty Thousand Observations, in Six periodic Reviews, from the year 1700 to the year 1756, both inclusive; and are adapted to every Five Degrees of Latitude and Longitude in the more frequented Oceans. By William Mountaine and James Dodson, Fellows of the Royal Society.
Dated London, Nov. 9th. 1757.
SIRS,
Read Nov. 10, 1757.
ON the 20th of March 1755, we presented an address to this illustrious Body, intituled, “An Attempt to point out, in a concise manner, the Advantages which would accrue from a periodic Review of the Variation of the Magnetic Needle, throughout the known World; requesting contributions thereto, by communicating such observations concerning it, as had then been lately made, or could be procured from correspondents in foreign parts.”
This address was read at the same time, and afterwards honoured with a place in the Transactions, vol. xlviii. part ii. for 1754: which favour we now acknowledge in the most grateful manner; and, pursuant to our engagements, beg leave to lay before you some account of the communications received, with a specimen of the uses and applications which we have been enabled to make of those, and other assistances with which we have been indulged.
On application to the Honourable the Commissioners of the Navy, we were obliged with an order of free access to all their masters log-books and journals.
The Directors of the Honourable East India Company granted the like privilege.
The Honourable Committee of the Hudson's Bay Company obliged us with sundry observations, made, and tabulated, by their own Captains.
James Bradley, D. D. Regius Professor of Astronomy, and F.R.S. favoured us with several observations made at the Royal Observatory at Greenwich.
John Hyde, Esq; F.R.S. communicated a sett of useful observations, extracted from two journals kept on board the Triton and Britannia East Indiamen.
A correct journal kept on board the Delawar East Indiaman was handed to us by a gentleman unknown.
Capt. George Snow furnished a considerable number of observations, made with care and accuracy by himself, in several successive voyages to, and from Barbadoes and Virginia; together with several remarks upon the subject: One, which we apprehend to be material, we beg leave to insert, as it meets with some confirmation by the tables annexed; viz. “At Barbadoes the variation seems at a stand very near; for in the road, 1752, I observed 5 degrees east; and by Mr. Halley's draught, in the year 1701, 5½ degrees: in 1747, at Port Royal keys, Jamaica, I observed the variation 7° 20' E.; and on the coast of Carthagena the same week, off the high land of Sancta Martha, 7° 45' E. nearly south of Port Royal: Therefore these curves are not much altered; and the curve at Jamaica is nearly at a stand, as tho' tied; and the south part of them, with the rest, dropping to the westward.”
Mr. Mungo Murray, author of a treatise on ship-building, presented us with several observations taken on board the Prince Edward and Chesterfield East Indiamen, and his Majesty's ship the Neptune.
For all these favours we return our sincere thanks.
No observations made upon land have been received, except Dr. Bradley's aforesaid; which has frustrated our intentions of continuing the curves from sea to sea.
By collecting, comparing, and adjusting, all these materials, we have been enabled to construct variation-curves upon Dr. Halley's mercator-chart, adapted to the year 1756; which will soon be in readiness to present to this Royal Society.
As a work of this kind requires much time, and a multitude of observations, both by sea and land, to render it more perfect and general; we hope the ingenious in all nations will lend their assistance: By this means every periodic review will be productive of improvement.
From the first instant that we made this affair the object of our more particular consideration, we have attended to the mode of increase and decrease in the variation: and as a considerable number of observations, made at periodic times, and duly registered, seem to be the most essential toward determining the laws of its mutation, or proving its irregularity, we have therefore formed a sett of tables, from actual observations collected for the years 1710, 1720, 1730, and 1744, the date of our last chart; which, together with Dr. Halley's for the year 1700, and the present chart now publishing, compleat six reviews: These are tabulated, and shew the quantity of the variation, at those several periods, to every 5 degrees of latitude and longitude in the more frequented oceans; which we hope will prove acceptable, as nothing of the like kind has yet appeared, or can easily be obtained.
Our materials have been so deficient, that even in the limits to which our tables are confined, we have been obliged to leave blanks in some of the above periods, for want of that concurrent testimony, on which the numbers inserted are founded: but, considering the difficulties unavoidably attending a work of this sort, and the little assistance which we have met with from private hands, we hope that this Royal Society will not only excuse those vacancies, but also those in the great tracts of sea, as well as land, concerning which we are very unwillingly obliged to be intirely silent.
Agreeable to our former address, we lay only what appear to be facts before you, without attempting to introduce any hypothesis for the solution of these phænomena; some of which (being very extraordinary) we recommend peculiarly to the notice of those gentlemen, who may endeavour the investigation of their causes.
Under the equator, in longitude 40° E. from London, the highest variation during the whole 56 years appears to be 17°¼ W. and the least 16°½ W.: and in latitude 15° N. longitude 60° W. from London, the variation has been constantly 5° E. but in other places the case has been widely different; for in the latitude 10° S. longitude 60° E. from London, the variation has decreased from 17° W. to 7°¼ W., and in latitude 10° S. longitude 5° W. from London, it has increased from 2°¼ W. to 12°¾ W.; and in latitude 15° N. longitude 20° W. it has increased from 1° W. to 9° W.
But there is still a more extraordinary appearance in the Indian seas: for instance, under the equator,
| Longitude from London | Variation in | |
| 1700. | 1756. | |
| Degrees. | Degrees. | Degrees. |
| 40 E | 16¾ W | 16¾ W |
| 45 E | 17¾ W | 14½ W |
| 50 E | 17½ W | 11¾ W |
| 55 E | 16½ W | 8¾ W |
| 60 E | 15¼ W | 6 W |
| 65 E | 13½ W | 4½ W |
| 70 E | 11½ W | 2¾ W |
| 75 E | 9¾ W | 1 W |
| 80 E | 7¾ W | 0¼ E |
| 85 E | 5½ W | 1¼ E |
| 90 E | 4¼ W | 1 E |
| 95 E | 3¼ W | 0½ W |
| 100 E | 2½ W | 1 W |
Where the west variation in the longitude 40° E. is the same in both the above years; and in 1700 the west variation seemed to be regularly decreasing from longitude 50° E. to the longitude 100° E.; but in 1756 we find the west variation decreasing so fast, that we have east variation in the longitude 80°, 85°, and 90° E; and yet, in the longitude 95° and 100° E. we have west variation again.
Such are the irregularities, that experience hath shewn us, in the variation of the magnetic needle; which appear so considerable, that we cannot think it wholly under the direction of one general and uniform law; but rather conclude, with the learned and judicious Dr. Gowen Knight, Fellow of this Society, in the 87th prop. of his treatise upon attraction and repulsion, That it is influenced by various and different magnetic attractions, in all probability occasioned by the heterogeneous compositions in the great magnet, the Earth.
Notwithstanding all which, should the sagacity of some eminent philosopher be able to exhibit rules, whereby the quantity of the variation may be computed for future times, yet then such a review, as we have now made, will be necessary at a proper interval, to prove the truth of them: and should no such rules appear, then will a continued succession of such reviews be necessary so long as commerce and navigation subsist among us.
What we have now done is intirely for the public service, the sale of the former chart never having made good its expence; and we propose to continue our endeavours for another review, at the proper time, if we shall then be alive, and capable of the task: but as the contrary may probably happen, we beg leave to conclude with recommending such a continuation, in the strongest manner, to such of the members of this Royal Society, or others, who may, at the proper intervals, have leisure and ability for such a performance.
We are, with the greatest deference,
Your Lordship's,
And the Royal Society's,
Most faithful and
most obedient Servants,
William Mountaine.
James Dodson.
A TABLE, exhibiting the different Variations of the Magnetic-Needle in the more frequented Oceans, from the Year 1700 to the Year 1756.
| Latitude. | Longitude, From London. | VARIATION. | |||||
|---|---|---|---|---|---|---|---|
| Anno 1700. | Anno 1710. | Anno 1720. | Anno 1730. | Anno 1744. | Anno 1756. | ||
| Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. |
| 0 | 0 | 4½ W | 10¼ W | 14¼ W | 15¼ W | ||
| 0 | 5 W | 2¾ W | 8¾ W | 12 W | 13¼ W | ||
| 0 | 10 W | 1½ W | 3½ W | 5½ W | 7 W | 10 W | 11 W |
| 0 | 15 W | 0½ W | 2 W | 3½ W | 5 W | 7½ W | 9 W |
| 0 | 20 W | 0¾ E | 0½ W | 1¾ W | 3 W | 5¼ W | 6½ W |
| 0 | 25 W | 1½ E | 0½ E | 0½ W | 1½ W | 3 W | 4 W |
| 0 | 30 W | 2½ E | 2 E | 1½ E | 1 E | 0¾ W | 0½ W |
| 0 | 35 W | 3¼ E | 3 E | 2¾ E | 2½ E | 1½ E | 1½ E |
| 0 | 40 W | 4¼ E | 4¼ E | 4 E | 3¾ E | 3½ E | 3½ E |
| 0 | 45 W | 5½ E | 5½ E | 5¼ E | 5 E | 4¾ E | 5 E |
| 0 | 50 W | 6¾ E | 5¾ E | 6 E | 6½ E | ||
| 0 | 5 E | 6 W | 12½ W | 15¾ W | 16½ W | ||
| 0 | 10 E | 7¾ W | 14¼ W | 17 W | 17½ W | ||
| 0 | 40 E | 16¾ W | 17 W | 17¼ W | 17 W | 16½ W | 16¾ W |
| 0 | 45 E | 17¾ W | 17¼ W | 16¾ W | 16¼ W | 15¾ W | 14½ W |
| 0 | 50 E | 17½ W | 16¾ W | 16 W | 15 W | 14 W | 11¾ W |
| 0 | 55 E | 16½ W | 15¼ W | 14 W | 13 W | 11½ W | 8¾ W |
| 0 | 60 E | 15¼ W | 13¾ W | 12½ W | 11 W | 9 W | 6 W |
| 0 | 65 E | 13½ W | 11¾ W | 10 W | 8¼ W | 6½ W | 4½ W |
| 0 | 70 E | 11½ W | 9¾ W | 7¾ W | 6 W | 4 W | 2¾ W |
| 0 | 75 E | 9¾ W | 7¾ W | 5¾ W | 4 W | 1¾ W | 1 W |
| 0 | 80 E | 7¾ W | 6 W | 4¼ W | 3 W | 0¼ W | 0¼ E |
| 0 | 85 E | 5½ W | 4 W | 2½ W | 1½ W | 0¼ E | 1¼ E |
| 0 | 90 E | 4¼ W | 3½ W | 1½ W | 0½ W | 1¼ W | 1 E |
| 0 | 95 E | 3¼ W | 2¼ W | 2 W | 0½ W | ||
| 0 | 100 E | 2½ W | 1 W | 2½ W | 1 W | ||
| 5 N | 0 | 4¾ W | 10½ W | 15 W | 15¼ W | ||
| 5 N | 5 W | 3¼ W | 9 W | 13 W | 13 W | ||
| 5 N | 10 W | 1¾ W | 7½ W | 10¾ W | 11¼ W | ||
| 5 N | 15 W | 0¾ W | 2¼ W | 3¾ W | 5½ W | 8½ W | 9¼ W |
| 5 N | 20 W | 0 | 1½ W | 2½ W | 3½ W | 6 W | 7¼ W |
| 5 N | 25 W | 1 E | 0 | 1 W | 2 W | 3¾ W | 4½ W |
| 5 N | 30 W | 1¾ E | 1¼ E | 0½ E | 0¼ W | 1½ W | 1½ W |
| 5 N | 35 W | 2½ E | 2¼ E | 1¾ E | 1½ E | 0½ E | 0½ E |
| 5 N | 40 W | 3½ E | 3¼ E | 3 E | 2½ E | 2¼ E | 2¼ E |
| 5 N | 45 W | 4½ E | 4¼ E | 4¼ E | 4 E | 3¾ E | 4 E |
| 5 N | 50 W | 5½ E | 5½ E | 5¼ E | 5¼ E | 5 E | 5¼ E |
| 5 N | 55 W | 6¾ E | 6¼ E | 6½ E | |||
| 5 N | 5 E | 6¼ W | 12¾ W | 16¼ W | 16½ W | ||
| 5 N | 10 E | 7¾ W | 14¼ W | 17½ W | 17½ W | ||
| 5 N | 45 E | 16¾ W | 16 W | 15¼ W | 14¾ W | 14 W | 13¾ W |
| 5 N | 50 E | 16¾ W | 15¾ W | 14¾ W | 13½ W | 12¼ W | 11 W |
| 5 N | 55 E | 15½ W | 14¼ W | 13 W | 12 W | 10 W | 8¼ W |
| 5 N | 60 E | 14¼ W | 12¾ W | 11¼ W | 10 W | 8¼ W | 6 W |
| 5 N | 65 E | 12¾ W | 11 W | 9½ W | 8 W | 6 W | 4½ W |
| 5 N | 70 E | 10¾ W | 9 W | 7¼ W | 5½ W | 3¾ W | 2¾ W |
| 5 N | 75 E | 8¾ W | 7 W | 5¼ W | 3¾ W | 1¾ W | 0¾ W |
| 5 N | 80 E | 6½ W | 5 W | 3½ W | 2½ W | 0¼ W | 0¼ E |
| 5 N | 85 E | 4¾ W | 3¾ W | 2¾ W | 1½ W | 0¼ W | 1¼ E |
| 5 N | 90 E | 3¾ W | 1¼ W | 0½ E | |||
| 5 N | 95 E | 2¾ W | 2¼ W | 0½ W | |||
| Latitude. | Longitude, From London. | VARIATION. | |||||
|---|---|---|---|---|---|---|---|
| Anno 1700. | Anno 1710. | Anno 1720. | Anno 1730. | Anno 1744. | Anno 1756. | ||
| Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. |
| 10 N | 15 W | 1¼ W | 4½ W | 6 W | 9¼ W | 10 W | |
| 10 N | 20 W | 0½ W | 2 W | 3¼ W | 4½ W | 7 W | 8 W |
| 10 N | 25 W | 0¼ E | 0¾ W | 1¾ W | 2¾ W | 4½ W | 5½ W |
| 10 N | 30 W | 1 E | 0½ E | 0 | 1 W | 2¼ W | 3 W |
| 10 N | 35 W | 1¾ E | 1¼ E | 0¾ E | 0¼ E | 0½ W | 1 W |
| 10 N | 40 W | 2½ E | 2¼ E | 2 E | 1¾ E | 1¼ E | 1 E |
| 10 N | 45 W | 3½ E | 3½ E | 3¼ E | 3 E | 2¾ E | 2½ E |
| 10 N | 50 W | 4½ E | 4½ E | 4¼ E | 4¼ E | 4 E | 4 E |
| 10 N | 55 W | 5½ E | 5½ E | 5½ E | 5¼ E | 5¼ E | 5½ E |
| 10 N | 60 W | 6½ E | 6½ E | 6¾ E | |||
| 10 N | 50 E | 16 W | 15 W | 14 W | 12¾ W | 11¼ W | 10½ W |
| 10 N | 55 E | 15 W | 13½ W | 12 W | 11 W | 9¼ W | 8 W |
| 10 N | 60 E | 13½ W | 12 W | 10½ W | 9¼ W | 7¾ W | 6 W |
| 10 N | 65 E | 12 W | 10¾ W | 9 W | 7½ W | 6 W | 4½ W |
| 10 N | 70 E | 10 W | 8¾ W | 6½ W | 5 W | 3¾ W | 3 W |
| 10 N | 75 E | 8 W | 6½ W | 5 W | 3½ W | 1¾ W | 1 E |
| 10 N | 80 E | 5¾ W | 4½ W | 3¼ W | 2 W | 0½ W | 0¼ E |
| 10 N | 85 E | 4½ W | 3½ W | 2¼ W | 1¼ W | 0 | 1 E |
| 10 N | 90 E | 3½ W | 1½ W | 0½ E | |||
| 10 N | 95 E | 2½ W | 2¼ W | 0½ W | |||
| 15 N | 20 W | 1 W | 2½ W | 4 W | 5½ W | 7 W | 9 W |
| 15 N | 25 W | 0½ W | 1½ W | 2½ W | 3½ W | 4¾ W | 6½ W |
| 15 N | 30 W | 0¼ E | 0¼ W | 1 W | 1¾ W | 2¾ W | 4½ W |
| 15 N | 35 W | 1 E | 0½ E | 0 | 0½ W | 1¼ W | 2½ W |
| 15 N | 40 W | 1½ E | 1¾ E | 1 E | 0½ E | 0 | 0½ W |
| 15 N | 45 W | 2¼ E | 2¼ E | 2 E | 1¾ E | 1½ E | 1 E |
| 15 N | 50 W | 3¼ E | 3¼ E | 3¼ E | 3 E | 2¾ E | 2½ E |
| 15 N | 55 W | 4 E | 4 E | 4 E | 4 E | 4 E | 3¾ E |
| 15 N | 60 W | 5 E | 5 E | 5 E | 5 E | 5 E | 5 E |
| 15 N | 65 W | 6 E | 5 E | 6 E | 6 E | ||
| 15 N | 70 W | 7 E | 5½ E | 6¾ E | 7 E | ||
| 15 N | 75 W | 7¾ E | 7 E | 7¾ E | |||
| 15 N | 80 W | 8¼ E | 7 E | 8 E | |||
| 15 N | 50 E | 15½ W | 14¼ W | 13 W | 11¾ W | 10½ W | 9¾ W |
| 15 N | 55 E | 14¼ W | 12¾ W | 11½ W | 10¾ W | 8¾ W | 7¾ W |
| 15 N | 60 E | 13 W | 11¾ W | 10¼ W | 9 W | 7½ W | 6 W |
| 15 N | 65 E | 11½ W | 10 W | 8¾ W | 7½ W | 6 W | 4½ W |
| 15 N | 70 E | 9¾ W | 8¼ W | 6¾ W | 5½ W | 4 W | 2¾ W |
| 15 N | 75 E | 8 W | 6½ W | 5 W | 3½ W | 2¼ W | 0¾ W |
| 15 N | 80 E | 5¾ W | 4½ W | 3½ W | 2½ W | 1¼ W | 0 |
| 15 N | 85 E | 4¼ W | 3¼ W | 2¼ W | 1 W | 0¼ W | 0¾ W |
| 15 N | 90 E | 3¼ W | 2½ W | 1¼ W | 0¾ W | 0½ W | |
| 15 N | 95 E | 2½ W | 1½ W | 2¼ W | 0½ W | ||
| 20 N | 20 W | 1½ W | 3 W | 4¼ W | 5¼ W | 7 W | 10 W |
| 20 N | 25 W | 1 W | 2 W | 2¾ W | 3½ W | 4¾ W | 8 W |
| 20 N | 30 W | 0½ W | 1 W | 1½ W | 2¼ W | 3¼ W | 5¾ W |
| 20 N | 35 W | 0¼ E | 0¼ W | 0¾ W | 1½ W | 2¼ W | 4 W |
| 20 N | 40 W | 0¾ E | ¼ E | 0 | 0½ W | 1 W | 2½ W |
| 20 N | 45 W | 1½ E | 1¼ E | 1 E | ¾ E | 0¼ E | 0¾ W |
| 20 N | 50 W | 2 E | 2 E | 1¾ E | 1½ E | 1¼ E | 0¾ E |
| 20 N | 55 W | 2¾ E | 2¾ E | 2¾ E | 2½ E | 2½ E | 2 E |
| 20 N | 60 W | 3¾ E | 3¾ E | 3¾ E | 3½ E | 3½ E | 3¼ E |
| 20 N | 65 W | 4¾ E | 4¼ E | 4 E | |||
| 20 N | 70 W | 5½ E | 5 E | 5 E | |||
| 20 N | 75 W | 6¼ E | 5¼ E | 5¼ E | |||
| 20 N | 80 W | 7 E | 5¼ E | 6 E | |||
| 20 N | 60 E | 12¾ W | 11¼ W | 10 W | 9 W | 7½ W | 6 W |
| 20 N | 65 E | 11½ W | 10 W | 8½ W | 7¼ W | 6 W | 4½ W |
| 20 N | 70 E | 9¾ W | 8½ W | 7 W | 5¾ W | 4½ W | 2¾ W |
| 20 N | 90 E | 3½ W | 2½ W | 1½ W | 1 W | 0½ W | 1 E |
| 25 N | 20 W | 2 W | 3¼ W | 4 W | 5¼ W | 7 W | 11 W |
| 25 N | 25 W | 1¾ W | 2¼ W | 2¾ W | 4 W | 5¼ W | 9½ W |
| 25 N | 30 W | 1¼ W | 1¾ W | 2¼ W | 3 W | 4 W | 7½ W |
| 25 N | 35 W | 1 W | 1½ W | 2 W | 2½ W | 3 W | 5½ W |
| 25 N | 40 W | 0½ W | 0¾ W | 1 W | 1½ W | 2¼ W | 3¾ W |
| 25 N | 45 W | 0¼ E | 0 | 0½ W | 1 W | 1½ W | 2½ W |
| 25 N | 50 W | 0¾ E | 0½ E | 0¼ E | 0 | 0½ W | 1 W |
| 25 N | 55 W | 1¼ E | 1 E | 1 E | ¾ E | 0½ E | 0 |
| 25 N | 60 W | 2 E | 2 E | 2 E | 1½ E | 1½ E | 1¼ E |
| 25 N | 65 W | 2¾ E | 2¼ E | 2¼ E | |||
| 25 N | 70 W | 3½ E | 3¼ E | 2¾ E | |||
| 25 N | 75 W | 4¼ E | 3½ E | 3 E | |||
| 25 N | 80 W | 4¾ E | 3½ E | 3 E | |||
| 25 N | 60 E | 12¾ W | 11½ W | 10¼ W | 9 W | 7½ W | 6 W |
| 25 N | 65 E | 11½ W | 10¼ W | 9 W | 7½ W | 6 W | 4½ W |
| 25 N | 70 E | 10 W | 8¾ W | 7½ W | 6 W | 4½ W | 2¾ W |
| 30 N | 10 W | 3½ W | 11½ W | 13¾ W | |||
| 30 N | 15 W | 3¼ W | 10¼ W | 12¾ W | |||
| 30 N | 20 W | 3 W | 4¼ W | 5½ W | 6¾ W | 8½ W | 12 W |
| 30 N | 25 W | 2¾ W | 3½ W | 4¼ W | 5½ W | 6¾ W | 10¾ W |
| 30 N | 30 W | 2½ W | 3 W | 3½ W | 4¼ W | 5¼ W | 9 W |
| 30 N | 35 W | 2¼ W | 2¾ W | 3¼ W | 3¾ W | 4¼ W | 7 W |
| 30 N | 40 W | 1¾ W | 2 W | 2½ W | 3 W | 3½ W | 5¼ W |
| 30 N | 45 W | 1¼ W | 1½ W | 2 W | 2¼ W | 2¾ W | 4 W |
| 30 N | 50 W | 0¾ W | 1 W | 1½ W | 1¾ W | 2¼ W | 3 W |
| 30 N | 55 W | 0¼ W | ½ W | 1 W | 1¼ W | 1½ W | 2¼ W |
| 30 N | 60 W | 0¼ E | 0 | ¼ W | 0½ W | 1 W | 1½ W |
| 30 N | 65 W | 0¾ E | ½ E | ¼ E | 0 | ¼ W | 1 W |
| 30 N | 70 W | 1½ E | 1¼ E | 1 E | ¾ E | ¼ E | ½ W |
| 30 N | 75 W | 2 E | 1½ E | 1¼ E | 1 E | ½ E | 0 |
| 30 N | 80 W | 2¼ E | ¾ E | 0 | |||
| 35 N | 10 W | 4¼ W | 9¾ W | 12¼ W | 14¾ W | ||
| 35 N | 15 W | 4 W | 9¼ W | 11½ W | 13¾ W | ||
| 35 N | 20 W | 4 W | 8¼ W | 10¼ W | 13 W | ||
| 35 N | 25 W | 3¾ W | 4¾ W | 6 W | 7½ W | 9 W | 12¼ W |
| 35 N | 30 W | 3¾ W | 4½ W | 5½ W | 6¾ W | 8 W | 10½ W |
| 35 N | 35 W | 3¾ W | 4¼ W | 5¼ W | 6 W | 7 W | 8¾ W |
| 35 N | 40 W | 3¾ W | 4 W | 4½ W | 5¼ W | 6¼ W | 7¼ W |
| 35 N | 45 W | 3½ W | 3¾ W | 4¼ W | 4¾ W | 5½ W | 6¼ W |
| 35 N | 50 W | 3½ W | 3¾ W | 4 W | 4¼ W | 5 W | 5½ W |
| 35 N | 55 W | 3½ W | 3¾ W | 4 W | 4¼ W | 4¾ W | 5 W |
| 35 N | 60 W | 3¼ W | 3¾ W | 4 W | 4¼ W | 5 W | 5¼ W |
| 35 N | 65 W | 3 W | 5¼ W | 6 W | |||
| 35 N | 70 W | 2½ W | 5¾ W | 6¾ W | |||
| 35 N | 75 W | 2¼ W | 6½ W | 7 W | |||
| 40 N | 10 W | 5 W | 10¾ W | 13¼ W | 15 W | ||
| 40 N | 15 W | 5¼ W | 10½ W | 12¾ W | 14½ W | ||
| 40 N | 20 W | 5¼ W | 10 W | 12¼ W | 14¼ W | ||
| 40 N | 25 W | 5½ W | 9½ W | 11¼ W | 13½ W | ||
| 40 N | 30 W | 5½ W | 6¾ W | 8 W | 9 W | 10¼ W | 12¾ W |
| 40 N | 35 W | 5¾ W | 6½ W | 7¼ W | 8¼ W | 9½ W | 11¼ W |
| 40 N | 40 W | 5¾ W | 6¼ W | 7¼ W | 8 W | 9 W | 10 W |
| 40 N | 45 W | 6 W | 7½ W | 8½ W | 9½ W | ||
| 40 N | 50 W | 6¼ W | 7¼ W | 8½ W | 9½ W | ||
| 40 N | 55 W | 6½ W | 7¾ W | 8¾ W | 10 W | ||
| 40 N | 60 W | 6¾ W | 8 W | 9¼ W | 11 W | ||
| 40 N | 65 W | 7 W | 8½ W | 10¼ W | 12 W | ||
| 40 N | 70 W | 7 W | 9 W | 11½ W | 12¾ W | ||
| Latitude. | Longitude, From London. | VARIATION. | |||||
|---|---|---|---|---|---|---|---|
| Anno 1700. | Anno 1710. | Anno 1720. | Anno 1730. | Anno 1744. | Anno 1756. | ||
| Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. |
| 45 N | 5 W | 6 W | 12½ W | 15½ W | 16½ W | ||
| 45 N | 10 W | 6½ W | 12¼ W | 15 W | 16½ W | ||
| 45 N | 15 W | 6¾ W | 11¾ W | 14¾ W | 16¼ W | ||
| 45 N | 20 W | 7 W | 11½ W | 14½ W | 16 W | ||
| 45 N | 25 W | 7½ W | 11½ W | 14 W | 16 W | ||
| 45 N | 30 W | 8 W | 11¾ W | 13¾ W | 15¾ W | ||
| 45 N | 35 W | 8¾ W | 11¾ W | 13¼ W | 15¼ W | ||
| 45 N | 40 W | 9½ W | 12 W | 13 W | 15 W | ||
| 45 N | 45 W | 10½ W | 12¾ W | 13¼ W | 15½ W | ||
| 45 N | 50 W | 11½ W | 13½ W | 14 W | 16 W | ||
| 45 N | 55 W | 12½ W | 14 W | 15¼ W | 17 W | ||
| 45 N | 60 W | 13¾ W | 14 W | 16 W | 18½ W | ||
| 50 N | 5 W | 7½ W | 17 W | 19¼ W | |||
| 50 N | 10 W | 7¾ W | 17¼ W | 19½ W | |||
| 50 N | 15 W | 8½ W | 17½ W | 20 W | |||
| 50 N | 20 W | 9 W | 17½ W | 20½ W | |||
| 50 N | 25 W | 9¾ W | 17¾ W | 21 W | |||
| 5 S | 0 | 4¼ W | 10 W | 13¼ W | 15 W | ||
| 5 S | 5 W | 2½ W | 8½ W | 11¼ W | 13 W | ||
| 5 S | 10 W | 1 W | 3 W | 4¾ W | 6½ W | 9¼ | 10¾ W |
| 5 S | 15 W | 0 | 1½ W | 3 W | 4½ W | 6¾ W | 8½ W |
| 5 S | 20 W | 1¼ E | 0¼ W | 0¾ W | 2¼ W | 4 W | 6 W |
| 5 S | 25 W | 2¼ E | 1¼ E | 0¼ E | 0¾ W | 2 W | 3 W |
| 5 S | 30 W | 3¼ E | 2¼ E | 1¾ E | 1 E | 0¼ E | 0 |
| 5 S | 35 W | 4¼ E | 4 E | 3½ E | 3¼ E | 2¾ E | 2¾ E |
| 5 S | 5 E | 6 W | 12½ W | 15 W | 16 W | ||
| 5 S | 10 E | 7½ W | 14¼ W | 16½ W | 17 W | ||
| 5 S | 40 E | 18 W | 17¾ W | 17¾ W | 17½ W | 17½ W | 18 W |
| 5 S | 45 E | 18½ W | 18¼ W | 18 W | 17½ W | 17 W | 16 W |
| 5 S | 50 E | 18½ W | 17¾ W | 17 W | 16¼ W | 15½ W | 12¾ W |
| 5 S | 55 E | 17½ W | 16½ W | 15½ W | 14¾ W | 13 W | 9¼ W |
| 5 S | 60 E | 16¼ W | 14¾ W | 13¼ W | 12 W | 10 W | 6½ W |
| 5 S | 65 E | 14¾ W | 12¾ W | 10¾ W | 9 W | 7 W | 4½ W |
| 5 S | 70 E | 13 W | 11 W | 9 W | 6¾ W | 4½ W | 3 W |
| 5 S | 75 E | 11 W | 9 W | 7 W | 5 W | 2¼ W | 1 W |
| 5 S | 80 E | 9 W | 7 W | 5 W | 3 W | 0¾ W | 0 |
| 5 S | 85 E | 7 W | 5½ W | 3¾ W | 2½ W | 0½ W | 0¾ E |
| 5 S | 90 E | 5 W | 4½ W | 2¾ W | 2 W | 1¼ W | 0¾ E |
| 5 S | 95 E | 3¾ W | 3½ W | 1½ W | 1½ W | 2 W | 0½ W |
| 5 S | 100 E | 3 W | 2½ W | 1½ W | 1 W | 2¾ W | 1½ W |
| 10 S | 0 | 3¾ W | 9½ W | 12½ W | 14¼ W | ||
| 10 S | 5 W | 2¼ W | 4¼ W | 6¼ W | 8¼ W | 10½ W | 12¾ W |
| 10 S | 10 W | 0¾ W | 2¾ W | 4¾ W | 6½ W | 8¼ W | 10¼ W |
| 10 S | 15 W | ½ E | 1 W | 2½ W | 4 W | 5¾ W | 7¾ W |
| 10 S | 20 W | 1¾ E | 0½ E | 0 | 1½ W | 3 W | 4¾ W |
| 10 S | 25 W | 3 E | 2½ E | 1¾ E | 0¾ E | 0¾ W | 2 W |
| 10 S | 30 W | 4 E | 3½ E | 3 E | 2½ E | 1¾ E | 1 E |
| 10 S | 35 W | 5¼ E | 5 E | 4¾ E | 4½ W | 4 E | 3½ E |
| 10 S | 5 E | 5¾ W | 12 W | 14½ W | 15¾ W | ||
| 10 S | 10 E | 7½ W | 14 W | 16 W | 16¾ W | ||
| 10 S | 15 E | 9¼ W | 15½ W | 17¼ W | 17¾ W | ||
| 10 S | 40 E | 18¾ W | 18¾ W | 18¾ W | 18¾ W | 19 W | 19¼ W |
| 10 S | 45 E | 19½ W | 19¼ W | 19 W | 18¾ W | 18½ W | 18 W |
| 10 S | 50 E | 19½ W | 19 W | 18½ W | 17¾ W | 16¾ W | 14¼ W |
| 10 S | 55 E | 18½ W | 17½ W | 16½ W | 15½ W | 14½ W | 10½ W |
| 10 S | 60 E | 17 W | 16 W | 15 W | 14 W | 11¼ W | 7¼ W |
| 10 S | 65 E | 15¾ W | 13¾ W | 11¾ W | 10 W | 8 W | 5 W |
| 10 S | 70 E | 14½ W | 12 W | 10 W | 8 W | 5½ W | 3½ W |
| 10 S | 75 E | 12½ W | 10¼ W | 9 W | 5¾ W | 3½ W | 2 W |
| 10 S | 80 E | 10½ W | 8 W | 5½ W | 4 W | 1¾ W | 1 W |
| 10 S | 85 E | 8½ W | 6¾ W | 5 W | 3¾ W | 1½ W | 0¼ W |
| 10 S | 90 E | 6¾ W | 5½ W | 4¼ W | 3 W | 1¾ W | 0¼ W |
| 10 S | 95 E | 5 W | 4½ W | 4 W | 3¼ W | 2½ W | 1 W |
| 10 S | 100 E | 3¾ W | 3½ W | 3¼ W | 3 W | 2¾ W | 2 W |
| 10 S | 105 E | 2¾ W | 2¾ W | 2½ W | 2½ W | 3¼ W | 2¾ W |
| 10 S | 110 E | 2 W | 3¾ W | 3¼ W | |||
| 15 S | 0 | 3½ W | 5½ W | 7½ W | 9½ W | 11¾ W | 14 W |
| 15 S | 5 W | 1¾ W | 3¾ W | 5¾ W | 7¾ W | 9½ W | 12 W |
| 15 S | 10 W | ¼ W | 2 W | 3¾ W | 5½ W | 7½ W | 9½ W |
| 15 S | 15 W | 1¼ E | 0¼ W | 1¾ W | 3¼ W | 4¾ W | 7 W |
| 15 S | 20 W | 2½ E | 1½ E | 0¾ E | 0½ W | 1¾ W | 4 W |
| 15 S | 25 W | 3¾ E | 3 E | 2¼ E | 1½ E | 0½ E | 1 W |
| 15 S | 30 W | 5 E | 4½ E | 4 E | 3½ E | 3 E | 2 E |
| 15 S | 35 W | 6½ E | 6¼ E | 5¾ E | 5½ E | 5 E | 4½ E |
| 15 S | 40 W | 7¾ E | 6¾ E | 6½ E | |||
| 15 S | 5 E | 5½ W | 11½ W | 13¾ W | 15¼ W | ||
| 15 S | 10 E | 7½ W | 14 W | 15½ W | 16½ W | ||
| 15 S | 40 E | 19¾ W | 19¾ W | 20 W | 20 W | 20 W | 20 W |
| 15 S | 45 E | 20½ W | 20½ W | 20¼ W | 20¼ W | 20 W | 19½ W |
| 15 S | 50 E | 20½ W | 20 W | 19½ W | 18¾ W | 18 W | 16¼ W |
| 15 S | 55 E | 19½ W | 18½ W | 17½ W | 16½ W | 15½ W | 12½ W |
| 15 S | 60 E | 18¼ W | 17 W | 16 W | 14½ W | 12½ W | 9 W |
| 15 S | 65 E | 17 W | 15½ W | 13½ W | 12 W | 9¾ W | 6 W |
| 15 S | 70 E | 15½ W | 12¾ W | 10¾ W | 9 W | 7¼ W | 4¼ W |
| 15 S | 75 E | 14 W | 12 W | 9¾ W | 7½ W | 5 W | 3¼ W |
| 15 S | 80 E | 12 W | 10 W | 8 W | 6 W | 3½ W | 2½ W |
| 15 S | 85 E | 10 W | 8 W | 6¼ W | 4¾ W | 2¾ W | 2¼ W |
| 15 S | 90 E | 8½ W | 7¼ W | 6 W | 4½ W | 3 W | 2¼ W |
| 15 S | 95 E | 6½ W | 5¾ W | 5 W | 4¼ W | 3¼ W | 2¾ W |
| 15 S | 100 E | 5 W | 4¾ W | 4½ W | 4¼ W | 3¾ W | 3½ W |
| 15 S | 105 E | 3½ W | 3½ W | 3¾ W | 3¾ W | 4¼ W | 3¾ W |
| 15 S | 110 E | 2½ W | 4½ W | ||||
| 20 S | 0 | 3¼ W | 5¼ W | 7¼ W | 9 W | 11 W | 13½ W |
| 20 S | 5 W | 1½ W | 3¼ W | 5 W | 6¾ W | 8¾ W | 11¼ W |
| 20 S | 10 W | 0½ E | 1¼ W | 3 W | 4¾ W | 6½ W | 8¾ W |
| 20 S | 15 W | 1¾ E | 0½ E | 0¾ W | 2 W | 3½ W | 5¾ W |
| 20 S | 20 W | 3 E | 2¾ E | 1½ E | 0½ W | 0½ W | 3 W |
| 20 S | 25 W | 4¾ E | 4¼ E | 3½ E | 2¾ E | 2 E | 0 |
| 20 S | 30 W | 6 E | 5½ E | 5¼ E | 4¾ E | 4¼ E | 2½ E |
| 20 S | 35 W | 7¾ E | 7½ E | 7¼ E | 6¾ E | 6½ E | 5 E |
| 20 S | 40 W | 9¼ E | 8 E | 7½ E | |||
| 20 S | 5 E | 5½ W | 11 W | 13¼ W | 15 W | ||
| 20 S | 10 E | 7½ W | 13½ W | 15 W | 16¼ W | ||
| 20 S | 15 E | 9½ W | 15½ W | 16½ W | 17¾ W | ||
| 20 S | 35 E | 19 W | 19¼ W | 19¾ W | 20¼ W | 20¾ W | 22 W |
| 20 S | 40 E | 20½ W | 20¾ W | 21¼ W | 21½ W | 21¾ W | 22 W |
| 20 S | 45 E | 21¼ W | 21¼ W | 21½ W | 21½ W | 21¾ W | 21¼ W |
| 20 S | 50 E | 21¼ W | 21 W | 20¾ W | 20¼ W | 19¾ W | 18¾ W |
| 20 S | 55 E | 20½ W | 20 W | 19¼ W | 18½ W | 17 W | 15 W |
| 20 S | 60 E | 19½ W | 18¼ W | 17 W | 5¾ W | 14½ W | 11¼ W |
| 20 S | 65 E | 18¼ W | 17 W | 15¾ W | 14¼ W | 12 W | 8 W |
| 20 S | 70 E | 16¾ W | 15½ W | 13½ W | 12 W | 10 W | 6 W |
| 20 S | 75 E | 15 W | 13 W | 10½ W | 9 W | 7¾ W | 4¾ W |
| 20 S | 80 E | 13½ W | 11¾ W | 9¾ W | 8 W | 6 W | 4½ W |
| 20 S | 85 E | 11½ W | 10 W | 8½ W | 7 W | 5 W | 4¼ W |
| 20 S | 90 E | 10 W | 8¾ W | 7½ W | 6¼ W | 4¾ W | 4½ W |
| 20 S | 95 E | 8 W | 7¼ W | 6½ W | 5¾ W | 4¾ W | 4½ W |
| 20 S | 100 E | 6½ W | 6¼ W | 6 W | 5½ W | 5 W | 4¾ W |
| 20 S | 105 E | 4¾ W | 5 W | 5 W | 5 W | 5 W | 4¾ W |
| 25 S | 0 | 3 W | 5 W | 7 W | 8¾ W | 10½ W | 12½ W |
| 25 S | 5 W | 1 W | 2¾ W | 4½ W | 6¼ W | 8 W | 10 W |
| 25 S | 10 W | 1 E | 0½ W | 2¾ W | 4 W | 5½ W | 7½ W |
| 25 S | 15 W | 2½ E | 1¼ W | 0 | 1¼ W | 2½ W | 4½ W |
| 25 S | 20 W | 4 E | 3¼ E | 2 E | 1¼ E | 0½ E | 2¾ W |
| 25 S | 25 W | 6 E | 5¼ E | 4½ E | 3¾ E | 3 E | 1 E |
| 25 S | 30 W | 7½ E | 7 E | 6½ E | 6 E | 5½ E | 3½ E |
| 25 S | 35 W | 9¼ E | 7½ E | 6 E | |||
| 25 S | 40 W | 11 E | 9 E | ||||
| 25 S | 5 E | 5¼ W | 7 W | 8¾ W | 10½ W | 12½ W | 14½ W |
| 25 S | 10 E | 7½ W | 14½ W | 16 W | |||
| 25 S | 15 E | 9½ W | 16¼ W | 17¾ W | |||
| 25 S | 35 E | 19½ W | 20¼ W | 20¾ W | 21½ W | 22¼ W | 23½ W |
| 25 S | 40 E | 21 W | 21½ W | 22 W | 22½ W | 23¼ W | 23¾ W |
| 25 S | 45 E | 22¼ W | 22½ W | 22¾ W | 23 W | 23¼ W | 23 W |
| 25 S | 50 E | 22½ W | 22½ W | 22¼ W | 22¼ W | 22 W | 21 W |
| 25 S | 55 E | 22 W | 21½ W | 21 W | 20½ W | 19¾ W | 18 W |
| 25 S | 60 E | 20¾ W | 19¾ W | 19 W | 18¼ W | 17 W | 14¾ W |
| 25 S | 65 E | 19¼ W | 18¼ W | 17¼ W | 16¼ W | 15 W | 11¾ W |
| 25 S | 70 E | 17¾ W | 16¾ W | 15¾ W | 14½ W | 13 W | 9½ W |
| 25 S | 75 E | 16¼ W | 15 W | 13¾ W | 12½ W | 11¼ W | 8 W |
| 25 S | 80 E | 14¾ W | 13½ W | 12¼ W | 10¾ W | 9¼ W | 7½ W |
| 25 S | 85 E | 13 W | 11¾ W | 10½ W | 9¼ W | 8 W | 7¼ W |
| 25 S | 90 E | 11¼ W | 10¼ W | 9¾ W | 8¼ W | 7¼ W | 7 W |
| 25 S | 95 E | 9½ W | 9 W | 8½ W | 7¾ W | 7 W | 6½ W |
| 25 S | 100 E | 7¾ W | 7½ W | 7¼ W | 7 W | 6¾ W | 6 W |
| Latitude. | Longitude, From London. | VARIATION. | |||||
|---|---|---|---|---|---|---|---|
| Anno 1700. | Anno 1710. | Anno 1720. | Anno 1730. | Anno 1744. | Anno 1756. | ||
| Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. | Degrees. |
| 30 S | 0 | 2¾ W | 4¼ W | 6 W | 7¾ W | 9½ W | 11¾ W |
| 30 S | 5 W | 0½ W | 2 W | 3½ W | 5¼ W | 7 W | 9 W |
| 30 S | 10 W | 1½ E | 0 | 1½ W | 3 W | 4½ W | 6¼ W |
| 30 S | 15 W | 3¼ E | 2¼ E | 0¾ E | 0¼ W | 1½ W | 3½ W |
| 30 S | 20 W | 5 E | 4¾ E | 3¾ E | 2¾ E | 1½ E | 0½ W |
| 30 S | 25 W | 7¼ E | 6½ E | 5¾ E | 5 E | 4 E | 2 E |
| 30 S | 30 W | 9 E | 6½ E | 4½ E | |||
| 30 S | 35 W | 11 E | 8½ E | 7¼ E | |||
| 30 S | 5 E | 5 W | 7 W | 8¾ W | 10¼ W | 11¾ W | 13¾ W |
| 30 S | 10 E | 7¼ W | 9¼ W | 11¼ W | 12¾ W | 14 W | 15½ W |
| 30 S | 15 E | 9½ W | 16 W | 17½ W | |||
| 30 S | 30 E | 17½ W | 18½ W | 19½ W | 20½ W | 21¾ W | 23¼ W |
| 30 S | 35 E | 20¼ W | 21 W | 21¾ W | 22½ W | 23½ W | 24¾ W |
| 30 S | 40 E | 21¾ W | 22½ W | 23¼ W | 24 W | 24¾ W | 25¼ W |
| 30 S | 45 E | 23 W | 23½ W | 24 W | 24½ W | 25¼ W | 24½ W |
| 30 S | 50 E | 23½ W | 23¾ W | 24 W | 24¼ W | 24½ W | 23¼ W |
| 30 S | 55 E | 23 W | 23 W | 23 W | 22¾ W | 22½ W | 21 W |
| 30 S | 60 E | 21¾ W | 21½ W | 21 W | 20½ W | 20 W | 18 W |
| 30 S | 65 E | 20¼ W | 19½ W | 19 W | 18½ W | 17¾ W | 15 W |
| 30 S | 70 E | 18¾ W | 18 W | 17¼ W | 16½ W | 15½ W | 13 W |
| 30 S | 75 E | 17¼ W | 16½ W | 15¾ W | 14¾ W | 13¾ W | 11½ W |
| 30 S | 80 E | 15¾ W | 15 W | 14 W | 13 W | 12 W | 10¾ W |
| 30 S | 85 E | 14 W | 13¼ W | 12½ W | 11½ W | 10½ W | 10¼ W |
| 30 S | 90 E | 12½ W | 11¾ W | 11 W | 10¼ W | 9½ W | 9½ W |
| 30 S | 95 E | 10½ W | 10 W | 9½ W | 9¾ W | 8¾ W | 9 W |
| 30 S | 100 E | 8¾ W | 8¼ W | ||||
| 35 S | 0 | 2½ W | 4 W | 5½ W | 7 W | 8½ W | 10½ W |
| 35 S | 5 W | 0 | 1 W | 2½ W | 4 W | 5¾ W | 7¾ W |
| 35 S | 10 W | 2¼ E | 1½ E | 0½ W | 1¾ W | 3¼ W | 5 W |
| 35 S | 15 W | 4¼ E | 0¼ W | 2¼ W | |||
| 35 S | 20 W | 6¾ E | 2½ E | 0½ E | |||
| 35 S | 25 W | 8¾ E | 5 E | 3 E | |||
| 35 S | 30 W | 10¾ E | 7¼ E | 5¾ E | |||
| 35 S | 35 W | 12¾ E | 9¼ E | 8¼ E | |||
| 35 S | 5 E | 5 W | 6½ W | 8 W | 9½ W | 11 W | 13 W |
| 35 S | 10 E | 7¼ W | 8½ W | 10¼ W | 11¾ W | 13½ W | 15¼ W |
| 35 S | 15 E | 9¾ W | 11¼ W | 12¾ W | 14¼ W | 15½ W | 17½ W |
| 35 S | 20 E | 12½ W | 14 W | 15½ W | 17 W | 18½ W | 19¾ W |
| 35 S | 25 E | 15¼ W | 16½ W | 18 W | 19¼ W | 20¾ W | 22½ W |
| 35 S | 30 E | 18¼ W | 19½ W | 20½ W | 21½ W | 22¾ W | 24¼ W |
| 35 S | 35 E | 21 W | 22 W | 22¾ W | 23½ W | 24½ W | 26 W |
| 35 S | 40 E | 22¾ W | 23½ W | 24¼ W | 25 W | 26 W | 26¾ W |
| 35 S | 45 E | 24¼ W | 25 W | 25 W | 26 W | 27 W | 26 W |
| 35 S | 50 E | 24¾ W | 25¼ W | 25¾ W | 26 W | 26½ W | 24¾ W |
| 35 S | 55 E | 24¼ W | 24½ W | 24½ W | 24¾ W | 25 W | 23 W |
| 35 S | 60 E | 23 W | 23 W | 23 W | 22¾ W | 22¾ W | 21 W |
| 35 S | 65 E | 21½ W | 21¼ W | 21 W | 20¾ W | 20¼ W | 18¾ W |
| 35 S | 70 E | 19¾ W | 19¾ W | 18¾ W | 18¼ W | 17¾ W | 16¾ W |
| 35 S | 75 E | 18¼ W | 17¾ W | 17¼ W | 17½ W | 16 W | 15¼ W |
| 35 S | 80 E | 16¾ W | 16¼ W | 15¾ W | 15 W | 14¼ W | 14¼ W |
| 35 S | 85 E | 15 W | 14½ W | 14 W | 13½ W | 13 W | 13½ W |
| 35 S | 90 E | 13½ W | 13 W | 12¾ W | 12½ W | 12 W | 12¾ W |
| 35 S | 95 E | 11½ W | 11½ W | 11¼ W | 11 W | 10¾ W | |
| 40 S | 0 | 2 W | 3½ W | 5 W | 6½ W | 7¾ W | 9¼ W |
| 40 S | 5 W | 0¾ E | 0½ W | 2 W | 3½ W | 5 W | 6¾ W |
| 40 S | 10 W | 3¼ E | 2½ W | 4¼ W | |||
| 40 S | 15 W | 5½ E | 0½ E | 1½ W | |||
| 40 S | 20 W | 8 E | 3¼ E | 1¼ E | |||
| 40 S | 25 W | 10½ E | 5½ E | 4 E | |||
| 40 S | 30 W | 12½ E | 8 E | 6½ E | |||
| 40 S | 5 E | 4½ W | 6 W | 7½ W | 9 W | 10¼ W | 12 W |
| 40 S | 10 E | 7¼ W | 8½ W | 10 W | 11½ W | 12¾ W | 14½ W |
| 40 S | 15 E | 9¾ W | 11¼ W | 12¾ W | 14 W | 15½ W | 17¼ W |
| 40 S | 20 E | 12¾ W | 14¼ W | 15½ W | 17 W | 18½ W | 20 W |
| 40 S | 25 E | 16 W | 17¼ W | 18½ W | 19¾ W | 21¼ W | 22¾ W |
| 40 S | 30 E | 19 W | 20 W | 21¼ W | 22¼ W | 23½ W | 25¼ W |
| 40 S | 35 E | 21¾ W | 22¾ W | 23½ W | 24½ W | 25½ W | 27 W |
| 40 S | 40 E | 23¾ W | 24½ W | 25 W | 26 W | 27 W | 28½ W |
| 40 S | 45 E | 25¼ W | 26 W | 26¾ W | 27½ W | 28¼ W | 27¼ W |
| 40 S | 50 E | 26 W | 26½ W | 27 W | 27½ W | 28¼ W | 26 W |
| 40 S | 55 E | 25¼ W | 25½ W | 25¾ W | 26 W | 26½ W | 24½ W |
| 40 S | 60 E | 24 W | 24 W | 24 W | 24¼ W | 24¼ W | 22¾ W |
| 40 S | 65 E | 22½ W | 22½ W | 22¼ W | 22¼ W | 22 W | 20¾ W |
| 40 S | 70 E | 20¾ W | 20½ W | 20¼ W | 20 W | 19½ W | 19½ W |
| 40 S | 75 E | 19¼ W | 18¾ W | 18¼ W | 17¾ W | 17¼ W | 18¼ W |
| 40 S | 80 E | 17½ W | 17 W | 16½ W | 16 W | 15½ W | 17¼ W |
Variation of the Magnetic-Needle, from the Islands of Orkney to Hudson's Straits, for the Year 1757.
| West Longitude From London. | Degrees of North Latitude. | ||||||||
| 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | ||
| Degrees. | Degrees of West Variation. | ||||||||
| 4 | 18 | 18 | 19 | 19 | |||||
| 10 | 19 | 19 | 20 | 20 | 21 | ||||
| 27 | 24 | 24 | 25 | 25 | |||||
| 45 | 29 | 29 | 30 | 31 | |||||
| 55 | |||||||||
| 65 | 39 | 40 | 41 | ||||||
Variation in Hudson's-Bay and Straits, for the Year 1757.
| West Longitude From London. | Degrees of North Latitude. | ||||||||||
| 52 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | ||
| Degrees. | Degrees of West Variation. | ||||||||||
| 65 | 39 | 40 | 41 | ||||||||
| 71 | 41 | 41 | |||||||||
| 79 | 43 | ||||||||||
| 81 | 38 | 39 | 40 | ||||||||
| 83 | 18 | 20 | 39 | 40 | |||||||
| 86 | 35 | 37 | |||||||||
| 92 | 17 | 17 | |||||||||
| 94 | 17 | 18 | |||||||||
| 95 | 18 | ||||||||||
We have been informed, that in Hudson's-Bay, there has been very little alteration in the variation of the compass during the twenty years last past.
