It is not meant to be insinuated, however, that Mr. Barton ever gave Mr. Rittenhouse any insight into the knowledge of fluxions; or, indeed, much instruction, if any at all, in other of the higher branches of mathematics: because the first named gentleman never did himself pretend to the character of a profound mathematician; and because, likewise, although always esteemed a man of learning, his pursuits in science and literature were chiefly directed to objects of a different nature. That Mr. Rittenhouse derived some instruction and information from his early acquaintance with Mr. Barton, is certain: but, whatever may have been the extent of the literary advantages which the latter was enabled to confer on his young friend and companion, they could not in any degree derogate from the intrinsic excellence and greatness of our Astronomer’s innate genius[genius].
That a mind so formed as that of our young philosopher—situated in life as he was—should have impelled him to assume the business of clock-making, can not be a matter of surprize: this occupation, connected with that of a mathematical instrument maker, is such as may be well supposed to have presented itself to his youthful ingenuity; being in accordance with the philosophical bent of his genius in his early years, while yet untutored in science and unknown to the world.
The great utility of the common clock, in measuring time, is universally known. It possesses numerous and manifest advantages, beyond those of sun-dials, clepsydræ, sand-glasses, and other horological instruments, by reason of its vastly superior accuracy: the sun-dial, indeed, is oftentimes wholly useless in all situations, even in the day-time; and always necessarily so, at night.
But the many improvements which have been made in modern times, in chronometers,—more especially in pendulum-clocks,—have very much advanced a correspondent accuracy in astronomical observations: and these improvements, together with those lately made in telescopes—chiefly by Dr. Herschel, the discoverer of the Georgium Sidus[[85]]—afford good grounds for hoping, that yet farther and more important additions will continue to be made to the recent discoveries in astronomy.
Further improvements may also be expected to take place, in the construction of watches and other spring-chronometers; so as to render them still more useful for the purposes of navigation, by ascertaining with greater precision the longitude at sea.[[86]] For this purpose, the finely-improved English time-keepers of Harrison, Mudge, and others, have been found of the greatest utility. Mr. de Zach, (in his Explanation and uses of the Tables of the Motions of the Sun,[[87]]) after some observations on determining differences of longitude by means of astronomical observation, says,[[88]]—“De cæteris longitudinem determinandi modis, non est hic disserendi locus;—de uno vero, horologiâ maritimâ seu nauticâ, quidquam adjicere non alienum erit. Triginta jam abhinc annis, ingeniosissimi horologiorum artifices, Harrison, Cummings, Kendal, Arnold, Mudge, apud Anglos,—Le Roy et Berthoud apud Gallos, varia navigantium usui, egregia excogitaverant, et ad magnum perduxerant perfectionis gradum, horologia nautica, (Anglis, Time-keeper.) Cum eorum in longitudinibus itenere maritimo definiendis, usum quisque norit, plura hic dicere abstineo; simile horologium ab ingenioso horolopega Thom. Mudge constructum, in Observatorio Regio Grenovicensi sæpius exploratum, anno 1784, a Clar. D. Campbell, classis navalis præfecto[[89]] ad Terram Novam (Newfoundland) vectum, et reductum, ab hoc tempore in Observatorio Excellentissimi Comitis de Bruhl, Londini, Doverstreet, assidue observatum est. Hoc ipsum horologium maritimum, anno 1786, in terrestribus, iteneris longitudines determinandi gratia, concreditum mihi fuit, cum â Serenissimo Duce Saxe-Gothanâ, omnium scientiarum bonarumque artium patrono, imprimis astronomiæ, faventissimo, Londino evocatus in Germaniam me conferrem, ubi amplissimæ splendidissimæ Speculæ, Astronomicæ Gothanæ extruendæ cura mihi demandata erat;[[90]] attuli eodem hoc tempore, ad Serenissimi mandatum, minoris molis horologium, quod in braccis gestari solet (Anglis, Pocket-chronometer,) a Londiniensi artifice, D. Josiah Emery,[[91]] constructum, quod summâ accuratione et subtilitate elaboratum, nil majoribus cedit horologiis nauticis, ut videre licet ex tribus horum motuum elenchis ab Ilustr. Comite de Bruhl, et â aliorum Dr. Arnold, nuperrime publici juris factis. Sub finem anni 1786 et ad initium 1787, Serenissimum in itenere per Germaniam, Galliam, et Italiam, comitatus sum: hoc itenere quorundam locorum et Specularum astronomicarum longitudines definitæ sunt ex comparatione temporis horologii maritimi (quod ad tempus solare medium Londinense, in Doverstreet incedebat) cum tempore medio loci, quod sextante Hadleianâ per solis altitudines, quas correspondentes dicimus, vel ex comparatione cum illo, quod in Speculis Astronomicis ab ipsis astronomis traditum nobis fuit. Iisdem itaque automatis, cum primum Gotham advenissem, observatorii futuri longitudinem maximâ cum curâ atque diligentiâ definivi, quam paucis post diebus Serenissimus Dux Londinum profectus, chronometro suo secum deportato denuo perbelle comprobaverat.”
