To an object, then, of such vast importance to science, were proportioned the expectations of our Observers. But they could not fail to experience, at the same time, in common with their astronomical brethren in other parts of the world, a large portion of anxious apprehensions, lest a cloudy day—nay, even a solitary passing cloud,—should baffle entirely their exalted hopes, and destroy all the fruits of their arduous labours! Yet such an occurrence, as one or the other of these events, was evidently within the calculations of a probable incident.
Mr. Rittenhouse participated largely in these blended hopes and fears. He had, for some time before,been laboriously employed in making the requisite preparatory observations and calculations: and, as Norriton was now rendered eminently conspicuous, by being fixed on as a principal site for observing the very interesting phænomenon so near at hand, he had been assiduously engaged, at the same time, in preparing and furnishing an Observatory at that place, suitable for the occasion. This he began to erect early in November, 1768,—“agreeably,” to use his own words, “to the resolutions of the American Philosophical Society;” but, through various disappointments from workmen and weather, he was not enabled to complete it till the middle of April, 1769.[111]
The Norriton Observatory was commodiously situated near Mr. Rittenhouse’s mansion, on a pretty elevated piece of ground, commanding a good range of horizontal view. This temporary edifice was as well adapted to the purpose for which it was chiefly designed, as the nature of the materials of which it was constructed, and other circumstances, would permit. Some monies had been previously appropriated by the Philosophical Society, towards defraying the expenses necessarily incident to this occasion, at the three several places of observation: but the funds of the society, at their disposal for such purposes, were very limited; and it is believed that the quota of these funds assigned for the expenditures actually incurred for making the observations of the transit, at Norriton, was quite inconsiderable in its amount.
In order that ample justice may be done to the merits of Mr. Rittenhouse, for all the preparatory arrangements made by him on this occasion, the readeris here presented with an extract from Dr. Smith’s subsequent Report, to the Philosophical Society, of the proceedings of the Norriton Committee, and made in their behalf.—“I am persuaded” says the doctor, “that the dependance which the learned world may place on any particular Transit-Account, will be in proportion to the previous and subsequent care, which is found to have been taken in a series of accurate and well conducted observations, for ascertaining thegoingof the time-pieces, and fixing the latitude and longitude of the place of observations, &c. And I am the more desirous to be particular in these points, in order to do justice to Mr.Rittenhouse, one of the committee; to whose extraordinary skill and diligence is owing whatever advantage may be derived, in these respects, to our observation of the Transit itself.”—“Our great discouragement at our first appointment,” continues the learned reporter, “was the want of proper apparatus, especially good Telescopes with Micrometers. The generosity of our Provincial Assembly soon removed a great part of this discouragement, not only by their vote to purchase one of the best reflecting Telescopes, with aDollond’smicrometer;[112]but likewiseby their subsequent donation of one hundred pounds,” (this was in sterling money, = $444) “for erecting Observatories and defraying other incidental expences.[113]It was forseen, that on the arrival of the Telescope, added to such private ones as might be procured in the city, together with fitting up the instruments belonging to the honourable the Proprietaries of the province—viz. the equal Altitude and Transit Instruments and the large astronomical Sector,—nothing would be wanted for the city Observatory in the State-House Square, but a good Time-piece, which was easily to be procured. We remained, however, still at a loss, how to furnish the Norriton Observatory:[114]But even this difficulty gradually vanished.”
Thus it appears, that while the public contributions, and such astronomical instruments suitable for the occasion as were the public property, were principally at the disposal of the Philadelphia committee, the Observatory at Norriton—which seems to have been considered as a private establishment, belonging to an individual,—depended almost entirely on other resources. Even an excellent reflecting telescope (though without a micrometer,) the property of the Library Company of Philadelphia, and to which institution it was a donation from the Hon. T. Penn,—the same that had been used by Messrs. Macon and Dixon, when employed in settling the boundary lines of Pennsylvania and Maryland—was necessarily appropriated to the use of Mr. Owen Biddle, who was appointed by the Society to conduct the Observation of the Transit, near Cape Henlopen.
The Norriton Observatory was, notwithstanding, at last completely furnished with every instrument proper for the occasion. In consequence of some previous communications made by Dr. Smith to the Hon. Mr. T. Penn of London, and to the Rev. Mr. Maskelyne, the British astronomer-royal at Greenwich, the former worthy and liberal gentleman had sent, for the use of the Norriton committee, a reflecting Telescope with Dollond’s Micrometer—such as the doctor had expressed a wish to obtain; and requested, that after the committee should have made their observations with it, it should be presented in his name to theCollege.[115]Through the means of Dr. Smith, likewise, an astronomical quadrant of two and an half feet radius, made by Sisson, the property of the East-Jersey proprietaries, was procured by Mr. Lukens from the Earl of Stirling, surveyor-general of that province. This had been pretty early sent up by Mr. Lukens to Mr. Rittenhouse, and was used by him in ascertaining the latitude of his Observatory.
In addition to these and some other apparatus used at Norriton on the occasion—a catalogue and description of the whole of which, are contained in Dr. Smith’s before-mentioned report—the zeal, industry, and talents of Mr. Rittenhouse enabled him to furnish his Observatory with the three following described instruments, made by himself,[116]as described by Dr. Smith.