XLII. An Account of some extraordinary Tumors upon the Head of a labouring Man, now in St. Bartholomew's Hospital. By James Parsons, M.D. F.R.S.
Read Nov. 10, 1757.
THIS poor man, whose name is John Tomlinson, gives this account of himself: That he was born at or near Rotherham in Yorkshire, and is now about 25 years of age: that when he was a boy of four or five years old, at play with other children, he received a blow from one of them upon the top of his head; and believes that hurt, he then received, was the beginning of the appearances, that are represented before you. See [Tab. XIV.] The tumor upon the top of his head, however, grew first, and, after having spread all over the vertex, extended gradually downwards over his right shoulder, and forwards over the os frontis, on the same side, till it stretched downwards into a lax flabby substance all over the right side of his face and shoulder: then the upper of the three anterior tumors arose from the large one; the middle one from the ala nasi, pulling it down by its weight, as you see it in [Figure 1.][198]; and the lower one was pendulous from the inside of the great tumor by a narrow neck. These are the appearances which present themselves at first sight; but those under the great tumor are no less extraordinary; for, upon lifting up the great tumor, and looking up under it, his right eye comes in sight, with which he sees very well, and the eye is clear and sound; but the under lid is pulled down, and stretched to six or seven inches long, to which a tumor hung also, as large as that anterior one at the chin, the lowest of the three; besides several flaps and rugæ of skin, and smaller tumors.
Philos. Trans. Vol. L. Tab. XIV. p. 350.
I. Parsons MD. ad viv. del.
J. Mynde sc.
The hairy scalp is so stretched by the vertical tumor, that the hairs are driven asunder; so that the tumor is in some places bald, and the whole is rugged and uneven. At its basis, all round, till we come to the extended part that goes away to the right shoulder, a bony edge may be distinctly felt, as if the skull was depressed at the top: and yet I cannot but believe, that there is no depression of the arch of the inner table, because the man was from his childhood ever very healthy; being never troubled with those symptoms, which usually attend a depression of the cranium. From this seeming edge the os frontis shoots out a great way over the ossa nasi, perhaps to two or three inches beyond the frontal sinus's; and is the basis, from which the great pendulous tumor hangs downwards and forwards.
From the root of the nose, under the upper of the three smaller tumors, arises a large trunk of a vein, which ramifies up to the vertical tumor, and to the right over the upper part of the great pendulous one: these are very conspicuous, and serve to bring back the residual blood from the tumors: nor is it unlikely that the arteries bear a proportion with these veins in their size, in order to supply the tumors with the matter, which has given them their great increase; but these, lying concealed, cannot be spoken to with any certainty.
If we compare this growth of the frontal bone with that of other exostoses, I believe there may this difference be rationally observed; that other exostoses are generally attended with ulcerous tumors, which are for the most part cancerous; and these may commence at any age. I have now drawings, taken from the right hand of a man of 50, which represent risings of the radius and ulna, with the fingers, to a most frightful degree; and these begun but six years before, and are attended with foul running ulcers; and now the bones of the arm and hand, on the left side, are beginning to have the same appearances: whereas the frontal bone of the present subject appears sound, as far as we are able to judge by examination: nor does there appear the least disposition to ulceration in any part of it. When this is the case, the growth generally begins while the subjects are young; upon which we shall be more particular a little further on. His sensation upon every part of these tumors, is exactly like that of every other part of his skin, having not the least uneasiness upon being handled. This poor man worked at day-labour in the fields till some months before he came to town.
Perhaps it may not be improper to lay down the dimensions of these tumors, as the case is so extraordinary; for the size of them is almost incredible: but I made my drawing in the presence of several of the gentlemen of that hospital, who allowed it to be very exact, and precise in the expression of the parts, as well as in the dimensions. The vertical tumor is about seven inches diameter at the basis, where the bony edge is felt, mentioned before, and about four inches high from that edge. From that edge, or the basis of the vertical tumor, to the bottom of the great tumor, is ten inches; so that the length of both, from the vertex to the end of the great one, is about 14 inches: and upon viewing it, when he turns his side towards you, the whole mass is eight or nine inches over all the way; hard at top, and flabby downwards, hanging in kinds of plaits. From the eye to the opposite outline of the great tumor is six inches; and lower down, from the left corner of his mouth to the opposite outline of the same tumor, eight inches. The upper small tumor, over the nose, is one inch three quarters long by one inch and a half; the middle tumor is two inches long from the ala nasi, to which it hangs, and of the same breadth; and the lowest tumor, shaped like a goose's egg, is four inches and a half long by near three inches over.
This man is under the care of Mr. Crane, an eminent surgeon of St. Bartholomew's Hospital, who has just now taken off the lowest of these three anterior tumors, and also the tumor mentioned, which hung underneath to the under lid of his right eye. He intends proceeding to take off that at the ala nasi next, and so on till he takes away all the smaller tumors first: afterwards the larger will be considered. The substance of those cut off was intirely fat; nor was there the least speck of blood in the lowest of the three smaller tumors; but there was an hæmorrhage from a vessel divided in taking off that hanging to the right eye-lid; which soon yielded to the methods he made use of, and went on successfully till quite healed.
It is pity no one of the people of condition in the country, where this poor man lived, took notice of him while he was a lad; because, when the vertical tumor begun, or even after it had made some progress, if he had been sent up to any of our hospitals, there would have been no difficulty in curing him. This leads me to some precautions, which, I hope, will render my account of the case of some use, considered in a physiological light; which was my intention in thus laying it before this learned Society.
There is a great deal of difference between injuries received in young subjects and in adults. In the latter, the consequences are not apt to be of so dangerous a nature as in the former (except indeed where there happen violent fractures or wounds, which immediately dispatch the person, young or old); because, in such as are so far advanced in years, as that the parts have done growing, or, in other words, are incapable of carrying the person to any larger size, preserving the natural proportion, a tumor arising from a blow on the head would be merely local, without extending to any neighbouring parts in so extraordinary a manner: but in children, as in the case before you, a tumor may increase every moment from a blow, and spread itself to the neighbouring parts, to the ruin of the child, unless timely care be taken to prevent it; because in such young subjects the parts are continually growing, the vessels enlarging in their diameters, and carrying more and more nutrition to every point, in proportion to the nature of each individual organ, always preserving such an equilibrium, in the distribution of the nutritive juices, as is proper to secure the due proportion of every part as it increases: but when a tumor arises from a blow in such a growing subject, if no wound is made, nor suppuration brought on in the tumor, then the parts of the tumor being only weakened, the equilibrium is destroyed, a greater flux of juices than ordinary is carried to it, the due resistance being impaired, and a luxuriancy of growth is produced in the place of the injury, which greatly exceeds that of the rest of the body; and will most certainly continue in the same manner, during the growth of the subject, when once thus begun. In the present subject, this luxuriancy was communicated even to the veins, which are apparent and large, and which were before, in their natural state, scarce visible; and not only to these, but to the very bones of the forehead: and as to the integuments and membranes of the body, their great distensibility is well known to every one. I have seen an ovarium so distended by water, and thickened as it grew, that it had substance enough to bear being dressed by a tanner, and contained nine gallons, which I saw poured into it after it was dressed. And does not every corpulent person shew the same power of distension in the membranes and integuments of the body, as well as wens of all kinds upon the surface?
I thought so extraordinary a case well worth the notice of the learned members of this Society in itself; and the more so, as these few hints fall naturally from it, to render its publication useful. We are taught by this, how necessary it is for all such as have the management of youth under their care, to have an early regard to every accident that may befall children; for many times injuries of this kind have been thought very trivial, which, being overlooked and neglected too long, have been followed by very direful circumstances. I have known about a young gentleman to have great hard swellings about his head, and become epileptic, losing his senses as he advanced in years, from a blow with the back of a book given him by a master. I am, with due respect,
The Society's
Most obedient Servant,
James Parsons.
Sept. 18. 1757.
XLIII. An Extract of the Register of the Parish of Great Shefford, near Lamborne, in Berkshire, for Ten Years: With Observations on the same: In a Letter to Tho. Birch, D. D. Secret. R. S. from the Rev. Mr. Richard Forster, Rector of Great Shefford.
Great Shefford, near Lamborne, Berks, July 8. 1757.
Rev. Sir,
Read Nov. 17, 1757.
WHEN I settled in the country, abundant leisure enabled me to keep an exact parish-register. I have now finished ten years, I trust, with sufficient care, having examined every thing accurately myself. The sight of three letters, lately published in the Transactions, upon the subject of political arithmetic, put me upon overlooking and methodizing my own account; which I here send you, to make what use you think proper of it.
From Lady-day 1747. to Dº. 1757.
| Baptized- | { Males | 73 } | ——— | 148 |
| { Females | 75 } | |||
| Buried- | { Males | 44 } | ——— | 83 |
| { Females | 39 } | |||
| Increase- | 65 |
| Buried | ||||
| Under | 2 years of age | —— | 25 | |
| Between | 2 & 5 | —— | 4 | |
| 5 - 10 | —— | 3 | ||
| 10 - 20 | —— | 4 | ||
| 20 - 30 | —— | 5 | ||
| 30 - 40 | —— | 9 | ||
| 40 - 50 | —— | 4 | ||
| 50 - 60 | —— | 4 | ||
| 60 - 70 | —— | 9 | ||
| 70 - 80 | —— | 11 | ||
| 80 - 87 | —— | 5 | ||
| 83 |
And but one alive above 87, who is 91.
The Number of People 425.
The Number of Houses 90.
The Number of Acres 2245. whereof ⅙ is waste.
I do not offer such trifling numbers as these, as a fit subject to build a canon of life upon; but only as they may furnish us with a few particulars, which may throw some small light upon a subject hitherto very little cultivated: and as what has been advanced this way has been always taken from great cities, a little from the country perhaps may not be disagreeable.
The first observable in my numbers is, that the two infancies of human life are exactly equal; i. e. as many die above 60 as under 2 years of age; and that these two periods of life are by much the most sickly, five eighths of the whole, nearly, dying in these two stages, which renders the intermediate numbers very small.
This will give us some reason to suspect, that capital cities are very improper to estimate the probabilities of life from. The continual flux of people from the circumjacent country, to seek for employment, makes the decrements of life seem much larger than they really are. London is very remarkable upon this account; and Breslaw must receive pretty large accessions, as a very considerable manufacture is carried on there.
The second thing I would observe from my table is, that it confirms what Dr. Brackenridge observes of the Isle of Wight; viz. that the births are to the burials as 2 to 1 almost; ours being as 15 to 8 nearly. Now if this is the case of all the country places in England, it will give us a strong presumption, that the increase of mankind is much quicker than Dr. Derham's proportion of 1 to 12; especially if we consider,
Thirdly, That of the living not 1 in 50 dies yearly; and this in a village not very healthy. We are situated upon the celebrated Lamborne stream, which dries up generally in August, and leaves a stagnated water, and stinking mud, at a critical season of the year, which bring on a putrid fever, and make our place sometimes very sickly. In the year 1751 we buried 17, and in 1756. 11: and therefore we may presume, that in the healthiest parts of the nation, the proportion is still greater, perhaps not one in 60. In order to clear up this, it were to be wished, that the actual number of the people was known, where-ever the bills of mortality are exhibited. All reasoning without this preliminary is really not much better than groping in the dark.
A fourth thing observable from my numbers is, that the quantity of people allotted to a house is too big in all former calculations: for if we divide 425, the number of people, by 90, the number of houses, it gives but 4.72, which is not quite 4¾ to a house; and therefore 5 to a house, I believe, is as much as ought to be allowed, taking the nation all together. Now if the number of houses, taken in Queen Anne's time, be any thing near the right, with one fourth more allowed for cottages, according to Dr. Brackenridge's computation, we shall make the people in England, allowing 5 to a house, to be only 4,556,550. which appears, at first sight, to be too small a number. However, of Shefford I would beg leave to observe, (and it is far from being the poorest of villages) that more than two thirds of all the houses are downright cottages, and must be excluded, one as much as another, from any proposed assessment. Upon this foundation we must grant, that at least half the houses in England, take towns and all together, must be cottages, and plead an exemption from taxation all alike. And thus the number of houses will be 1,458,096. which, multiplied by 5, will give us the number of people, 7,290,480. If to this we add the proposed increase, 789,558. we shall have 8,080,038 for the number of people now alive in England.
The fifth and last thing I would observe from my numbers is, that we may hence guess at the number of people in the whole kingdom: for if 1871, the good acres in Shefford, demand 425 persons for their cultivation, then will 25,300,000 good acres in England require 5,704,168 for the cultivation of the land only. Now supposing one third part of the people only to live in towns, above what is necessary for the cultivation of the land belonging to such towns, then we must add 2,852,084 to the above sum, which gives us 8,556,252 for the number of people in England. It may probably here be said, that this is but little better than reckoning at random. Indeed I allow it is so. But then I must beg leave to observe, that it has full as good a foundation to stand upon, as any calculation, that I have seen hitherto advanced. It has one datum, viz. a certain number of persons to a certain number of acres. It ought to be noted at the same time, that we are an inland place, have no sort of manufacture carried on, and consequently no accession of strangers.
If we examine the calculation arising from the consumption of wheat, we shall see some reason to suspect, that the number of inhabitants in England is not short of eight millions. I am persuaded I do not exaggerate, when I affirm, that three fourths of the people north of Trent, and in Wales, do not eat wheat: and as this is near a third part of England, it will follow, that one fourth of the whole is left out of the calculation, and that we must add near two millions to it to make it complete.
Again, I compute, that in my parish there are killed annually 160 fat hogs, viz. above one to three persons; and that this humour of pig-killing prevails over half of England at least, and is in some measure indulged in all parts. Now we will suppose, that there are but six millions of people in the nation, and that what is killed in the northern half makes up for what is deficient by reason of towns in the southern half; we must from hence conclude, that a million of fat hogs are killed in England every year. Now one hog with another takes two quarters of corn, sometimes barley, sometimes pease: if we put half barley, we shall be under the truth. And here we shall have a million quarters of barley, not only to balance the exportation of wheat, but also to be equivalent to, as much bread-corn as will maintain a full million of people.
Farther, it is well known, that the greatest part of the corn-trade is, of late years, got into the hands of millers: and it has been whispered about for a considerable time, and, I think, now the millers do not deny it, that some whiting is carried to all the great mills. The excuse alleged for it is, that it makes the flour wet, and consequently bake, the better. I am rather inclined to be of opinion, that it is to give a colour to something that wants colour. And indeed, who-ever tastes the common bakers bread against a piece of genuine wheat-bread, will have some reason to suspect, that all is not gold, that glitters. Every body knows, that the millers buy large quantities of barley and pease, they say, to fat hogs: but then they have pollard, middlings, &c. to fat them with; and so may possibly mix the barley and pease with wheat to grind. But as this is all surmise, I would have no more weight laid upon it than it deserves.
The next article is of the same nature; I mean, something of a mystery in trade; and therefore to be touched very gently. What I would hint is, that it is the opinion of many very intelligent persons, that a good deal of malt is made, which does not pay the excise. I do not pretend to ascertain the quantity: perhaps one eighth may not be an extravagant supposition. And if this be the case, we shall find as much barley, as will weigh against bread for half a million of people.
