APPENDIX.
AN ORATION,
DELIVERED FEBRUARY 24, 1775,
BEFORE
THE AMERICAN PHILOSOPHICAL SOCIETY,
HELD AT PHILADELPHIA,
FOR PROMOTING USEFUL KNOWLEDGE.
BY DAVID RITTENHOUSE, A. M.
MEMBER OF THE SAID SOCIETY.
(INSCRIBED)
To the Delegates of the thirteen United Colonies, assembled in Congress, at Philadelphia, to whom the future liberties, and consequently the virtue, improvement in science and happiness, of America, are intrusted, the following Oration is inscribed and dedicated, by their most obedient and humble servant, the Author.
Gentlemen,
It was not without being sensible how very unequal I am to the undertaking, that I first consented to comply with the request of several gentlemen for whom I have the highest esteem, and to solicit your attention on a subject which an able hand might indeed render both entertaining and instructive; I mean Astronomy. But the earnest desire I have to contribute something towards the improvement of Science in general, and particularly of Astronomy, in this my native country, joined with the fullest confidence that I shall be favoured with your most candid indulgence, however far I may fall short of doing justice to the noble subject, enables me chearfully to take my turn as a member of the society, on this annual occasion.
The order I shall observe in the following discourse, is this: In the first place I shall give a very short account of the rise and progress of astronomy, then take notice of some of the most important discoveries that have been made in this science, and conclude with pointing out a few of its defects at the present time.
As, on this occasion, it is not necessary to treat my subject in a strictly scientific way, I shall hazard some conjectures of my own; which, if they have but novelty to recommend them, may perhaps be more acceptable than retailing the conjectures of others.
The first rise of astronomy, like the beginnings of other sciences, is lost in the obscurity of ancient times. Some have attributed its origin to that strong propensity mankind have discovered, in all ages, for prying into futurity; supposing that astronomy was cultivated only as subservient to judicial astrology. Others with more reason suppose astrology to have been the spurious offspring of astronomy; a supposition that does but add one more to the many instances of human depravity, which can convert the best things to the worst purposes.
The honour of first cultivating astronomy has been ascribed to the Chaldeans, the Egyptians, the Arabians, and likewise to the Chinese;[[A1]] amongst whom, it is pretended, astronomical observations are to be found of almost as early a date as the flood. But little credit is given to these reports of the Jesuits, who it is thought were imposed on by the natives; or else perhaps from motives of vanity, they have departed a little from truth, in their accounts of a country and people among whom they were the chief European travellers.
Not to mention the prodigious number of years in which it is said the Chaldeans observed the heavens, I pass on to what carries the appearance of more probability;[[A2]] the report that when Alexander took Babylon, astronomical observations for one thousand nine hundred years before that time were found there, and sent from thence to Aristotle. But we cannot suppose those observations to have been of much value; for we do not find that any use was ever after made of them.[[A3]]
The Egyptians too, we are told, had observations of the stars for one thousand five hundred years before the Christian era. What they were, is not known; but probably the astronomy of those ages consisted in little more than remarks on the rising and setting of the fixed stars, as they were found to correspond with the seasons of the year;[[A4]] and, perhaps, forming them into constellations. That this was done early, appears from the book of Job, which has by some been attributed to Moses, who is said to have been learned in the sciences of Egypt.[[A5]] “Canst thou bind the sweet influences of Pleiades, or loose the bands of Orion? Canst thou bring forth Mazzaroth in his season, or canst thou guide Arcturus with his sons?” Perhaps too, some account might be kept of eclipses of the sun and moon, as they happened, without pretending to predict them for the future. These eclipses are thought by some to have been foretold by the Jewish prophets in a supernatural way.
As to the Arabians, though some have supposed them the first inventors of astronomy, encouraged to contemplate the heavens by the happy temperature of their climate, and the serenity of their skies, which their manner of life must likewise have contributed to render more particularly the object of their attention; yet it is said, nothing of certainty can now be found to induce us to think they had any knowledge of this science amongst them before they learned it from the writings of Ptolemy, who flourished one hundred and forty years after the birth of Christ.
But notwithstanding the pretensions of other nations, since it was the Greeks who improved geometry, probably from its first rudiments, into a noble and most useful science; and since we cannot conceive that astronomy should make any considerable progress without geometry, it is to them we appear indebted for the foundations of a science, that (to speak without a metaphor) has in latter ages reached the astonishingly distant heavens.
Amongst the Greeks, Hipparchus[[A6]] deserves particular notice; by an improvement of whose labours Ptolemy formed that system of astronomy which appears to have been the only one studied for ages after, and particularly (as was said before) by the Arabians; who made some improvements of their own, and, if not the inventors, were at least the preservers of astronomy. For with them it took refuge, during those ages of ignorance which involved Europe, after an inundation of northern people had swallowed up the Roman empire; where the universally prevailing corruption of manners, and false taste, were become as unfavourable to the cause of science, as the ravages of the Barbarians themselves.
From this time, we meet with little account of astronomical learning in Europe[[A7]] until Regiomontanus,[[A8]] and some others, revived it in the fifteenth century; and soon afterwards appeared the celebrated Copernicus,[[A9]] whose vast genius, assisted by such lights as the remains of antiquity afforded him, explained the true system of the universe, as at present understood. To the objection of the Aristotelians, that the sun could not be the centre of the world, because all bodies tended to the earth, Copernicus replied, that probably there was nothing peculiar to the earth in this respect; that the parts of the sun, moon and stars, likewise tended to each other, and that their spherical figure was preserved amidst their various motions, by this power; an answer that will at this day be allowed to contain sound philosophy. And when it was further objected to him, that, according to his system, Venus and[and] Mercury ought to appear horned like the moon, in particular situations; he answered as if inspired by the spirit of prophecy, and long before the invention of telescopes, by which alone his prediction could be verified, “That so they would one day be found to appear.”
Next follows the noble Tycho,[[A10]] who with great labour and perseverance, brought the art of observing the heavens to a degree of accuracy unknown to the ancients; though in theory he mangled the beautiful system of Copernicus. The whimsical Kepler, too, (whose fondness for analogies frequently led him astray, yet sometimes happily conducted him to important truths) did notable services to astronomy: and from his time down to the present, so many great men have appeared amongst the several nations of Europe, rivalling each other in the improvement of astronomy, that I should trespass on your patience were I to enumerate them. I shall therefore proceed to what I proposed in the second place, and take notice of some of the most important discoveries in this science.
Astronomy, like the Christian religion, if you will allow me the comparison, has a much greater influence on our knowledge in general, and perhaps on our manners too, than is commonly imagined. Though but few men are its particular votaries, yet the light it affords is universally diffused amongst us; and it is difficult for us to divest ourselves of its influence so far, as to frame any competent idea of what would be our situation without it.[[A11]] Utterly ignorant of the heavens, our curiosity would be confined solely to the earth, which we should naturally suppose a vast extended plain; but whether of infinite extent or bounded, and if bounded, in what manner, would be questions admitting of a thousand conjectures, and none of them at all satisfactory.
The first discovery then, which paved the way for others more curious, seems to have been the circular figure of the earth, inferred from observing the meridian altitudes of the sun and stars to be different in distant places. This conclusion would probably not be immediately drawn, but the appearance accounted for, by the rectilinear motion of the traveller; and then a change in the apparent situations of the heavenly bodies would only argue their nearness to the earth: and thus would the observation contribute to establish error, instead of promoting truth, which has been the misfortune of many an experiment. It would require some skill in geometry, as well as practice in observing angles, to demonstrate the spherical figure of the earth from such observations.[[A12]]
But this difficulty being surmounted, and the true figure of the earth discovered, a free space would now be granted for the sun, moon, and stars to perform their diurnal motions on all sides of it; unless perhaps at its extremities to the north and south; where something would be thought necessary to serve as an axis for the heavens to revolve on. This Mr. Crantz in his very entertaining history of Greenland informs us, is agreeable to the philosophy of that country, with this difference perhaps, that the high latitude of the Greenlander makes him conclude one pole only, necessary: He therefore supposes a vast mountain situate in the utmost extremity of Greenland, whose pointed apex supports the canopy of heaven, and whereon it revolves with but little friction.
A free space around the earth being granted, our infant astronomer would be at liberty to consider the diurnal motions of the stars as performed in intire circles, having one common axis of rotation. And by considering their daily anticipation in rising and setting, together with the sun’s annual rising and falling in its noon day height, swiftest about the middle space, and stationary for some time when highest and lowest, he would be led to explain the whole by attributing a slow motion to the sun, contrary to the diurnal motion, along a great circle dividing the heavens into two equal parts, but obliquely situated with respect to the diurnal motion. By a like attention to the moon’s progress the Zodiac would be formed, and divided into its several constellations or other convenient divisions.
The next step that astronomy advanced, I conceive, must have been in the discovery attributed to Pythagoras;[[A13]] who it is said first found out that Hesperus and Phosphorus, or the Evening and Morning Star, were the same. The superior brightness of this planet, and the swiftness of its motion, probably first attracted the notice of the inquisitive: and one wandering star being discovered, more would naturally be looked for. The splendor of Jupiter, the very changeable appearance of Mars, and the glittering of Mercury by day light, would distinguish them. And lastly, Saturn would be discovered by a close attention to the heavens. But how often would the curious eye be directed in vain, to the regions of the north and south, before there was reason to conclude that the orbits of all the planets lay nearly in the same plane; and that they had but narrow limits assigned them in the visible heavens.
From a careful attendance to those newly discovered celestial travellers, and their various motions, direct and retrograde, the great discovery arose, that the sun is the centre of their motions; and that by attributing a similar motion to the earth, and supposing the sun to be at rest, all the phænomena will be solved. Hence a hint was taken that opened a new and surprizing scene. The earth might be similar to them in other respects. The planets too might be habitable worlds. One cannot help greatly admiring the sagacity of minds, that first formed conclusions so very far from being obvious; as well as the indefatigable industry of astronomers, who originally framed rules for predicting eclipses of sun and moon, which is said to have been done as early as the time of Thales;[[A14]] and must have proved of singular service to emancipate mankind from a thousand superstitious fears and notions, which juggling[juggling] impostors (the growth of all ages and countries) would not fail to turn to their own advantage.
For two or three centuries before and after the beginning of the Christian era, astronomy appears to have been held in considerable repute; yet very few discoveries of any consequence were made, during that period and many ages following.
The ancients were not wanting in their endeavours to find out the true dimensions of the planetary system. They invented several very ingenious methods for the purpose; but none of them were at all equal, in point of accuracy, to the difficulty of the problem. They were therefore obliged to rest satisfied with supposing the heavenly bodies much nearer to the earth than in fact they are, and consequently much less in proportion to it. Add to this, that having found the earth honoured with an attendant, while they could discover none belonging to any of the other planets, they supposed it of far greater importance in the Solar System than it appears to us to be: And the more praise is due to those few, who nevertheless conceived rightly of its relation to the whole.
Tycho took incredible pains to discover the parallax of Mars in opposition; the very best thing he could have attempted in order to determine the distances and magnitudes of the sun and planets. But telescopes and micrometers were not yet invented! so that not being able to conclude any thing satisfactory from his own observations, he left the sun’s parallax as he found it settled by Ptolemy, about twenty times too great. And even after he had reduced to rule the refraction of the atmosphere, and applied it to astronomical observations, rather than shock his imagination by increasing the sun’s distance, already too great for his hypothesis, he chose to attribute a greater refraction to the sun’s light, than that of the stars, altogether contrary to reason; that so an excess of parallax might be balanced by an excess of refraction. Thus when we willingly give room to one error, we run the risk of having a whole troop of its relations quartered upon us. But Kepler afterwards, on looking over Tycho’s observations, found that he might safely reduce the sun’s parallax to one minute; which was no inconsiderable approach to the truth. Alhazen,[[A15]] an Arabian, had some time before, discovered the refraction of light in passing through air; of which the ancients seem to have been entirely ignorant. They were indeed very sensible of the errors it occasioned in their celestial measures; but they, with great modesty, attributed them to the imperfections of their instruments or observations.
I must not omit, in honour of Tycho, to observe that he first proved, by accurate observations, that the comets are not meteors floating in our atmosphere, as Aristotle,[[A16]] that tyrant in Philosophy, had determined them to be, but prodigious bodies at a vast distance from us in the planetary regions; a discovery the lateness of which we must regret, for if it had been made by the ancients, that part of Astronomy (and perhaps every other, in consequence of the superior attention paid to it), would have been in far greater perfection than it is at this day.
I had almost forgot to take notice of one important discovery made in the early times of Astronomy, the precession of the equinoxes. An ancient astronomer, called Timocharis, observed an appulse of the Moon to the Virgin’s Spike, about 280 years before the birth of Christ. He thence took occasion to determine the place of this star, as accurately as possible; probably with a view of perfecting the lunar theory. About four hundred years afterwards, Ptolemy, comparing the place of the same star, as he then found it, with its situation determined by Timocharis,[[A17]] concluded the precession to be at the rate of one degree in an hundred years; but later astronomers have found it swifter.
Whatever other purposes this great law may answer, it will produce an amazing change in the appearance of the heavens; and so contribute to that endless variety which obtains throughout the works of Nature. The seven stars that now adorn our winter skies, will take their turn to shine in summer. Sirius, that now shines with unrivalled lustre, amongst the gems of heaven, will sink below our horizon, and rise no more for very many ages! Orion too, will disappear, and no longer afford our posterity a glimpse of glories beyond the skies! glittering Capella, that now passes to the north of our zenith, will nearly describe the equator:[[A18]] And Lyra, one of the brightest in the heavens, will become our Polar Star: Whilst the present Pole Star, on account of its humble appearance, shall pass unheeded; and all its long continued faithful services shall be forgotten! All these changes, and many others, will certainly follow from the precession of the equinoxes; the cause of which motion was so happily discovered and demonstrated by the immortal Newton: A portion of whose honors was nevertheless intercepted by the prior sagacity of Kepler, to whom I return.
Kepler’s love of harmony encouraged him to continue his pursuits, in spite of the most mortifying disappointments, until he discovered that admirable relation which subsists between the periodic times of the primary planets, and their distances from the sun; the squares of the former being as the cubes of the latter. This discovery was of great importance to the perfection of Astronomy; because the periods of the planets are more easily found by observation, and from them their several relative distances may be determined with great accuracy by this rule. He likewise found from observation, that the planets do not move in circles; but in elipses, having the sun in one focus. But the causes lay hid from him, and it was left as the glory of Sir Isaac, to demonstrate that both these things must necessarily follow from one simple principle, which almost every thing in this science tends to prove does really obtain in Nature: I mean, that the planets are retained in their orbits by forces directed to the sun; which forces decrease as the squares of their distances encrease.
Kepler also discovered that the planets do not move equally in their orbits, but sometimes swifter, sometimes slower; and that not irregularly, but according to this certain rule; That in equal times, the areas described by lines drawn from the planet to the sun’s centre, are equal. This, Sir Isaac likewise demonstrated must follow, if the planet be retained in its orbit by forces directed to the sun, and varying with the distance in any manner whatsoever. These three discoveries of Kepler, afterwards demonstrated by Newton, are the foundation of all accuracy in astronomical calculations.[[A19]]
We now come to that great discovery, which lay concealed from the most subtle and penetrating geniuses amongst mankind, until these latter ages; which so prodigiously enlarged the fields of astronomy, and with such rapidity handed down one curiosity after another, from the heavens to astonished mortals, that no one capable of raising his eyes and thoughts from the ground he trod on, could forbear turning his attention, in some degree, to the subject that engages us this evening.
Galileo, as he himself acknowledges, was not the first inventor of the telescope, but he was the first that knew how to make a proper use of it.[[A20]] If we consider that convex and concave lenses had been in use for some centuries, we shall think it probable that several persons might have chanced to combine them together, so as to magnify distant objects; but that the small advantage apparently resulting from such a discovery, either on account of the badness of the glasses or the unskilfulness of the person in whose hands they were, occasioned it to be neglected.
But Galileo, by great care in perfecting his telescope, and by applying a judicious eye, happily succeeded; and with a telescope magnifying but thirty times, discovered the moon to be a solid globe, diversified with prodigious mountains and vallies, like our earth; but without seas or atmosphere. The sun’s bright disk, he found frequently shaded with spots, and by their apparent motions proved it to be the surface of a globe, revolving on its axis in about five and twenty days. This it seems was a mortifying discovery to the followers of Aristotle; who held the sun to be perfect without spot or blemish.[[A21]] Some of them, it is said, insisted that it was but an illusion of the telescope and absolutely refused to look through one, lest the testimony of their senses should prove too powerful for their prejudices.
Galileo likewise discovered the four attendants of Jupiter, commonly called his satellites:[[A22]] Which at first did not much please that great ornament of his age, the sagacious Kepler. For by this addition to the number of the planets, he found their Creator had not paid that veneration to certain mystical numbers and proportions, which he had imagined. Let us not blush at this remarkable instance of philosophical weakness, but admire the candour of the man who confessed it.
Galileo not only discovered these moons of Jupiter, but suggested their use in determining the longitude of places on the earth; which has since been so happily put in practice, that Fontenelle does not hesitate to affirm, that they are of more use to Geography and Navigation,[[A23]] than our own moon. He discovered the phases of Mars and Venus; that the former appears sometimes round and sometimes gibbous, and that the latter puts on the shapes of our moon: And from this discovery, he proved to a demonstration, the truth of the Copernican System.[[A24]] Nor did that wonderful ring, which surrounds Saturn’s body, without touching it, and which we know nothing in nature similar to, escape his notice; though his telescope did not magnify sufficiently to give him a true idea of its figure.
Amongst the fixed stars too, Galileo pursued his enquiries. The Milky-Way, which had so greatly puzzled the ancient Philosophers, and which Aristotle imagined to be vapours risen to an extraordinary height, he found to consist of an innumerable multitude of small stars; whose light appears indistinct and confounded together to the naked eye. And in every part of the heavens, his telescope shewed him abundance of stars, not visible without it. In short, with such unabated ardour did this great man range through the fields of Astronomy, that he seemed to leave nothing for others to glean after him.
Nevertheless, by prodigiously encreasing the magnifying powers of their telescopes, his followers made several great discoveries; some of which I shall briefly mention. Mercury was found to become bisected, and horned near its inferior conjunction, as well as Venus. Spots were discovered in Mars, and from their apparent motion, the time of his revolution on an axis nearly perpendicular to its orbit, was determined. A sort of belts or girdles, of a variable or fluctuating nature, were found to surround Jupiter, and likewise certain spots on his surface, whence he was concluded to make one revolution in about ten hours on his axis; which is likewise nearly perpendicular to his orbit. Five[[A25]] moons or satellites were found to attend Saturn, which Galileo’s telescope; on account of their prodigious distance, could not reach:[[A26]] And the form of his ring was found to be a thin circular plane, so situated as not to be far from parallel to the plane of our equator; and always remaining parallel to itself. This ring, as well as Saturn, evidently derives its light from the sun, as appears by the shadows they mutually cast on each other.
Besides several other remarkable appearances, which Hugenius[[A27]] discovered amongst the fixed stars, there is one in Orion’s Sword, which, I will venture to say, whoever shall attentively view, with a good telescope and experienced eye, will not find his curiosity disappointed. “Seven small stars, (says he,) of which three are very close together, seemed to shine through a cloud, so that a space round them appeared much brighter than any other part of heaven, which being very serene and black looked here as if there was an opening, through which one had a prospect into a much brighter region.” Here some have supposed old night to be entirely dispossessed, and that perpetual daylight shines amongst numberless worlds without interruption.