This very respectable testimony of an eminent German astronomer affords incontestable proof of the great accuracy, of which nautical chronometers are susceptible, and to which they have actually been brought by some artists of celebrity, mostly English.[[92]]
The general use of the common clock ought not to derogate from the ingenuity of an invention of such universal importance in the affairs of human life. The pendulum-clock now in use was brought to some degree of perfection, if not invented, by Huygens,[[93]] who was one of the first mathematicians and astronomers of the age in which he lived: and the date of this invention is about the middle of the seventeenth century; although Galileo[Galileo] disputed with him the discovery, a few years earlier. Clocks of some kind date their antiquity much higher; some writers pretending to carry their invention back as far as the year 510 of the Christian era. However, on the authority of Conrad Gesner,[[94]] the honour of inventing the clock, before the application of the pendulum to these machines was made by Huygens, belongs to England: He says, that “Richard Wallingford, an English abbot of St. Albans, who flourished in the year 1326, made a wonderful clock by a most excellent art; the like of which could not be produced in all Europe.”[[95]] This was forty-six years before Henry de Vic, a German, made his clock for Charles V. king of France; and fifty-six years before the duke of Burgundy ordered one, which sounded the hour, to be carried away from the city of Courtray, in Flanders.
Within our own day and a short period of time preceding it, great improvements have been made in the construction of the pendulum-clock,[[96]] as well as in other descriptions of Chronometers.[[97]] Mr. Rittenhouse’s early zeal in his practical researches into astronomy, prompted him to desire the greatest possible accuracy in the construction of time-pieces adapted to astronomical purposes; and uniting, as he did, operative skill with a thorough knowledge of the principles upon which their construction depends, he was enabled—impelled by so powerful a motive—to display to the world, by his own manual ingenuity, the near approach to perfection to which the pendulum-chronometer may be brought. Besides his astronomical pursuits, his early employment in ascertaining the limits and fixing the territorial boundaries of Pennsylvania, and of some of the neighbouring states, obliged him to supply himself with chronometers of the greatest possible accuracy: and these were either made by his own hands, or under his immediate inspection by his brother, who, with the aid of his instruction, became an excellent mechanician. One of these fine instruments, bearing on its face the name of Benjamin Rittenhouse as the maker, and the date of the year 1786, is now in the possession of Mr. Norton Prior,[[98]] of Philadelphia: but that admirable one, the workmanship of which was executed by our Philosopher himself, and which was part of the apparatus of his Philadelphia Observatory, is now placed in the hall of the American Philosophical Society.[[99]] This is constructed on a greatly improved plan of his own, which improvement was afterwards applied to that now belonging to Mr. Prior; and the latter is the same chronometer, it is believed, that was used by Mr. D. Rittenhouse, in fixing the northern line which divides Pennsylvania from New York, and in establishing the boundary line between the last mentioned state, and Pennsylvania and Massachusetts, respectively, in the years 1786 and 1787.—A description[description] of the principles of his observatory-chronometer here mentioned, together with some account of its mechanism, will be found in the Appendix: the former having been communicated to the writer of these memoirs by the ingenious Robert Patterson, Esq. director of the Mint; and the latter by that able mechanician, Mr. Henry Voight, chief coiner in that institution,—a person who, by reason of his well-known skill as a clock and watch-maker, was employed by Mr. Rittenhouse more than forty years since, in the fabrication of some of his philosophical instruments.
The great accuracy and exquisite workmanship displayed in every thing belonging to the profession he pursued, that came through his hands, soon became pretty extensively known: and this knowledge of his mechanical abilities, assisted by the reputation he had already acquired as a mathematician and astronomer, in a short time procured him the friendship, respect and patronage, of some eminent scientific characters; while it promoted his interest, in the profession he had thus newly chosen. In this he was, nevertheless, self-taught; for he never received the least instruction from any person, in any mechanic art whatever: and, therefore, if he were to be considered as being merely an excellent artist, in an occupation intimately connected with the science of mathematics—untutored, as he was, in any art or science,—he would deservedly be deemed an extraordinary and eminent man. It will be perceived, however, that it was the union of the almost unbounded powers of his genius, and his prodigious acquirements in a sublime science, with his wonderful abilities as a philosophical mechanic—and these faculties and attainments, moreover, combined with an amiable and virtuous character,—which constituted that celebrity so justly attached to his name.
Our young philosopher lived a retired, though by no means an inactive life, in his father’s family, for several years after he arrived to (what is usually termed) lawful age. In this situation, which was a pleasant one in many respects, he long continued to enjoy the tranquil scenes of rural life, amidst the society of an amiable and very intelligent family-circle, and surrounded by many worthy and estimable neighbours, by whom he was both loved and respected. His chief occupation was the profession he had chosen; but in such occasional intervals of personal abstraction from the mechanical part of his business, as the assistance the workmen he employed enabled him to obtain, he devoted much of the time to philosophical pursuits and study. Frugal in his expenditures, his industry furnished him amply with the means of comfort; and in the plentiful and decent mansion of his father’s family he experienced, with contentment, almost every gratification that a reasonable mind could desire. Good health seemed alone to be wanting to complete his happiness, in his earlier years; a privation which he felt through the greater part of his life.