But here, in all probability, you will object, that if all these articles be admitted, we shall make the number of people near eleven millions; which is undoubtedly too much. I am ready to grant it. And here, if I might take the liberty to speak my mind, I think, that the allowance of one quarter of wheat to three persons is too scanty, and must quite starve the poor, whose chief provision is bread: and therefore, two persons to a quarter may be pretty near the truth. And then the numbers will stand thus:
| Such as eat wheat, by supposition | 4,500,000 |
| In the North, and in Wales | 1,500,000 |
| Against the fatting article | 1,000,000 |
| Against the two last articles | 1,000,000 |
| 8,000,000 |
I cannot conclude this long scroll without recommending it strongly to the members of the Royal Society, who have many of them seats in parliament, and most of them interest in those that have, to get an Act passed for perfecting registers. The trouble is trifling; the expence nothing. It would be of great service likewise to number the people: and this might be done with great ease. I was not three hours in finishing mine on foot; tho' it is, perhaps, as extensive, for the number of people, as most in England, being near five miles in length. I am,
Reverend Sir,
Your affectionate Brother,
and very humble Servant,
Richard Forster, Rector.
XLIV. A remarkable Case of an Aneurism, or Disease of the principal Artery of the Thigh, occasioned by a Fall. To which is prefixed a short Account of the Uncertainty of the distinguishing Symptoms of this Disease. By Jos. Warner, F.R.S. and Surgeon to Guy's Hospital.
Read Nov. 17, 1757.
WHEN the coats of an artery become by any means præternaturally distended, when they become wounded, or when they become ruptured in such a manner as to discharge and deposit their former contents under the neighbouring integuments, under the aponeurosis, or tendinous expansion of a neighbouring muscle, or still more deeply under the muscles themselves; the natural consequence attending this accident will sooner or later be a degree of elevation, or tumor: which species of tumor is known by the term aneurism.
If a true aneurism happens, that is, a swelling arising from a general weakness of the coats of an arterial vessel, or from a wound or rupture of some of its coats, it may be often distinguished from a tumor proceeding from any other cause by a degree of pulsation, supposing the situation of the injured vessel be superficial; as may be evinced in recent aneurisms of the humeral artery, which sometimes happen from bleeding near the bending of the elbow-joint; as well as in aneurisms of the inferior part of the radical artery, of the ulnary artery, or of the anterior artery of the leg called tibialis antica; and as may be observed to be sometimes the case too in those arteries, whose situations are not superficial; to wit, in aneurisms of the aorta ascendens, the curvature of the aorta, and of the carotides.
The symptom of pulsation in tumors, which take their rise from a partial wound, or from a general weakness, and subsequent dilatation of the coats of an artery, is not confined to this species of aneurism, but is frequently attendant upon false aneurisms (that is, such tumors, as are occasioned by extravasated arterial blood), supposing the disease to be a recent one of either of the preceding vessels, or of any other arterial vessel not deeply situated: and this symptom of pulsation in false aneurisms will sometimes be accompanied with a discoloration, or variegated appearance, of the integuments dependent upon the insinuation of the blood underneath them.
But if the extravasation be confined under an aponeurosis, or if the disease has been of so long standing, as to admit of the thinner parts of the extravasated blood being absorbed, or by any other means dispersed, and the fibrous parts, which are left behind, should be accumulated in considerable quantities, and acquire so compact and solid an appearance, as to resemble brown macerated leather in their colour and texture, which I have always observed to be the case in old diseases of this kind; under these circumstances, the original symptoms of pulsation on the swelling, and a discoloration of the integuments, for the most part become imperceptible: for which reasons the true nature of the disease must be attended with a degree of uncertainty.
It must be acknowleged by all those, whose experience has given them opportunities of examining into these diseases, that the symptoms of a pulsation, and a discoloration of the teguments from extravasated blood, are not only very often wanting in old aneurisms, but in the most recent ones: which proves the non-existence of these symptoms to be no certain characteristics of tumors not being aneurismal: and the reason why this often happens may be readily explained, and conceived of, from demonstrating the very deep or low situation of many arteries, that are known to be liable to these injuries; such as the femoral arteries, the arteriæ tibiales posticæ, the arteriæ peroneæ, and some others.
Notwithstanding I have treated of pulsation on tumors, and a discoloration of the integuments or coverings of the part, when they do exist, as being the truest marks of aneurisms; yet it must not be inferred from what has hitherto been advanced, that the appearances of these symptoms are unexceptionable rules of tumors being aneurismal; seeing it does happen, that mere imposthumations, or collections of matter, arising from external as well as from internal causes, are sometimes so immediately situated upon the heart itself, and at other times upon some of its principal arteries, as to partake in the most regular manner of their contraction and dilatation (systole and diastole).
Some years ago I saw an instance of a boy, about 13 years of age, who had his breast-bone much broken by a fall. On this account he was admitted into Guy's Hospital; but not till a fortnight after the accident happened.
Upon examination, there appeared an evident separation of the broken parts of the bone, which were removed at a considerable distance from each other: the intermediate space was occupied by a tumor of a considerable size: the integuments were of their natural complexion: the tumor had as regular a contraction and dilatation as the heart itself, or the aorta could be supposed to have.
Upon pressure, the tumor receded; upon a removal of the pressure, the tumor immediately resumed its former size and shape. All these are the distinguishing signs of a true recent aneurism. The situation and symptoms of this swelling were judged sufficient reasons for considering the nature of the disease as uncertain; on which account it was left to take its own course. The event was, the tumor burst in three weeks after his admittance, discharged a considerable quantity of matter, and the patient did well.
From what has been above advanced it is plain, if these arguments can be supported by facts, that the laying down such rules for infallibly distinguishing aneurismal tumors from tumors proceeding from very different causes, must be a matter of the greatest difficulty: and, as a further proof of their uncertainty, I take the liberty of offering the following short history of a remarkable case, which has lately occurred in my own experience.
In the month of December 1756. John Yates, aged 35 years, received an hurt upon and about his knee, by falling upon the ground from a man's back. The accident was immediately followed with a considerable degree of lameness and pain; which upon standing or walking were greatly increased.
He continued in much the same state for about six weeks after the accident. At the end of this time, the calf or the leg was attacked with an œdematous or doughy swelling; which, in a fortnight, became so painful, as to disable him from walking. The tumor continued to increase for about eight weeks; and at length extended itself so far upwards, as to affect the greatest part of the thigh, the whole of which was attended with excessive pain, but more particularly so about the knee.
N. B. So far I relate from the patient's own account.
On the 28th of April 1757. he was admitted into Guy's Hospital under my care.
Upon examination, the thigh appeared enlarged to a very great size. The tumor was uniform, and extended from the inside of the knee to within a very small space of the groin. The integuments were in every part of their natural colour.
Upon pressing the tumor on the inside, it appeared soft, and there was a very evident fluctuation to be felt on its internal and lateral part; but there was not the least appearance of pulsation.
The tumor, on its superior and posterior parts, was of a stony hardness.
The leg, which, according to the patient's account, had some time ago been much swelled, did not now appear to be at all so.
He was continually in great pain, and had been for some time incapable of getting any sleep. His appetite was bad. He was a good deal emaciated. He had a constant slow fever, which arose about five weeks before his admission into the hospital. He appeared pale and sallow in his complexion.
From the time of his being placed under my care to the end of ten days, there was no alteration in the swelling, or in the symptoms attending it.
In expectation therefore of affording him that relief, which could by no other means be procured, I judged it adviseable to make an opening into the tumor; which I did by incision into the most prominent and fluctuating part; upon which there immediately gushed out a large stream of thin florid blood, and at this instant discovered to me the true state of that disease; which, till now, could not be ascertained by any peculiar symptom distinguishable by the touch, or perceptible to the eye.
Seeing this, I immediately filled up the wound with lint and tow; and then proceeded, in as expeditious a manner as possible, to apply a tight bandage upon the thigh, near to the groin; and, lest this might accidentally break, I applied a second ligature below the first, and proceeded to amputate the limb upon the spot.
During the operation the man fainted, but soon recovered from this deliquium; and, without any bad symptoms, gradually recovered his rest, appetite, and strength, and is now in perfect health.
Upon a dissection of the thigh and leg, I discovered the following appearances:
A great part of the fleshy portions of two of the extensor muscles of the leg, to wit, the vastus internus, and crureus, were destroyed, with the subjacent periosteum.
Four of the muscles, whose uses are to bend the leg, and which compose the internal and external hamstrings; to wit, gracilis, semitendinosus, semimembranosus, and biceps tibiæ, together with that adductor and flexor muscle of the leg called sartorius, were removed at a considerable distance from the thigh-bone on its inferior part, and from the tibia and fibula on their superior parts; by which means a large bed or cavity was formed for containing the extravasation, which consisted partly of a fluid, and partly of a coagulated blood; but by far the greatest part of the coagulum had acquired so firm and fibrous a consistence and appearance, as nearly to resemble brown macerated leather in its colour and texture. The neighbouring muscles appeared livid and lacerated.
The os femoris was become carious on its inferior and posterior parts; and, at about an inch distance above the condyle of that bone internally, there arose a considerable exostosis.
The capsular ligament of the knee-joint was become much thickened, and contained about two ounces of a viscid yellow synovia.
The femoral artery, on its inferior part, just above its division into tibialis antica and postica, was diseased; which disease extended four inches upwards.
The coats of the artery were considerably thickened, and lacerated longitudinally.
The smallest diameter of the diseased part of the artery was two inches and one quarter: the largest diameter of the diseased part of the artery was two inches and one half.
Hatton-Garden, Nov. 17. 1757.
XLV. Farther Experiments for increasing the Quantity of Steam in a Fire-Engine. By Keane Fitz-Gerald, Esq; F.R.S.
Read Nov. 24, 1757.
I Gave a former account to the Royal Society of some experiments made for increasing the quantity of steam in a fire-engine, by blowing air thro' boiling water[199]. The effects then evidently produced left me, and I believe many others, who came to view the experiments, no room to doubt the seeming cause. In which error I should probably have still remained, had not farther experiments demonstrated the mistake.
Whatever apology I ought to make this learned Society, for having given in that account prematurely, I believe their great regard to truth, which has always been the basis of their researches for the improvement of natural knowlege, will require none for this. I shall therefore, as briefly as I can, relate the further experiments, that were made, which evidently demonstrate the error of the former; and from which some phænomena have occurred, perhaps hitherto unknown.
In order to try what difference the air passing thro' a thinner body of water might occasion, I brought the horizontal pipe, which (as mentioned in the former account) was placed 12 inches under the surface of the water, to within six inches; and found, on setting the engine to work, that the leaden pipe, for the conveyance of air from the bellows into the boiler, became much hotter than I had perceived it before; which could not happen, if a constant cool air had passed thro': and on shutting the cock, which was fixed in the leaden pipe to hinder the steam from ascending into the bellows before the engine should be set to work, tho' no air could then possibly pass thro', yet the bellows still continued to move with the same regularity as before; which, on examination, was found defective on the inside, where the middle board, that divides the two bodies, was warped and cracked in several places, thro' which the air passed very regularly from one body to the other at each stroke, instead of passing thro' the pipe into the boiler, as imagined. By this, the cause of deception was evident; which I was still in hopes of remedying, by having a new pair of bellows made, somewhat larger, and much stronger. When this was fixed, and the engine worked a few strokes, I was surprised to find the bellows did not come down, but remained fully charged with air, tho' it had 400 lb. weight upon it; and that, on increasing the weight gradually to 1400 lb. which was as much as the bellows could support, the air was not forced thro'.
I also made several experiments, by lowering the horizontal pipe two feet under the surface of the water, and raising it at different times to within four inches of the surface, and could not at any depth force the air thro', whilst the engine worked; but on opening the steam-pipe, which is a pipe for letting the steam pass from the boiler whenever the engine stops, the bellows could then readily force the air thro', tho' the water boiled ever so strong, and seemingly made a surprising increase of steam.
I had the leaden pipe to convey the air from the bellows, which was first put thro' the top into the boiler, carried on the outside, and passed horizontally into it, about the height the water generally stands, that by opening a cock, fixed for the purpose close to the boiler, I could readily discharge all the steam lodged in the pipe; and by shutting the cock, and making small holes at three or four inches distance, I could almost find the point, where the air and steam met in opposition, cool air being strongly expelled thro' one, and hot steam thro' the other.
It was also perceptible, that the air was impelled somewhat, tho' not considerably, more forward by the addition of each hundred weight on the bellows:
That the deeper the horizontal pipe was placed in the water, the less resistance was made by the steam:
That in proportion as the heat of the steam was increased, by making the water boil more strongly, the resistance to the pressure of the air by the weight on the bellows became greater.
It is a very doubtful matter, whether air forced thro' boiling water would have answered the purpose intended: but I believe it was never imagined, that air could not be readily forced thro', until proved by the foregoing experiments. The attempt, tho' it has failed demonstrably in that point, has produced the same effect from another cause, as to saving coals, and throwing up more water. For, by the constant care, that was taken during the time of making these experiments, to measure the coals, to admit only a proper quantity of fuel to be laid on, and also to mark the time exactly it took in burning; the engine then did, and still continues to require eight bushels of coals less, in every 24 hours work, than it did before; and also, from the regularity of its stroke, to throw up more water; the same care being required from the engineer, who can have no pretence for consuming more coals now, than appeared sufficient during the time the experiments were making.
Tho' some of the properties of steam are well known; yet the degrees of expansion it is capable of; whether air be mixed with, or necessary to, its formation; as also how far its power of resistance may reach; are probably not yet known, to a proper degree of exactness. Niewentit fixes the expansion of a cubical inch of water, converted into steam, at 13365, Dr. Desaguliers at 14000, and Mr. Payne at 4000 times. The great scope in this subject from a plenum to a vacuum, if I may be allowed the expression, as also the very useful purposes, to which it has already been, and possibly may be still further applied, will, I hope, be an inducement to those, who are much better qualified, to proceed in so useful an inquiry.
XLVI. Observatio Eclipsis Lunæ Die 27 Martii, Ann. 1755. habita Ulissipone in Domo Patrum Congregationis Oratorii à Joanne Chevalier ejusdem Congregationis Presbytero, Regiæ Londinensis Societatis Socio, Regiæque Parisiensis Scientiarum Academiæ correspondente.
Tubo optico 8 pedum peracta est observatio cœlo sereno, claroque.
Read Dec. 8, 1757.
| Immersiones. | Hora postmeridiana temporis veri. | ||
| h | ' | " | |
| Initium penumb rædubium | 10 | 29 | 50 |
| Initium eclipsis dubium | 10 | 33 | 35 |
| Certe jam incæperat | 10 | 34 | 05 |
| Umbra ad mare humorum | 10 | 44 | 00 |
| Umbra ad Grimaldum | 10 | 44 | 53 |
| Grimaldus totus in umbra | 10 | 47 | 58 |
| Mare humorum totum in umbra | 10 | 51 | 14 |
| Thico incipit mergi | 10 | 53 | 29 |
| Thico totus mergitur | 10 | 55 | 14 |
| Umbra ad Reinholdum | 11 | 08 | 04 |
| Umbram ingreditur Copernicus | 11 | 19 | 22 |
| Umbra ad mare nectaris | 11 | 24 | 52 |
| Totum in umbra | 11 | 33 | 50 |
| Umbra ad mare tranquillitatis | 11 | 35 | 24 |
| Promontorium acutum in umbra | 11 | 45 | 46 |
| Emersiones. | |||
| h | ' | " | |
| Incipit emergere ab umbra Copernicus | 12 | 04 | 38 |
| Totus Copernicus extra umbram | 12 | 07 | 40 |
| Incipit egredi Grimaldus | 12 | 09 | 38 |
| Totus Grimaldus extra umbram | 12 | 12 | 38 |
| Incipit emergere mare fœcunditatis | 12 | 31 | 37 |
| Emergit mare humorum | 12 | 36 | 11 |
| Incipit emergere Capuanus | 12 | 39 | 40 |
| Egreditur Schicardus | 12 | 48 | 30 |
| Emergit Thico | 12 | 51 | 40 |
| Totum mare nectaris egreditur | 12 | 58 | 09 |
| Finis eclipsis | 13 | 13 | 02 |
| Finis penumbræ dubius | 13 | 16 | 50 |
XLVII. Eclipsis Lunæ Die 4ᵃ Februarii, Ann. 1757. habita Ulissipone à Joanne Chevalier Presbytero Congregationis Oratorii, Regiæ Londinensis Societatis Socio, Regiæque Scientiarum Parisiensis Academiæ correspondente, et a Theodoro de Almeida ejusdem Congregationis Presbytero, ac Physicæ publico Professore.
Read Dec. 8. 1757.
HANC observationem peregi tubo optico novem pedes longo, cujus lens ocularis focum habebat ad 4 pollices, et lineam unam: adhibui preterea vitrum planum cæruleum, quod oculum inter et ocularem lentem interponebam, ut ingressum macularum in umbram observarem juxta ea quæ in observatione eclipsis lunæ ann. 1755. invenit clarissimus vir Josephus Soares de Barros ex regia Berolinensi academia. Primum igitur vitro cæruleo adhibito observabam ingressum maculæ in umbram, et tempore notato iterum solo tubo optico ingressum ejusdem maculæ in umbram observabam, et differentiam utriusque ingressûs notabam.
Initio eclipsis cœlum serenum ac clarum fuit, postea nubilum, et post maximam obscurationem vapores horizontis et claritas incipientis diei observationem peragere impediere.
| Manè. | |||
| H. | M. | S. | |
| Initium penumbræ | 4 | 52 | 49 |
| Initium dubium eclipsis | 4 | 55 | 29 |
| Certo jam incæperat | 4 | 57 | 30 |
| Umbra ad Aristarchum observata vitrocæruleo plano | 5 | 00 | 19 |
| Solo tubo optico adhibito | 5 | 00 | 50 |
| Keplerus umbram ingreditur observatus tubo, et vitro cæruleo plano | 5 | 13 | 20 |
| Observatus solo tubo optico | 5 | 14 | 00 |
| Plato umbram ingreditur observatus tubo, et vitro cæruleo | 5 | 15 | 2 |
| —— Solo tubo | 5 | 15 | 40 |
| Umbra ad Eudoxum | 5 | 17 | 18 |
| Mare serenitatis incipit mergi | 5 | 30 | 10 |
| Copernicus observatus tubo et vitro cæruleo umbram ingreditur | 5 | 36 | 48 |
| —— Solo tubo | 5 | 37 | 22 |
| Mare Crisium ingreditur umbram | 5 | 53 | 51 |
| —— Medium in umbra | 5 | 59 | 30 |
| —— Totum mergitur | 6 | 5 | 21 |
| Mare fœcunditatis occultari incipit | 6 | 7 | 41 |
| Umbra ad promontorium acutum | 6 | 8 | 33 |
| Umbra tangit mare nectaris | 6 | 22 | 51 |
| Umbra ad Langrenum | 6 | 23 | 33 |
Observationes Eclipsium Satellitum Jovis Ulissipone habitæ a Joanne Chevalier, &c.
| ANNO 1757 telescopio Gregoriano 7 pedum nocte serenâ, nullâque lunari luce illustratâ, observavi immersionem totalem primi satellitis die 21 Martii tempore vero postmeridiano | 11h | 13' | 1" |
| Die vero 22 Martii tempore vero, et antemeridiano, observavi immersionem totalem tertii satellitis | 0h | 13' | 32" |
XLVIII. Observationes Eclipsium Satellitum Jovis Ulissipone habitæ à Joanne Chevalier, Presbytero Congregationis Oratorii, Regiæque Londinensis Societatis Socio, Anno 1757.
Read Dec. 8, 1757.
| TElescopio Gregoriano 7 pedum observavi emersionem primi satellitis die7 Junii cum cœlum serenum ac clarum esset, hora postmeridiana temporis veri | 10h | 29' | 12" |
| Die 8 Junii eodem telescopio observavi emersionem secundi satellitishora postmeridiana | 8h | 32' | 48" |
| cœlum aliquantum nubilum erat. | |||
| Eadem die observavi emersionem tertii satellitis hora postmeridiana | 9h | 36' | 25" |
| cœlo claro. | |||
| Die 15 Junii cœlo claro observavi emersionem secundi satellitis horapostmeridiana | 11h | 6' | 15" |
| Sequenti die 16 Junii observavi immersionem tertii satellitis horamatutina temporis veri | 0h | 0' | 29" |
XLIX. A remarkable Case of the Efficacy of the Bark in a Mortification. In a Letter to William Watson, M.D. F.R.S. from Mr. Richard Grindall, Surgeon to the London Hospital.
Austin-Friars, Dec. 7th, 1757.
SIR,
Read Dec. 8, 1757.
THE following case being very singular has induced me to lay it before the Royal Society, and beg the favour to do it through your means. Although numerous instances are related in the records of medicine, of the great danger in interrupting nature in her operations, there is not one (so far as I know), in which more violent and extraordinary effects have been produced, than in the following.
It may happen also, that this instance may be of service in ascertaining the virtue of the medicine in intermittents, when in the hands of men of judgment.
On the 28th of June 1757. Mary Alexander, aged 31 years, of the parish of Whitechapel, was brought into the London hospital, having a mortification in both hands, which reached about an inch and half above the wrists. All her toes, and about an inch of one foot beyond the last joint, were mortified; her nose was also intirely destroyed by a mortification; and all these happened at the same time. Upon inquiry into the cause of this misfortune, I found, that on Monday the 30th of May she was seized with a quotidian ague, which usually began about three of the clock in the afternoon, and lasted near two hours; which was succeeded by a hot fit, and then a violent sweat. And in this manner she was afflicted for seven days without any material alteration; when, being informed by a neighbour, of a person, who had an infallible remedy for the cure of an ague, she applied to him. He brought her two phials, containing about an ounce and half each, of a pale yellowish liquor; one of which he directed her to take directly, promising, that she should have no return of the fit of consequence; and that, if she had any small return, the second bottle should cure her effectually. In consequence of which, she took one dose, which was at the time the cold fit had been on about a quarter of an hour: she had no sooner swallowed it, but, as she says, her stomach was on fire, and felt as if she had swallowed the strongest dram possible. The cold fit left her instantly; but she was immediately seized with so violent a fever, as to make her burn, and be extremely thirsty, all the following night; much more so than ever she had been before, till the next morning, when a sweat a little relieved her from the violent heat. When she rose in the morning, she was much troubled with a great itching in the hands, feet, and nose; and soon after all those parts began to feel numbed, or, as she describes it, as if her hands and feet were asleep; which she took but little notice of, till the evening of that day, when she found the nails of both hands and feet were turning black, and, at the same time feeling great pain in both, as also in her nose, and that they appeared of a darkish red colour, like the skin in cold weather. Upon which, at nine o'clock that night she sent for an apothecary, from whom, I have since been informed, the person before mentioned had bought the medicine, which he gave her. The apothecary was not at home; his journeyman went, and finding the woman had a difficulty of breathing, ordered her a mixture with sperma ceti and ammoniacum to be taken occasionally. The apothecary did not see her himself till the 16th of June, when finding her in a very bad condition, that her hands, and feet, and nose, were intirely black, and had many vesicles or small bladders upon them, filled with a blackish bloody water; he opened them, and let out the fluid, and dressed them with yellow basilicon; and in this manner continued treating her till the 20th of the same month, when, finding no material alteration for the better, he ordered her a brownish mixture, of which she was to take four spoonfuls every four hours; which, he informed me, was a decoction of the bark; and says, on taking this, she was better, as the mortification seemed inclined to stop. But as it was a bad case, he advised the woman to be carried to an hospital: and in this condition was she brought in, when she was immediately put into a course of the bark, taking a drachm of the powder every four hours; and in 48 hours taking it there was a perfect separation of all the mortified parts. She was then ordered to take it only three times in 24 hours; and pursuing this method for eight days, there was a very good digestion from the parts above the mortification.
The mortified part became now so offensive, that the poor woman pressed me much to take off her hands, assuring me she would go through the operations with good courage, being very desirous to live, though in this miserable condition.
On the 12th of July I took off both her hands: I had very little more to do, than saw the bones, nature having stopped the bleeding, when she stopped the mortification. In a day or two after, I took off all the toes from both feet, and now discontinued the bark, the parts appearing in a healthy and healing condition; which went on so for five weeks, when, on a sudden, the parts began to look livid, her stomach failed her, and she was feverish; but, upon taking an ounce of the bark, in 36 hours her sores began again to look well. She was not suffered to leave off the bark so soon this time, but continued taking it twice a day for a month. She is now almost well: that part of her face, from whence the nose mortified, was healed in seven weeks; the stumps of both arms are intirely healed; and both feet are well, only waiting for one piece of bone scaling off, which I believe will be in a very short time; and she is now in good health.
The person, who gave her this medicine, is a Barber and Peruke-maker at Bow. I applied to him several times, to inform me what it was he had given her. The affair was talked of so much in his neighbourhood, and the man threatned by the woman's husband, that for a long time I could not get him to tell me, till I told him, I had been informed where he bought the medicines; and the time of the day, that he had them, corresponding with the time of his giving them to the woman, and that I knew it was tincture of myrrh, he at last told me, that he had frequently given the above quantity of an ounce and half of it in an ague; that it had never done any harm; and hardly ever failed to cure. Upon which information, I carried some tincture of myrrh to the woman, who tasted it, and is well assured it is the same liquor the barber gave her in her ague-fit.
I am, with respect,
Your obliged and obedient Servant.
Richard Grindall.
L. A Letter to the Rev. Tho. Birch, D.D. Secret. R.S. from John Pringle, M.D. F.R.S. inclosing Two Papers communicated to him by Robert Whytt, M.D. F.R.S.
Pallmall-Court, St. James's, Dec. 10. 1757.
SIR,
Read Dec. 15, 1757.
ABOUT three weeks ago I put into your hands an extract of a letter, I had then received from Dr. Whytt, containing a postscript to his Observations on Lord Walpole's Case; and slightly mentioning some doubts he had then about the justness of Dr. Springsfeld's experiments with lime-water, from some trials he himself had made, upon reading that gentleman's curious treatise on the extraordinary lithontriptic quality of the waters at Carlsbad in Bohemia. Within these few Days, Dr. Whytt having favoured me with a full account of those experiments, I have herewith sent you his paper, in order, if you please, to lay it before the Society; which the author desires may be done, in case these observations should be judged useful.
The other paper inclosed was sent me by the same hand, to be likewise presented to the Society, as a well-attested instance of the electrical power in the cure of a palsy. To the other testimonies I have subjoined what Dr. Whytt says in his letter to me, by way of strengthening the evidence. I shall only add, that since Mr. Brydone, the author of this account, has omitted telling how long the patient has continued in perfect health since the operation, it appears she must have been well for some months before the date of his paper; because, before the end of last summer, Dr. Whytt transmitted the same case to me, which I then returned, in order to have it drawn up in a fuller manner, and with other vouchers besides the gentleman, who performed the cure. The Doctor has been so good as to comply with my request, having procured a more ample account of the circumstances from Mr. Brydone, and the attestation of two ministers, besides that of the patient herself.[200] My difficulties being thus removed, I believe I may now with freedom offer this very curious case to the attention of the Society.
I am,
SIR,
Your most obedient humble Servant,
John Pringle.
Postscript to Dr. Whytt's Observations on Lord Walpole's Case[201].
Read Dec. 8, 1757.
“ I Do not know, if it be worth while to observe, that lately, in making some experiments with different calculi, there was one almost as white as chalk, but of a less hard substance than the others; and which was not in the least degree dissolved or softned by being infused 20 days in oystershell lime-water, but yielded somewhat to a solution of Spanish soap in common water.
From this experiment one may conclude, that it is better to prescribe both soap and lime-water for the stone, than any one of them alone; and that if one of these remedies has failed of giving relief, the other ought to be tried: for as the above white calculus, which yielded a little to the solution of soap, resisted lime-water; so there may perhaps be others, that are readily dissolved by lime-water, but little affected by soap.
Dr. Springsfeld's experiments with lime-water are somehow not just; for in several calculi I have found the dissolving power of oystershell lime-water above eight times greater than he makes it.”
Some Observations on the lithontriptic Virtue of the Carlsbad Waters, Lime-water, and Soap: In a Letter to Dr. John Pringle, F.R.S. from Dr. Robert Whytt, F.R.S. and Professor of Medicine in the University of Edinburgh.
SIR,
Read Dec. 15, 1757.
FROM the experiments related in Dr. Springsfeld's Commentatio de prærogativa thermarum Carolinarum, &c. which you were so good as to send me some time ago, it appears, that these waters are not only possessed of a very extraordinary power of dissolving the stone, but that in this respect they greatly exceed lime-water.
(A) Thus, Dr. Springsfeld having infused, for 14 Days, in a heat of 96 degrees of Fahrenheit's scale, three pieces of the same calculus, each weighing 30 grains, in eggshell lime-water, the Carlsbad water, and in the urine of one who daily drank this last water, renewing these several menstruums every day, he found, on the 15th day, that the calculus in the lime-water had lost 1 grain, the calculus in the Carlsbad water 6 grains, and that in urine 5 grains.
(B) Again, having divided another calculus into four parts, each of which was reduced to 80 grains, he put the first in oystershell lime-water, the second in Carlsbad water, and the third in the urine of a person who drank this water. After 20 days, during which time the menstruums were renewed every day, and kept in a heat of 96 degrees, the dried calculi had lost of their weight as follows: the first 3 grains, the second 18 grains, and the third 14 grains.
Altho' I make no doubt that Dr. Springsfeld, who appears to be a man of candour, as well as learning, has faithfully related the event of the experiments, which he made; yet either the lime-water he used must have been very weak, or some other mistake must have happened in his experiments: for in all the numerous trials I made, about 15 years ago, of lime-water, as a solvent for the stone, I always found its dissolving power much greater, than it appears in Dr. Springsfeld's experiments. And as in these trials different urinary stones were used, it can scarcely be imagined, that it was owing to the peculiar hardness of Dr. Springfeld's calculi, that the lime-water made so little impression on them. However, to be still further satisfied of this matter, I made the following experiments.
1. I put a piece of a very hard calculus, which I shall call x, weighing 80 grains, in oystershell lime-water, renewing the lime-water every day, and keeping it in a heat between 90 and 106 degrees of Fahrenheit's scale. After 20 days, I took out the calculus; and having set it by for some days, till it was become quite dry, I brushed away all the rotten part of it, which was reduced to a kind of chalky powder, and found that the undissolved part of it weighed 57 grains.
2. At the same time a piece of another calculus, z, weighing 15 grains, was, after a like infusion of 20 days in oystershell lime-water, reduced to 10 grains.
3. I put a piece of z, weighing 14 grains, in a solution of half an ounce of the internal part of Spanish soap in nine ounces of water, and every third day renewed the solution, which was kept in a heat of about 60 degrees. After 14 days, I found the undissolved part not to exceed 11 grains.
4. A piece of a white chalky calculus, y, weighing 30 grains, had near 4 grains of its substance dissolved, by being 14 days infused as above in a solution of soap.
From Nº. 1. above, compared with Dr. Springsfeld's Exper. (B), it appears, that the dissolving power of oystershell lime-water is to that of the Carlsbad water as 23 to 18, supposing the calculi used in these experiments to have been equally easy to dissolve.
Nº. 3. compared with Dr. Springsfeld's Exper. (A), shews, that the dissolving power of a solution of the inner part of Spanish soap, in a heat of 60 degrees, is to that of the Carlsbad water, in a heat of 96 degrees, as 15 to 14.
From Nº. 4. compared with (A), the dissolving power of soap is to that of the Carlsbad water only as 4 to 6; but it is probable, that had the solution of soap been kept in a heat of 96 degrees, its dissolving power would, even in this experiment, have nearly equalled that of the Carlsbad water. It may, perhaps, be worth while to observe, that a piece of the white chalky calculus of Nº 4. was not in the smallest degree dissolved by lying in lime-water 20 days.
5. In Exper. 19. of my Essay on the Virtue of Lime-water, a piece of a calculus, b, weighing 31 grains, lost 7 grains by being infused 36 hours, in a heat of above 100 degrees, in very strong oistershell lime-water. And in the same water, of a moderate strength, another piece of b lost, in the same time, 5 grains.
In this last experiment, the lithontriptic virtue of lime-water appears to be stronger than in Nº. 1. and 2. above; and greatly exceeds that of the Carlsbad water in Dr. Springsfeld's Exper. (A) and (B).
But altho', from what has been said, it appears not only that lime-water, but also a solution of soap, dissolves the stone in close vessels as fast, nay faster, than the thermæ Carolinæ; yet these last waters, when the calculi were so placed in open vessels, that the water from the fountain might constantly flow along them, effected a much quicker dissolution than lime-water, or even soap-lye, or indeed any known menstruum, except, perhaps, strong spirit of nitre: for, in the first experiment made by Dr. Springsfeld, a calculus of two ounces and a half was, in this manner, quite dissolved in six days. From this experiment, compared with that of Dr. Springsfeld mentioned above (B), it will be found, upon calculation, that the dissolving power of the Carlsbad water, when it is allowed to flow constantly from the fountain along the stone, is nearly 39 times greater than when it is only poured fresh on the calculus once a day[202]. What may have been the reason of this surprising difference of the lithontriptic power of the Carlsbad water in these different circumstances, I will not pretend to say. I think it can scarcely be accounted for from the gentle motion of the water along the surface of the calculus. Was it then owing to some very volatile active part, which the water quickly loses, after being taken from the fountain?
But how great soever the dissolving power of the Carlsbad waters may be, when they issue from the bowels of the earth, yet that they do not communicate a much greater dissolving power to the urine, than lime-water, will appear from comparing the two following experiments.