This is a short account of the discoveries made with the telescope. Well might Hugenius congratulate the age he lived in, on such a great acquisition of knowledge: And recollecting those great men, Copernicus, Regiomontanus, and Tycho, so lately excluded from it by death, what an immense treasure, says he, would they have given for it. Those ancient philosophers too, Pythagoras, Democritus, Anaxagoras, Philolaus, Plato, Hipparchus; would they not have travelled over all the countries of the world, for the sake of knowing such secrets of nature, and of enjoying such sights as these?
Thus have we seen the materials collected, which were to compose the magnificent edifice of astronomical Philosophy; collected, indeed, with infinite labour and industry, by a few volunteers in the service of human knowledge, and with an ardour not to be abated by the weaknesses of human nature, or the threatened loss of sight, one of the greatest of bodily misfortunes! It was now time for the great master-builder to appear, who was to rear up this whole splendid group of materials into due order and proportion. And it was, I make no doubt, by a particular appointment of Providence, that at this time the immortal Newton appeared. Much had been done preparatory to this great work by others, without which if he had succeeded, we should have been ready to pronounce him something more than human. The doctrine of atoms had been taught by some of the ancients. Kepler had suspected that the planets gravitated towards each other, particularly the earth and moon; and that their motion prevented their falling together: and Galileo first of all applied geometrical reasoning to the motion of projectiles. But the solid spheres of the ancients, or the vortices of Des Cartes,[[A28]] were still found necessary to explain the planetary motions; or if Kepler had discarded them, it was only to substitute something else in their stead, by no means sufficient to account for those grand movements of nature. It was Newton alone that extended the simple principle of gravity, under certain just regulations, and the laws of motion, whether rectilinear or circular, which constantly take place on the surface of this globe, throughout every part of the solar system; and from thence, by the assistance of a sublime geometry, deduced the planetary motions, with the strictest conformity to nature and observation.
Other systems of Philosophy have been spun out of the fertile brain of some great genius or other; and for want of a foundation in nature, have had their rise and fall, succeeding each other by turns. But this will be durable as science, and can never sink into neglect, until “universal darkness buries all.”
Other systems of Philosophy have ever found it necessary to conceal their weakness, and inconsistency, under the veil of unintelligible terms[[A29]] and phrases, to which no two mortals perhaps ever affixed the same meaning: But the Philosophy of Newton disdains to make use of such subterfuges; it is not reduced to the necessity of using them, because it pretends not to be of nature’s privy council, or to have free access to her most inscrutable mysteries; but to attend carefully to her works, to discover the immediate causes of visible effects, to trace those causes to others more general and simple, advancing by slow and sure steps towards the great First Cause of all things.
And now the Astronomy of our planetary system seemed compleated. The telescope had discovered all the globes whereof it is composed, at least as far as we yet know. Newton with more than mortal sagacity had discovered those laws by which all their various, yet regular, motions are governed, and reduced them to the most beautiful simplicity: laws to which not only their great and obvious variety of motions are conformable, but even their minute irregularities; and not only planets but comets likewise. The busy mind of man, never satiated with knowledge, now extended its views further, and made use of every expedient that suggested itself, to find the relation that this system of worlds bears to the whole visible creation. Instruments were made with all possible accuracy, and the most skilful observers applied themselves with great diligence to discover an annual parallax, from which the distances of the fixed stars would be known. They found unexpected irregularities, and might have been long perplexed with them to little purpose, had not Dr. Bradley happily accounted for them, by shewing that light from the heavenly bodies strikes the eye with a velocity and direction, compounded of the proper velocity and direction of light, and of the eye, as carried about with the earth in its orbit; compared to which, the diurnal motion and all other accidental motions of the eye, are quite inconsiderable. Thus, instead of what he aimed at, he discovered something still more curious, the real velocity of light, in a way entirely new and unthought of.
All Astronomical knowledge being conveyed to us from the remotest distances, by that subtle, swift and universal messenger of intelligence, Light; it was natural for the curious to enquire into its properties, and particularly to endeavour to know with what velocity it proceeds, in its immeasurable journeys. Experimental Philosophy, accustomed to conquer every difficulty, undertook the arduous problem; but confessed herself unequal to the task.[[A30]] Here, Astronomy itself revealed the secret; first in the discovery of Roemer, who found that the farther Jupiter is distant from us, the later the light of his satellites always reaches us; and afterwards in this of Dr. Bradley, informed us, that light proceeds from the sun to us in about eight minutes of time.[[A31]]
As the apparent motion of the fixed stars, arising from this cause, was observed to complete the intire circle of its changes in the space of a year, it was for some time supposed to arise from an annual parallax, notwithstanding its inconsistency in other respects with such a supposition. But this obstacle being removed, there followed the discovery of another apparent motion in the heavens, arising from the nutation of the earth’s axis; the period whereof is about nineteen years. Had it not been so very different from the period of the former, the causes of both must have been almost inexplicable. This latter discovery is an instance of the superior advantages of accurate observation: For it was well known that such a nutation must take place from the principles of the Newtonian Philosophy; yet a celebrated astronomer had concluded from hypothetical reasoning, that its quantity must be perfectly insensible.
The way being cleared thus far, Dr. Bradley assures us, from his most accurate observations, that the annual parallax cannot exceed two seconds, he thinks not one; and we have the best reason to confide in his judgment and accuracy. From hence then we draw this amazing conclusion; that the diameter of the earth’s orb bears no greater proportion to the distance of the stars which Bradley observed, than one second does to the radius; which is less than as one to 200,000. Prodigiously great as the distance of the fixed stars from our sun appears to be, and probably their distances from each other are no less, the Newtonian Philosophy will furnish us with a reason for it: That the several systems may be sufficiently removed from each other’s attraction, which we are very certain must require an immense distance; especially if we consider that the cometic part, of our system at least, appears to be the most considerable though so little known to us. The dimensions of the several parts of the planetary system, had been determined near the truth by the astronomers of the last age, from the parallax of Mars. But from that rare phenomenon the transit of Venus over the sun’s disk, which has twice happened within a few years past, the sun’s parallax is now known beyond dispute to be 8 seconds and an half, nearly; and consequently, the sun’s distance almost 12,000 diameters of the earth.
If from the distances of the several planets, and their apparent diameters taken with that excellent instrument, the micrometer, we compare their several magnitudes, we shall find the Moon, Mercury, and Mars, to be much less than our Earth, Venus a little less, but Saturn many hundred times greater, and Jupiter above one thousand times. This prodigious globe, placed at such a vast distance from the other planets, that the force of its attraction might the less disturb their motions, is far more bulky and ponderous than all the other planets taken together. But even Jupiter, with all his fellows of our system, are as nothing compared to that amazing mass of matter the Sun. How much are we then indebted to Astronomy, for correcting our ideas of the visible creation! Wanting its instruction, we should infallibly have supposed the earth by far the most important body in the universe, both for magnitude and use. The sun and moon would have been thought two little bodies nearly equal in size, though different in lustre, created solely for the purpose of enlightening the earth; and the fixed stars, so many sparks of fire, placed in the concave vault of heaven, to adorn it, and afford us a glimmering light in the absence of the sun and moon.
But how does Astronomy change the scene!—Take the miser from the earth, if it be possible to disengage him; he whose nightly rest has been long broken by the loss of a single foot of it, useless perhaps to him; and remove him to the planet Mars, one of the least distant from us: Persuade the ambitious monarch to accompany him, who has sacrificed the lives of thousands of his subjects to an imaginary property in certain small portions of the earth; and now point it out to them, with all its kingdoms and wealth, a glittering star “close by the moon,” the latter scarce visible and the former less bright than our Evening Star:—Would they not turn away their disgusted sight from it, as not thinking it worth their smallest attention, and look for consolation in the gloomy regions of Mars?[[A32]]
But dropping the company of all those, whether kings or misers, whose minds and bodies are equally affected by gravitation, let us proceed to the orb of Jupiter; the Earth and all the inferior planets will vanish, lost in the sun’s bright rays, and Saturn only remain; He too sometimes so diminished in lustre, as not to be easily discovered. But a new and beautiful system will arise. The four moons of Jupiter will become very conspicuous; some of them perhaps appearing larger, others smaller than our moon; and all of them performing their revolutions with incredible swiftness, and the most beautiful regularity:—varying their phases from[from] full to new and from new to full, and frequently eclipsing the sun and each other, at least to the equatorial parts of Jupiter; and almost in every revolution suffering eclipses themselves by falling into Jupiter’s shadow; excepting that the outermost will seem, like a traveller fond of the sun-beams, cautiously to avoid the shadow for whole years together. Since we are advanced so far, if not tired of the journey, let us proceed a step further; it is but 400 millions of miles to the globe of Saturn. Here again all will be lost, but Jupiter itself. The Sun will put on something of a starlike appearance, but with excessive brightness. The five[[A33]] satellites of Saturn will exhibit appearances similar to those of Jupiter, but they will very rarely eclipse the Sun, or suffer eclipses themselves. The particular phænomena of Saturn’s ring, we cannot explain, unless we knew the time and plane of Saturn’s revolution on his axis. But this we know, that it must sometimes appear, by night, like a prodigious luminous arch, almost equal to one quarter of the heavens; and at other times, dark, so as to afford no light itself, but to intercept the light of every star beyond it, by night, and of the sun itself by day. And to conclude, if borne on the wings of a comet we should travel with it to the remotest part of its orbit; our whole planetary system would disappear, and the sun become a star, only more refulgent than Sirius perhaps, because less distant.
The opinion of the earth’s rotation on its axis was once violently opposed, from a notion of its dangerous tendency with respect to the interests of religion:[[A34]] But, as truth is always consistent with itself, so many new proofs were furnished from time to time by new discoveries, that a mistaken interpretation of some passages in the bible was compelled to give way to the force of astronomical evidence. The doctrine of a plurality of worlds, is inseparable from the principles of Astronomy; but this doctrine is still thought, by some pious persons, and by many more I fear, who do not deserve that title, to militate against the truths asserted by the Christian religion. If I may be allowed to give my opinion on a matter of such importance, I must confess that I think upon a proper examination the apparent inconsistency will vanish. Our religion teaches us what philosophy could not have taught; and we ought to admire with reverence the great things it has pleased divine Providence to perform, beyond the ordinary course of Nature, for man, who is undoubtedly the most noble inhabitant of this globe. But neither religion nor philosophy forbids us to believe that infinite wisdom and power, prompted by infinite goodness, may throughout the vast extent of creation and duration, have frequently interposed in a manner quite incomprehensible to us, when it became necessary to the happiness of created beings of some other rank or degree.
How far indeed the inhabitants of the other planets may resemble man, we cannot pretend to say. If like him they were created liable to fall, yet some, if not all of them, may still retain their original rectitude. We will hope they do: the thought is comfortable.—Cease, Galileo, to improve thy optic tube: and thou, great Newton, forbear thy ardent search into the distant mysteries of nature: lest ye make unwelcome discoveries. Deprive us not of the pleasure of believing that yonder radiant orbs, traversing in silent majesty the etherial regions, are the peaceful seats of innocence and bliss: where neither natural nor moral evil has ever yet intruded; where to enjoy with gratitude and adoration the creator’s bounty, is the business of existence. If their inhabitants resemble man in their faculties and affections, let us suppose that they are wise enough to govern themselves according to the dictates of that reason their creator has given them, in such manner as to consult their own and each other’s true happiness, on all occasions. But if, on the contrary, they have found it necessary to erect artificial fabrics of government, let us not suppose that they have done it with so little skill, and at such an enormous expence, as must render them a misfortune instead of a blessing. We will hope that their statesmen are patriots, and that their kings, if that order of beings has found admittance there, have the feelings of humanity.—Happy people! and perhaps more happy still, that all communication with us is denied. We have neither corrupted you with our vices, nor injured you by violence. None of your sons and daughters, degraded from their native dignity, have been doomed to endless slavery by us in America, merely because their bodies may be disposed to reflect or absorb the rays of light, in a way different from ours. Even you, inhabitants of the moon, situated in our very neighbourhood, are effectually secured, alike from the rapacious hand of the haughty Spaniard, and of the unfeeling British nabob. Even British thunder impelled by British thirst of gain, cannot reach you: And the utmost efforts of the mighty Frederick, that tyrant of the north and scourge of mankind, if aimed to disturb your peace, becomes inconceivably ridiculous and impotent.
Pardon these reflections; they rise not from the gloomy spirit of misanthropy. That being, before whose piercing eye all the intricate foldings and dark recesses of the human heart become expanded and illuminated, is my witness with what sincerity, with what ardor, I wish for the happiness of the whole race of mankind: how much I admire that disposition of lands and seas, which affords a communication between distant regions, and a mutual exchange of benefits:[[A35]] how sincerely I approve of those social refinements which really add to our happiness, and induce us with gratitude to acknowledge our great Creator’s goodness:—how I delight in a participation of the discoveries made from time to time in nature’s works, by our Philosophic brethren in Europe.
But when I consider, that luxury and her constant follower tyranny, who have long since laid in the dust, never to rise again, the glories of Asia, are now advancing like a torrent irresistible, whose weight no human force can stem, and have nearly completed their conquest of Europe; luxury and tyranny, who by a vile affectation of virtues they know not, pretend at first to be the patrons of science and philosophy, but at length fail not effectually to destroy them; agitated I say by these reflections, I am ready to wish—vain wish! that nature would raise her everlasting bars between the new and old world; and make a voyage to Europe as impracticable as one to the moon. I confess indeed, that by our connections with Europe we have made most surprising, I had almost said unnatural, advances towards the meridian of glory; but by those connections too, in all probability, our fall will be premature. May the God of knowledge inspire us with wisdom to prevent it: let our harbours, our doors, our hearts, be shut against luxury. But I return to my subject, and will no longer indulge these melancholy thoughts.
Some have observed, that the wonderful discoveries of the microscope ought to go hand in hand with those of the telescope; lest whilst we contemplate the many instances of the wisdom and power of divine Providence, displayed in the great works of creation, we should be tempted to conclude that man, and other less important beings of this lower world, did not claim its attention. But I will venture to affirm, without at all derogating from the merits of those who have so greatly obliged the world with the success of their microscopical enquiries, that no such danger is to be apprehended. Nothing can better demonstrate the immediate presence of the Deity in every part of space, whether vacant or occupied by matter, than astronomy does. It was from an astronomer St. Paul quoted that exalted expression, so often since repeated; “In God we live, and move, and have our being.” His divine energy supports that universal substratum on which all corporal substances subsist, that the laws of motion are derived from, and that wings light with angelic swiftness.
If the time would permit, how agreeable the task to dwell on the praises of Astronomy: to consider its happy effects as a science, on the human mind. Let the sceptical writers forbear to lavish encomiums on their cobweb Philosophy, liable to be broken by the smallest incident in nature. They tell us it is of great service to mankind, in banishing bigotry and superstition from amongst us. Is not this effectually done by Astronomy? The direct tendency of this science is to dilate the heart with universal benevolence, and to enlarge its views. But then it does this without propagating a single point of doctrine contrary to common sense, or the most cultivated reason. It flatters no fashionable princely vice, or national depravity. It encourages not the libertine by relaxing any of the precepts of morality; nor does it attempt to undermine the foundations of religion. It denies none of those attributes, which the wisest and best of mankind, have in all ages ascribed to the Deity: Nor does it degrade the human mind from that dignity, which is ever necessary to make it contemplate itself with complacency. None of these things does Astronomy pretend to; and if these things merit the aim of Philosophy, and the encouragement of a people, then let scepticism flourish, and Astronomy lie neglected; then let the names of Berkeley, and Hume, become immortal, and that of Newton be lost in oblivion.
I shall conclude this part of my discourse with the words of Dr. Barrow—It is to Astronomy we owe “that we comprehend the huge fabric of the universe, admire and contemplate the wonderful beauty of the divine workmanship, and so learn the invincible force and sagacity of our own minds, as to acknowledge the blessings of heaven with a pious affection.”
I now come, in the last place, to point out some of the defects of Astronomy at this day. Which I am induced to undertake by the hopes I entertain that some of those defects may be removed under the auspices of this society, and of you my fellow citizens, who have so zealously promoted its institution. “The advantages arising from Astronomy, the pleasure attending the study of it, the care with which it was cultivated by many great men among the ancients, and the extraordinary attention paid to it in Europe by the present age,” all contribute to recommend it to your protection, under which we have the best reason to expect that it will flourish.
The mildness of our climate and the serenity of our atmosphere, perhaps not inferior to that of Italy, and likewise our distant situation from the principal observatories in the world (whence many curious phænomena must be visible here that are not likely to be observed any where else) are so many circumstances greatly in our favour.
And I trust there will not be wanting men of genius, to arise in this new world, whose talents may be particularly adapted to astronomical enquiries. Indeed I am persuaded that nature is by no means so nigardly in producing them, as we are apt to imagine. Some are never tempted forth from obscurity, some are untimely snatched away by death, a striking instance whereof we have in Horrox; and many are accidentally led to other pursuits.
The Astronomy of comets is still in its infancy; not that the attention of the learned and ingenious has at all been wanting for more than a century past; but because it will necessarily require many ages to bring it to perfection. I wish we were in a condition to promote it in some degree, by carefully observing such comets as may appear. As yet we scarce dare affirm that any one has or will return a second time. It has never, that I know of, been certainly proved by observation, that a comet has descended within a parabolic orbit, and until that is done we have only a coincidence of periods and orbits (none of which have been very precise) to depend on for their return. Far less are astronomers able to determine the changes that may, and probably do, happen in their orbits[[A36]] and velocities in every period, so as to predict their nearer or more remote approach to the earth or any planet. Whether their business be to repair or destroy, whether they are worlds yet in formation or once habitable worlds in ruins; whether they are at present habitable and regular attendants of our Sun only, or whether they are the vast links that connect the distant parts of creation by surrounding more suns than one, we know not.
If we descend to the Planetary System, there are still many things wanting to compleat Astronomy.
The orbits of the primary planets have at one time been supposed moveable with various irregularities, at other times fixed and permanent. It seems now generally granted, that according to the theory of gravity they must change their situations; yet not long since, some great astronomers warmly contended that this change was altogether insensible.
According to the best tables we now have, the planes of the orbits of Jupiter, the Earth and Mercury are immoveable, though the orbits themselves have a progressive motion in their planes. On the contrary, the poles of the orbits of Saturn, Mars and Venus are supposed to revolve about the poles of the earth’s orbit, with such velocities as at present nearly reconcile calculation to appearances. But there is good reason to apprehend that such a supposition is not true in fact, and a mistake in this matter will have some important consequences. More probable is it, that the poles of the orbits of all the planets, the earth not excepted, revolve about some common centre. The several quantities of these motions, I am confident, are to be had from observation, and not from theory alone. If such a motion of the earth’s orbit be admitted, it will account for the diminution[[A37]] of the obliquity of the ecliptic; which seems now incontestible; and that in whatever manner we divide the forces producing such motion, amongst the two superior planets and Venus, or even amongst all of them. And I should suspect the further diminution of obliquity, from this cause, will amount to about one degree and an half.
But as Astronomy now stands, it seems doubtful whether this change is owing to a deviation in the diurnal or annual motion of the earth; which introduces a very disagreeable uncertainty in conclusions drawn from some nice and useful observations.
The Lunar Astronomy has been brought so much nearer to perfection, by the celebrated[celebrated] Mayer,[[A38]] than could have been expected, that I shall mention no deficiency in it, but this. We do not certainly know whether that apparent acceleration of the moon’s motion, which Mayer with other great astronomers has admitted, ought to be attributed to a real increase of velocity in the moon, or to a diminution of the earth’s diurnal motion. If to the former, the destruction of this beautiful and stupendous fabric, may from thence be predicted with more certainty than from any other appearance in Nature: But if to the latter, it may be prettily accounted for, by Dr. Halley’s ingenious hypotheses concerning the change of variation in the magnetical needle. The Doctor supposes the external crust or shell of the earth to contain a nucleus detatched from it, and that the impulse which first caused the diurnal motion, was given to the external parts, and from thence in time communicated to the internal nucleus, by means of an intervening fluid; but not so as perfectly to equal the velocity of the superficial parts of the globe. Whence it will follow, that the external shell of the earth is still communicating motion to the internal parts, and losing motion itself proportionably. The diurnal motion must therefore become slower and slower, yet can never be retarded, by this cause, beyond certain limits; nor can we conceive that any inconvenience will follow.
There is another physical question relating to the moon, which to me appears extremely curious; it is this—Whence is it that the moon always turns the same side to us? or, which is the same thing, How comes the moon’s rotation on her axis, and her monthly revolution about the earth, to be performed in the same time? None I believe will suppose it to be accidental, nor will the astronomer be easily satisfied with a final cause. Was it not originally brought about by a natural cause which still subsists? Can the attraction of any foreign body change a rotatory motion into a libratory one, and a libratory motion into rest, in spaces so very free from all resistance as those wherein the planets move? There are other defects in Astronomy that are purely optical. Removing of those, depends on the further improvement of telescopes, or rather on the more judicious use of them, at times and places the most favourable.
In speaking of telescopic discoveries I purposely reserved those made on Venus for this place, because they are still uncertain. Burratini in Poland first discovered spots in Venus, then Cassini in Italy; and afterwards Bianchini got a sight of them. But from all their observations it is uncertain, whether Venus revolves on its axis once in 23 hours, or once in 24 days. Perhaps it does neither. Nor is their determination of the axis’ situation much more satisfactory. These spots on Venus are not to be seen but through an excellent telescope and a pure atmosphere.
In the year 1672 and 1676 Cassini saw a small star near Venus, which he thought might be a satellite attending on her. It appeared to have the same phase with Venus. In 1740 Mr. Short with a telescope of 16 inches saw a small star at the distance of ten minutes from Venus, which from its apparent shape he likewise thought might be a satellite. And in 1761 Mr. Montaigne, in France, saw what he took to be the satellite of Venus, on the 3d, 4th, 7th and 11th of May.[[A39]] But whether Venus has a satellite or not, must still be left amongst the doubtful things of Astronomy.
The spots on the sun, and those on the surfaces of several planets, have been many years observed without our approaching any nearer towards discovering their nature and cause. Dr. Wilson of Glasgow, has lately succeeded in advancing one step at least, with respect to those of the sun. He has proved from observation that those spots are vast cavities, whose bottoms lie far below the general surface of the sun, and whose sloping sides form the border which we generally see surrounding them. If I should venture to add one conjecture of my own, to those of this ingenious gentleman, I would suppose that those prodigious cavities in the surface of the sun, some of them capable of containing half our earth, are not repeatedly formed by unaccountable explosions of a semifluid substance, but permanent and solid, like the cavities within the moon. And that it is the dark matter sometimes lodging in them, that distinguishes them, and is only accidental.
The diurnal rotations of Saturn and Mercury are yet unknown; but when further improvements shall be made in the art of using telescopes, this circumstance will hardly escape the vigilance of astronomers.
These are a few of the many things that are still left to the industry of the ingenious in this science.
But if all higher and more sublime discoveries are not reserved for us in a future and more perfect state; if Astronomy shall again break those limits that now seem to confine it, and expatiate freely in the superior celestial fields; what amazing discoveries may yet be made amongst the fixed stars! That grand phænomenon the Milky-Way seems to be the clue that will one day guide us. Millions of small stars compose it, and many more bright ones lie in and near it, than in other parts of heaven. Is not this a strong indication that this astonishing system of worlds beyond worlds innumerable, is not alike extended every way, but confined between two parallel planes, of immeasureable, though not infinite extent? Or rather, is not the Milky-Way a vein of a closer texture, running through this part of the material creation? Great things are sometimes best explained by small and small by great. Material substances, such as we daily handle, have been thought composed of impenetrable particles in actual contact: then again it has seemed necessary to suppose them at a distance from[from] each other, and kept in their relative situations by attraction and repulsion. Many appearances require that those distances should be very great in proportion to the size of the particles. Hence some, with no small reason, have concluded that matter consists of indivisible points endued with certain powers. Let us compare these smaller portions of it with that great aggregate of matter which is the object of Astronomy; Light will then appear to have as free passage through a piece of glass, as the comets have in the planetary regions; and several other new considerations will arise.
If instead of descending we ascend the scale. If we consider that infinite variety which obtains in those parts of nature with which we are most intimate: how one order of most curiously organized bodies, infinitely diversified in other respects, all agree in being fixed to the earth, and receiving nourishment from thence: how another order have spontaneous motion, and seek their food on different parts of the earth, whilst by gravity they are confined to its surface, but in other respects diversified like the former. How a third float in, and below the surface of, a dense fluid, of equal weight with their bodies, which would soon prove fatal to both the others: And a fourth consisting of a vast variety too, have this property in common, that by a peculiar mechanism of their bodies, they can soar to great heights above the earth, and quickly transport themselves to distant regions in a fluid so rare as to be scarcely sensible to us. But not to pursue this boundless subject any further, I say, when we consider this great variety so obvious on our globe, and ever connected by some degree of uniformity, we shall find sufficient reason to conclude, that the visible creation, consisting of revolving worlds and central suns, even including all those that are beyond the reach of human eye and telescope, is but an inconsiderable part of the whole. Many other and very various orders of things unknown to, and inconceivable by us, may, and probably do exist, in the unlimited regions of space. And all yonder stars innumerable, with their dependencies, may perhaps compose but the leaf of a flower in the Creator’s garden, or a single pillar in the immense building of the Divine Architect.
Here is ample provision made for the all-grasping mind of man!
If it shall please that Almighty Power who hath placed us in a world, wherein we are only permitted “to look about us and to die;” should it please him to indulge us with existence throughout that half of eternity which still remains unspent; and to conduct us through the several stages of his works; here is ample provision made for employing every faculty of the human mind, even allowing its powers to be constantly enlarged through an endless repetition of ages. Let us not complain of the vanity of this world, that there is nothing in it capable of satisfying us: happy in those wants, happy in those restless desires, forever in succession to be gratified; happy in a continual approach to the Deity.
I must confess that I am not one of those sanguine spirits who seem to think, that when the withered hand of death hath drawn up the curtain of eternity, almost all distance between the creature and creator, between finite and infinite, will be annihilated. Every enlargement of our faculties, every new happiness conferred upon us, every step we advance towards the perfection of the divinity, will very probably render us more and more sensible of his inexhaustible stores of communicable bliss, and of his inaccessible perfections.
Were we even assured that we shall perish like the flowers of the garden, how careful would a wise man be to preserve a good conscience, during the short period of his existence; because by his very constitution, which he cannot alter, this is his pride and glory, and absolutely necessary to his present happiness; because this would insure to him at the approach of death, the soothing reflection, that he was going to restore, pure and uncorrupted, that drop of divinity within him, to the original ocean from whence it was separated. How much more anxiously careful ought we to be, if we believe, as powerful arguments compel us to believe, that a conduct in this life depending on our own choice, will stamp our characters for ages yet to come. Who can endure the thought of darkening his faculties by an unworthy application of them here on earth, and degrading himself to some inferior rank of being, wherein he may find both his power and inclination to obtain wisdom and exercise virtue, exceedingly diminished? On the other hand, if that humble admiration and gratitude, which sometimes rises in our minds when we contemplate the power, wisdom and goodness of the Deity, constitutes by far the most sublimely happy moments of our lives, and probably will forever continue to do so, there cannot be a stronger incitement to the exercise of virtue and a rational employment of those talents we are entrusted with, than to consider that by these means we shall in a few years be promoted to a more exalted rank amongst the creatures of God, have our understandings greatly enlarged, be enabled to follow truth in all her labyrinths with a higher relish and more facility, and thus lay the foundation of an eternal improvement in knowledge and happiness.
[TRANSLATED FROM THE LATIN ORIGINAL.]
To the illustrious and celebrated Society of Sciences, at Philadelphia,
Christian Mayer, Astronomer to the most serene Prince, the Elector Palatine, wisheth prosperity.
I have concluded on due reflection, that the opportunity of writing, afforded me by the eminent Mr. Ferdinando Farmer, ought the less to be neglected, as by this means I might make some small return for the honour which the illustrious Society conferred on me, when they enrolled me in the list of their members.
I learnt with great pleasure, by a work printed in Philadelphia, and transmitted to me about three years since, that even there Astronomy is cultivated. That book, together with my own astronomical papers, having been destroyed by an unfortunate fire about two years ago, I have been induced to address something to your illustrious Society, concerning some of my new discoveries in the heavens.
I occupy a new Observatory at Manheim, accommodated to all astronomical purposes: nor is it deficient in any of the most valuable London-made instruments. Among these, the one which principally excels, is a mural quadrant of brass, of eight feet radius, made by that celebrated artist Bird, in the year 1776; fitted with an achromatic telescope, and firmly affixed to a wall, in the meridian; which I use daily, when the weather permits. I observed, nearly two years since, that, among the fixed stars, many of them from the first to the sixth degree of magnitude, other small attendant stars (or satellites) were distinguishable: some of which, by reason of their steady and dim light, resemble an order of planets, while others do not exceed the smallness of the telescopic size. The circumstance which principally excited my surprize, is, that I found none of those little attendant stars, a very few only excepted, contained in any known catalogue; although I could clearly discover that their use, for the purpose of determining the proper motion of the fixed stars, is very obvious. For where the difference of right ascension and declination, of a few seconds at most, is found between the brighter fixed star and its attendant, the lapse of time could scarcely give any other variation to the fixed star, than to its satellite: from what cause soever that variation may arise, whether from the precession of the equinoxes, the variation in the obliquity of the ecliptic, the deviation of the instrument, or from the aberration of light or the nutation, or from any other cause whatever, which may depend on the mutable state of the atmosphere or the latitude of places, the fact is evident, that every change of situation, observed, between the fixed star and its satellite, affords the most certain proof of its actual motion; whether this be referred to the fixed star or its satellite.
I knew that Halley, the celebrated English astronomer, was the first, who, in the year 1719, from an actual comparison of Flamstead’s observations with those of Ptolemy, respecting some few fixed stars, Syrius, Arcturus, and Aldebaran, discovered that these stars moved, with a motion peculiar to themselves: But I knew at the same time, that in Flamstead’s British Celestial History, so long ago as the year 1690, the name of attendant (or satellite) was assumed by Flamstead; when that great man had not even thought of the proper motion of the fixed stars.
Other astronomers, since the time of Halley, so far as they examined the proper motion of the fixed stars, have followed the Halleian method, in a comparison of their own observations with those of the ancients. This method requires long and laborious calculations; and continues liable to many doubts, on account of its uncertainty, as well by reason of the inaccurate nature of the instruments, as of the observations of the ancients. But this is not the case with my new method; from which, by means of the variation observed between the satellite and its brighter fixed star, it necessarily results, that the appropriate motion, either of the one star or the other, is to be attributed to it. Hence it is, that, within two years past, I have observed almost two hundred attendants of divers fixed stars; moving nearly in the same parallel, immediately before or after their respective fixed stars: and I have communicated many observations of this kind to the celebrated English astronomer, Nevil Maskelyne, who assures me they prove highly acceptable to him.
From amongst many of my observations, I transmit to your illustrious society a few, by way of specimen; the corresponding observations to which, I find in the Britannic Celestial History of Flamstead; whence at the same time it is obvious, that observations of this kind are eminently useful, for the purpose of discovering the proper motion of such stars.
[The Table, containing the Observations here referred to, will be found in the second volume of the Society’s Transactions, annexed to Mr. Mayer’s communication: he then proceeds thus, referring to that Table.]
The first and second left-hand column of the following Table are easily understood, from the title. The third column shews the difference of right ascension, in mean time, between the star and its satellite: The attendant, preceding the fixed star, is set down in the first place, in the table; the attendant, following, is placed after its fixed star. The fourth column notes the difference between the fixed star and its attendant, as I have observed it at Manheim. The letter A denotes, that the attendant is to the southward; letter B more northward. The following columns contain the observations of the same star, made by Flamstead.
It appears from the whole of the observations, that, of all the stars, Arcturus is carried with the greatest celerity, by his own motion, westward; since the same attendant, which in Flamstead’s time, on the 14th of February, 1690, preceded Arcturus 5″ in time, now enters the meridian 6″ after him. From the diminished difference also, of declination between Arcturus and his attendant, it is evident, that Arcturus progresses annually, by his own appropriate motion, nearly 2″ in a circular course, towards the south. From this it clearly results, that the declination of the attendant, as observed by me, reduced to the parallel of Greenwich, produces the same altitude of the Greenwich pole, as that deduced from Flamstead’s observation; but not so, the declination of Arcturus, observed at the present day, even with the aberration and nutation corrected.
A similar investigation may be made, with respect to the other fixed stars and their attendants; and, from the comparison already begun with other fixed stars, it may be ascertained whether an appropriate motion is to be attributed to the fixed star or its attendant, or to both.
All my observations are made in a meridienal plane with a mural quadrant, at Manheim, in his Serene Highness the Elector Palatine’s new Observatory, erected for me: its longitude, East from Greenwich, is nearly 34′ 6″, in time; its latitude, nearly 49° 27′ 50″.
It will give me very great pleasure, if I shall learn that these observations of mine do not prove unacceptable to your illustrious society: to whose goodness I most respectfully commend myself; being ever the very devoted admirer and humble servant of your illustrious and celebrated Society.
Christian Mayer,
Astronomer to his Serene Highness the Elector
Palatine and Duke of Bavaria.
Manheim, in Germany, April 24, 1778.
Letter from Mr. Rittenhouse to Professor Mayer of Manheim, in Germany.
Philadelphia, August 20th. 1779.
Sir,
I am directed by the Philosophical Society to acknowledge your letter of the 24th of April, 1778, and to return you their thanks for communicating the Observations it contains, wishing you success in further prosecuting so curious a Discovery. They likewise embrace this occasion to replace the volume of their Transactions which shared the fate of your more valuable papers.
This country having been the seat of war, our meetings have been interrupted for two years past, and the publication of a second volume thereby prevented; but as the Society is again revived, and we have materials for the purpose, it will not be much longer delayed.
You will please to accept, by this conveyance, a discourse delivered some years ago before the Philosophical Society, which I the rather present you with, because I, therein, gave my opinion that the fixed stars afforded the most spacious field for the industry of future Astronomers, and expressed my hopes that the noblest mysteries would sometime be unfolded in those immensely distant regions.[[A40]] Your excellent discovery has proved that passage to be well founded, and I shall be happy in hearing farther from you on this subject. It is unnecessary for me to suggest to you a comparison between the many Observations you have made, in order to determine whether the several changes observed will agree with any imagined motion of our system. Those you have communicated seem to favour such a supposition. I am, Sir, your most obedient and humble servant.
David Rittenhouse, Vice-President.
Some Remarks of Mr. Rittenhouse, on the famous Problem of Archimedes.[[A41]]
To the Printers of the Pennsylvania Gazette.
Philadelphia, Oct. 8th. 1767.
Gentlemen,
In your paper, No. 2017, an ingenious gentleman who signs himself T. T. has favoured the public with remarks upon that celebrated saying of the famous Syracusean geometrician: “Give me a place to stand on, and I will move the Earth.” When these remarks appeared, I was engaged in matters that would not allow me to pay that attention to them, which they deserved. The justice, however, due to Archimedes, and the respect I bear for that truly great man’s memory, oblige me now (though late) to offer my sentiments upon this interesting subject.
I readily agree with your sensible correspondent, as to the conclusion he has drawn from the principles whereon he seems to have founded his calculation, without being at the trouble to examine his numbers. All that I propose is, to place this grand mechanical problem in another light, wherein it will appear more feasible.
If a ball of earth, weighing 200 pounds, were left at liberty near the surface of this globe, it would descend, by its own gravity, about 15 feet in one second of time, and about 20 miles in 80 seconds: And if, as this gentleman supposes, there are about 2000 trillions of such balls in the whole Earth,—the Earth, by their mutual attractions, in 80 seconds of time; will move toward the ball 1/1736,000,000,000,000 of an inch; and if the same force were to act continually for 105 years, it would move about one inch. Therefore, the force wherewith a man acts, when he lifts a weight of 200 pounds, if applied without intermission for the space of 105 years, is sufficient, without any machinery, to move the Earth one inch in that time;[[A42]] and it must, from the velocity received by that force alone, continue for ever after to move at the rate of one inch in about 50 years.
A Mechanic.
Letter from Mr. Rittenhouse, to the Rev. Mr. Barton.
Norriton, July 20th. 1768.
Dear Brother,
In Hall and Sellers’ paper of last Thursday, we have some curious remarks on an Essay for finding the Longitude, lately published in the Pennsylvania Chronicle, and which I had before seen in the London papers.
The first remark is no doubt just, and is perhaps the only one made, which Mr. Wood’s essay gave just occasion for; how he could commit such a mistake, is not easy to conceive. But the remarker immediately charges him with another: for he tells us, that he (Mr. Wood I suppose) says, that Mr. Harrison’s Machines were finished about Christmas 1765; whereas his father (whether Wood’s father or Harrison’s, is not clear,) made three, which the remarker saw in motion about 18 years since. He then proceeds to assure us, (by the spirit of prophecy I presume, at least I cannot conceive how he could come by this piece of knowledge in a natural way,) that neither the father or his son will ever be able to finish their machines.
A machine, says the remarker, to measure the mean motion, will be far preferable to any other method yet proposed; and immediately afterwards he confesses, he cannot conceive that a true meridian can be found at sea, to several minutes. Now this “uncertain error” must certainly affect any other machine for that purpose, as well as Wood’s Sand-Glass, and exceed the error occasioned by turning the glass somewhat quicker at one time than another. Besides, it would not be easy to shew, why a machine to measure the Earth’s mean motion on its axis, with respect to the Sun, will be preferable to one that will measure the Earth’s true motion on its axis, with respect to the fixed Stars.
I would not be thought to recommend Wood’s project. He himself takes notice of two disadvantages attending it, viz. the wearing of the orifice through which the sand passes, and the sand itself becoming polished in time, so as to run more freely; to which if we add, that perhaps it may be greatly affected by heat and cold, there seems to be but little probability of its usefulness. Nor do I see how it can even have the merit of being new: for the scheme itself, with all the remarker’s objections that have any weight in them, must readily occur to every person that thinks at all on the subject. I shall only observe, that it appears doubtful to me, whether the remarker does not equally deserve the censure he so freely bestows on Mr. Woods—“His works are full of errors, and his writings of contradictions.”
* * * * * * * * * *
I remain your affectionate brother.
David Rittenhouse.
Dr. Rittenhouse’s Chronometer.
The construction of this Time-piece is thus described by Mr. Henry Voight, chief coiner in the Mint, heretofore an eminent clock and watch maker in Philadelphia; an artist of great ingenuity, and well known for the excellence of his workmanship. The description is given in Mr. Voight’s own words.
“The Clock which Dr. Rittenhouse made use of in his Observatory was a construction of his own. It had but three wheels in its movement, of high numbers. Only one pinion, without a wheel, driven by the main wheel; whose axis goes through the front plate, that carried the dial-work; and this wheel[[A43]] has a perpetual rochet.[[A44]] The seconds are eccentric, as in the common clocks.
“The pallet-wheel moves outside of the back-plate, and the pallets are fastened to the rod of the pendulum, which has double suspending springs fixed in a cross-bar, to which the rod is rivetted in the middle. These springs are suspended as in common; but they are not so long as in general, and have only one-and-an-half inch free action, which keeps the pendulum very steady in its vibrations.
“On the rod of the pendulum there is fixed a glass tube, of the thickness of a strong thermometer-tube, and is in the whole as long as the rod: but it is bent, about one-third upwards; like a barometer, but longer; and upon that end, on the top, the tube is as wide again as it is below, for about one-and-an-half inch in length: the other two-thirds of the length is filled with spirits of wine; and at this end, the tube is hermetically sealed. The shorter part is filled with mercury, so high as to fill the widest part of it, about half an inch, and is not sealed but remains open. The bend is close together, and there is no more space between the tubes than three-eighths of an inch.
“This tube is fastened to the pendulum-rod with common sewing-thread, and rests upon two pins fixed in the bob of the pendulum, as high up as possible. The bob has no slide, but is immoveable; and the regulation of the pendulum is performed by adding to, or diminishing the mercury, in the part where the tube is widest.”
In addition to the foregoing description of the mechanism of this Time-piece, obligingly furnished to the Writer of these Memoirs by Mr. Voight, he has been likewise favoured by Robert Patterson, Esq. director of the mint, with the following account of the same extremely accurate instrument, which will greatly assist the reader in understanding the principles on which it is constructed.
“In the Astronomical Clock made by Dr. Rittenhouse, and now in the Hall of the Philosophical Society, I do not know,” says Mr. Patterson, “that there is any thing peculiar, which requires mentioning, except the pendulum; especially the apparatus for counteracting the effects of change of temperature.
“For this purpose, there is fastened on the pendulum-rod (which is of iron or steel) a glass tube of about thirty-six inches long; bent in the middle into two parallel branches, at the distance of about an inch from each other; the bend being placed downwards, immediately above the bob of the pendulum. The tube is open at one end, and close at the other: the arm which is close at top is filled, within about two inches of the lower end or bend, with alcohol, and the rest of the tube, within about one half of an inch of the upper extremity or open end, with mercury; a few inches of the tube, at this extremity, being about twice the width of the rest of the tube.
“Now, when the heat of the air encreases, it will expand the pendulum-rod; and would thus lower the centre of oscillation, and cause the clock to go slower: but this effect is completely counteracted, by the expansion of the alcohol chiefly, and of the mercury in part; which equally raises the centre of oscillation; and thus preserves an equable motion in all the variable temperatures of the atmosphere.”
Description of an Hygrometer; first contrived and used by Dr. Rittenhouse, about the year 1782.[[A45]]
The essential part of this Hygrometer consists of two very thin strips of wood, about a foot long and half an inch broad, glued together, in such a manner that the grain or fibres of the one shall be at right angles with the other; so that when this compound strip was placed in erect position, the grain of one of the pieces of wood would have a vertical, and that of the other an horizontal position. One end of this simply constructed instrument is to be made fast to a wall, or plane board, with the edge outward, and the other end is to be at liberty to move.
Then, as moisture has little or no effect on the length of a piece of wood, or in the direction of its fibres, but a very sensible one on its breadth, or transverse direction, especially when thin, it follows, that on any increase of moisture in the air, this Hygrometer becomes bent into a curve, convex on the side of the transverse fibres; and vice versâ. The degrees, from the greatest dryness to the greatest moisture, are to be marked on a curve drawn on the board or wall, described by the motion of the free end of the Hygrometer; and an index, attached to the moving end of it, will point out, on this graduated arch, the existing state of the atmosphere at the moment, in relation to its condition of moisture or dryness: The relative degree of either, on the smallest change from the one to the other, will be indicated with much precision; and probably, with much more uniformity and truth, in the results of long-continued observations, than can be attained to by the use of Hygrometers constructed of metal, or any other substance than wood.[[A46]]
Astronomical Observations, made in the years 1776, 1777 and 1778, at Philadelphia, by the Rev. Dr. W. Smith, and David Rittenhouse, John Lukens, and Owen Biddle, Esquires: copied from a manuscript account of those Observations, drawn up by Dr. Smith; never before published.
ASTRONOMICAL OBSERVATIONS, 1776.
This year exhibiting little else but scenes of confusion and distress amidst the calamities of an unhappy war, scarce any attention was paid, by the members of the American Philosophical Society, to astronomical or any other literary subjects. It was agreed, however, by Mr. Rittenhouse, Mr. Lukens and myself, to look out whether Mercury would touch the Sun’s disc the 2d of November this year; as a very small difference of latitude from what the Tables give, would have carried the planet clear of the Sun: but, from our observation of the transit of this planet, in 1769, we had reason to expect it would pass further on the Sun, than Halley’s Catalogue gives it.
The following were the observations made, viz.
Nov. 2d, 1776. I got ready the two f. reflector with the largest object-glass, and shortest eye-tube, magnifying about 95 times.
At 4h per clock—No appearance of the planet on the Sun, and did not expect it until about half an hour past 4; but as Mr. Lukens and Mr. Rittenhouse had not yet come to me in the college, I sent to hasten them.
At 4h 5′ per clock—took my eye from the tube to adjust it, and fix the smoked glass, to give clearer vision, the atmosphere being hazy. Having fixed the smoked glass in the proper place, so as to prevent its sliding or falling with its own weight, and before I had applied my eye to the telescope again, Mr. Rittenhouse came in; and I desired him to see if the focus and dark glass were all suitable to his eye, as they were to mine. I had been about 4′ employed in this adjustment.
At 4h 9′, Mr. Rittenhouse having put his eye to the tube, immediately called out, that he saw the planet on the Sun.
At 4h 10′ per clock, we judged ☿ had entered one-third of his diameter on the Sun.
At 4h 17′, we clearly noted the internal contact of the limbs.
At 4h 45′, we judged the least distance of the nearest limbs to be rather more than one diameter of ☿; or that the distance of the limbs was 10″. We-did not apply the micrometer to make any measures; as we presumed that we could judge the distance as accurately by the eye, as it could be measured; on account of the haziness of the atmosphere and the small altitude of the Sun. We kept viewing the planet till sun-set, the distance of the limbs continuing so nearly the same, that we could scarce perceive any diminution thereof; though we were sure also, that it did increase above 10″.[[A47]]
The following were the Observations made for ascertaining the Going of the Clock, by William Smith.
| Equal Altitudes. | |||||||||
| d h | ′ ″ | h ′ \″ | |||||||
| Nov. | 3 9 | 14 9 | 2 37 12 |  | ☉ on Merid. per clock | | h ′ ″ | ||
| 15 44 | 2 35 35 | or mean noon | 11 55 40 | ||||||
| Equat. Correspond. Alt. | + 14.4 | ||||||||
| Correct Noon per Clock | 11 55 54.4 | ||||||||
| 4 9 | 32 48 | 20 56 |  | Mean Noon, or ☉ on | | 11 56 53 | |||
| 34 33 | 19 13 | Merid. per. Clock | |||||||
| 36 14 | 17 31 | Equat. of equal | + 13.8 | ||||||
| 37 20 | 16 23 | Altitudes | |||||||
| 14 39 | |||||||||
| 40 54 | 2 12 53 | Correct Noon per Clock | 11 57 6.8 | ||||||
| 7 8 | 51 9 | 9 29 | | Mean Noon | | 12 0 19 | |||
| 52 37 | 8 0 | per Clock | Equat Eq. | Alt. + 12 | |||||
| 54 1 | 3 6 37 | 12 0 19 | |||||||
| Cor. Noon | 12 0 31 | ||||||||
| per Clock | |||||||||
Per Meridian Mark.
| d | h ′ ″ | ||
| 8 | ☉ | West Limb on Merid. | 12 0 36 |
| East Limb on do. | 12 2 52 | ||
| —-—— | |||
| Centre | 12 1 44 | ||
| Correct Noon per Clock. | |||
Applied to Going of Clock.
| Nov. 3d, at Noon | ′ ″ | | |||
| Clock slower than ☉ | 4 5.6 | Daily gaining of the Clock over mean or equal time. | |||
| ☉ faster than mean time | 16 11 | ||||
| Clock faster than m. time | 12 5.4 | ||||
| 4th, | | ||||
| Clock slower than ☉ | 2 53.2 | ′ ″ | |||
| ☉ faster than mean time | 16 9 | From 3d to 4th | 1 10.4 | ||
| Clock faster than m. time | 13 15.8 | ||||
| 7th, | | ||||
| Clock faster than ☉ | 0 31 | From 4th mean to 7 that a mean per day | | 1 5.1 | |
| ☉ faster than mean time | 16 00 | ||||
| Clock faster than m. time | 16 31 | ||||
| 8th, | | ||||
| Clock faster than ☉ | 1 44 | ||||
| ☉ faster than mean time | 15 56 | From 7th to 8th | 1 9 | ||
| Clock faster than m. time | 17 40 | ||||
| Thus the Clock gains at a mean, per day, 1′ 8″. | |||||
Whence, Nov. 2d, at noon, the Clock was 10′ 57″ faster than mean time, gaining 68″ per day; and 4h 17′ gains 12″, wherefore at the internal contact, the Clock was 11′ 9″ faster than mean time.
Whence the contact was at 4h 5′ 51″ mean time; or 4h 21′ 2″ apparent time.
Eclipse of the Sun, January 9th, 1777.
The Gregorian Reflector, with the magnifying power of 95, was made use of for this Observation; which, as well as the Observation of the Transit of Mercury, was made in the College-Library, to which the Telescope belongs.
While Mr. Rittenhouse was endeavouring to adjust the two-f. reflector belonging to the Library of the city of Philadelphia, made by Short, and which had been borrowed on this occasion, I observed with the greatest certainty the first contact of ☾’s limb with the ☉, which was shining very bright, and the telescope in the best order, viz. at 8h 57′ 27″ per clock.
The same was visible, in about 3″ more, to Mr. Lukens, with the equal altitude instrument, magnifying about 25 times.
Mr. Rittenhouse had not got the other reflector ready to observe the beginning of the eclipse: but the end was observed by both of us to the same instant, viz. at 11h 48′ 50″ per clock.
The clock, at noon, was 23″ slower than mean time, whence
| Beginning of the Eclipse | 8h 49′ 55″ | | Apparent time. |
| End of the same | 11 41 15 |
N.B. The clock stopped once during the Observation, owing, it was supposed, to the cold weather; but was oiled a little, and set a going again by a stop-watch that beats seconds, and which was set with the clock at the beginning of the eclipse: so that she lost no time. She was examined at noon, and found as above by the meridian mark. But this mark itself, having been lately shaken with the stormy weather, is to be re-examined, and also equal altitudes taken the following days.
The annexed micrometer measures were taken for determining the quantity of the eclipse, chiefly by Mr. Rittenhouse. More would have been taken, but the Sun was hid under clouds for about an hour after the middle of the eclipse, and broke out again a little before the end.
Micrometer Measures.
| h | ′ | ″ | inches. | tenths. | 500ths. | ||
| 9 | 15 | 0 | 2 | 2 | 6 | | distances of the cusps. |
| 31 | 0 | 3 | 1 | ½ | |||
| 10 | 17 | 5 | 1 | 1 | 14 | | enlightened parts remaining. |
| 22 | 0 | 1 | 1 | 23 | |||
| 11 | 37 | 0 | 1 | 7 | 6 | | |
| 38 | 46 | 1 | 5 | 21 | distances of the cusps. | ||
| 42 | 26 | 1 | 2 | 18 | |||
Continuation of the Observations for adjusting the Clock.
| Jan. 11th. | ☉’s | W. limb on Merid. | | [[A48]] |
| E. limb on do. | ||||
| Centre on do. |
Whence clock faster than mean time 0 1′ 46″ per merid. mark.
| Equal Altitudes. | |||||||||||
| h | ′ | ″ | |||||||||
| 20th. | 9 | 37 | 20 | 59 | 49 | | |||||
| 39 | 1 | 58 | 6 | Mean noon per clock 12 18 34 | |||||||
| 40 | 41 | 2 | 56 | 26 | |||||||
| 21st. | W. limb on Merid. | 12 | 20 | 3 | |||||||
| E. limb on do. | 22 | 22 | |||||||||
| Centre on do. | 12 | 21 | 12.5 | ||||||||
| Eq. Alt. | |||||||||||
| 22d. | 9 | 14 | 10 | 3 | 31 | 10 | Mean noon per clock 12 23 50 | ||||
Eclipse of the Sun, June 24, 1778: Observed by D. Rittenhouse, John Lukens, Owen Biddle, and William Smith, at the College of Philadelphia.
The morning being very cloudy, the beginning of the eclipse was not seen.
At 10h 7′ 40″ per clock, the following micrometer-measure of the enlightened parts was taken, while the Sun appeared for a few minutes between clouds, viz. 1in. 9-10ths. 13-500ths. = 16′ 23″.
11h 6′ 57″ per clock end of eclipse distinctly seen, the Sun having shone clearly for several minutes, the clouds now wholly dispersing, and the remainder of the day continuing clear.
Observations upon the Clock.
| h | ′ | ″ | ||
| 27th. | ☉ on meridian per clock | 11 | 54 | 50 |
| ☉’s app. time of passing meridian | 12 | 2 | 33.5 | |
| Clock slow of app. time | 0 | 7 | 43.5 | |
| July 2d. | ☉ on meridian per clock | 11 | 54 | 50.5 |
| ☉’s app. time of passing meridian | 12 | 3 | 33 | |
| Clock slow of app. time | 0 | 8 | 42.5 |
A versification of “The Zephyrs”—from Gesner’s Idyls;—a fragment: copied from a loose scrap of paper, containing, in the hand-writing of the late Dr. Rittenhouse, all but the three last verses; which have been now added, by a lady.
First Zephyr.
Why, amidst these blooming roses,
Idly fluttering, dost thou stay?
Come with me to yonder valley,
There we’ll spend the cheerful day.
There, in purest crystal fountain,
Sportive, bathe the am’rous maids;
Where tall willows, on the margin,
Form the closest deepest shades.
Second Zephyr.
No, with thee I will not wander;
To the vale alone repair:
Fan the nymphs you so admire;
A sweeter task employs my care.
Here, in the bosom of these roses,
I cool my wings in pearly dew,
As I lightly skim them over,
Gath’ring all their fragrance too.
First Zephyr.
Your wings in dew of roses steep’d
With all their grateful fragrance stor’d;—
Can you find employment sweeter,
Than yonder cheerful nymphs afford?
Second Zephyr.
Yes, in this path, along the mount,
Each rosy morn a maid appears,
To yon lonely cot advancing,
A basket on her arm she bears.
Two tender infants, and their mother,
Are by her constant bounty fed:
A helpless widow, there residing,
From her receives her daily bread.
See! where she comes,—of all the graces,
The youngest and the fairest too;
Her cheeks, with sweetest blushes glowing,
Are moist’ned with the morning dew.
I haste, with fragrant airs, so cooling,
To fan her tender glowing cheek,—
And kiss the pearly drops, while falling
From her blue eyes, so chaste and meek.[[A49]]
First Zephyr.
Yes! much more pleasing is your task;
I would imbrue my wings in dew,
And bear the fragrance of these flow’rs,
Melinda to refresh, like you.
But see! she breaks through yonder grove,
Refulgent as a summer’s morn;
Her step is grace—her lip of rose
The smiles of modest worth adorn.
Like you, transported, let me fan her;
Like you, admire the bounteous maid:
For, sure, a fairer face I never
Spread forth my cooling wings to aid.
Diploma.
Praeses et Professores Collegii, seu Universitatis, Gulielmi et Mariæ, omnibus at quos præsentes literæ pervenerint[pervenerint], Salutem.—Cum eum in finem gradus academici majoribus nostris prudenter instituti fuerint, ut viri optimé meriti, seu in gremio nostræ matris educati, seu aliundi bonarum artium disciplinis eruditi, istis insignibus a literatorum vulgo secernerentur; sciatis, quod nos, ea sola quæ possumus viâ, gradu Artium Magistri libenter studioséque concesso, testamur quanti facimus Davidem Rittenhouse Philosophorum Principem, qui ingenio nativo Machinam celeberrimam, motus et phænomena cœlestium manifestius exhibentem, commentus est:—Idcirco, in solenni convocatione, tricessimo die decembris, Anno Domini millesimo septingentesimo octogesimo quarto, habito, conspirantibus omnium suffragiis, eundem virum egregium, Davidem Rittenhouse, Artium Magistrum creavimus et constituimus.—In cujus rei testimonium, sigillum Universitatis, quo in hac parte utimur, præsentibus apponi fecimus. Datum in domo nostræ convocationis, anno domini, die et mense, prædictis.
J. Madison, Præses, et prof. Ma. and Nat. Phil. G. Wythe, Leg. et Polit. Prof. Robertus Andrews, Math. Prof. Carolus Bellini, Neot. Ling. Prof.
Diploma.
Præses et Curatores Collegii Neo-Cæsariensis, omnibus has Literas lecturis, plurimam Satutem.
Quandoquidem æquum sit et ratione prorsus, consentaneum, ut ii qui labore et studio bonas didicerunt artes præmia suis meritis digna referant ut et ipsis benè sit, et aliorum provoceter industria.
Quando etiam huc potissimum spectant amplissima illa jura nostro Collegio publico Diplomate collata. Quumque clarissimus vir David Rittenhouse sit non tantum Moribus inculpatus et Ingenio insignis, sed et sibi tantam in Artibus liberalibus cognitionem Industria laudabili acquisivit, ut summos Honores Academicos probe mereatur.
Idcirco notum sit omnibus, quod nos, Senatus-consulto Academico nec non Facultatis Artium decreto, supradictum Davidem Rittenhouse Titulo Graduque Doctoris in Legibus adornandum, et dehinc pro Adepto et Doctore habendum volumus; cujus, hæc Membrana, Sigillo nostri Collegii rata et Chirographis nostris munita, Testimonio sit.
Datum Aulæ Nassovicæ, Pridie Calendas Octobris Anno MDCCLXXXIX.
Joannes Witherspoon, Præses. Joannes Rodgers, Joannes Bayard, Joannes Woodhull, Guls. Paterson, Isaacus Snowden, Jacobus Boyd, Joannes Beatty, Guliel. M. Tennent, Andreas Hunter, Curatores.
An English Obituary Notice of Dr. Rittenhouse: Extracted from the European Magazine, for July, 1796.
In the sixty-fourth year of his age, died David Rittenhouse, The American Philosopher. His history is curious, from the admiration in which his character was held.