1. AnEqual Altitude Instrument—its telescope three and an half feet focal length, with two horizontal hairs, and a vertical one in its focus; firmly supported on a stone pedestal, and easily adjusted to a plummet-wire four feet in length, by two screws, one moving in a North and South, the other in an East and West direction.
2. ATransit Telescope, fixed in the meridian, on fine steel points; so that the hair in its focus could move in no other direction than along the meridian; in which were two marks, South and North, about 330 yards distance each; to which it could be readily adjusted in an horizontal position by one screw, as it could in a vertical position, by another.
3. An excellentTime-piece—having for its pendulum-rod a flat steel bar, with a bob weighing about twelve pounds, and vibrating in a small arch. This went eight days, did not stop when wound up, beatdead seconds, and was kept in motion by a weight of five pounds.[117]
Thus was the Norriton Observatory furnished with all the more immediately necessary apparatus, in readiness for the important event which was the main object of these arduous exertions. Much credit was due to Dr. Smith, much to Mr. Lukens and the other gentlemen engaged on this occasion, for the assistance which he, and they, afforded Mr. Rittenhouse. Yet the doctor himself very candidly says—in reporting the proceedings of the Norriton committee to the Philosophical Society,—“other engagements did not permit Mr. Lukens or myself to pay much attention to the necessary preparations; but we knew that we had entrusted them to a gentleman on the spot, who had joined to a complete skill inmechanics, so extensive anastronomicalandmathematicalknowledge, that the use, management, and even the construction of the necessary apparatus, were perfectly familiar to him. Mr. Lukens and myself could not set out for his house till Thursday, June 1st; but, on our arrival there, we found every preparation so forward, that we had little to do, but to adjust our respective telescopes to distinct vision. He had fitted up the different instruments, and made a great number of observations, to ascertain the going of his Time-piece, and to determine the latitude and longitude of his Observatory. The laudablepains he hath taken in these material articles,” continues Dr. Smith in his report, “will best appear fromthe work itself,—which he hath committed into my hands, with the following modest introduction; giving me a liberty, which his own accuracy, care and abilities, leave no room to exercise.”[118]
Norriton, July 18th 1769.“Dear Sir,“The enclosed is the best account I can give ofthe Contacts, as I observed them; and of what I saw during the interval between them. I should be glad you would contract them, and also the other papers, into a smaller compass,—as I would have done myself, if I had known how. I beg you would not copy any thing merely because I have written it, but leave out what you think superfluous.—I am, with great esteem and affection, yours, &c.David Rittenhouse.[119]To Rev. Dr. Smith.”
Norriton, July 18th 1769.
“Dear Sir,
“The enclosed is the best account I can give ofthe Contacts, as I observed them; and of what I saw during the interval between them. I should be glad you would contract them, and also the other papers, into a smaller compass,—as I would have done myself, if I had known how. I beg you would not copy any thing merely because I have written it, but leave out what you think superfluous.—I am, with great esteem and affection, yours, &c.
David Rittenhouse.[119]
To Rev. Dr. Smith.”
The result of the Norriton Observations of the Transit of Venus—as well as those also made under the auspices of the American Philosophical Society, at Philadelphia and Cape Henlopen—will be found, in detail, in the first volume of the Transactions of that Society.[120]And “the Work itself,” to whichDr. Smith refers, in his Report of the Proceedings of the Norriton Committee, bears ample testimony to thetranscendent Astronomical Abilities of Mr. Rittenhouse.—Four days after the Transit, Dr. Smith transmitted to the Hon. Mr. Penn, in London, a short account of the Norriton Observations, more particularly mentioning the times of the Contacts, and a few other circumstances attending them. This was speedily communicated by Mr. Penn to the Rev. Mr. Maskelyne,[121]the Astronomer Royal; who, acknowledgingthe receipt of the communication, by a note, dated at Greenwich the 2d of August, 1769, says—“I thank you for the account of the Pennsylvania Observations (of the Transit,) which seemexcellentandcomplete,[122]and do honour to the gentlemen whomadethem[123], and those who promoted the undertaking;—among whom, I reckon yourself[124]in the first place.”[125]
Here the observation will emphatically apply;—Laus est, â viro laudato laudari.
Before this interesting occurrence in the life of Mr. Rittenhouse is finally passed over, the reader’sattention is solicited to the beautiful and animated description given by Dr. Rush, in his Eulogium, of the sensations which must have been more particularly experienced by that extraordinary man, on the near approach of the long-expected Phænomenon.—“We are naturally led here,” says the learned Professor, “to take a view of our Philosopher, with his associates, in their preparations to observe a phænomenon which had never been seen but twice[126]before,by any inhabitant of our earth, which would never be seen again by any person then living, and on which depended very important astronomical consequences. The night before the long-expected day, was probably passed in a degree of solicitude which precluded sleep. How great must have been their joy, when they beheld the morning sun!—‘and the whole horizon without a cloud;’ for such is the description of the day, given by Mr. Rittenhouse, in the report referred to by Dr. Smith. In pensive silence and trembling anxiety, they waited for the predicted moment of observation: it came,—and brought with it all that had been wished for, and expected, by those who saw it.—In our Philosopher, it excited—in the instant of one of the contacts of the planet with the sun, an emotion of delight so exquisite and powerful, as to induce fainting. This,” then remarks Dr. Rush, “will readily be believed by those who have known the extent of that pleasure which attends the discovery, or first perception of Truth.”