In Dr. Springsfeld's Exper. (A) above, the urine of a person, who drank the Carlsbad waters, reduced, in 14 days, a piece of calculus, weighing 30 grains, to 25 grains. And in an experiment made by Dr. Newcome, now Lord Bishop of Llandaff, who drank four English pints of oystershell lime-water daily, his Lordship's urine reduced, in four months, a piece of calculus, weighing 31 grains, to three small bits, weighing in all 6 grains[203]. Whence it follows, that the dissolving power of his Lordship's urine must have been to the dissolving power of the urine of the person who drank the Carlsbad waters nearly as 35 to 65[204]. But if we consider, that the calculus infused in the urine of the person who drank the Carlsbad waters was kept always in a heat of 96 degrees, while in Dr. Newcome's experiment, which was made during part of the autumn and winter, no artificial heat was used, it will appear probable, that the dissolving power of his Lordship's urine was little inferior to that of the person who drank the Carlsbad waters; for lime-water, in a heat of 96 degrees, dissolves the calculus at least twice as fast, as in the common heat of the air in winter. Further, if it be attended to, that the quantity of Carlsbad waters drank every day before dinner is from six to eight lib. while his Lordship only drank four lib. of lime-water in 24 hours, it will follow, that whatever the different dissolving powers of the lime-water and Carlsbad waters may be out of the body, yet the former seems, in proportion to the quantity drank, to communicate at least an equal dissolving power to the urine.
But without presuming to decide certainly, as to the comparative virtue of the Carlsbad waters and lime-water, I shall conclude with observing, that tho' the Carlsbad waters are less disagreeable to the taste, and may be drank in larger quantity, than lime-water, yet this last may be drank equally good in all places, and at all seasons of the year; which is not the case with the Carlsbad waters.
November 30. 1757.
An Instance of the Electrical Virtue in the Cure of a Palsy. By Mr. Patrick Brydone.
Read Dec. 15, 1757.
ELizabeth Foster, aged 33, in poor circumstances, unmarried, about 15 years ago was seized with a violent nervous fever, accompanied with an asthma, and was so ill, that her life was despaired of. She recovered however from the violence of her distemper, but the sad effects of it remained. For, from this time, she continued in a weakly uncertain state of health till the month of July, 1755, when she was again taken ill of the same kind of fever; and after it went off she was troubled with worse nervous symptoms than ever, ending at last in a paralytic disorder, which sometimes affected the arm, sometimes the leg, of the left side; in such a manner as that these parts, tho' deprived of all motion for the time, yet still retained their sensibility. In this condition she remained till the spring 1756, when unexpectedly she grew much better; but not so far as to get quite rid of her paralytic complaints; which, in cold weather, seldom failed to manifest themselves by a numbness, trembling, sensation of cold, and a loss of motion in the left side.
This paralytic tendency made her apprehensive of a more violent attack; which accordingly soon happened: for, about the end of August, in the same year, her symptoms gradually increased, and in a very short time she lost all motion and sensation in her left side. In this state she continued throughout last winter with the addition of some new complaints; for now her head shook constantly; her tongue faltered so much, when she attempted to speak, that she could not articulate a word; her left eye grew so dim, that she could not distinguish colours with it; and she was often seized with such an universal coldness and insensibility, that those who saw her at such times scarce knew whether she was dead or alive.
Whilst the woman was in this miserable condition, observing that she had some intermissions, during which she could converse and use her right leg and arm, in one of those intervals I proposed trying to relieve her by the power of electricity. With this view, I got her supported in such a manner as to receive the shocks standing, holding the phial in her right hand, whilst the left was made to touch the gun-barrel. After receiving several very severe shocks, she found herself in better spirits than usual; said she felt a heat, and a prickling pain in her left thigh and leg, which gradually spread over all that side; and after undergoing the operation for a few minutes longer, she cried out, with great joy, that she felt her foot on the ground.
The electrical machine producing such extraordinary effects, the action was continued; and that day the woman patiently submitted to receive above 200 shocks from it. The consequence was, that the shaking of her head gradually decreased, till it intirely ceased; that she was able at last to stand without any support; and on leaving the room quite forgot one of her crutches, and walked to the kitchin with very little assistance from the other. That night she continued to be well and slept better than she had done for several months before, only about midnight she was seized with a faintishness, and took notice of a strong sulphureous taste in her mouth; but both faintness and that taste went off, upon drinking a little water. Next day, being electrised as before, her strength sensibly increased during the operation, and when that was over she walked easily with a stick, and could lift several pounds weight with her left hand, which had been so long paralytic before. The experiment was repeated on the third day; by which time she had received in all upwards of 600 severe shocks. She then telling us that she had as much power in the side that had been affected as in the other, we believed it unnecessary to proceed farther as the electricity had already, to all appearance produced a compleat cure. And indeed the patient continued to be well till the Sunday following, viz. about three days after the last operation; but upon going that day to church, she probably catched cold; for on Monday she complained of a numbness in her left hand and foot; but, upon being again electrised, every symptom vanished, and she has been perfectly well ever since.
Coldingham, Nov. 1757.
Patrick Brydone.
That the above is a true and exact account of my case, and of the late wonderful cure wrought on me, is attested by
Elizabeth Foster.
I was eye witness to the electrical experiments made by my son on Elizabeth Foster, and saw with pleasure their happy effects. By the blessing of God accompanying them, from a weak, miserable, and at sometimes almost an insensible state, she was, in a very short time, restored to health and strength; of which the above is in every respect a true account.
Robert Brydone, Minister of Coldingham.
Extract of a Letter from Dr. Whytt to Dr. Pringle, relating to this Account: Dated Edinburgh, 1 Dec. 1757.
SOME days ago I had transmitted to me Mr. Brydone's account (inclosed) of the success of the electrical shocks in a paralytic patient, attested by the patient herself, and by Mr. Brydone's father, who is minister at Coldingham, in the shire of Berwick. At the same time I had a letter from the Reverend Mr. Allan, Minister of Eymouth (in the neighbourhood), informing me, that he had examined the patient particularly, and found Mr. Brydone's account to be perfectly true. He further informs me, that he never observed the electrical shock so strong from any machine, as from Mr. Brydone's. It seems, that gentleman has not only applied himself to the study of natural philosophy, but also of medicine.
Robert Whytt.
LI. An Account of some fossile Fruits, and other Bodies, found in the Island of Shepey. By James Parsons, M.D. F.R.S.
To the Right Honourable the Earl of Macclesfield, President of the Royal Society.
Sept. 25, 1757.
My Lord,
Read Dec. 15, 1757.
BEING ever desirous to promote the business of this learned Society, I could not lose the opportunity that presented, of laying before you an account, and drawings (See [Tab. XV.] & [XVI.]), of a most curious parcel of fossil fruits, and some other bodies, sent me from Shepey-Island, by my ingenious friend Mr. Jacob, of Faversham, Surgeon, and Fellow of the Antiquary Society.
I do not remember, that fossil seeds, or fruits, are recorded in our Transactions, tho' many of other kinds have places in them; nor indeed that the memoirs of other academies have made mention of any such fruits; and therefore, as these are chiefly pyritical, and consequently liable to fall to pieces, I thought it necessary to make drawings of them while in a sound state, in order for engraving, if the Society shall think fit; lest their being so subject to moulder away might put it out of my power to preserve their forms. However, I have great hopes I shall be able to preserve the greater part of them intire till they are shewed to the Society.
In describing these bodies, we shall be obliged to make the best conjectures we can of some of them only; for several are sufficiently obvious to every naturalist, and easily known by comparing them to such recent fruits, as are frequent enough among us. Some of them are absolutely exotics; and indeed they are all rare and curious, and, in my humble opinion, well worth the notice of the Royal Society.
Doctor Woodward's catalogue[205], which is so ample and full of all kinds of fossil bodies, has only a very few fruits; and these are only some hazle nuts found in different places, a few pine-cones, and laryxes; and one fruit, which was taken for an unripe nutmeg. In this collection before us they are all very different, and such as have not been seen before.
It will not be amiss, in this place, to give a short detail of such bodies as are capable of either being petrified themselves, or of leaving their impressions in stony matter. By being petrified, is meant being impregnated with stony, pyritical, or any other metalline or sparry matter; for there are inumerable specimens, wherein all these are apparent.
Testaceous and Crustaceous Animals.
The shelly matter of these is of so compact and dry a nature, that they will endure for ages: and if in a soil or bed where moisture has access, they will receive stony matter into their pores, and become ponderous in proportion to the quantity imbibed. If in a dry place, they will remain fair and sharp, suffering very little change by any length of time; whilst the flesh of these, being subject to putrifaction, is soon destroyed; and yet, according to circumstances that happen, some of these may be replaced in due form by stony particles. I have a gryphites, with the form of the fish in its place, as is the case in several of the oyster kinds. This may be occasioned by the shells being close, or nearly so, and stony matter gradually insinuating into their cavity, so as to fill up the whole.
Wood.
The kinds of wood found fossil are very different: some are of a firmer texture than others: and this too is according to the places wherein they are deposited. Some I have seen so highly impregnated with a fine stony and pyritical matter, as to bear a polish like a pebble; some, tho' quite reduced to stone, yet preserving the fibrous appearance of the original state; and some which is found in boggy bottoms, being not at all changed, except in color: this is called bog oak, or bog deal, well known to country people in many places of these three kingdoms, who light themselves about their business with slips of this wood, cut on purpose instead of candles, as it burns with a clear and durable flame. It is remarkable, that altho' oak or fir shall lie ages immersed in water under ground, it shall not putrify; but acquire such sulphureous particles by lying in steep, in the bog-water, as to qualify it for this use. Other wood, deposited in marly ground, is found incrusted over, trunk and branches, with a white crust; the wood remaining intire within. At other times, wood thus incrusted shall be eroded by the matter which covers it, having something acrimonious in its substance. We may add to these, clusters of the twigs of shrubs, and small wood, which we find flakes of, incrusted with sparry or calcarious matter, in many places; parts of which are totally changed into that matter, whilst others are only inveloped with it.
Bones of Animals.
We see, by every day's experience, that the human skeleton moulders to dust in a very few years, when buried in mould: so it does even in vaults, where the coffins are kept dry. In the first case, the moisture and salts of the earth divide and dissolve the texture of the bones; in the latter, those of the air, which gradually insinuate themselves into them, and at length destroy them. How long a skeleton whose bones are well dried and prepared, being totally deprived of its medullary substance, will last, as we now order them for anatomical purposes, we cannot say: but it may be reasonably conjectured, that they will undergo the fate of the softer kinds of wood, such as beech, which grows rotten in no great number of years; because their internal substance is spungy and cellular, and their crust is very thin, except about the middle of the bones of the arm and thigh, I mean the humerus and fœmur. The same destruction would happen, if bodies were deposited in a sandy soil; because water finds its way either by dripping downwards, or by springs underneath. But human skeletons have been found intire within a rock, where neither moisture nor air could get at them. Mr. Minors, an eminent Surgeon and Anatomist of the Middlesex-hospital, when he was in the Army, at Gibraltar, saw an intire skeleton, standing upright, in a dry rock, part of which had been blown up with gunpowder, in carrying on some works in the fortifications, which left the skeleton quite exposed. Indeed, the bones of Elephants have been found in Shepey-Island, but much destroyed, several of which I have in my Collection; an account of which we have in the last volume but one[206] of our Transactions; their size and substance being so considerable, as to resist for a long time that decay which those of the human could not withstand. To these we may add the horns of large animals, as the elk, and others, which have been found in bogs, preserved as the bog-oak, &c. mentioned.
Teeth and Palates of Fishes and other Animals.
These are of so hard and firm a texture, as to suffer no great change, wheresoever found; for we see, that no erosion appears in them, their enamel and its polish being intirely preserved; yet sometimes their roots will be found changed, especially in the yellow ones, having no enamel to guard them in their roots.
Parts of Vegetables.
The leaves of plants, whose fibres are firm and dry, will endure for a long time; but those of a succulent nature never can, as they putrify very soon. We see the leaves of ferns of several kinds, polypodium, tricomanes, and other capillary plants, with nodules of stone formed about them; flags, reeds, rushes, equisetum, and many such, of a firm texture, are found in slate and stone; and even the iuli of trees are said to have been found fossil as well as their leaves.
Seeds and Fruits.
All seeds and the stones of fruits, having a firm texture, are also capable of being strongly impregnated with stony and pyritical matter; and I make no doubt but that the smaller seeds, if carefully looked for, might be found fossil, as well as these before you; such, I mean, as have a firmness in the covering; but being small, and mixt with the dirt, sand, and the like, probably is the reason of their being overlooked. Fruits of various kinds are found petrified; but this is only in their green state, when they are hard enough to endure till they are impregnated with stony or mineral particles. The rudiments of fruits, when once well formed, and a little advanced, are firm and acid: and the more remote they are from maturity, the more secure from putrifaction; and their acid juice is no small help to their preservation from growing soon rotten. But indeed, when the fruit advances in growth, the texture grows gradually more lax; the acid juices are now beginning to be replaced by saccharine or others more soft; the fibres are driven farther asunder, and they now arrive at their most ripe state: and the utmost maturity of fruits is the next step to putrifaction. Hence they are destroyed before stony or other particles can have time enough to impregnate them: and this is exactly the case with the flesh of animals of every kind. The husks and hard calyces of fruits, as well as their stones, are also susceptible of petrifaction.
If these fruits, which I have the honour to lay before you, are antediluvian, one would be apt to imagine they, in some measure, point out, with Dr. Woodward, the time of year in which the deluge began; which he thinks was in May: and yet this very opinion is liable to some objections; because altho' fruits capable of being petrified, from their green state, may be pretty well formed in May here, as well as in the same latitude elsewhere, in favour of this opinion; yet there are the stones of fruits, found fossil, so perfect, as to make one imagine they were very ripe, when deposited in the places where they are discovered; which would induce one to think the deluge happened nearer Autumn, unless we could think them the productions of more southern latitudes, where perhaps their fruits are brought to perfection before ours are well formed.
What follows is a catalogue of these fossil fruits &c. before you: and I should be glad, if any of the gentlemen would take the trouble of examining them, in order to assist in our conjectures about such of them, as appear doubtful: but first beg leave to insert the following remark:
I cannot omit an observation of Doctor Mason, Woodwardian professor, in this place; which is well worth notice, and indeed which I never attended to. It regards the impressions of fishes upon slate. Now there are several kinds of slate, which have such impressions upon them: in some there remains only the bare impression, without any part of the fish; in others the scales only, but retaining the intire form of the animal; and in others no part adheres to the slate, but the skeleton, or part of it, most commonly the spine. He says that he always observed, that the bones are never seen but upon the grey or blue slate, or their impressions; and that the scales or skin are to be found only upon the black stone or slate; which makes him conjecture, that something erosive in the grey slate destroys every part but the bony system; but that the black, being of a more soft and unctuous nature, preserves the scales, and often the very skin. This, however, must be referred to further observation.
Philos. Trans. Vol. L. Tab. XV. p. 403.
IP MD. delin.
J. Mynde sc.
Fig. 1, 3. These two bodies seem to be figs, petrified when hard and green; being, as I have just observed, then capable of receiving the pyritical particles, with which they are manifestly impregnated. One is more perfect in its form than the other; and they are now shooting their salts, and will soon fall to pieces.
Fig. 2. appears to be a Myrobalan, distinguished from the other species of that name by its round figure; and is called the belleric Myrobalan. It is nearly destroyed by the pyritical matter, and will not long remain whole.
Fig. 4. seems to be a species of Phaseolus, one of those especially distinguished by the fruits. Fructibus splendentibus nigris.
Fig. 5. Another Phaseolus.
Fig. 7. Another. See Fig. 4.
Fig. 8. Semen Cucurbitæ, a large species of American gourd.
Fig. 9. Coffee-berries.
Fig. 10, 11. Two species of Beans, very apparent.
Fig. 12. Unknown. This, however, appears to be a fruit, with the calyx running up, and embracing it, in its hard green state; being somewhat compressed on the upper part, as it lay confined in the earth.
Fig. 13. An Staphilodendri species? The learned and reverend Dr. Hales gave me, some years ago, a handful of the recent fruits, one or two of which are sent with this fossil one, for your consideration. He had them from Bengal, and called them, in the Indian name, Neermelis; and said the natives used them to fine down liquors.
Fig. 14. A compressed pod of the Arachidna, or Underground-Pea. The full-grown pods are much larger, but of various sizes, as are other kinds. This, however, seems to have been, when deposited where it was found, not so far advanced. It has the reticulated surface, the apex on one side, and every other character of that fruit or seed-pod, but somewhat compressed.
Fig. 15. is evidently an Acorn. We have of this species here, and in America also.
Fig. 16. An exotic fruit, like a small melon; but uncertain. It is somewhat deformed by compression.
Fig. 17. This I took at first for a fruit; but now I rather believe it a Fungoides of a very pretty kind.
Fig. 18. An Anguria? I take it for a seed of a species of water-melon.
Fig. 19. seems a small plumb-stone.
Fig. 20. Unknown. The calyx seems to run up and embrace this fruit towards the apex.