Rittenhouse was a native of America; and, in the early part of his life, he mingled the pursuits of science with the active employments of a farmer and watch-maker.[[A50]] In 1769, he was invited by the American Philosophical Society to join a number of gentlemen who were then occupied in making some astronomical observations, when he particularly distinguished himself by the accuracy of his calculations and the comprehension of his mind. He afterwards constructed an observatory,[[A51]] which he superintended in person, and which was the source of many important discoveries, as well as greatly tending to the diffusion of knowledge in the western world. During the American war, he was an active assertor of the cause of independence. Since the establishment of the peace, he successively filled the offices of Treasurer of the State of Pennsylvania and Director of the National Mint; in both of which capacities, he was alike distinguished for strength of judgment and integrity of heart. He succeeded the illustrious Franklin in the office of President of the Philosophical Society; a situation which the bent of his mind and the course of his studies had rendered him eminently qualified to fill: and towards the close of his days, he retired from public life to the enjoyment of domestic happiness; when he formed a circle of private friends, who will continue to admire his Virtues as a Man, while the world will applaud his Talents as a Philosopher.
Letter from the Rev. Mr. Cathcart, to the Writer of these Memoirs.
York, 13th. Nov, 1812.
Dear Sir,
The following is a statement of the conversation which took place between Drs. Sproat and Rittenhouse, mentioned by me to Bishop White.
At a time when Dr. Rittenhouse was confined by sickness to his room, or perhaps to his bed,[[A52]] he sent for the Rev. Dr. Sproat to visit him. The Doctor was somewhat surprised, on receiving the message: but as he had made it an uniform rule to visit all who sent for him, he expressed his surprise at being sent for; observing, that he could offer no comfort or consolation to any person, who was not a Believer in the Christian Religion. On hearing this declaration, Dr. Rittenhouse immediately asked, if Dr. Sproat considered him among the number of such? To which the Doctor answered; that the world had generally classed him with them. Dr. Rittenhouse on hearing this, with great mildness and a smile on his countenance, replied, that the opinion of the world was sometimes wrong; and, as it respected himself, he could with truth declare, that ever since he had examined Christianity and thought upon the subject, he was a firm believer in it; and, that he expected salvation only in the way and manner, as proposed in the Gospel.
The above is the substance of what Dr. Sproat mentioned to myself; and I might add, that when the good old man told it, his eyes overflowed with tears of joy. It gives me pleasure to be able to furnish you with this satisfactory proof of Dr. Rittenhouse’s faith; and which I once introduced into a sermon preached in the city, as justice due to the character of the deceased, and who had been triumphantly claimed by the Infidels. I am happy to find that you are engaged in the laudable business of[of] writing the Life of that worthy Man. Yours, respectfully,
Robert Cathcart.
William Barton, Esquire.
Character of Dr. Rittenhouse:
Communicated to the Author of the Memoirs of his Life, in a letter from Andrew Ellicott, Esq.
Lancaster, December 30th, 1812.
Dear Sir,
I felt no small degree of pleasure and satisfaction, on understanding that you are about publishing Memoirs of the Life of Dr. Rittenhouse; knowing, from your connexion, and intimacy with him for many years, you have it in your power to delineate, and transmit his true character and a knowledge of his rare virtues to posterity, with as much, if not more accuracy than any other person. As I also have had the pleasure and advantage of Dr. Rittenhouse’s acquaintance and friendship, I request you to accept of the following short sketch of his character, as a small testimony of my esteem for him when living, and of my veneration for his memory, now he is no more. I am, dear Sir, your sincere friend,
Andrew Ellicott.
William Barton, Esq.
I became acquainted with the late Dr. Rittenhouse, in the sixteenth year of my age, being first introduced to him, after he removed to the city of Philadelphia, by the late Joseph Galloway, Esq. and my Father; both of whom were sincerely attached to him, not only on account of his scientific talents and acquirements, but for his public and private virtues. From that period, to the end of his life, we enjoyed an uninterrupted friendship.
In my scientific pursuits, I was frequently aided by him; particularly, in that part which relates to Astronomy, with which he was better acquainted, both in theory and practice, than any other person in this country; and when he ceased to calculate the Almanacks for the middle states, at his request I continued them several years.
In the years 1784 and 1785, Dr. Rittenhouse and myself were engaged in determining the boundaries between this commonwealth and the state of Virginia; and in the year 1786, in determining the boundary between this commonwealth and the state of New-York. In those arduous employments, I had many opportunities of witnessing his address in overcoming the numerous difficulties we necessarily had to encounter, in the then wilderness, in which our operations were performed.
As a gentleman of general science, Dr. Rittenhouse would have held a respectable rank in any country; but as a Mechanist and Astronomer, he has had but few equals. It has been frequently asked,—why he has not left more evidences of his talents, for the use of posterity? In answer to this question, it is to be observed, that almost from his childhood, he had a complaint in his breast; which increased so much with his age, that for the last fifteen years of his life,—and in which he had the most leisure for composition,—it was painful for him to support the position a person must occupy, when writing. This circumstance I have frequently heard him lament, in a feeling manner; as it prevented him from answering letters with promptitude, and writing to his friends as often as he wished.
Though Dr. Rittenhouse had not the advantage of a liberal education, he wrote not only correctly but with ease: he made himself master of the German language, to which he was partial: and of the French, so far as to read the scientific works in that tongue, with facility.
As an Husband, and a Father, he might be taken as an example and a pattern, in the most virtuous community that ever existed. He was a good Citizen,—and warm and sincere in his friendships; and though reserved in large mixed companies, he was cheerful and communicative, when in a small circle of his friends. His mind appeared formed for contemplation, and therefore not calculated for the noisy and busy scenes of this world: from this placid turn of mind, he had a singular antipathy to all mobs and riots; and I recollect to have heard him speak of the riots of the Paxton-boys, (as they were called,) with greater acrimony than on any other occasion,—more than twenty years after they happened. Being a philanthropist by nature, he wished the happiness and welfare of the whole human race; and viewed slavery, in all its forms, with feelings of horrour: from this attachment to the happiness, the rights, and the liberty of his fellow-creatures, he was led to take an active and useful part in favour of our revolution, which separated the colonies (now the United States,) from the mother-country.
His contemplative mind naturally carried him to piety; but his liberality was so great, that he did not appear to give a very decided preference to any one of the sects into which Christianity is divided: he practised the morality of a sincere Christian, without troubling himself about the dogmas of the different churches.
His manners were plain and unassuming, though not without a sufficient share of dignity; and, from a consciousness of his own talents, he did not envy those of others.
It has too frequently happened, for the honour of science and literature, that men of great and commanding talents, have been obstinately dogmatical, and impatient of contradiction;—of those blemishes, Dr. Rittenhouse had not the least tincture.
To conclude,—if Dr. Rittenhouse was not the greatest man, of the age, his character has fewer blemishes in it; and, if his talents were not of that kind which are usually considered the most brilliant, they were—like those of Washington—of the most solid and useful order.
Some particulars concerning the Residence, the Tomb, &c. of Copernicus: communicated to the late Dr. Rittenhouse, Pres. A. P. S. by the Earl of Buchan.
“In the year 1777,” says his Lordship, “my learned friend John Bernouilli, of Berlin, on one of his tours having happened to meet with the Bishop of Warmia,[[A53]] in the Abbey of Oliva, near Dantzic, was informed by that prelate, that he had the pleasure to discover, in the Cathedral of Frauenburg, the Tomb of Copernicus, so long fruitlessly sought for.
“In the year 1778, Mr. Bernouilli having occasion to pass through Frauenburg, on his road to St. Petersburg, did not fail to visit the Cathedral, and explore the Monument of Copernicus. Acquainted with no one in the place, he was yet lucky enough to meet with a Canon, in the street, whose countenance invited him to accost him on this subject, and who proved very attentive to his researches. He informed him, that as for the Ashes of Copernicus, they were mingled in the charnel-house with the bones of the fraternity of the Canons; but that, for the Tombstone of the Philosopher, it was no more than a tablet of marble, simple, as the mode was of his days, and had no other inscription than these words—Nic. Copernicus, Thor:—-That this tablet had remained hidden for some time, in rubbish; and when recovered, was placed in the chapter-house, till a more suitable place should be destined for it. Mr. Bernouilli expresses his regret to me, that he had not urged the Canon to indulge him with a sight of this Stone; and to look for a further inscription, to support the assertion of Gassendi, who mentions (page 325), That the Bishop Martin Cromer, an eminent Polish historian, caused a mural marble monument to be inscribed and erected to the memory of Copernicus, with the following inscription:
D. O. M.
R. D. NICOLAO COPERNICO,
Torunensi, Artium et
Medicinæ Doctori,
Canonico Warmiensi,
Præsenti Astrologo, et
Ejus Disciplinæ
Instauratori;
Martinus Cromerus,
Episcopus Warmiensis,
Honoris, et ad Posteritatem
Memoriæ, Causâ, posuit;
M. D. L. X. X. X. I.
“Gassendi adds, that this Monument was not erected until thirty-six years after the death of Copernicus, which does not agree with this date of 1581.
“The good Canon informed Bernouilli, that he was lodged in the apartment of Copernicus, of which he was very proud; and invited the Prussian Philosopher to visit him in that place, which he accordingly did; and was shewn by the Canon another place, above the Dormitories, which had been used by Copernicus as his study and observatory, in which the Canon had a portrait of that eminent man, concerning the original of which he would not say. This little Observatory had an extensive view; but when Copernicus had occasion for one more extensive, he was wont to observe on the gallery of the steeple, which communicates with this place.
“Charmed with these classic footsteps, Bernouilli forgot to look at the Monument on the chapter-house, above mentioned. In a repository adjoining to the Cathedral, the Canon shewed Bernouilli the remains of a hydraulic machine said to have been invented and used by Copernicus. The construction seemed interesting, but in great disrepair; and Bernouilli had not leisure to examine it particularly. The use of the machine was to force and convey water into the most elevated apartments of the house of the Canons, who are now under the necessity of having it fetched from a distance, from the lower Town.”
“I remember to have seen (says Bernouilli), in some old German Journal, that the Library of the ancient town of Konigsberg contained some books, chiefly mathematical, which were part of the Library of Copernicus; and also his Portrait, which had been purchased at Thorn, where the remains of his family still possessed the house in which he was born, as late as the year 1720. In P. Freher’s Theatrum Virorum eruditorum, there is a Chronostick on the year of Copernicus’s death, 1543. p. 1447.
eX hoC eXCessIt trIstI CopernICVs eVo,
IngenIo astronVM et CognItIone potens.
“In the above mentioned book, p. 1442, there is a neat little Print of Copernicus. In Hartknoch’s Alter und newes Preusen, here is a print of Copernicus, from a picture on wood which hangs in what they call his Cenotaph, at Thorn; and which represents him kneeling, in his canonicals, before a Crucifix;—and below this portrait are these sapphic verses:
Non parem Pauli gratiam requiro,
Veniam Petri neque posco; sed quam
In Crucis ligno dederas sationi,
Sedulus oro.
(a little lower)
Nicolao Copernico, Thoruniensi, absolutæ subtilitatis mathematico, ne tanti viri apud exteros celeb. in sua patria periret memoria, hoc monumentum positum.
Mort. Varmiæ, in suo Canonicatu, Anno 1543—
die 4 + ætatis LXXIII.
(lastly, lowest.)
Nicolaus Copernicus, Thoruniensis, Mathematicus celeberrimus.
“This Monument of Copernicus was erected by Melchior Pyrnesius, M. D., who died in 1589.
“On the same altar-piece, or picture, is represented the portrait of John D’Albert, with the following inscription.
Illustris Princeps Dn. Joh. Albertus, Polo. Rex, apoplexiâ hic Thoru. mortuus, Anno 1501, die 17 Maii, ætat. 41; cujus viscera hic sepulta, Corpore Craco translato; Reg. Ann. VIII.
“Upon the whole,” concludes Lord Buchan, “it appears the likeness I send, of Copernicus, is most to be depended on; and, as such, I flatter myself it will be an Heir-loom to infant America! Concerning Napier, it is needless for me to enlarge; the learned Dr. Minto having enabled me to do justice to his memory.”
Although the following particulars respecting Dr. Rittenhouse were not communicated by the writer, Professor Barton, until it was too late to give them a place in the body of the work, the Author nevertheless is glad to have an opportunity of presenting to the public, even at the close of his book, the interesting circumstances this communication contains.
As Optics were one of his favourite studies, so he at one time contemplated a course of public, and I think popular, lectures on this beautiful and important branch of physics. On this subject he mentioned to me his intention in the winter of 1785-1786. The enthusiasm, indeed, with which he developed his design, and I may add the warmth of zeal with which his manner at the time inspired me, I can never forget. And, indeed, I cannot but regret, that our excellent friend never made his appearance in publick, as a LECTURER. As such, he would, unquestionably, have greatly advanced the love and the knowledge of natural philosophy in the United-States. He may, perhaps, have wanted some of the qualifications of a popular teacher. He would not have aspired to finished eloquence of style: to the eloquence of gesture and of manner, he was still more a stranger. But there is an eloquence of physiognomy, which Mr. Rittenhouse most eminently possessed. The modesty and amenity of his manner would have effected much, whether his audience had been a class of philosophers, or an assembly of ladies. Of his own discoveries, and opinions, and theories, he would have always spoken with that sweet and modest reserve, for which he was ever distinguished. He would have dwelt with the most generous and ample enthusiasm upon the great discoveries of Newton; and if, at any time, he could have forgotten that impartial conduct, which it is the duty of the historian of a science to observe, it would have been when he might have had occasion to defend the theories of that great man, against the objections of succeeding and minor philosophers.
In Physics, Newton was his favourite author. Of HIM he ever spoke with a species of respect bordering upon veneration. He considered him as one of those few great leaders in science whose discoveries and services can never be forgotten: whose fame, instead of diminishing, is destined to be augmented, with the progress of time. I had many opportunities of being witness to the exalted opinion which he entertained of the immortal British philosopher. He read Dr. Bancroft’s objections to some parts of Sir Isaac’s theory of colours, with a firm conviction, that the Newtonian principles were still unshaken: and I well remember, that he once referred me to a paper which he had published, in one of our magazines, in answer to some objections which the late Dr. Witherspoon had urged against some of the theories of Newton.
It has been observed by a celebrated writer, that mathematicians in general read but little of each other’s works. This remark, if I mistake not, is very strongly illustrated in Mr. Rittenhouse. However it may have been in his earlier age, I am confident that during the last thirteen years of his life, when my intercourse with him was great, and indeed but little interrupted; I am confident, that at this matured and auspicious era of his life, our friend was not a laborious student. He looked into many books, and he often passed quickly from one kind of reading to another: from philosophy to poetry; from poetry perhaps to philosophy again. His reading may be said to have been desultory. I have little doubt that this rather irregular manner of reading was, in some measure, the result of his extreme delicacy of constitution, which rendered a more unvaried application to any one kind of reading, irksome and oppressive. Often have I seen him lay down his book or pen, to recline upon his sopha, the circumscribed flush upon his cheeks plainly indicating the physical state of his feelings. A short repose would enable him to return to his studies again.
Mr. Rittenhouse’s application to books, had, no doubt, been more regular and constant in the earlier part of his life; before I knew him well, or before I had accustomed myself to watch the progress of his mind. He was, certainly, profoundly, acquainted with the Principia and other writings of Newton, which he read partly in the original, and partly through the medium of translation. And although, within the period of my better acquaintance with him, his reading I have said, was not intense, he suffered no important discovery in philosophy to escape his notice. Although his own library was small, he had ample opportunities, through the medium of the valuable library belonging to the Philosophical Society, and other collections in Philadelphia, of observing the progress of his favourite studies in Europe. He took much interest in the discoveries of Mr. Herschel, whose papers he eagerly read as they arrived from Europe: and I well remember the time (in 1785) when he was engaged in reading Scheel’s work on Fire, which had recently appeared, in an English dress. He then assured me, that some of this great Swedish philosopher’s notions concerning the nature and the laws of heat, had long before suggested themselves to his mind.
The chemical discoveries of Crawford and Priestley solicited some of Mr. Rittenhouse’s attention, about the year 1785-1786, and for some time after. The brilliant discoveries of Priestley, in particular, were not unknown to him. Upon the arrival of this illustrious philosopher in Philadelphia, in 1794, Mr. Rittenhouse stood foremost among the members of the Philosophical Society in publicly welcoming the exiled philosopher to the country which he had chosen as the asylum of his declining years; and in expressing his high sense of his estimable character, and of the vast accessions which he had brought to science. I often met Dr. Priestley at the house of our friend. Their regard for each other was mutual. It is to be regretted that their immediate intercourse with each other could not be more frequent. Priestley had unfortunately chosen the wilderness, instead of the capital or its vicinity, as his place of residence: and Rittenhouse, alas! did not live two years after the arrival of Priestley in America.
On the death of Mr. Rittenhouse, Dr. Priestley wrote me a letter of condolence on the great loss which the publick had sustained; on the irreparable loss which I, in particular, had suffered. When the Doctor afterwards returned from Northumberland to Philadelphia, he discovered much solicitude to know from me Mr. Rittenhouse’s religious sentiments, and the manner and circumstances of his death; and he evinced no small satisfaction in receiving from me that relation which I have already given you, of the last hours, and of the last words, of one of the best of men.
Mr. Rittenhouse had not studied natural history as a science: but to some of the branches of this science he had paid particular attention; and upon some of them he was capable of conversing with the ablest, and the most experienced. In Botany, he was not acquainted with the scientific or classical names: but the habits, and in many instances, the properties of plants were known to him. I well recollect how great were his pleasure and satisfaction, in contemplating the Flora of the rich hills of Weeling, and other branches of the Ohio, when I accompanied him into those parts of our union, in the year 1785. In this wilderness, he first fostered my love and zeal for natural history. Upon his return from the woods, in the month of October, he brought with him, as ornaments to his garden, many of the transmontain plants of the state of Pennsylvania: and long before I knew that it grew wild in the vicinity of Philadelphia, upon the banks of his native Schuylkill, he had naturalized in his garden, the beautiful Silene virginica, which he designated with the name of “Weeling Star.”
It is a fact, that in the last months of his life he devoted a good deal of his time to an examination of the structure of the most important organs of plants. Acquainted with that doctrine which forms the basis of the sexual system, he was fond of examining plants during the period of their inflorescence: and I remember, with what apparent pleasure, he pointed out to me the tube in the styles of some of the plants which grew in his garden.
He had made many observations upon the buds of trees, some of which I think were new. I regret that the memorandums which he kept of these observations have not been found among his papers.
Not fifteen days before his death, he had finished the perusal of a German translation of Rousseau’s beautiful letters on Botany, which I had put into his hands.
Mr. Rittenhouse, like Newton and many other men of great talents, employed much of his time in the perusal of works on the subject of natural and revealed religion. This was, I think, more especially the case in the latter part of his life. Among other books which I could mention, I well recollect that he read the Thoughts of the celebrated French philosopher Pascall: and he acknowledged, that he read them with pleasure. But that pleasure, he observed to me, was diminished, when he learned, what was often the state of Pascall’s mind:—a state of melancholy and gloom: and sometimes even of mental derangement. At the time of his death, the American Philosopher was engaged in the perusal of Mosheim’s Ecclesiastical History: and he had just before finished the perusal of the Meditations of the Emperor Marcus Antoninus; that excellent work, replete with the sublimest morality, and with much of a sublime religion.
About three weeks before his death, I had put into his hands the first volume of Dr. Ferguson’s Elements of Moral and Political Science. I took the liberty of particularly directing his attention to the last chapter of the volume: the chapter on the future state. He read it with so much satisfaction, that he afterwards sent it to his elder daughter, with a request that she would peruse it.
The benevolent dispositions of our friend were well known to you. You have, doubtless, done justice to this portion of his character; yet permit me to mention a few detached facts, which have came under my own immediate notice, and the relation of which may serve to augment even your respect and veneration for Mr. Rittenhouse.
The year 1793 is memorable in the history of Philadelphia. During the prevalence of the yellow fever, in the summer of that year, Mr. Rittenhouse wrote to me a note requesting me to visit a number of poor people, in his vicinity, labouring under the malignant fever; and making it a condition of my attendance upon them, that I should charge him for my services.
In the month of March of the same year, I had a good deal of conversation with Mr. Rittenhouse, on the subject of penal laws. He did not think that the late judge Bradford, whose essay on this subject he greatly admired, and recommended to my perusal, was too lenient in his views of the subject. He observed, that although he had often served on juries, he thanked God, that he never had in any case where life and death were immediately involved; observing, that his conscience would ever reproach him, if he had, in any instance, given his verdict for death. “Of all murders (he added) legal murders are the most horrid.” He did not think that death ought to be the punishment for any crime.
The union of sensibility with benevolence is frequently observed. The sensibility of Rittenhouse was exquisitely nice; perhaps, I might say, it was somewhat morbid. In a conversation which I had with him on the subject of the analogies between animals and vegetables, when I had observed to him, that the further we push our inquiries into this interesting subject, the more reason we have for supposing, that those two series of living beings constitute, as many eminent naturalists have supposed, but one vast family, he said it appeared so to him, but he hoped it would never be discovered that vegetables are endowed with sensibility. “There is, he observed, already too much of this in the world.”
His religion was sublime and pure. It had no tincture of superstition or credulity. Accustomed, from an early period of his life, to contemplate the largest and the smallest objects of Creation; and with respect to the former to view their arrangement and harmony in the construction of a system of immeasurable extent; in these objects and in these places, he beheld one of the revelations of our Creator. He could not be insensible of the ills, infirmities, and miseries of human life, and even of the life of inferior animals. But still he discovered, as he often observed to me, the existence and even the dominion of much benevolence through the world. He was wont to consider our benevolent dispositions, and our virtuous affections, as among the strongest proofs of the existence of a Creator. These dispositions, these affections, and our intellectual powers, are the genuine emanations of a God.
Benjamin Smith Barton.
Philadelphia, December, 1813.
Letter from Lady Juliana Penn to the Rev. Peter Miller, Ephrata.
Septr. 29th. 1774.
Sir,
Your very respectable character would make me ashamed to address you with words merely of form. I hope therefore you will not suspect me of using any such, when I assure you I received the favour of your letter with very great pleasure. And permit me, sir, to join the thanks I owe to those worthy women, the holy sisters at Ephrata, with those I now present to you, for the good opinion you, and they, are pleased to have of me. I claim only that of respecting merit, where I find it; and of wishing an increase in the world, of that piety to the Almighty, and peace to our fellow-creatures, that I am convinced is in your hearts: and, therefore, do me the justice to believe, you have my wishes of prosperity here, and happiness hereafter.
I did not receive the precious stone, you were so goad to send me, till yesterday. I am most extremely obliged to you for it. It deserves to be particularly distinguished on its own, as well as the giver’s account. I shall keep it with a grateful remembrance of my obligations to you.
Mr. Penn, as well as myself, were much obliged to you for remarking to us, that the paper you wrote on, was the manufacture of Ephrata: It had, on that account, great merit to us; and he has desired our friend, Mr. Barton, to send him some specimens of the occupation of some of your society. He bids me say, that he rejoices to hear of your and their welfare.
It is I that should beg pardon for interrupting your quiet, and profitable moments, by an intercourse so little beneficial as mine; but trust your benevolence will indulge this satisfaction to one who wishes to assure you, sir, that she is, with sincere regard, your obliged and faithful well-wisher,
Juliana Penn.
Mr. Peter Miller, President of the Cloister at Ephrata.
To the Memory of the Honourable Thomas Penn, Esq. who died March 21. 1775.
Peace, worthy shade! Peace to thy virtuous soul;
Life’s contest past, thou now hast gain’d the goal,
Destin’d for honest innate truth, like thine,
Where moral goodness rises to divine.
True to thy friendship, sacred to each trust,
In every duty most exactly just:
A princely wealth fill’d not thy heart with pride,
Thou nobly cast the glitt’ring bait aside;
Made it subservient to some useful aim,
Some gen’rous purpose, or some proper claim:
As bounteous streams in pleasing currents glide,
It roll’d, refreshing, like some charming tide;
Cheer’d the lone widow in her humble dome,
And scatter’d comfort o’er her lonely home.
Thy guardian angel snatch’d thee from below,
E’er Pennsylvania was consign’d to woe:
Thou now may’st view, without one kindred tear,
What we deem harsh, oppressive and severe;—
Life’s motley picture, at one view, may’st scan,—
Unwind its tangled, complicated plan,—
Where this great truth is clearly understood,
That “partial evil’s universal good.”
In broken parts, man the dark system spies,
While all lies open to celestial eyes;
The links, united, of our scatter’d chain,
Shew why Penn suffer’d tedious years of pain,—
Shew why one patient virtuous mind doth mourn,
And why sweet Peace is from a people torn.
For, individuals of earth’s humble vale
Mount, in gradation, on a heav’nly scale:
Yet Virtue, only, has a charm in death;
Wealth droops his plumes, as man resigns his breath;
Its social merits can’t ascend the skies,
Terrestrial substance can’t to heav’n arise;
Too gross to enter the abodes divine,
In earthly darkness it can only shine.
Letter from General Washington to the Writer of these Memoirs.
Mount Vernon, Sep. 7th. 1788.
Sir,
At the same time I announce to you the receipt of your obliging letter of the 28th of last month, which covered an ingenious essay on Heraldry, I have to acknowledge my obligations for the sentiments your partiality has been indulgent enough to form of me, and my thanks for the terms in which your urbanity has been pleased to express them.
Imperfectly acquainted with the subject, as I profess myself to be; and persuaded of your skill, as I am; it is far from my design to intimate an opinion, that Heraldry, Coat-Armour, &c, might not be rendered conducive to public and private uses, with us,—or, that they can have any tendency unfriendly to the purest spirit of Republicanism: on the contrary, a different conclusion is deducible from the practice of Congress and the States; all of which have established some kind of Armorial Devices, to authenticate their official instruments. But, sir, you must be sensible, that political sentiments are very various among the people in the several states; and that a formidable opposition to what appears to be the prevailing sense of the Union, is but just declining into peaceable acquiescence. While, therefore, the minds of a certain portion of the community (possibly from turbulent or sinister views) are, or affect to be, haunted with the very spectre of innovation;—while they are indefatigably striving to make the credulity of the less-informed part of the citizens subservient to their schemes, in believing that the proposed General Government is pregnant with the seeds of Discrimination, Oligarchy and Despotism;—while they are clamourously endeavouring to propagate an idea, that those whom they wish, invidiously, to designate by the name of the “well-born,” are meditating in the first instance to distinguish themselves from their compatriots, and to wrest the dearest privileges from the bulk of the people; and while the apprehensions of some, who have demonstrated themselves the sincere, but too jealous, friends of Liberty, are feelingly alive to the effects of the actual Revolution and too much inclined to coincide with the prejudices above described,—it might not perhaps be advisable to stir any question that would tend to reanimate the dying embers of faction, or blow the dormant spark of jealousy into an inextinguishable flame. I need not say, that the deplorable consequences would be the same, allowing there should be no real foundation for jealousy: (in the judgment of sober reason,) as if there were demonstrable, even palpable, causes for it.
I make these observations with the greater freedom, because I have once been a witness to what I conceived to have been a most unreasonable prejudice, against an innocent institution: I mean, the Society of the Cincinnati. I was conscious that my own proceedings on that subject were immaculate. I was also convinced, that the members,—actuated by motives of sensibility, charity and patriotism,—were doing a laudable thing, in erecting that memorial of their common services, sufferings and friendships;—and I had not the most remote suspicion, that our conduct therein would have been unprofitable, or unpleasing to our countrymen. Yet have we been virulently traduced, as to our designs: and I have not even escaped being represented as short-sighted, in not foreseeing the consequences,—or wanting in patriotism, for not discouraging an establishment, calculated to create distinctions in society and subvert the principles of a republican government. Indeed, the phantom seems now to be pretty well laid; except on certain occasions,—when it is conjured up, by designing men, to work their own purposes upon terrified immaginations:—You will recollect there have not been wanting, in the late political discussions, those who were hardy enough to assert, that the proposed General Government was the wicked and traitorous fabrication of the Cincinnati!
At this moment of general agitation and earnest solicitude, I should not be surprised to hear a violent outcry raised, by those who are hostile to the New Constitution, that the proposition contained in your paper had verified their suspicions, and proved the design of establishing unjustifiable discriminations. Did I believe that to be the case, I should not hesitate to give it my hearty disapprobation. But I proceed on other grounds:—Although I make not the clamour of credulous, disappointed, or unreasonable men, the criterion of Truth; yet, I think, their clamour might have an ungracious influence at the present critical juncture: and, in my judgment, some respect should not only be paid to prevalent opinions,—but even some sacrifices might innocently be made to well meant prejudices, in a popular government. Nor could we hope the evil impression would be sufficiently removed, should your Account, and Illustrations, be found adequate to produce conviction on candid and unprejudiced minds.
For myself, I can readily acquit you of having any design of facilitating the setting up an “Order of Nobility:”—I do not doubt the rectitude of your intentions. But, under the existing circumstances, I would willingly decline the honour you have intended me, by your polite Inscription; if there should be any danger of giving serious pretext (however ill-founded in reality) for producing or confirming jealousy and dissention, in a single instance; when harmony and accommodation are most essentially requisite to our public prosperity,—perhaps, to our national existence.
My remarks, you will please to observe, go only to the expediency, not to the merits of the proposition: what may be necessary and proper hereafter, I hold myself incompetent to decide; as I am but a private citizen. You may, however, rest satisfied, that your composition is calculated to give favourable impressions of the science, candour and ingenuity, with which you have handled the subject; and that, in all personal considerations, I remain with great esteem, Sir, your most obedient and most humble servant,
Go. Washington.
Wm. Barton, Esq.
Dr. Benjamin Rush.
The foregoing Memoirs were entirely completed and prepared for the press, before the decease of this Professor occurred; as is mentioned in the preface.
Benjamin Rush was born in the county of Philadelphia, on the twenty-fourth day of December, 1745, O.S. Having graduated in the Arts at Princeton College, in the autumn of the year 1760, and afterwards studied medicine under the direction of the late John Redman, M. D. of Philadelphia, he completed his medical education at the University of Edinburgh; where he received the degree of Doctor in Medicine, in the spring of 1768. Returning to Philadelphia in the summer of 1769, he was, on the 31st of July, in that year, appointed Professor of Chemistry, in the College of Philadelphia; that chair having been supplied for some time before, by the late John Morgan, M. D. F. R. S. &c. About twenty years after this appointment (viz. in 1789), he succeeded Dr. Morgan in the Professorship of the Theory and Practice of Physic, in the same College: and in the year 1791, on the union of that College with the University of Pennsylvania, he was chosen Professor of the Institutes and Practice of Physick, &c. in the conjoint institution.
At divers times, and on various occasions, his talents were employed in affairs of political concern. Besides having held, at different[different] periods, several other public stations, he was appointed a member of Congress for Pennsylvania, on the 20th of July, 1776: when he, together with some of his colleagues, appointed at the same time, subscribed the Declaration of American Independence; which great national act had received the sanction of congress, and been generally signed by the members, sixteen days before.
He died of a typhus fever, in Philadelphia, on the 19th day of April, 1813; being then advanced a few months beyond the sixty-seventh year of his age.
At the time of his decease, Dr. Rush was Professor of the Institutes of Medicine, of the Theory and Practice of Physic, and of Clinical Medicine, in the University of Pennsylvania: to which chair, vacated by his death, Dr. Benjamin Smith Barton, Professor of Materia Medica, Natural History and Botany, in the same institution, was elected in the month of July, 1813.
FINIS.
[A1]. The reader will find a very learned and interesting dissertation on the astronomy of these and other nations of antiquity, in Lalande’s Astronomie, liv. ii. W. B.
[A2]. Our orator might well pass on, without noticing more particularly the fabulous annals of the Chaldeans. They assigned to the reigns of their ten dynasties, 432 thousand years: and Lalande observes, that this number, 432, augmented by two or by four noughts, frequently occurs in antiquity. This prodigious number of years expresses, according to the notions of the inhabitants of India, the duration of the life of a symbolical cow: in the first age, this cow, serving as a vehicle for innocence and virtue, advances with a firm step upon the earth, supported by her four feet; in the second, or silver age, she becomes somewhat enfeebled, and walks on only three feet; during the brazen, or third age, she is reduced to the necessity of walking on two; finally, during the iron age, she drags herself along; and, after having lost, successively, all her legs, she recovers them in the succeeding period, all of them being reproduced in the same order.
The Bramins thus make up their fabulous chronological account of the age of the world; viz.
| The duration of the first age, | 1,728,000 | years |
| The second | 1,296,000 | do. |
| The third | 864,000 | do. |
| The fourth will continue | 432,000 | do. |
| Making the total duration of the world | 4,320,000 | years. |
Mr. Lalande remarks, that these four ages have a relation to the numbers 4, 3, 2, 1, which seem to announce some other thing than an historical division. Therefore, to give this fabulous duration of the world some semblance of truth. Mr. Bailly[[A2a]] rejects, in the first place, the fourth age, of which, at present, (that is, when Lalande wrote,) only 4887 years have passed: the residue of this duration could not be considered by Bailly as any thing more than a reverie: and as for the three first ages, he takes the years for days; in order to shew, that, in reality, they reckoned by days, before they computed by solar years. By these means, Bailly has reduced the pretensions of the people of India to 12,000 years; and he identifies this calculation for the Indians with that of the Persians, who give, likewise, 12,000 years for the duration of the world. The accordance thus produced in the two chronologies, seemed to Bailly to strengthen the authenticity of the recital; and makes it appear, that these notions prevailed alike among the Egyptians and the Chinese.
Such are the data, such the calculations, and such the reasoning of Mr. Bailly, on this subject.
But, although Mr. Lalande has noticed the retrograde series of the progressive numbers (1,) 2, 3, 4, in the Asiatic account of the age of the world, a kind of mysterious constitution of the amount of the years, in the several ages which make up the entire sum of its duration, seems to have escaped the observation of that acute philosopher; and probably the same circumstance passed also unnoticed by Mr. Bailly: it may be considered as a species of chronological abracadabra, engendered in the prolific brain of some eastern philosopher: the following is the circumstance here meant. It will be perceived, in the first place, that the arrangement of the numerical figures, in making up the years allotted to the fourth age of the world, is apparently artificial, and therefore, probably, altogether arbitrary. It will then be seen, that the number of years in the third age is double the amount of those in the fourth; that those in the second is made up by adding together the years in the fourth and third ages; and, that those in the first age are constituted by an addition of the number of years in the fourth and second ages. This being the fact, it does not seem to bear out Mr. Bailly, in his hypothesis, and the calculations founded on it. W. B.
[A2a]. Mr. Bailly was the author of a History of Ancient and modern Astronomy. His Essay on the Theory of Jupiter’s Satellites, which is said to be a valuable treatise, was published in the year 1766. Both works are in the French language, and were printed in France.
[A3]. Lalande observes that Mr. Bailly has gone back, in his astronomical researches, to the first traditions of an antedeluvian people, among whom there remained scarcely any traces of such knowledge; and that he has presented us, in his work, with ingenious conjectures and probabilities; or, more properly, appearances of truth, (“vraisemblables,”) written with many charms of extensive information. But, according to Mr. Lalande himself, all the ancient astronomy down to the time of Chiron, which was about fourteen centuries before the Christian era, may with probability be reduced to the examining of the rising of some stars at different times of the year, and the phases of the moon; since, long after that period, as this great astronomer remarks, the Chaldeans and Egyptians yet knew nothing of either the duration or the inequalities of the planetary movements. W. B.
[A4]. See the preceding note.
[A5]. Some of the constellations appear to have been named, even before the time of Moses, who was born 1571 years before Christ: but, probably, most of them received their names about the time of the Argonautic expedition, which took place in the year 1263, B. C
Hesiod and Homer who were co-temporaries, or, at least, flourished nearly at the same time, that is to say, about nine centuries before the Christian era, mention several of the constellations; and, among the rest, the Bear and the Hyades: and it is noticed by Mr. Lalande, that La Condamine says the Indians on the river Amazons gave to the seven stars in the Hyades, the name of the Bull’s-head, as we do; and that Father Lasitau tells us, the Iroquois called that assemblage of stars to which we give the name of the Bear, by the same name; and named the polar star “the star that does not move.”
These are interesting facts. There is not the least resemblance, whatever, in the two constellations which have been mentioned, to the animals whose names they bear. Is it not, then, a matter of great curiosity, as well as one which may prove important in its result, to enquire, why two great tribes of uncivilized men, (supposed, by some, to be aborigines,) in the northern and southern sections of the western hemisphere, should apply the same denominations to two assemblages of stars, by which those constellations were known to Hesiod and Homer, if not earlier, and at least twenty-five hundred years before? W. B.
[A6]. Hipparchus (of Nicæa, in Bithynia,) was a very celebrated mathematician and astronomer of antiquity. Mr. Lalande styles him the most laborious and most intelligent astronomer of antiquity, of whom we have any record; and asserts, that the true astronomy which has come down to us, originated with him. He divided the heavens into forty-eight (some say forty-nine) constellations, and assigned names to the stars. He is also said to have determined latitude and longitude and to have computed the latter from the Canaries; and he is supposed to be the first who, after Thales, calculated eclipses with some degree of accuracy: but he makes no mention of comets. Hipparchus died one hundred and twenty five years before the Christian era. W. B.
[A7]. Friar Bacon is said to have been almost the only astronomer of his age; he informs us that there were then but four persons in Europe who had made any considerable proficiency in the mathematics.
[A8]. Regiomontanus was born in the year 1436, at Kœnigsberg, a town of Franconia, subject to the house of Saxe-Weimar. His real name was John Müller: but he assumed the name of Regiomontanus from that of the place of his nativity, which signifies Regius Mons.
This astronomer, who was greatly celebrated in his time, was the first, according to Lalande, who calculated good Almanacks; which he had composed for thirty successive years; viz. from 1476 to 1506. In these (which were all published at Nuremberg in 1474, two years before his death,) he announced the daily longitudes of the planets, their latitudes, their aspects, and foretold all the eclipses of the sun and moon; and these ephemerides were received with uncommon interest by all nations. After noticing these, Lalande mentions the ephemerides which are published annually at Bologna, Vienna, Berlin, and Milan; but he pronounces the Nautical Almanack, of London, to be the most perfect ephemeris that was ever published. Regiomontanus compiled several other works, which greatly promoted his reputation, He died in 1476, at the age of forty years. W. B.
[A9]. See some interesting particulars respecting this great man in Lord Buchan’s account of the Tomb of Copernicus, and in the note thereto, inserted in the Appendix. W. B.