On the 9th of November, following, there was a Transit of Mercury over the Sun. An account of this phænomenon,—as observed at Norriton by WilliamSmithSmith, d. d. John Lukens, Esq. and Messrs. David Rittenhouse and Owen Biddle, the Committee appointed for that Observation by the American Philosophical Society,—was drawn up and communicated to the Society, by direction and in behalf of the Committee, by Dr. Smith: this will be found in the first volume of the Society’s Transactions. In this report it is remarked, that—“the first time that ever Mercury was observed on the Sun’s disk, was by Gassendus at Paris, October 28th 1631, O. S. and that the Transit of Nov. 9th was the fourth in that class; the two intermediate ones, each at forty-six years distance, having been observed by Dr. Halley, in 1677 and 1723.”
Mr. Maskelyne, the celebrated English Astronomer before mentioned,[127]—in a letter to Dr. Smith, of the 26th of December, 1769—expressed a wish “that thedifference of Meridians of Norriton and Philadelphia, could be determined by some measures and bearings, within one-fiftieth or one-hundredth partofofthe whole; in order to connect,” continues Mr. Maskelyne, “your observations of the Longitude ofNorritonwith those made by Messrs. Mason and Dixon, in the course of measuring the degree of Latitude.”—This request of the Astronomer Royal was communicated to the Philosophical Society of Philadelphia; in consequence of which, Dr. Smith, Mr. Lukens and Mr. Rittenhouse, were appointed to make the terrestrial measurement required. These gentlemen, having taken to their assistance Mr. Archibald M’Clean and Mr. Jesse Lukens, two able and experienced Surveyors, commenced their operations at Norriton, early on the 2d day of July following, and completed their survey on the 4th day of that month. The Report of the able Committee, to which this business was assigned by the American Philosophical Society, is also contained in the first volume of the Transactions of that learned Body. After giving various calculations, resulting from the operations of that committee, the Reporter says—“Hence, by the above measurement and work, we get Norriton Observatory 52″ of time West of the Observatory in the State-house Square; which is exactly what we got by that excellent element, the external contact of Mercury with the Sun, Nov. 9th 1769.”—“The external contact,” continues the Reporter, “gave it something more; owing, no doubt, to the difference that willarise among Observers, in determining the exact moment when the thread of light is compleated: and the mean of all our Observations gives the difference of Meridians, between Norriton and Philadelphia, only 4″ of time more than the terrestrial measurement, and the external contact of Mercury, gave it,—which may be taken as a very great degree of exactness; if we consider that the difference of Meridians, between the long-established Observatories of Greenwich and Paris, (as Mr. De la Lande writes, Nov. 18th 1762,) was not then determined within 20″ of time—For, he says, ‘some called it 9′ 15″; others, 9′ 40″;’ but that he himself commonly used 9′ 20″, though he could not tell from what Observations it was deduced.[128]—Finally, the Report fixes Philadelphia to be 5h0′ 37″, and Norriton, 5h1′ 29″ West from Greenwich.[129]The Latitude of Norriton, as deduced from the actual mensuration just mentioned, connected with Observations previously made by Mr. Rittenhouse—predicated also,in part, on antecedent Calculations of Messrs. Mason and Dixon, who, (having been furnished with a complete Astronomical Sector,) had ascertained the southernmost point of the City of Philadelphia to be in Latitude 39° 56′ 29″,4. N.—is stated, in the same Report, as being 40° 9′ 31″. It came out, by the measurement, 25″.09 less North, with respect to the southernmost point of Philadelphia, than Mr. Rittenhouse’s Observations had given it; and, in making these, he had no better Instrument than Sisson’s two-and-an half feet Quadrant. Nevertheless, the framer of the Report remarks, “as both were fixed by celestial observations and experienced Men, the small difference ought perhaps to be divided; and if a mean be taken, to reconcile it with the terrestrial measure, the Lat. of the south point of Philadelphia would be 39° 56′ 42″; and that of Norriton, 40° 9′ 43″.[130]
The same Volume of the American Philosophical Transactions that comprehends the communications of these Proceedings—as well as various Observations, made at different places, on the then recent Transit of Venus—contains also a Memoir, by Dr. Smith, deducing the Sun’s Parallax from a comparison of the Norriton and some other American Observations of the Transit of Venus, in 1769, with the Greenwichand some other European Observations of the same: And with this paper, its learned writer has incorporated a communication, on the same subject, made to him by Mr. Rittenhouse.
Until about the period at which the latest of these favourite transactions of Mr. Rittenhouse took place—namely, his geometrical employment in ascertaining the Latitude and Longitude of Norriton and Philadelphia, respectively,—he continued to reside on his farm at Norriton. And here he still carried on, with the aid of some apprentices and journey-men, his self-acquired occupation of a Clock and Mathematical Instrument-maker: combining, at intervals, with these mechanical pursuits, an unceasing attention to his philosophical studies and researches; and occasionally employing himself, principally with a view to his health, in some of the occupations of Husbandry. Ever an economist of Time, of which he well knew the inestimable value, none of his hours which could be spared from necessary sleep were suffered to be unemployed. In this rural abode, he enjoyed the comforts of domestic life amidst his little family, consisting only of an amiable wife and two young children. In short, no part of his time was unengaged, or uselessly passed; although he, not unfrequently, felt the solace of friendly calls, and was gratified by visits from persons of science, worth, and distinction.
