To Benjamin Franklin from Edward Nairne, 19 November 1784
From Edward Nairne
ALS: American Philosophical Society
London Novr: 19: 1784
Dear Sir
I did my self the pleasure of writing to you the 8th of last Month8 & sent it to your grandson. I last night had the pleasure of seeing him at the R.S. He told me he was detained longer than he expected. But that he should go Sunday or Monday next which oppertunity I have taken of sending you the identical hygrometer, I mentioned in mine of the 8th of Octr. that I took down to Ramsgate. It has never grown so dry as to be equal to that wch. I kept in London, though before I took it down they moved very well together.9 I hear there is a wonderful Electrical Machine at Paris made of oiled silk.1 Major Gardener told me that the single sparks drawn from it are sufficient to knock down an Ox, that the sparks are two or three inches thick & about three feet long.2 When I have the pleasure of hearing from you, if you would favor me with some Account of its construction, it would be an addition to the many favors already received by Dear Sir Your Most Obliged Hble servt:
Edwd: Nairne
PS I have had no returns since I was electrified, of my old disorder.3 I hope you will do me the pleasure of accepting of the Hygrometer
Addressed: His Excellency / Benjn: Franklin Esqr / passey near / Paris
8. Not found.
9. In December, 1783, Nairne had sent drawings of a hygrometer he proposed to build based on ideas suggested to him by BF in October of that year: XLI, 118, 251–3; XLII, 443. The two hygrometers mentioned here were undoubtedly based on that design. The one that Nairne sent with WTF has not been found. The other, which he retained, is now in the collection of the Science Museum, London.
1. This was the endless-band electrical machine invented by Charles-Louis Walckiers de Saint-Amand and investigated by a commission of the Académie des sciences in early 1784. BF was appointed to that commission on Jan. 31, but his name did not appear on its report of March 17. The machine featured a five-foot-wide, 25-foot-long band of varnished silk that ran continuously over two wooden rollers located on opposite ends of a wooden frame and operated by cranks. Electricity was generated by friction as the silk rubbed against cushions covered with fur. The prime conductor was suspended by silk cords in the center of the endless band. The commissioners recorded sparks of more than 15 inches in length: XXXII, 345n; Académie des sciences, Procès-verbaux, CIII (1784), 19, 62–9.
2. Valentine Gardner (XLII, 498–9), who had heard about the machine from Ami Argand, described it at a meeting of the Coffee House Philosophical Society on Nov. 12. Nairne was also a member of the society but did not attend that meeting: Trevor H. Levere and Gerard L’E. Turner, eds., Discussing Chemistry and Steam: the Minutes of a Coffee House Philosophical Society, 1780–1787 (Oxford and New York, 2002), pp. 26, 83.
3. Like BF, Nairne suffered from the stone: XXXVIII, 42; XXXIX, 91.