[A10]. Tycho-Brahé, as Lalande remarks, was the first who, by the accuracy and the number of his observations, prepared the way for the renewal of astronomy. The theories, the tables, and the discoveries of Kepler, are founded on his observations; and Lalande thinks, that their names, after those of Hipparchus and Copernicus, ought to be transmitted with immortal honour to posterity.
Tycho was born in the year 1546, at Knudsturp in Scania in Denmark, of a noble family, which subsisted also in Sweden under the name of Brahé, and to which the marshal count Lœwendahl was allied. He died in 1601, at the age of fifty-five years.
Frederick II, king of Denmark, gave to Tycho the little island of Huen, called in Latin Venusin, towards the Sound, and about ten leagues, northward, from Copenhagen: where that prince erected for him a castle, named Uraniberg, and an observatory attached to it, completely furnished with the best instruments. Yet only fifty-one years after the death of Tycho, Mr. Huet, whose curiosity led him to visit a place so celebrated could find no vestige of the observatory. One solitary old man, who yet retained some recollection of it, told him that the tempestuous winds to which they were subject along the Sound, had demolished it. Even the name of Tycho was then unknown in that savage island, as Mr. Lalande indignantly styles it: and Mr. Picard, who was sent by the French academy, in 1671, to ascertain the exact situation of the observatory, was obliged to have the earth dug away, in order to discover its foundation. W. B.
[A11]. “Certain it is,” says the learned and pious Dr. Samuel Clarke (in his Discourse on the Evidences of Nat. and Rev. Religion,) “and this is a great deal to say, that the generality, even of the meanest and most vulgar and ignorant people,” (among Christians,) “have truer and worthier notions of God, more just and right apprehensions concerning his attributes and perfections, deeper sense of the difference of good and evil, a greater regard to moral obligations and to the plain and more necessary duties of life, and a more firm and universal expectation of a future state of rewards and punishments, than, in any heathen country, any considerable number of men were found to have had.”
In like manner, Archdeacon Paley (in his View of the Evidences of Christianity) observes:—“Christianity, in every country in which it is professed, has obtained a sensible, although not a complete influence, upon the public judgment of morals. And this is very important. For without the occasional correction which public opinion receives, by referring to some fixed standard of morality, no man can foretell into what extravagances it might wander.” “From the first general notification of Christianity to the present day,” says the same ingenious writer, “there have been in every age many millions, whose names were never heard of, made better by it, not only in their conduct, but in their dispositions; and happier, not so much in their external circumstances, as in that which is inter præcordia, in that which alone deserves the name of happiness, the tranquillity and consolation of their thoughts. It has been since its commencement, the author of happiness and virtue to millions and millions of the human race.” He then asks: “Who is there, that would not wish his son to be a Christian?” W. B.
[A12]. Some of the commentators inform us, that Mahomet taught that the earth is supported by the tip of the horn of a prodigious ox, who stands on a huge white stone; and that it is the little and almost unavoidable motions of this ox which produce earthquakes.
[A13]. Pythagoras, who was one of the most celebrated among the Greek philosophers, in the knowledge and study of the heavens, was born about 540 years before the Christian era. It is believed that he was the first who made mention of the obliquity of the ecliptic, and of the angle which this circle makes with the equator; although Pliny attributes this discovery to Anaximander, whose birth was seventy years earlier. Among the remarkable things which Pythagoras taught his disciples, was the doctrine that fire, or heat, occupied the centre of the world; it is supposed he meant to say, that the sun is placed in the centre of the planetery system, and that the earth revolves around him, like the other planets. He also maintained each star to be a world; and that these worlds were distributed in an ethereal space of infinite extent. W. B.
[A14]. Thales, who died about five centuries and an half before the Christian era, in the ninety-sixth year of his age,[[A14a]] first taught the Greeks the cause of eclipses, He knew the spherical form of the earth; he distinguished the zones of the earth by the mean of the tropicks and the polar circles; and he treated of an oblique circle or zodiac, of a meridian which intersects all these circles in extending north and south, and of the magnitude of the apparent diameter of the sun.
Herodotus, Cicero, and Pliny, assert, as is noticed by Mr. Lalande, that Thales had predicted, to the Ionians a total eclipse of the sun, which took place during the war between the Lydians and the Medes, But the manner in which Herodotus (who lived about one century, only, after the time of Thales) speaks of this prediction, is so vague, that one finds some difficulty in believing that it was fact, If it were true, says Lalande, that Thales had actually foretold an eclipse of the sun, it could be no otherwise, than by means of the general period of eighteen years, of which he would have acquired a knowledge from the Egyptians or the Chaldeans: for the period had not yet arrived, when eclipses could be prognosticated by an exact calculation of the motion of the moon. W. B.
[A14a]. But, according to Dufresnoy, he was born in the first year of the 35th Olympiad, and died the first year of the 52d, those periods corresponding, respectively, with the years 640 and 572, B. C.: and if so, he lived only sixty-eight years.
[A15]. Alhazen was one of the greatest of the Arabian astronomers. He went, about the year 1100, to Spain, where many of his nation had established themselves in the eighth century, and carried thither their knowledge of astronomy; yet, from the year 800 down to about 1300, science remained shrowded with the darkest ignorance, throughout Europe.
Mr. Lalande observes, that the theory of Refractions is an important one, in astronomy; although it was considered of little consequence until the time of Alhazen. W. B.
[A16]. Aristotle, as though he had been of the race of the Ottomans, thought he could not reign except he first killed all his brethren. Insomuch as he never nameth or mentioneth an ancient author or opinion, but to confute or reprove. Bacon. Advancement.
[A17]. Timocharis of Alexandria endeavoured, with Aristillus, a philosopher of the same school, to determine the places of the different stars in the heavens, and to trace the course of the planets. Dr. Lempriere places him 294 years before Christ; and the Abbé Barthelemy has inserted his name in the list of illustrious men, who flourished in the fourth century before the Christian era: he probably lived some time after the commencement of that century. W. B.
[A18]. By its peculiar situation it will continue to do so for a long time.
[A19]. According to Lalande, Kepler was as celebrated in astronomy by the consequences he drew from the observations of Tycho Brahé, as the latter was for the immense mass of materials which he had prepared for him: and the Abbé Delaporte (in his Voyageur François) represents him as precursor of Descartes in opticks, of Newton in physicks, and as a law-giver (“legislateur”) in astronomy.
John Kepler, for this was the name of that famous mathematician, was born at Wiel, in the duchy of Wirtemberg, in the year 1571; and the Abbé Delaporte says, his family was illustrious. He died at Ratisbon, in 1630. W. B.
[A20]. The true invention of the telescope cannot be carried back to an earlier date than the beginning of the seventeenth century. Johannes Baptista Porta, a Neapolitan, in his Natural Magic, which was published in the year 1589, says, “Si utramque (lentem concavam et convexam) recté componere noveris, et longinqua et proxima majora et clara videbis:” and he is said to have made a telescope, accordingly, about the year 1594. But Porta is represented as having made this discovery such as it was, by accident; and, as not well understanding the proper use of his own invention.
According to Baron Bielfeld,[[A20a]] however, telescopes were first constructed a long time after, in Holland; some say, by John Lippersheim, a spectacle-maker at Middelbourg in Zealand; others, by James Metius, brother to the celebrated professor Adrian Metius, of Franeker. Although the invention of this instrument, of indispensable use in astronomy, is sometimes attributed to the great Galileo, he has himself acknowledged, in his treatise, entitled Nuncius Siderius, that he took the hint from a report of a German having invented an instrument, by means of which, and with the assistance of certain glasses, distant objects might be distinguished as clearly as those that were near. This is precisely what Porta had mentioned in his book, in 1589; and therefore, if Galileo had not referred to a German, he might be supposed to have had in his view the Neapolitan’s conception of a telescope, announced long before such an instrument was properly constructed.
Whatever may have been the merit of Porta’s discovery, or the pretensions of Lippersheim, the spectacle-maker, and Metius, Peter Borel (in his treatise De vero Telescopii Inventore) is of the opinion that Zachariah Johnson, who, like Lippersheim, was a spectacle-maker, and in the same city, made this discovery by chance, about the year 1500; that Lippersheim imitated him, after making numerous experiments; and that he instructed Metius. There are others, who have been considered as having had some sort of claim to this important invention; among whom were a Mr. Digges, of England, and a M. Hardy, of France, both towards the commencement of the seventeenth century.
It is certain, however, that Galileo in Italy, (who died in 1642, aged seventy-eight years,) and, according to Bielfeld, Simon Marius in Germany, were the first that applied the telescope to the contemplation of celestial objects. W. B.
[A20a]. Elem. of Univ. Erud. b. i. ch. 49.
[A21]. In treating of the astronomy of the Greeks, Lalande contents himself with barely introducing the name of Aristotle, among their philosophers; seeming to consider him as one who had done very little for astronomical science. This philosopher (who died in the sixty-third year of his age, and only 322 years B. C.) among his other doctrines, not only maintained the eternity of the world; but, that Providence did not extend itself to sublunary beings: and as to the immortality of the soul, it is uncertain whether he believed it or not. Bayle calls his logic and his natural philosophy, “the weakest of his works:” and says, further; “It will be an everlasting subject of wonder to persons who know what philosophy is, to find that Aristotle’s authority was so much respected in the schools, for several ages, that, when a disputant quoted a passage from this philosopher, he who maintained the thesis durst not say, Transeat; but must either deny the passage or explain it in his own way.” W. B.
[A22]. This discovery was made on the 8th of January, 1610. It was, as Mr. Vince observes, a very important one in its consequences; as it furnished a ready method of finding the longitude of places, by means of their eclipses. W. B.
[A23]. Although both Geography and Navigation have been wonderfully improved by the important discoveries made by the moderns in astronomy, they have nevertheless, derived the most essential aid from the application of the Compass to their purposes.
The invention of this instrument, which is of indispensible utility, is almost universally ascribed to Flavio Gioia, a native of Amalfi in the kingdom of Naples. He is called, by some writers, Flavio de Melfi, (by which is meant, Flavio of Amalfi, this town being the place of his nativity;) and his invention of the Compass is placed in the year 1302. But it is affirmed by others, that Paulus Venetus brought the Compass first into Italy from China, in the year 1260.[1260.] The Chinese Compass, however, whatever may be its antiquity, appears to have been a very imperfect instrument, compared with the modern Mariner’s Compass; and, more especially, with the Azimuth Compass, as improved by Dr. Knight and Mr. Smeaton. The Chinese Compass, now used, is represented as being nothing more than a magnetic needle kept floating, by means of a piece of cork, on the surface of water, in a white china ware vessel, divided at bottom into twenty-four points.
It is worthy of observation, that the French have laid claim to the invention of the Compass, upon no better foundation than the circumstance of a fleur de lys being always placed at the north point of the chard; although it is known, that Gioia decorated the north end of the needle with that flower in compliment to his own sovereign, who bore it in his arms, as being descended from the royal house of France. “It hath been often,” says Dr. Robertson,[[A23a]] “the fate of those illustrious benefactors of mankind, who have enriched science and improved the arts by their inventions, to derive more reputation than benefit from the happy efforts of their genius. But,” continues this eminent historian, “the lot of Gioia has been still more cruel; through the inattention or ignorance of contemporary historians, he has been defrauded even of the fame to which he had such a just title. We receive from them no information with respect to his profession, his character, the precise time when he made this important discovery, and the accidents and enquiries which led to it: the knowledge of this event, though productive of greater effects than any recorded in the annals of the human race, is transmitted to us without any of those circumstances which can gratify the curiosity that it naturally awakens.” W. B.
[A23a]. Hist. of America, vol. i, b. i.
[A24]. Galileo Galilei was a strenuous defender of the system of Copernicus; for which he was condemned by the inquisition, in the year 1635, under Pope Urban VIII. This extraordinary man was a native of Florence, and born in 1564. He died in 1642, aged seventy-eight years.
W. B.
[A25]. It has been since ascertained that Saturn has seven satellites, as is more particularly mentioned in the subsequent note. W. B.
[A26]. It was about six years after the delivery of this oration, (viz. on the 13th of March, 1781,) that Herschel discovered the Georgium Sidus. And nearly eight years and an half after this first discovery, he made two others: on the 28th of August, 1789, he was enabled to ascertain, by means of his telescope of forty feet focal length, that Saturn has a sixth satellite; and, on the 17th of September following, he found that he has a seventh. The same celebrated astronomer has since made several important discoveries. Thus, under the liberal patronage of his sovereign, has the great Herschel succeeded, by his extraordinary skill and industry in the making of very large specula, in constructing telescopes, which, in the words of the learned Mr. Vince, “have opened new views of the heavens, and penetrated into the depths of the universe; unfolding scenes which excite no less our wonder than our admiration.”
Many important discoveries (some of which are noticed in the foregoing pages of these memoirs) have been made by other eminent astronomers[eminent astronomers], since the date of Dr. Rittenhouse’s Oration; some of them, indeed, since his decease; among which are the discoveries of three new planets. W. B.
[A27]. The celebrated Huygens, who, in his Latin works, is styled Hugenius. W. B.
[A28]. Among the many eminent astronomers in the sixteenth and seventeenth centuries, mentioned by Mr. Lalande, in his Astronomie, with interesting particulars concerning most of them, the only notice he there takes of his ingenious countryman, who endeavoured to establish the theory of Vortices which he had projected, is in these words: “Descartes (René,) né en Touraine en 1596, mort à Stockholm en 1650. Sa vie a été écrite fort au long par Baillet, à Paris, 1691, in 4o.” W. B.
[A29]. The philosophy of Aristotle retained terms so very obscure, that it seems the Devil himself did not understand, or at least could not explain them; otherwise we can hardly suppose, that, when the good patriarch of Venice had summoned his attendance for this very purpose, he would have been so rude as to put him off with an answer not only unintelligible but inarticulate. See Bayle, in Art. Barbaro.
[A30]. Alluding to the experiments made in France, for determining the velocity of light; which, though unsuccessful, discovered a noble philosophical spirit.
[A31]. This prodigious velocity of light can be no argument against its materiality, as will appear from the following considerations. The greatest velocity which we can communicate to any body, is that of a cannon-ball, impelled by gun-powder; this may be at the rate of about 20 miles in a minute of time. The planet Saturn moves about 360 miles in a minute, that is 18 times swifter than a cannon-ball; and the comet of 1680, in its perihelion, moved near 56.66 times swifter than Saturn, or 990.5 times swifter than a cannon-ball. Now these are material bodies, moving with very various, and all of them exceedingly great velocities; and no reason appears why the last mentioned velocity should be the utmost limit, beyond which nature cannot proceed; or that some other body may not move 7 or 8 hundred times swifter than a comet, as light is found to do.
That the different refrangibility of the rays of light, on which their colours depend, arises from their different velocities, seems so natural a conjecture, that it has perhaps occurred to every one who has thought on this subject. To this there are three principal objections. The first is, that, according to this hypothesis, when the satellites of Jupiter are eclipsed, their colour ought to change, first to a green and then to a blue, before their light becomes extinct; which is contrary to experience. But this objection appears to me of no weight; for we do not lose sight of the satellite because there is no light coming from thence to the eye, but because there is not light enough to render it visible. Therefore at the time a satellite disappears, there is still light of all colours arriving at the eye: and though the blue light should predominate on account of its slower progress, yet the red may predominate on another account; for along the edge of Jupiter’s shadow, as it passes over the satellite, a greater proportion of red light, than of blue, will be thrown by the refraction of Jupiter’s atmosphere. The second objection is, that since the velocity of the earth in its orbit, causes an aberration of about 20 seconds in the place of a star, if the different colours of light depended on different velocities, the aberration of blue light ought proportionably to exceed that of red light, which would give such an oblong form to a fixed star as might be discovered with a good telescope. This objection is of no more force than the former. The effect ought indeed to follow, but not in a sensible quantity; for at the altitude of 70 degrees, the apparent place of a fixed star is likewise removed 20 seconds by refraction, and the very same separation of the rays must take place; yet this I think is not discoverable with the best telescope. Perhaps by uniting these two equal causes, which may be readily done, and thereby doubling the effect, it may become sensible.
The third objection arises from that curious discovery of Dollond, by which we are enabled so greatly to improve refracting telescopes. And this objection I shall for the present leave in its full force; as well against the above hypothesis, as against every other which I have seen for the same purpose.
[A32]. Mars appears to be surrounded by a very great and dense atmosphere.
[A33]. Dr. Herschel discovered, in the year 1789, (fourteen years after the delivery of this Oration,) two other satellites of Saturn. These are the innermost of his (now) seven secondary planets.
W. B.
[A34]. In 745, Virgilus, bishop of Saltzburg, having publicly asserted in some of his sermons, that there were antipodes, he was charged with heresy, by Boniface, bishop of Mentz, and cited to appear before the Pope, who recommended the hearing of the cause to Utilo, King of Bohemia, and at the same time wrote to him in favour of Boniface. The event was, the bishop of Saltzburg lost his cause, and was condemned for heresy.
[A35]. It has been shewn, in a preceding note, how much the means of communicating between distant regions, separated by seas, ware facilitated by the discovery and use of the Compass: but those means have been still further and very greatly improved, since the introduction of the use of the Quadrant at sea, especially that called Hadley’s Quadrant.
The true inventor of the reflecting Quadrant was Dr. Robert Hook, a very ingenious English mathematician and philosopher, who died in the year 1702, at the age of sixty-seven years. This instrument, now commonly styled Hadley’s, was afterwards rendered much more complete than Dr. Hook’s invention had made it, by Sir Isaac Newton: but our modern artists, more skilful than those of former times, as Mr. Lalande has observed, have profited of the ideas of the great Newton himself, on the subject; and among the later improvers of the Sea Quadrant, or Octant, is Mr. Hadley, whose name the instrument usually bears.
It would, however, be doing an act of injustice to the memory of an American who possessed an extraordinary genius, to omit, in the course of these memoirs, some notice of his merits in relation to this matter. Mr. Thomas Godfrey, a native of Pennsylvania, is said to have turned his attention to this subject, so early as the year 1730; and in the Transactions of the Royal Society of London, No. 435, will be found, an “Account of Mr. Thomas Godfrey’s Improvement of Davis’s Quadrant transferred to the Mariner’s Bow,” drawn up by James Logan, Esq. formerly of Philadelphia, a gentleman of extensive learning, and a very eminent mathematician, Mr. Godfrey is stated to have “sent the instrument (which he had constructed) to be tried at sea by an acquaintance of his, an ingenious navigator, in a voyage to Jamaica, who shewed it to a captain of a ship there, just going for England; by which means, it came to the knowledge of Mr. Hadley, though perhaps without his being told[told] the name of the real inventor.” [See The American Magazine, for July 1758.] In a letter, dated at Philadelphia the 25th of May, 1732, Mr. Logan, who very ably as well as meritoriously patronized Godfrey, communicated to the celebrated Dr. Edmund Halley a detailed account and description of the improved Sea-Quadrant constructed by that ingenious citizen of America, of which his patron confidently believed him to be the original inventor. On the 28th of June, 1734, a further account of Godfrey’s invention was drawn up by Mr. Logan, and subscribed with his name; which, it is presumed, was also communicated to the Royal Society: and on the 9th of November, in the same year, Mr. Godfrey transmitted an account of it, draughted and signed by himself, to the same learned body. The whole of these interesting letters, with some accompanying observations on the subject, are published in the valuable Magazine just referred to, and in the one for the succeeding month.
In the Transactions of the Royal Society, for the months of October, November and December, 1731, No. 421, is contained a Proposal, by Dr. Edmund Halley, for finding the longitude at sea, within a degree or twenty leagues, &c. In the conclusion of this paper, Dr, Halley, in speaking of John Hadley, Esq. VP.R.S, (“to whom,” as he observes, “we are highly obliged for his having perfected and brought into common use the reflecting telescope,”) says—He “has been pleased to communicate his most ingenious instrument for taking the angles by reflection,” (referring, here, to the Philos. Trans. No. 420;) “it is more than probable that the same may be applied to taking angles at sea, with the desired accuracy.”
In Mr. Logan’s account of Mr. Godfrey’s invention, dated June 28, 1734, he says: “Tis now four years since Thomas Godfrey hit on this improvement; for, his account of it, laid before the (Royal) Society last winter, in which he mentioned two years, was wrote in 1732; and in the same year, 1730, after he was satisfied in this, he applied himself to think of the other, viz. the reflecting instrument, by speculums for a help in the case of longitude, though ’tis also useful in taking altitudes: and one of these, as has been abundantly proved by the maker, and those who had it with them, was taken to sea and there used in observing the latitudes the winter of that year, and brought back again to Philadelphia before the end of February 1730–1, and was in my keeping some months immediately after.”
In Mr, Logan’s prior letter to Dr. Halley (dated May 25, 1732,) he says, that about eighteen months before, Godfrey told him, “he had for some time before been thinking of an instrument for taking the distances of stars by reflecting speculums, which he believed might be of service “at sea;” and that, soon after, Godfrey shewed him an instrument, which he had procured to be made, for the purpose. Thus, the time to which Mr. Logan refers Godfrey’s communication of his improvement to him, would make its date to be about the month of November, 1730.
In the Rev. Mr. Vince’s great work, entitled, A Complete System of Astronomy, (and contained in “A Treatise on Practical Astronomy,” at the end of the second volume of that work,) is an entire chapter on “Hadley’s Quadrant;” giving a particular description of the instrument, with rules for the computations from the observations and illustrations of them by examples. In this Treatise, the author says, that the instrument took its name from the “inventor,” John Hadley, Esq. and observes, that not only the science of navigation is greatly indebted, to this “incomparable instrument,” but such are its various uses in astronomy, that it may not improperly be called “a portable observatory.” Mr. Vince further observes, that in the year 1742, about ten years after Mr. Hadley’s invention (for so he styles it) was published, a paper in Sir Issac Newton’s own hand-writing was found among Dr. Halley’s papers, after the Doctor’s death, containing a figure and description of an instrument (referring to Philos. Transactions, No. 465,) not much different in its principle from this of Hadley. He adds, that as Dr. Halley was alive when Mr. Hadley’s instrument was shewn to the Royal Society, and he took no notice of this paper of Sir Isaac Newton, it is probable he did not know there was such an one. In another part of his work (under the head of The History of Astronomy, vol. ii. p. 280.) Mr. Vince asserts, that the first person who formed the idea of making a Quadrant to take angles by reflection, was Robert Hook; and he was born in 1635. On the whole, however, the learned author draws this conclusion:—“Both Sir Isaac Newton and Mr. Hadley therefore seem entitled to this invention.”
Mr. Lalande, speaking of this instrument, says: “Le[“Le] Quartier de Reflexion, exécuté en 1731 par Hadley, a donné un moyen facile de mesurer les distances sur mer, à une minute pris, aussi bien determiner le lieu de la Lune en mer.” See his Astronomie, vol. iii. p. 654.
From these facts, and a careful examination of the papers themselves, here quoted and referred to, the scientific reader will be enabled to decide upon the true merits of the controversy that has so long subsisted, concerning the respective claims of Godfrey and of Hadley, to the invention of the instrument that bears the name of the latter.
Before this subject is dismissed, however, it will not be deemed improper to add, that the late Dr. John Ewing communicated to the Am. Philosophical Society an account of an Improvement in the construction of (what he terms) “Godfrey’s double reflecting Quadrant,” which he had discovered in the spring or summer of the year 1767: this will be found in the first volume of the Society’s Transactions. In the conclusion of this communication, Dr. Ewing says:—“This improvement of an instrument, which was first invented and constructed by Mr. Godfrey of this city, and which I do not hesitate to call the most useful of all astronomical instruments that the world ever knew, I hope will make it still more serviceable to mankind.”
This communication to the Society by Dr. Ewing, was made in the year 1770. In one concerning the comet of that year, and made by Dr. Rittenhouse about the same time, the instrument to which Dr. Ewing’s improvement applies, is called Hadley’s Quadrant: but perhaps Dr. Rittenhouse so named it, in conformity to common usage.
[A36]. This I know has been pretended to. But it is easy to make geometrical conclusions come out as we would have them, when the data they are founded on, are so uncertain that we may chuse them as suits our purpose.
[A37]. This circumstance tends gradually to lessen the variety of the seasons.
[A38]. This was Tobias Mayer, who was born at Marbach in the principality of Wurtemberg, in the year 1723: he rendered himself celebrated in astronomy, by having calculated the best tables of the moon, and by an excellent catalogue of stars. He died at Gottingen in 1762, at the age of thirty-nine years. W. B.
[A39]. It may happen that any of the planets, about the time they become stationary, shall describe a loop about some small fixed star, in such manner as might be easily mistaken for the star making part of a revolution about the planet. This I suspected to have been the case with the above observation of Montaigne. But the times set down do not confirm the suspicion.
[A40]. See page [320] of the foregoing Memoirs.
[A41]. See page [154] of the foregoing Memoirs.
[A42]. Mr. T. T. proceeding on a different supposition, has computed twenty-seven billions of years necessary for that purpose.
[A43]. “The main-wheel, which is fixed on the barrel on which the cat-gut runs.” Mr. Voight.
[A44]. “A perpetual rochet is a spring lying between the main-wheel, and a plate which is so high in diameter as to be nearly of a height with the bottom of the main-wheel teeth, and is cut with fine teeth all round, in the shape of a fine saw. A click on an axis is fixed between the two frame-plates, with a weak spring that forces this click into the fine saw-teeth, which keeps the plate from moving backwards when the clock is winding up. This fine rochet-wheel is fixed on the barrel-arbour or axis, the same as the main-wheel. The barrel-rochet comes close against the plate of the fine rocket, which has a click screwed on the front, corresponding with the barrel-rochet, and a spring above that rochet’s click, which forces that click into the barrel-rochet’s teeth: it is this that makes the clattering noise, which is heard when a clock is winding up: There is a middling strong spring placed between two arms of the cross of the main-wheel, bent like the space of the two arms between which it acts; and this spring is as broad as the thickness of the cross-arms. One end of that spring is fastened to the inside of the fine rochet-plate: the other end lies on the other cross-arm, and acts on that like a gun-lock mainspring on the cock-tumbler. When the clock or time is set a going, and the maintaining power or weight of the fusee or barrel, this power will raise that spring so far as to resist the maintaining power, and becomes stationary as long as the time-piece is going; and when it is wound up, this spring in the main-wheel cross will expand itself, press on the cross-arm, and force that wheel forward, with nearly the same power as the maintaining power would give: the click for the fine-teethed rochet falls into one of those fine teeth, and keeps that rochet steady, without having the least motion, as long as the winding-up of the clock continues; and by this means a time-piece can lose no time in winding up: hence it is called a perpetual rochet; which requires the most accurate workmanship, in its construction.” Mr. Voight.
[A45]. This description is drawn up from two separate accounts of the instrument, with which the Writer of these Memoirs was obligingly furnished, in writing, by Robert Patterson and the late David Rittenhouse Waters, Esquires, of Philadelphia. Mr. Patterson mentions, that he recollects his having seen the Hygrometer so described, in Dr. Rittenhouse’s Observatory, about thirty years ago.
[A46]. The second volume of the Transactions of the American Philosophical Society contains a letter, written on the 13th of November, 1780, by Dr. Benjamin Franklin, then in France, to Mr. Nairne, of London: but it was not communicated to the Society, until January, 1786.
In that letter, Dr. Franklin suggests to Mr. Nairne (an eminent optician, and mathematical instrument maker,) the idea of an Hygrometer made of wood; in preference to metalline instruments, for the purpose of discovering “the different degrees of humidity in the air of different countries;”—an idea which occurred to the Doctor, in consequence of a casual circumstance, mentioned in his letter.
Dr. Franklin supposed “a quick sensibility of the instrument, to be rather a disadvantage” to it; “since,” says he, “to draw the desired conclusions from it, a constant and frequent observation day and night, in each country—when the design is, to discover the different degrees of humidity in the air of different countries—will be necessary for a year or years, and the mean of each different set of observations is to be found and determined.”—“For these reasons,” continues the Doctor, “I apprehend that a substance which, though capable of being distended by moisture and contracted by dryness, is so slow in receiving and parting with its humidity that the frequent changes in the atmosphere affect it sensibly, and which therefore should, gradually, take nearly the medium of all those changes and preserve it constantly, would be the most proper substance, of which to make an Hygrometer:”—and he believes good mahogany wood to be that substance. In the concluding part of this letter, Dr. Franklin says to his correspondent: “I would beg leave to recommend to you—that you would take a number of pieces of the closest and finest grained mahogany that you can meet with; plane them to the thinness of about a line, and the width of about two inches across the grain, and fix each of the pieces in some instrument that you can contrive, which will permit them to contract and dilate, and will shew, in sensible degrees, by a moveable hand upon a marked scale, the otherwise less sensible quantities of such contraction and dilatation.”
Hence it appears, that Franklin and Rittenhouse conceived an idea of the same kind, nearly at the same time: but that the latter carried his invention into practice, three or four years before the theory of the former, founded on similar principles, had been announced to the American public, or, as it is believed, was made known to any other person than Mr. Nairne. W. B.
[A47]. In a table (in the 2d vol. of Lalande’s Astronomie,) entitled, “Passages de Mercure sur le Soleil, calculés pour trois siècles[siècles] par les nouvelles Tables,” the transit of that planet, above referred to, is thus set down by Lalande, at Paris; viz.
| Year. | Conjunct. | Mean Time. | Geocentric Long. | Mid. Mean Time | Semi-dura. | Short. dist. |
| 1776. | Nov. 2. | 9h10′7″. | 7.11°3′36″. | 9h49′53″. | 0h36′42″. | 15′43″.A |
W. B.
[A48]. The calculations are here wanting, in Dr. Smith’s MSS.
[A49]. Here Dr. Rittenhouse’s ends: The remainder of the versification is continued by another hand.
[A50]. He never professed the business of making watches: the first mechanical occupation he assumed was that of a clock maker, an employment he pursued many years, in the earlier part of his life. W. B.
[A51]. Having, in the preceding note, adverted to the unimportant error in the text, wherein our Philosopher is stated to have pursued the employment of a watch-maker, instead of that of a clock-maker; it becomes necessary to notice, in this place, another mistake, though likewise an inconsiderable one, into which the liberal and candid writer of the article, above quoted, has been led. Dr. Rittenhouse’s Observatory, at Norriton—the place of his original residence and the seat of his farm-house—was erected prior to the celebrated “Astronomical Observations” made by him, in the year 1769; which were those relating to the Transit of Venus over the Sun’s disk, on the 3d of June in that year. W. B.
[A52]. The time above referred to, is supposed to have been in the year 1790 or 1791; though perhaps it may have been somewhat earlier. Dr. Sproat died in the autumn of 1793. W. B.
[A53]. An uncle of Copernicus was Bishop of Warmia, (in Ermeland, a little province of Poland,) and gave him a canonry in his cathedral of Frawenberg, a city in ducal Prussia, situated on the Frische Haff, at the mouth of the Vistula: it was there he began to devote himself to astronomy, at the age of twenty-eight years. His great work, De Revolutionibus Orbium Cœlestium, was completed about the year 1530: but his apprehensions of meeting with persecution from the bigotted ignorance of the age, in consequence of the system he therein promulgated, deterred him from publishing it until thirteen years after that period; and it is supposed that the agitation of his mind, occasioned by its appearance in the world, produced the sudden effusion of blood, which terminated his life on the 24th day of May, in the year 1543. W. B.
Transcriber’s Note
In the main sections of the text there are many numbered textual notes, many quite lengthy, which the writer chose to keep as close as possible to their references in the text. In the printed book, this resulted in many pages containing only two lines of the main text. The writer acknowledges this in the Preface, but points out the need to keep the notes as close to their references as possible. Many of these notes have footnotes of their own, denoted with the traditional *, †, ‡ symbols.
Notes in the Introduction and Appendix also employ those traditional symbols, which have been resequenced for the sake of uniqueness. The three notes in the Introduction become I1, I2, I3, and those in the Appendix become A1, A2, A3, ... An. If a note is itself footnoted, that note is indicated as ‘Ana’, etc.
The main text employs 386 numeric notes which started with ‘1’ for each section. These have been resequenced across the entire text, again for the sake of uniqueness. Many notes had footnotes of their own, denoted with those traditional symbols. These have have been resequenced as ‘na’, ‘nb’, ‘nc’, etc., where ‘n’ is the note number. Those notes are placed following the note.
Any internal references to the notes, of course, were modified to employ the new sequence.
In this version, footnotes have been collected at the end of the text, and are linked for ease of reference.
Given the publication date (1813), spelling remained somewhat fluid. So, especially in quoted text, the text mostly remains as printed unless it is very obviously a typo (e.g. ‘celebratrd’, or ‘inhahitants’), or where there is a great preponderance of another variant of a word elsewhere. There were two instances of a missing ‘of’ which may have been in error.
| [131.31] | The making [of] good mathematical instruments | Sic |
| [145.11] | on the fourth day [of] July, 1760. | Sic |
A quoted translation in note 38 ends abruptly with ‘and spreads her light:’ ([lvi.29]) without a closing quotation mark. This has been amended as ‘spreads her light[.”]’
On two pages (pp. 134, 135), ‘Galileo’ is printed as ‘Gallileo’ ([134.33], [134.37] and [135.3]), which we take to be a printer’s lapse.
On p. 182, The ’Rudolphine’ Tables are misspelled two ways ([182.27], [182.29]). Both are corrected.
On pp. [327-329], the symbol for Uranus (♅) as printed is not quite the same as the symbol available to us. In the text, the small circle is on the top.
Other errors, deemed most likely to be the printer’s, have been corrected, and are noted here. The references are to the page and line in the original.
| [xii.15] | not be deemed pre[p/s]umptuous | Replaced. |
| [xxxii.28] | the [sun] stood still in the centre | See [Note] |
| [xxxix.16] | Pyth[oga/ago]ras | Transposed. |
| [xlvii.4] | of his Physics.[”]) | Removed. |
| [li.9] | Pronaque cum spectent an[a/i]malia | Replaced. |
| [lii.3] | he may be enabled t[e/o] know himself | Replaced. |
| [lvii.12] | Hyberni[./,] vel quæ tardis | Replaced. |
| [lxii.9] | and [security] of navigation | See [Note] |
| [lxxii.1] | wa[n/s] Johannes de Sacro-Bosco | Replaced. |
| [lxxiv.17] | for its truth than novelty;[”] | Replaced. |
| [91.11] | purer morality and sounder [s/p]olicy. | Replaced. |
| [104.22] | to his friend | Removed. |
| [105.7] | personally acquain[t]ed with him | Inserted. |
| [107.1] | [in]asmuch as the instruments | Restored. |
| [107.7] | [“]It is observable | Removed. |
| [110.18] | so long distinguis[n/h]ed | Replaced. |
| [122.13] | Astronomer’s innate ge[u/n]ius | Replaced. |
| [140.12] | A descript[t/i]on of | Replaced. |
| [148.35] | with our guns.[’/”] | Replaced. |
| [149.10] | as f[o/a]r as the barracks | Replaced. |
| [164.10] | and these,[”] | Added. |
| [177.30] | la mesure du temps.[’/”] | Replaced. |
| [184.1] | by William Sm[ti/it]h | Transposed. |
| [185.3] | one-hundredth part of[ of] the whole | Removed. |
| [192.15] | See Laland[e]’s Astron. | Inserted. |
| [198.16] | it has never been done.[”] | Removed. |
| [198.17] | [“]I send you a description | Added. |
| [207.7] | good quality and wor[k]manship | Inserted. |
| [207.24] | the gl[s/a]ss-works have not | Replaced. |
| [219.25] | three [hun]hundred pounds | Removed. |
| [220.25] | reached this country[;/,] | Replaced. |
| [226.25] | History of the America[u/n] Revolution | Inverted. |
| [249.22] | the repeated occas | Removed. |
| [251.16] | Pennsyl[e/v]ania would not yield | Replaced. |
| [254.1] | in the ex[u/e]cution of his trust | Replaced. |
| [260.13] | of this Anti-Newtonian essayist[:/.] | Replaced. |
| [261.4] | Those of anoth[o/e]r cast | Replaced. |
| [262.2] | at one of your brothers[,’/’,] | Transposed. |
| [269.7] | most embar[r]assing circumstances | Inserted. |
| [303.10] | 26th of January, 1[726-7/627] | Replaced |
| [344.8] | dated “Philadelphia, Oct. 14, 1787[”] | Added. |
| [360.20] | The agency of i[m/n]formation | Replaced. |
| [367.10] | annexed to that statio[n.] | Added. |
| [372.30] | to the Linn[e/æ]an system | Replaced. |
| [375.24] | that Linn[e/æ]us pronounced him | Replaced. |
| [388.18] | on such occa[r/s]ions | Replaced. |
| [400.22] | precisely the reverse.[”] | Removed. |
| [420.22] | Mr. Ceracchi became embarr[r]assed | Removed. |
| [455.34] | Professor of Eng[g]lish | Removed. |
| [458.13] | Mr. Ritten[ten]house was not himself | Removed. |
| [477.19] | [“]Observations on a Comet | Removed. |
| [495.20] | classical learning,[”] | Added. |
| [498.2] | different systems of theology.[”] | Removed. |
| [508.17] | will be annihilated[:/.] | Replaced. |
| [512.12] | of the human mind.[”] | Removed. |
| [513.24] | the inha[h/b]itants of the British colonies | Replaced. |
| [519.1] | that Dr. Ritten[ten]house | Removed. |
| [533.23] | the language of Dr. Reid, [“]fruitful | Added. |
| [534.5] | [“/‘]In God we live, and move, | Replaced. |
| [534.6] | and have our being.[’]” | Inserted. |
| [548.8] | Venus a[u/n]d Mercury | Inverted. |
| [551.22] | which jug[g]ling impostors | Inserted. |
| [557.25] | in the year 1260[,/.] | Replaced. |
| [558.42] | by other e[n/m]inent astro[t/n]omers | Replaced. |
| [564.18] | their phases f[o/r]om full to new | Replaced. |
| [567.18] | without his being to[./l]d the name | Replaced. |
| [568.31] | [“]Le Quartier de Reflexion | Added. |
| [572.12] | by the celebrat[r/e]d Mayer | Replaced. |
| [574.36] | a distance fr[e/o]m each other | Replaced. |
| [588.38] | pour trois si[e/è]cles | Replaced. |
| [593.28] | præsentes literæ pervener[I/]nt | Replaced. |
| [597.8] | in the laudable business of[ of] writing | Removed. |
| [614.11] | at dif[f]erent periods | Inserted. |