The writer of these memoirs designed to narrate those circumstances most worthy of notice, in the Life and character of Mr. Rittenhouse, in their chronological order; and this plan will be generally adhered to. Having followed our philosopher in his astronomical and mechanical pursuits, up to the year 1770, it therefore becomes proper to recur to a period of his life some few years earlier, in order to introduce the history of his Orrery,[131]before mentioned; a piece ofmechanism which is admitted, by all competent judges of its merit, to be one of the greatest of his works.
The Planetarium invented by Mr. George Graham,[132]—and a model of which was improperly retained by Mr. Rowley, its constructor,—had, long before the appearance of Mr. Rittenhouse’s machine, acquired the name of an Orrery; in compliment to Richard Boyle, Earl of Orrery,[133]who merely patronized the construction of one, from the artist Rowley’s pirated model. This complimentary appellation of Mr. Graham’s then newly invented Planetarium issaid to have been bestowed upon it by Lord Orrery’s friend, Sir Richard Steele:[134]and, the name being thus applied tothatmachine, all those of the nature ofPlanetaria, subsequently constructed,—however variant in usefulness or design, from the original one bearing the name of an “Orrery,”—were denominatedOrreries.[135]In compliance, then, with long establishedusage, Mr. Rittenhouse modestly called his Planetarian-machine, from the first projection of it, an Orrery; although the entire merit, both of the invention and construction, belonged to himself.[136]
It is not ascertained, at what time Mr. Rittenhouse first conceived the plan of that extensive, complicated and inestimable Orrery, which he afterwards executed. Probably, he had long thought on the subject, before he publicly announced his design. It is certain, however, that before the beginning of the year1767, there was some correspondence and some understanding, respecting it, between himself and the Rev. Mr. Barton. It appears in fact, that, prior to that period, Mr. Barton had been fully apprized of his brother-in-law’s desire to carry into effect his meditated design of constructing a complete Orrery, on a plan entirely new; and that some arrangement was previously made, between these gentlemen; by which Mr. Barton undertook to indemnify Mr. Rittenhouse, for such actual expenditures as he should incur in making the machine and his loss of time while employed in the work, not exceeding a stipulated sum; provided he should not be able to dispose of it, when finished, at a price then fixed on. The prudential caution of our young Philosopher (then about thirty-four years of age,) and the public spirit of his friend, grounded on the confidence he had in the artist’s talents and abilities, were alike evinced on this occasion.
The first written communication made by Mr. Rittenhouse to Mr. Barton, on the subject of the Orrery, is contained in a letter under the date of Jan. 28th, 1767: it is in these words:—“I am glad you took the pains to transcribe, and send me, Martin’sAccount of Orreries.”[137]“Two forms (he says) have principally obtained, the Hemispherical Orrery and the Whole Sphere. But the idea given us by the former,is very unnatural and imperfect. An Orrery, then, adapted to an Armillary Sphere is the only machine that can exhibit a just idea of the true System of the World.”—“But in my opinion,” says Mr. Rittenhouse, “the latter is likewise very unnatural; for, what has a Sphere, consisting of a great number of metaline Circles, to do with the true System of the World? Is there one real, or so much as apparent Circle, in it? (the bodies of the Sun and Planets excepted.) Are they not all merely imaginary lines, contrived for the purpose of calculation? I did not intend to let one of them have a place in my Orrery, except the Zodiac, on which I would have the true latitude and longitude of each planet pointed out by its proper Index.”
“I did not design a Machine, which should give the ignorant in astronomy a just view of the Solar System: but would rather astonish the skilful and curious examiner, by a most accurate correspondence between the situations and motions of our little representatives of the heavenly bodies, and the situations and motions of those bodies, themselves. I would have my Orrery really useful, by making it capable of informing us, truly, of the astronomical phænomena for any particular point of time; which, I do not find that any Orrery yet made, can do.”
“But,” continues Mr. Rittenhouse, “perhaps it may be necessary to comply with the prevailing taste: Ifso, my plan must be entirely altered;—and this is a matter that must be settled between you and me, before I can proceed. However, I shall send you, in my next, a particular account of my design; such as I would have it, if not limited by the fear of making it too expensive.—A specimen (if I may so call it) of the most curious part of it, though much smaller than that intended for the Orrery, is now in hand, and I hope will soon be finished.”
To this letter Mr. Barton returned the following answer.
“Lancaster, February 21st, 1767.“Dear Brother,“I received, a few days ago, yours of the 28th ult.—after it had undergone the torture of some Dutchman’s pocket, which compelled it to force its way through the cover: However, the inside did escape without many fractures; so that I had the pleasure of getting it into my hands in such a condition that I could read it.“Had I known your distress, at the time you received my letter, I should have sincerely felt for you. I well know the anxiety of an husband, on such occasions, and my heart will ever join in sympathy with him: For you, my feelings would have been doubled, as a husband, as my friend and brother. Glad I am, therefore, that I have no occasion to condole with you, but rather to rejoice; and I most sincerely and affectionately congratulate you, on the escape and recoveryof your good girl, and wish you joy of your daughter. I desire to offer my best regards to sister Nelly, for the compliment she intended me, had her child been a boy. Her intention was kind, and I hope to have the continuance of her favourable opinion of me.“I am much pleased with your remarks on Spherical Orreries, or rather on the circles generally adapted to such Orreries. Mr. Rowning seems to be so much of the same opinion, that I could not deny myself the pleasure of transcribing some part of his account of Orreries, and of an imaginary machine, which he thinks might be made very useful.[138]Several of his hints appear to me ingenious, and I hope they will not be unacceptable to you.“I would have you pursue your Orrery in your own way, without any regard to an ignorant or prevailing taste. All you have to study is truth, and to display the glorious system of Copernicus in a proper manner;—and to make your machine as much an original, as possible. I beg you will not limit yourself in the price. I am now perfectly convinced, that you can dispose of it to advantage; and should be sorry you would lose one hour more in fears or doubts about it. In fact, I have laid such plans for the disposal of it, that I have almost a moral certainty of having a demand for more than one of the kind. I have not time to write you as fully as I could wish, as the transcribingfrom Rowning has detained me so long, and I am this moment setting out for Caernarvon.“My letter to the Proprietor[139]is delayed, till I can send him the account of your design, which you are pleased to promise me. You say you have “a specimen” in hand: I should be glad to know what it is.“I shall not neglect the things you mentioned to me, as I shall always receive a pleasure in serving you.... She joins me in love to father, mother and all friends.—I am, in haste, dear Davy, your very affectionate friend and brother,“Thomas Barton.“P. S. Forgive this wretched scrawl—I have not time to examine whether I have committed any errors in copying Mr. Rowning.“I beg leave to recommend Huygens’, Cotes’, Helsham’s, and Power’s Philosophy to you. You will be much pleased with them.
“Lancaster, February 21st, 1767.
“Dear Brother,
“I received, a few days ago, yours of the 28th ult.—after it had undergone the torture of some Dutchman’s pocket, which compelled it to force its way through the cover: However, the inside did escape without many fractures; so that I had the pleasure of getting it into my hands in such a condition that I could read it.
“Had I known your distress, at the time you received my letter, I should have sincerely felt for you. I well know the anxiety of an husband, on such occasions, and my heart will ever join in sympathy with him: For you, my feelings would have been doubled, as a husband, as my friend and brother. Glad I am, therefore, that I have no occasion to condole with you, but rather to rejoice; and I most sincerely and affectionately congratulate you, on the escape and recoveryof your good girl, and wish you joy of your daughter. I desire to offer my best regards to sister Nelly, for the compliment she intended me, had her child been a boy. Her intention was kind, and I hope to have the continuance of her favourable opinion of me.
“I am much pleased with your remarks on Spherical Orreries, or rather on the circles generally adapted to such Orreries. Mr. Rowning seems to be so much of the same opinion, that I could not deny myself the pleasure of transcribing some part of his account of Orreries, and of an imaginary machine, which he thinks might be made very useful.[138]Several of his hints appear to me ingenious, and I hope they will not be unacceptable to you.
“I would have you pursue your Orrery in your own way, without any regard to an ignorant or prevailing taste. All you have to study is truth, and to display the glorious system of Copernicus in a proper manner;—and to make your machine as much an original, as possible. I beg you will not limit yourself in the price. I am now perfectly convinced, that you can dispose of it to advantage; and should be sorry you would lose one hour more in fears or doubts about it. In fact, I have laid such plans for the disposal of it, that I have almost a moral certainty of having a demand for more than one of the kind. I have not time to write you as fully as I could wish, as the transcribingfrom Rowning has detained me so long, and I am this moment setting out for Caernarvon.
“My letter to the Proprietor[139]is delayed, till I can send him the account of your design, which you are pleased to promise me. You say you have “a specimen” in hand: I should be glad to know what it is.
“I shall not neglect the things you mentioned to me, as I shall always receive a pleasure in serving you.... She joins me in love to father, mother and all friends.—I am, in haste, dear Davy, your very affectionate friend and brother,
“Thomas Barton.
“P. S. Forgive this wretched scrawl—I have not time to examine whether I have committed any errors in copying Mr. Rowning.
“I beg leave to recommend Huygens’, Cotes’, Helsham’s, and Power’s Philosophy to you. You will be much pleased with them.
“I wish you would purchase Bion’s Description of Philosophical and Mathematical Instruments, &c.”
“Mr. David Rittenhouse.”
His next letter to Mr. Barton, covering the promised Account of his Orrery, is dated the 27th of March, 1767: and this, it will be perceived, is very nearly a year before a description of it was communicated to the American Philosophical Society in Philadelphia. In this letter, he says—“Rowning’s opinion of Orreries pleases me more than any thing I had met with before. The idea of hisimaginarymachine naturally presents itself to persons conversant in Astronomy; but, if actually made, it could not answer the purpose, unless prodigiously large,—which I presume is the reason it has never beendone.done.
“I send“I sendyou a description ofmyimaginary machine: the foundation of it is now laid; and I hope that part of it, containing the mechanical Astronomy of the Moon, will be finished some time this spring:thenwe shall be able to judge, whether my abilities are equal to the undertaking.”
