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 Greenwich and 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 of mechanism which is admitted, by all competent judges of its merit, to be one of the greatest of his works. ----- Footnote 131: