To Charles Thomson
Paris Oct. 8. 1785.
The last letter received from you was of Mar. 6. Since that I have written one to you of June 21. by Mr. Otto, and another of July 14. by Mr. Houdon. In yours of Mar. you express a wish of an opportunity of getting the Cylinder lamp. Colo. Senf going to America furnishes me an opportunity of sending you one, which you must do me the favor to accept. There is but one critical circumstance in the management of it; that is the length of the wick above the top of the cylinder. If raised too high it fills the room with smoke. If not high enough it will not yeild it’s due light. The true medium is where it first ceases to give a sensible smoke in the room. Two or three experiments will set you to rights in this. I send some spare wicks, and a set of spare glasses.
The Emperor and Dutch have signed preliminaries. You will see them in the papers sent to Mr. Jay.—Two artists at Javel, about 4 miles hence, are pursuing the art of directing the baloon. They ascend and descend at will, without expending their gaz, and they can deflect 45°. from the course of the wind when it is not very strong. We may certainly expect that this desideratum will be found. As the birds and fish prove that the means exist, we may count on human ingenuity for it’s discovery. I am with very great esteem Dear Sir Your friend & servant,
RC (PHi). PrC (DLC). Recorded in SJL as sent “With a lamp. By Mr. Fitzhugh”; entry in SJPL reads: “Thomson Charles. Cylinder lamp. Europe. Baloon.”
TJ later sent Thomson an English lamp; a note by John Fanning Watson, the Philadelphia historian, is attached to the present letter and reads: “The annexed Letter of Mr. Jefferson to Chs. Thomson Esqre. was made a gift to J. F. Watson with the Lamp referred to therein, by John Thomson Esqre. (his nephew) in 1825. Another letter from Mr. Jefferson to Mr. Thomson dated London April 22, 1786 thus writes to wit: ‘In your former letters you expressed a wish to have one of the Newly invented Lamps. I find them made here much better than at Paris, and take the liberty of asking you to accept of one which will accompany this letter. It is found that any tolerable oil may be used in them. Spermaceti is best of the cheap Kind.’ [Note the Argand Lamp, such as is here spoken of was Patented I find in the year 1784.]—But this Lamp which I have as above referred to was made in London by Mr. Meigs a nominal Quaker of Cow-cross. I lately saw in business in Philada. a man who was then his apprentice when this identical Lamp was made and was very glad to see it. Meigs managed to Evade the Patent. Argand had been a shoemaker and made his first cylinder of leather. J. F. W. 1826.” For a description and illustration of different types of the Argand lamp, see F. W. Robins, The Story of the Lamp, 1939, p. 112–14; plate xxiv.