The “Description” here referred to, in Mr. Rittenhouse’s own hand-writing, is new before the writer of these Memoirs; and is thus endorsed by the Rev. Mr. Barton—“Original Description of Mr.Rittenhouse’s Orrery, first communicated to Thomas Barton.”—For the satisfaction of those, who may not have an opportunity of seeing the American Philosophical Society’s Transactions, in which this short account of the Orrery was afterwards published; and, as thisoriginaldescription of it differs somewhat from theprintedone, it is presumed that the introduction of the former into this work, will not be unacceptable to the reader.
The impossibility of conveying to the mind of any one, even the most intelligent and skilful, by means of either any delineation upon paper in the nature of a diagram, or by words, an adequate idea of so complex and multiform a machine as the one now about to be described, will instantly be conceived. Indeed no description, alone, can render the nature of its construction, and the many curious and useful purposes it is capable of answering, perfectly intelligible to the most scientific Astronomer. Mr. Rittenhouse’s very concise description of his Orrery will, therefore, necessarily be found defective: it is thus worded by himself.
–—
“DESCRIPTION OF A NEW ORRERY.
“DESCRIPTION OF A NEW ORRERY.
“DESCRIPTION OF A NEW ORRERY.
“This Machine is intended to have three faces, standing perpendicular to the horizon: that in thefront to be four feet square, made of sheet-brass, curiously polished, silvered, and painted in proper places, and otherwise ornamented. From the centre arises an axis, to support a gilded brass ball, intended to represent the Sun. Round this ball move others, made of brass or ivory, to represent the Planets: They are to move in elliptical orbits, having the central ball in one focus; and their motions to be sometimes swifter, and sometimes slower, as nearly according to the true law of an equable description of areas as is possible, without too great a complication of wheel-work. The orbit of each Planet is likewise to be properly inclined to those of the others; and their Aphelia and Nodes justly placed; and their velocities so accurately adjusted, as not to differ sensibly from the tables of Astronomy in some thousands of years.
“For the greater beauty of the instrument, the balls representing the planets are to be of a considerable bigness; but so contrived, that they may be taken off at pleasure, and others, much smaller, and fitter for some purposes, put in their places.
“When the Machine is put in motion, by the turning of a winch, there are three indexes which point out the hour of the day, the day of the month, and the year (according to the Julian account,) answering to that situation of the heavenly bodies which is then represented; and so continually, for a period of 5000 years, either forward or backward.
“In order to know the true situation of a Planet at any particular time, the small set of balls are to be put each on its respective axis; then the winch to be turned round until each index points to the given time. Then a small telescope, made for the purpose, is to be applied to the central ball; and directing it to the planet, its longitude and inclination will be seen on a large brass circle, silvered, and properly graduated, representing the zodiac, and having a motion of one degree in seventy-two years, agreeable to the precession of the equinoxes. So, likewise, by applying the telescope to the ball representing the earth, and directing it to any planet,—then will both the longitude and latitude of that planet be pointed out (by an index and graduated circle,) as seen from the earth.
“The two lesser faces are four feet in height, and two feet three inches in breadth. One of them will exhibit all the appearances of Jupiter and his Satellites—their eclipses, transits, and inclinations; likewise, all the appearances of Saturn, with his ring and satellites. And the other will represent all the phænomena of the moon, particularly, the exact time, quantity, and duration of her eclipses—and those of the sun, occasioned by her interposition; with a most curious contrivance for exhibiting the appearance of a solar eclipse, at any particular place on the earth: likewise, the true place of the moon in the signs, with her latitude, and the place of her apoge in the nodes; the sun’s declination, equation of time &c. It mustbe understood, that all these motions are to correspond exactly, with the celestial motions; and not to differ several degrees from the truth, in a few revolutions, as is common in Orreries.
“If it shall be thought proper, the whole is to be adapted to, and kept in motion by, a strong pendulum-clock; nevertheless, at liberty to be turned by the winch, and adjusted to any time, past or future.”
“N. B. The diurnal motions of such planets as have been discovered to revolve on their own axes, are likewise to be properly represented; both with regard to the Times, and the situation of their Poles.”
–—
The foregoing is a literal copy of the original manuscript; and such readers of this article as may think proper to compare it with the printed description of Mr. Rittenhouse’s Orrery, communicated to the American Philosophical Society by Dr. Smith, on the 21st of March 1768, and contained in the first volume of that Society’s Transactions, will find some (though, on the whole, not very essential) differences, in the two descriptions. The concluding paragraph, indeed,—designated, in each, by a N. B.—is materially variant in the two: and it appears, by its having been announced in the published (and later) account of this machine, that, “the clock part of it maybe contrived to play a great variety of Music,” (a suggestion wholly omitted in Mr. Rittenhouse’s original communication, made to the Rev. Mr. Barton,) that the philosophic Artist had been afterwards induced, in one particular at least, “to comply with the prevailing taste.”[140]But this may be readily accounted for: our artist had previously made some extremely curious and beautiful Time-pieces, to each of which was attached the mechanism of a Musical Clock, in addition to a limited Planetarium, in miniature. These were in the hands of gentlemen of respectability and taste:[141]and they were much and generally admired,as well for the great ingenuity displayed by the constructor, in these combined and pleasing operations of his machinery, as for the superior accuracy and beauty of the workmanship; qualities eminently conspicuous in all his mechanical productions.
It appears, that when Mr. Rittenhouse sent the foregoing description of his projected Orrery to Mr. Barton—that is to say, on the 27th of March, 1767[142]—the“foundation” of it was “laid.” But, notwithstanding his earnest wishes prompted him to the utmost diligence, in his exertions to finish it, many circumstances concurred to retard its completion. The magnitude of the undertaking—the multiplicity of the work—and, perhaps, the difficulty of sometimes readily procuring, even from Philadelphia, the necessary materials,—all conspired, to prevent as early a completion of the machinery as he had anticipated: and, added to these causes of unavoidable delay, was the yet unabandoned pursuit of his professional business.
The Orrery was, nevertheless, then his favourite object. On the 18th of June, 1767, he wrote to Mr. Barton, thus—“I hope you will persuade your Pequea friends to stay for the clocks, till harvest is over; and then, I think, I may venture to promise them, for ready money: but, at this time, one part of the Orrery is in such forwardness, that I am not willing to lay it by till it is done. I hope it will far exceed the description I gave you of it. To-morrow morning I am to set off for Reading, at the request of the Commissioners of Berks county, who wrote to me about their town-clock. They had employed a ... to make it, who, it seems, is not able to go through withit: if I should undertake to finish it, this will likewise retard the great work.”
Amidst the more important philosophical pursuits which engaged Mr. Rittenhouse’s attention before his removal to Philadelphia, as well as after he fixed his residence in that city, he now and then relaxed the energy of his mind from its employment in laborious investigations, by bestowing a portion of his time on minor objects in physical science; and indeed, sometimes, even on little matters of ingenuity, curiosity and amusement. As instances of this, he addressed to the Rev. Mr. Barton the letter under the date of the 20th of July, 1768, which will be found in the Appendix; and also another, dated the 4th of February, 1770, to which there is the following postscript:
“I have,” says he, “seen a little curiosity, with which you would be pleased; I mean the glass described by Dr. Franklin, wherein water may be kept in a boiling state, by the heat of the hand alone, and that for hours together. The first time I shall be in Lancaster, where I hope to be next June, I expect to prevail on you to accompany me to the Glass-house,[143]where we may have some of them made, aswell as some other things I want.”—A description of this instrument, then usually calledDr. Franklin’s Pulse-Glass,[144]by means of which water may be made to boil,in vacuo, by the heat of the human hand, was communicated by Mr. Rittenhouse to Mr. Barton in a subsequent letter.
1. Hence, in conformity to this sentiment, Mr. Pope says, when animadverting on the insufficiency of talents, alone, for acquiring an honourable fame and meriting a character truly great,—“If parts allure thee, think how Bacon shin’d,The wisest, brightest, meanest of mankind;Or, ravish’d with the whistling of a name,See Cromwell damn’d to everlasting fame.”[Essay on Man.]
1. Hence, in conformity to this sentiment, Mr. Pope says, when animadverting on the insufficiency of talents, alone, for acquiring an honourable fame and meriting a character truly great,—
“If parts allure thee, think how Bacon shin’d,The wisest, brightest, meanest of mankind;Or, ravish’d with the whistling of a name,See Cromwell damn’d to everlasting fame.”[Essay on Man.]
“If parts allure thee, think how Bacon shin’d,The wisest, brightest, meanest of mankind;Or, ravish’d with the whistling of a name,See Cromwell damn’d to everlasting fame.”[Essay on Man.]
“If parts allure thee, think how Bacon shin’d,The wisest, brightest, meanest of mankind;Or, ravish’d with the whistling of a name,See Cromwell damn’d to everlasting fame.”[Essay on Man.]
“If parts allure thee, think how Bacon shin’d,
The wisest, brightest, meanest of mankind;
Or, ravish’d with the whistling of a name,
See Cromwell damn’d to everlasting fame.”
[Essay on Man.]
2. The miserable consequences which have resulted to the civilized world, from the mode of reasoningabstractly, and from the meresyntheticalplan of philosophising, are too apparent to need much comment. Even somegeometriciansof great name have been seduced, by such means, into monstrous absurdities in physics; and into the maintenance of doctrines, alike subversive of religion and morals, as destructive of the foundations of civil society. Such were Descartes, Leibnitz and Spinoza, of the seventeenth century: and such have been, and even now are, too many of that class of modern philosophers, as well in this country as on the continent of Europe,—whose metaphysical notions of religion and government, (although some of them may, perhaps, be pretty correct on the subject of physics, alone,) have been the means of inundating the world with scepticism; and, after overturning regular, orderly, and peaceable states, of establishing despotism and misery on the ruins of rational government, in many of the fairest portions of the old world.Even Voltaire, who had, himself, been instrumental in corrupting the mind of the great Frederick of Prussia, and, thus, of furnishing the means for the subsequent overthrow of that once powerful monarchy; eventhis infidelcould not help exclaiming, in a moment of sober reflection, “Who could have believed, thatgeometricianshave been wild enough to imagine, that, in the exaltation of the soul, we may possess the gift of divination; yet more than one philosopher took it into their heads, by the example ofDescartes, to put themselves into God’s place, and create a world with a word! But now, allthese philosophical folliesare reproved by the wise; and even their fantastical edifices, overthrown by reason, have left in their ruins, materials, of which reason has made some use.—A like extravagance has infected themoralworld: there have been some understandings so blind as to undermine the very foundation of society, at the time they thought to reform it. They have been mad enough to maintain that the distinctions ofmeum & tuumare criminal, and that one ought not to enjoy the fruits of one’s own labour; that not only all mankind are upon a level, but that they have perverted the order of nature, in forming societies; that men are born to be separated from each other, like wild beasts; and that amphibious animals, with bees and ants, confound the eternal laws, by living in common! These impertinences, worthy of an hospital of madmen,” continues Mr. de Voltaire, sarcastically, “have been for some time in fashion, just as it is customary to lead apes to dance, at fairs.” [SeeThe Age of Louis XV.ch. 39.]But although it cannot be doubted; that the society of Voltaire contributed to support, if not to generate, the deistical principles of Frederick II. other foreigners, whom he had patronized and cherished in his own capital, and with whom he associated, most of them Frenchmen, did much towards debauching his mind, in regard to religion. The Prince de Ligne, a distinguished Austrian field-marshal, has verified this remark. In a letter written to the king of Poland, in the year 1785, the prince narrates some particulars of a conversation which took place between the Prussian monarch and himself, in the year 1770; and observes, that the king expressed his libertine sentiments too freely, even making a boast of his irreligion. The prince de Ligne, on this occasion, charges freethinkers with a want of candour, in promulgating opinions fraught with infidelity, while many of them heartily dread the consequences of what they affect to renounce. But this, he remarks, is not their only fault: “they are also apt,” says he, “to make a parade of free-thinking; which betrays, at least, a want of taste. It was,” continues the prince, “from having been surrounded by men of bad taste, such as D’Argens, Maupertuis, La Beaumelle, La Mettrie, the Abbé de Brades, and some clumsy infidels of his academy, that the king had contracted the habit of abusing religion, and talking of dogmas, Spinozism, the court of Rome, &c.”Letters and Reflexions of the Prince de Ligne.
2. The miserable consequences which have resulted to the civilized world, from the mode of reasoningabstractly, and from the meresyntheticalplan of philosophising, are too apparent to need much comment. Even somegeometriciansof great name have been seduced, by such means, into monstrous absurdities in physics; and into the maintenance of doctrines, alike subversive of religion and morals, as destructive of the foundations of civil society. Such were Descartes, Leibnitz and Spinoza, of the seventeenth century: and such have been, and even now are, too many of that class of modern philosophers, as well in this country as on the continent of Europe,—whose metaphysical notions of religion and government, (although some of them may, perhaps, be pretty correct on the subject of physics, alone,) have been the means of inundating the world with scepticism; and, after overturning regular, orderly, and peaceable states, of establishing despotism and misery on the ruins of rational government, in many of the fairest portions of the old world.
Even Voltaire, who had, himself, been instrumental in corrupting the mind of the great Frederick of Prussia, and, thus, of furnishing the means for the subsequent overthrow of that once powerful monarchy; eventhis infidelcould not help exclaiming, in a moment of sober reflection, “Who could have believed, thatgeometricianshave been wild enough to imagine, that, in the exaltation of the soul, we may possess the gift of divination; yet more than one philosopher took it into their heads, by the example ofDescartes, to put themselves into God’s place, and create a world with a word! But now, allthese philosophical folliesare reproved by the wise; and even their fantastical edifices, overthrown by reason, have left in their ruins, materials, of which reason has made some use.—A like extravagance has infected themoralworld: there have been some understandings so blind as to undermine the very foundation of society, at the time they thought to reform it. They have been mad enough to maintain that the distinctions ofmeum & tuumare criminal, and that one ought not to enjoy the fruits of one’s own labour; that not only all mankind are upon a level, but that they have perverted the order of nature, in forming societies; that men are born to be separated from each other, like wild beasts; and that amphibious animals, with bees and ants, confound the eternal laws, by living in common! These impertinences, worthy of an hospital of madmen,” continues Mr. de Voltaire, sarcastically, “have been for some time in fashion, just as it is customary to lead apes to dance, at fairs.” [SeeThe Age of Louis XV.ch. 39.]
But although it cannot be doubted; that the society of Voltaire contributed to support, if not to generate, the deistical principles of Frederick II. other foreigners, whom he had patronized and cherished in his own capital, and with whom he associated, most of them Frenchmen, did much towards debauching his mind, in regard to religion. The Prince de Ligne, a distinguished Austrian field-marshal, has verified this remark. In a letter written to the king of Poland, in the year 1785, the prince narrates some particulars of a conversation which took place between the Prussian monarch and himself, in the year 1770; and observes, that the king expressed his libertine sentiments too freely, even making a boast of his irreligion. The prince de Ligne, on this occasion, charges freethinkers with a want of candour, in promulgating opinions fraught with infidelity, while many of them heartily dread the consequences of what they affect to renounce. But this, he remarks, is not their only fault: “they are also apt,” says he, “to make a parade of free-thinking; which betrays, at least, a want of taste. It was,” continues the prince, “from having been surrounded by men of bad taste, such as D’Argens, Maupertuis, La Beaumelle, La Mettrie, the Abbé de Brades, and some clumsy infidels of his academy, that the king had contracted the habit of abusing religion, and talking of dogmas, Spinozism, the court of Rome, &c.”
Letters and Reflexions of the Prince de Ligne.