Part 29

On an address of the Philosophical Society to the general assembly, dated the 15th of October, 1768, the latter “Resolved, That a sum, not exceeding one hundred pounds sterling, be provided and appropriated for purchasing a reflecting telescope with a micrometer, for the purpose mentioned in the said address” (observing the Transit of Venus, then near at hand,) “and, afterwards, for the use of the house; and that the speaker do write to Benjamin Franklin, Esq. in London, to purchase the same.”

Footnote 113:

On a similar address of the Philosophical Society, dated the 7th of February, 1769, the assembly granted them one hundred pounds, “to be laid out towards defraying the expenses necessary for observing the (then) ensuing Transit of Venus.” This grant was made on the 11th of February, 1769.

But the sum then granted proving very inadequate to the object, the society petitioned the assembly on the 11th of February, 1773; stating, that the erecting the different observatories, fitting up instruments, engraving various plates, and publishing the different transit papers alone, cost the society near 400l. and praying assistance to discharge that debt.

Footnote 114:

Mr. Lalande, in the preface to his Astronomie (3d edit. 1792,) mentions, that he did not then know of any other observatory in America than that of Mr. Rittenhouse.

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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 the College. 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.

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Footnote 115:

This was one instance among many of the munificence of Mr. Penn to the College of Philadelphia, and of his zealous wish to promote the interests of science in Pennsylvania. The trustees of the college say, in a letter written to Mr. Penn the 1st of August, 1769, thanking him for his donation of the fine instrument above mentioned, together with a pair of “Adams’s new-invented Globes;” “We have likewise the pleasure to acknowledge a fresh instance of your benevolence, in sending us a chemical apparatus under the care of Dr. Rush.” “The many great and valuable favours this College has received at your hands, have always been conferred in a manner which has rendered them peculiarly acceptable; and cannot fail to leave the most lasting impressions of gratitude and esteem in the heart of every person concerned in the institution.”

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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, as described by Dr. Smith.

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Footnote 116:

Mr. Lalande (in his Astronomie) has been careful to mention, that the celebrated astronomer Hevelius possessed a similar merit. He constructed, himself, the very large telescopes and other instruments, described (with plates) in his great work entitled, Machina Cœlestis, and with which he furnished the Observatory that he established at his own residence, in the year 1641. Hevelius (whose true name was John Hoelké.) was the son of a brewer; but was well educated. He was born at Dantzic the 28th of January, 1611: and after having made the tour of England, France and Germany, from 1630 to 1634, he was, on his return to his native city, occupied for some time in the affairs of that little republic; of which he officiated as consul, in 1651. He died on the anniversary of his birth-day, at the age of seventy-six years.

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1. An Equal 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. A Transit 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 excellent Time-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, beat dead seconds, and was kept in motion by a weight of five pounds.

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Footnote 117:

For some of the reasons which induced the writer to describe the instruments used on that occasion, see Note 125.

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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 in mechanics, so extensive an astronomical and mathematical knowledge, 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 laudable pains he hath taken in these material articles,” continues Dr. Smith in his report, “will best appear from the 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.”

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Footnote 118: