Note 118 — MEMOIRS OF THE LIFE OF DAVID RITTENHOUSE; ANTERIOR TO HIS SETTLEMENT IN PHILADELPHIA.
Reading edition
In addition to this publicly declared testimony of Dr. Smith, to the merits of Mr. Rittenhouse on that occasion, are the following extracts of a letter from the Dr. to Mr. Barton, dated July the 8th, 1769.
“Mr. Jesse Lukens left my house on Tuesday evening, at half an hour past six, where he waited till I scrawled out a pretty long letter to Mr. Rittenhouse, for whom my esteem encreases the more I see him; and I shall long for an opportunity of doing him justice for his elegant preparations to observe the Transit, which left Mr. Lukens and me nothing to do, but to sit down to our telescopes. This justice I have already in part done him, in a long letter to the proprietor” (Thomas Penn, Esq.) “yesterday, and I hope Mr. Rittenhouse will not deprive us of the opportunity of doing it in a more public manner, in the account we are to draw up next week.”
“I did not chuse to send Mr. Rittenhouse’s original projection of the Transit, as it is a society paper, to be inserted in our minutes: but I have enclosed an exact copy. Pray desire him to take the sun’s diameter again carefully, and examine the micrometer by it. The mean of our diameters come out, Hor. Diam. 31′ 34″, 3—Polar Diam. 31′ 32″, 8—Ven. Diam. 57, 98.—The Sun’s is bigger than the Naut. Almanac gives: That of Venus very well. The diameters of the State-house micrometer come out less. I have compared some of our” (the Norriton) “micrometer-observations with those made in town, and do not find a difference of one second: but all theirs do not seem to have been taken with equal care, and differ from each other sometimes; a fault I do not find among ours. Our nearest distance of the centres comes out, I think, 10′ 3″, in which we agree within about one second with their nearest distance: and our time of the nearest approach of the centres, viz. 5h 20′ 32″, reduced to mean time, is within one minute of the time marked for their nearest approach.”
“With my compliments to Mr. Rittenhouse and family, I am, in great haste,” &c.
Mr. Barton was then at Norriton, and Dr. Smith wrote from Philadelphia.