Fig. 21. Unknown. This resembles an American seed, which I have in my collection, but do not know its name. Its apex is inclining to one side; and it appears to have had a strong pedicle.
Fig. 22. An Lachryma Jobi?
Fig. 23. A Cherry-stone.
Philos. Trans. Vol. L. Tab. XVI. p. 406.
IP MD. delin.
J. Mynde sc.
Fig. 1. An Euonymi species? If this be an Euonymus, it is not so far advanced as to form the seeds: and is therefore to be considered only in its progress from the flower towards seeding: which is the case in several of these, whose calyces appear still upon them, and hinder us from absolutely determining what they are.
Fig. 2. A berry of the Sapindus, or Soap-tree, of America, being not at all deformed, only having a little lump of pyrites upon it: but there is another quite free.
Fig. 3. Huræ Germen. This is undoubtedly the young Sand-box, or fruit of the Hura, so well known for its beautiful form to the curious, who collect specimens of natural history; and seems to shew the time of the deluge.
Fig. 4. This, I think, is certainly the stone of an eastern Mango; such as comes over to us pickled, and, the stone being opened on one side, is generally stuffed with spices.
Fig. 5. Euonymi latifolii species. This is a large species of Euonymus, perhaps of Clusius.
Fig. 6. This body seems to be a Milleped, or Wood-louse. It is turned round, the two extremities meeting; which is the attitude assumed by these animals, upon being in any-wise obstructed in their passage, or handled.
Fig. 7. A small long Bean, like our horse-bean; but longer than any we have in England.
Fig. 8. Unknown to me.
Fig. 9. A species of Horse-chesnut from America.
Fig. 10. The external husk of the fruit of the Sapindus, or Soap-tree.
Fig. 11. I cannot determine whether this be an Olive, or the yellow Myrobalan; but believe it the Myrobalan.
Fig. 12. A Palmæ species? It seems a small Palma-coco.
Fig. 13, 14. unknown, as well as fig. 15.
Fig. 16. Unknown. The reason of the four last being not to be distinguished is, that they seem to be the buds of their several species, before they were perfectly formed. So that while some of the antediluvian productions are mature, others appear to be premature; and consequently one would be inclined to think them the inhabitants of places of different latitudes.
Fig. 17. A species of foreign Walnut, injured and compressed.
Fig. 18. A Plumb-stone.
Fig. 19. The claw of an American Crab; which, being on the opposite side of the mass containing the body, could not come in view with it at the same time.
Fig. 20. The body of the crab, with other parts, appearing thro' the stony matter that invelopes it, which appears to be an induration of yellow clay.
Fig. 21. seems a long American Phaseolus. Part of the petrified husk is upon it.
Fig. 22. An American Echinite of the flat kind, much resembling that species which Rumphius calls Echinus sulcatus primus.
Fig. 23. Arista cujusdam Graminis. This body has all the characteristics of an ear of corn, or some species of grass, of which there are many.
This has been taken for a spine of an Echinus: but, as we are to consider its nearest resemblance to whatsoever body, we must conclude it as we have said. I never saw any spine in the least like it; but an ear of corn, ripe and dry, is as susceptible of being petrified, as a crustaceous animal, in every respect. Indeed the spiculæ of the ear, each arising from the grain, being very slender, are of course destroyed during the petrifaction; but the form of the ear is actually preserved, as much as the nature and circumstances of the thing will allow.
Fig. a. A manifest species of Pediculus Marinus crumped up.
b. A Seed-vessel, given me by Mr. Da Costa, found in a clay-pit in Staffordshire.
c. Cocculus Indicus.
LII. Observations upon the Comet that appeared in the Months of September and October 1757, made at the Royal Observatory by Ja. Bradley, D.D. Astronomer Royal, F.R.S. and Member of the Royal Academy of Sciences at Paris.
Read Dec. 22, 1757.
I Deferred to give an account of my observations upon the Comet that hath lately appeared, till I could settle the places of the stars with which it had been compared; several of them not being inserted in the British catalogue, and those which are, requiring some small corrections, which I have since made from my own observations.
When I first discovered this Comet, it appeared to the naked eye like a dull star of the 5th or 6th magnitude; but viewing it thro' a seven-foot Telescope, I could perceive a small Nucleus (surrounded, as usual, with a nebulous atmosphere), and a short tail extended in a direction opposite to the sun.
Some small stars then appearing in the field of the telescope with the Comet, I measured its distance from them with a Micrometer; and on September 12d at 16h 2' mean time, I found it to be 1° 13' 5" distant from a small star, whose right ascension was afterwards found to be 89° 49' 40" and declination 36° 11' 30" north: and near the same time the Comet was observed to be 43' 10" from another star, whose right ascension was 90° 20' 0" and declination 35° 12' 0" north.
Hence I collected, that the Comet's right ascension was 89° 29' 10" and its declination 35° 0' 20" north.
September 13d 12h 37' mean time (which is likewise made use of in the following observations), the Comet had the same right ascension with a small star, whose right ascension was 93° 5' 30" and declination 34° 36' 40" north; and it was about two minutes more northerly than the star. Hence the Comet's right ascension was 93° 5' 30" and its declination 34° 38' 40" north.
September 14d 14h 0' the Comet preceded θ Geminorum 1° 31' 35" in right ascension, and was 11' 35" more southerly. The apparent right ascension of θ Geminorum was then 99° 11' 40" and its declination 34° 13' 25" north. Hence the right ascension of the Comet was 97° 40' 5" and its declination 34° 1' 50" north.
Sept. 17d 13h 0' a small star (whose right ascension was 109° 55' 20" and declination 31° 27' 40") preceded the Comet 47' 10" in right ascension, and was 12' 30" more northerly. Hence the Comet's right ascension was 110° 42' 40" and its declination 31° 15' 10" north.
Sept. 19d 15h 17' a star (whose right ascension was 118° 29' 40" and declination 28° 9' 45") preceded the Comet 1° 14' 0" in right ascension, and was more southerly 15' 45". Hence the Comet's right ascension was 119° 43' 40" and declination 28° 25' 30" north.
Sept. 23d 15h 57' a star (whose right ascension was 134° 55' 45" and declination 22° 15' 55" north) preceded the Comet 12' 30" in right ascension, and was 29' 0" more northerly. Hence the Comet's right ascension was 135° 8' 15" and its declination 21° 46' 55" north.
Sept. 24d 15h 21' the Comet had the same declination with a small star that preceded it 10' 15" in right ascension. This star's right ascension was afterwards found to be 138° 13' 45" and its declination 20° 5' 20". Hence the Comet's right ascension was 138° 24' 0" and its declination 20° 5' 20" north.
Sept. 28d 16h 22' the Comet followed Regulus 1° 7' 12" in right ascension, and was 14' 45" more northerly. The right ascension of Regulus being then 148° 51' 13" and its declination 13° 8' 35" north; the Comet's right ascension was 149° 58' 25" and its declination 13° 23' 20" north.
Sept. 30d 16h 24' ρ Leonis (whose right ascension was 155° 0' 10" and declination 10° 32' 53" north) followed the Comet 18' 45" in right ascension, and was 7' 53" more northerly. Hence the Comet's right ascension was 154° 41' 25" and its declination 10° 25' 0" north.
October 2d 16h 48' the 37th star Sextantis. Hevel. in the British Catalogue (whose right ascension was 158° 21' 25" and declination 7° 38' 40" north) preceded the Comet 32' 50" in right ascension, and was 3' 20" more southerly. Hence the Comet's right ascension was 158° 54' 15" and its declination 7° 42' 0" north.
October 3d 16h 45' c Leonis (whose right ascension was 162° 2' 15' and declination 7° 24' 0" north) followed the Comet 1° 12' 55" in right ascension, and was 56' 40" more northerly. Hence the Comet's right ascension was 160° 49' 20" and its declination 6° 27' 20" north.
October 4d 17h 0' d Leonis (whose right ascension was 162° 0' 15" and declination 4° 54' 57" north) preceded the Comet 40' 15" in right ascension, and was more southerly 20' 53". Hence the Comet's right ascension was 162° 40' 30" and its declination 5° 15' 50" north.
October 7d 16h 54' the 79th Leonis in the British Catalogue (whose right ascension was 167° 53' 37" and declination 2° 44' 15" north) followed the Comet 13' 0" in right ascension, and was more northerly 38' 35". Hence the Comet's right ascension was 167° 40' 37" and its declination 2° 5' 40" north.
October 8d 16h 53' the Comet preceded v Leonis 1° 53' 30" in right ascension, and was 37' 20" more northerly. The right ascension of this star was 171° 7' 45" and its declination 0° 30' 55" north; therefore the Comet's right ascension was 169° 14' 15" and its declination 1° 8' 15" north.
October 11d 16h 52' the Comet followed v Leonis 2° 33' 30" in right ascension, and appeared 1° 55' 5" more southerly; but it being near the horizon, the difference of right ascension must have been contracted by refraction about 1' 5", and the difference of declination about 1' 30": so that the corrected right ascension of the Comet was 173° 42' 20" and its declination 1° 25' 40" south.
Immediately after this observation a fog arose, which prevented me from repeating it; and several mornings following proving hazy or cloudy, I could not see the Comet again till October 18th, about an hour and a quarter before sun-rising; when the twilight being strong, and the Comet low, it appeared very faint. However, I was unwilling to omit the opportunity of determining its place, as near as I could, by a single observation, in the following manner.
At 6h 59' 54" ½ sidereal time, I observed the passage of the Comet over the perpendicular wire of my equatorial Sector; then leaving the instrument in the same position till the next evening, I observed, that at 22h 8' 15" sidereal time, the 17th star of Eridanus in the British Catalogue passed over the same wire (or horary circle) 9' 30" more southerly than the Comet. And at 23h 45' 36" sidereal time the star marked b in Eridanus passed, 19' 55" more northerly than the Comet.
I found that the situation of my instrument was not sensibly altered between the 18th and 19th of October; for the transits and the difference of declination of the same stars being observed with it again on the 19th of October, they agreed very well with those that were taken the preceding night. It may therefore be supposed, that the position of the instrument continued the same likewise during the time of the foregoing observations.
The right ascension of the 17th star of Eridanus being 49° 39' 10" and its declination 5° 55' 25" south; and the right ascension of b of Eridanus being 73° 59' 15" and its declination 5° 25' 10" south; I collected, that when the Comet passed the wire (or horary circle) which was October 17d 17h 12' mean time, its right ascension was 182° 34' 0" and its declination 5° 45' 35" south.
The last time that I saw the Comet was on the 19th of October in the morning; but it then appeared so faint, that I could not observe its place. Its elongation from the sun was then but about 20 degrees; and from that day to the present it hath always been less; which is the principal reason why it was invisible to us at the time when it was in its perihelion, and hath remained so ever since. The elongation will indeed soon become greater, and yet it is probable that we shall not be able to see the Comet again; because its real distance from the sun will be greater than it was when I first saw it, and it will be also four times further from us than it was at that time.
The Comet kept nearly at the same distance from the earth for ten or twelve days together after I first saw it; but its brightness gradually increased then, because it was going nearer to the sun. Afterwards, when its distance from the earth increased, altho' it continued to approach the sun, yet its lustre never much exceeded that of stars of the second magnitude, and the tail was scarce to be discerned by the naked eye.
All the forementioned observations were made with a Micrometer in a seven-foot Tube, excepting those of the 3d, 11th, and 17th days of October, which were taken with a curious Sector constructed for such purposes by the late ingenious Mr. George Graham; of which Dr. Smith has given a very exact description in his third book of Optics.
Supposing the Trajectory of this Comet to be parabolic, I collected from the foregoing observations, that its motion round the sun is direct, and that it was in its perihelion October the 21st, at 7h 55' mean (or equated) time at Greenwich. That the inclination of the plane of its Trajectory to the ecliptic is 12° 50' 20"; the place of the descending Node ♉ 4° 12' 50"; the place of the Perihelion ♄ 2° 58' 0"; the distance of the Perihelion from the descending Node 88° 45' 10"; the Logarithm of the Perihelion distance 9.528328; the Logarithm of the diurnal motion 0.667636.
From these Elements (which are adapted to Dr. Halley's general Table for the Motion of Comets in parabolic Orbits), I computed the places of this Comet for the respective times of the foregoing observations, as in the following table; which contains likewise the longitudes and latitudes deduced from the observed right ascensions and declinations, and also the differences between the computed and observed places. These differences (no-where exceeding 40") shew, that the elements here set down will be sufficient to enable future astronomers to distinguish this Comet upon another return; but as they do not correspond with the elements of the orbit of any other Comet hitherto taken notice of, we cannot determine at present the period thereof.
| Greenwich, 1757. Mean Time. | Comet. Long. Observ. | Latit. Observ. | Long. Comp. | Latit. Comput. | Diff. Long. | Diff. Latit. | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| d. | h. | ' | S. | ° | ' | " | ° | ' | " | S. | ° | ' | " | ° | ' | " | " | " | |||
| Sept. | 12 | 16 | 2 | ♊ | 29 | 34 | 13 | 11 | 32 | 16 | No. | ♊ | 29 | 34 | 11 | 11 | 32 | 20 | No. | -2 | +4 |
| 13 | 12 | 37 | ♋ | 2 | 35 | 34 | 11 | 12 | 13 | ♋ | 2 | 35 | 47 | 11 | 12 | 11 | +13 | -2 | |||
| 14 | 14 | 0 | 6 | 27 | 45 | 10 | 44 | 3 | 6 | 27 | 42 | 10 | 43 | 43 | -3 | -20 | |||||
| 17 | 13 | 0 | 17 | 49 | 40 | 9 | 3 | 31 | 17 | 50 | 16 | 9 | 3 | 11 | +36 | -20 | |||||
| 19 | 15 | 17 | 26 | 6 | 8 | 7 | 36 | 49 | 26 | 5 | 50 | 7 | 36 | 30 | -18 | -19 | |||||
| 23 | 15 | 57 | ♌ | 11 | 19 | 18 | 4 | 33 | 38 | ♌ | 11 | 19 | 4 | 4 | 33 | 32 | -14 | -6 | |||
| 24 | 15 | 21 | 14 | 44 | 19 | 3 | 49 | 37 | 14 | 44 | 3 | 3 | 49 | 39 | -16 | +2 | |||||
| 28 | 16 | 22 | 27 | 23 | 43 | 1 | 3 | 44 | No. | 27 | 23 | 32 | 1 | 3 | 52 | No. | -11 | +8 | |||
| 30 | 16 | 24 | ♍ | 2 | 45 | 43 | 0 | 5 | 30 | So. | ♍ | 2 | 45 | 39 | 0 | 5 | 17 | So. | -4 | -13 | |
| Octob. | 2 | 16 | 48 | 7 | 37 | 43 | 1 | 5 | 50 | 7 | 37 | 42 | 1 | 5 | 32 | -1 | -18 | ||||
| 3 | 16 | 45 | 9 | 51 | 36 | 1 | 32 | 22 | 9 | 51 | 29 | 1 | 31 | 55 | -7 | -27 | |||||
| 4 | 17 | 0 | 12 | 1 | 4 | 1 | 56 | 42 | 12 | 0 | 25 | 1 | 56 | 23 | -39 | -19 | |||||
| 7 | 16 | 54 | 17 | 51 | 3 | 2 | 56 | 48 | 17 | 51 | 6 | 2 | 56 | 24 | +3 | -24 | |||||
| 8 | 16 | 53 | 19 | 39 | 45 | 3 | 13 | 7 | 19 | 39 | 33 | 3 | 12 | 28 | -12 | -39 | |||||
| 11 | 16 | 52 | 24 | 47 | 22 | 3 | 48 | 49 | 24 | 47 | 47 | 3 | 49 | 29 | +25 | +40 | |||||
| 17 | 17 | 12 | ♎ | 4 | 38 | 58 | 4 | 15 | 42 | So. | ♎ | 4 | 38 | 36 | 4 | 15 | 2 | So. | -22 | -40 | |
LIII. The Resolution of a General Proposition for Determining the horary Alteration of the Position of the Terrestrial Equator, from the Attraction of the Sun and Moon: With some Remarks on the Solutions given by other Authors to that difficult and important Problem. By Mr. Tho. Simpson, F.R.S.
Read Dec. 22, 1757.
SINCE the time, that that excellent Astronomer, my much honoured friend Dr. Bradley, published his observations and discoveries concerning the inequalities of the precession of the equinox, and of the obliquity of the ecliptic, depending on the position of the lunar nodes, mathematicians, in different parts of Europe, have set themselves diligently to compute, from physical principles, the effects produced by the sun and moon, in the position of the terrestrial equator; and to examine whether these effects do really correspond with the observations.
Two papers on this subject have already appeared in the Philosophical Transactions; in which the authors have shewn evident marks of skill and penetration. There is, nevertheless, one part of the subject, that seems to have been passed over without a due degree of attention, as well by both those gentlemen, as by Sir Isaac Newton himself.
This part, which, upon account of physical difficulties, is indeed somewhat slippery and perplexing, I shall make the principal subject of this essay.