1From Thomas Jefferson to David Rittenhouse, 6 September 1793 (Jefferson Papers)
Th: Jefferson presents his friendly respects to Mr. Rittenhouse. He has two young ladies at his house whose time hangs heavily on their hands, and the more so, as their drawing master cannot attend them. If Mr. Rittenhouse then does not take his Camera obscura with him into the country, Th:J. will thank him to permit them the use of it a few days, that they may take a few lessons in drawing...
2From Thomas Jefferson to David Rittenhouse, 1 August 1790 (Jefferson Papers)
I do myself the honour of inclosing you a printed copy of the report on measures &c. You asked in your letter whether the papers I had sent you were to be kept or returned. They are now useless and therefore may be done what you please with. They were only copies of what I had retained. Congress will rise this week, and I hope to be able within a fortnight after them to leave this place for...
3From Thomas Jefferson to David Rittenhouse, 1[5] June 1790 (Jefferson Papers)
I inclosed you, the day before yesterday a rough draught of the report I had prepared on the subject of weights and measures. I have this morning recieved from Mr. Short a proposition made by the Bishop of Autun to the National assembly of France on the same subject, which I inclose you, and will beg the favor of you to return it by post after you shall have perused it. He mentions that the...
4From Thomas Jefferson to David Rittenhouse, 22 February 1791 (Jefferson Papers)
Th: Jefferson will be obliged to Mr. Rittenhouse to inform him who has the best assorted shop of Mathematical instruments in town. RC (Miss Elizabeth Sergeant Abbot, Philadelphia, 1954). Not recorded in SJL . TJ’s inquiry was made in behalf of George Wythe (see Wythe to TJ, 10 Jan. 1791 ; TJ to Wythe, 14 Mch. 1791 ).
5From Thomas Jefferson to David Rittenhouse, 8 June 1792 (Jefferson Papers)
Th: Jefferson incloses to Mr. Rittenhouse the first criticism which has come to his hands on the rod-pendulum as a standard of measure. It is from a clergyman of Scotland. The author’s language is so lax, that it is difficult to know with precision what idea he means to express. It is particularly so in the following sentence at the bottom of the 1st. page. ‘It is therefore impossible to fix...
6From Thomas Jefferson to David Rittenhouse, 11 April 1793 (Jefferson Papers)
I received yesterday your note on the subject of Michaud’s instructions, and think it would be better to have a meeting of the society that they may accept the charge proposed to them by the subscribers, and may appoint a committee to draw instructions, and a person to collect the fourth of the subscriptions and pay it to Mr. Michaud. My attendance on the society will be precarious, as it must...
7From Thomas Jefferson to David Rittenhouse, 30 June 1790 (Jefferson Papers)
Your favor of the 25th. came to hand last night, for which I give you many thanks. The conversion of 36.71428 pouce[s] into 39.1923 inches was an error in division, and consequently the mean taken between that and Graham’s computation is wrong. It has rendered it necessary for me to suppress the note on that subject, and to put it into the form now inclosed. In this I state the reaso[n] for...
8From Thomas Jefferson to David Rittenhouse, 20 June 1790 (Jefferson Papers)
I inclosed you on the 17th. the alterations I had made in my report in consequence of the Bp. of Autun’s proposition which had come to my hands two days before. On the 18th. I received from Mr. Cutting in London a packet of newspapers, among which were the two inclosed, containing the speech in parliament of Sr. John Riggs Miller on the subject of weights and measures. I observe he states the...
9From Thomas Jefferson to David Rittenhouse, 8 May 1791 (Jefferson Papers)
You mentioned to me once, information which you had recieved and which satisfied you that the pouch of the Opossum disappeared after weaning the young. As I knew that Mr. Randolph intended this spring to make observations on that animal I communicated to him your information that he might pay particular attention to it. You will see what he says. Tho a single observation is not conclusive, yet...
10George Washington to David Rittenhouse, [9 July 1792] (Jefferson Papers)
Having had under consideration the letter of the Director of the mint of this day’s date, I hereby declare my approbation of the purchase he has made of the house and lot for the mint, of the employment of Mr. Voight as Coiner, of the procuring fifteen tons of copper, and proceeding to coin the cents and half cents of copper and dismes and half dismes of silver: and I leave to his discretion...