From William Henly
ALS: American Philosophical Society
[December 30, 17723]
I send you herewith the paper of your experiments, and shall think myself under great obligation for the addition.4 I am quite at a loss what to think or say about the Bell. The effects are so contrary to the notions I [had] entertained of Electricity; and yet I scarse know how to disbelieve my Friends relation, for though by his Letter he appears to be no Schollar at all, yet [he] is as sensible, and as clever a Man in Conversation as you would wish to converse with.5
Going up. In the Stone Gallery Thermometer 28. no Ch[arge8]. Wind very troublesome quite round the Building. In the Golden Gallery Thermometer 31. Balls diverged 1 Inch full. In the Lanthorn a very warm Room Thermometer 35. The Rod being projected through a Hole its whole length, on the side opposite to that, from which the Wind blew: the balls diverged I think 1¾ Inch and were nearly stationary.
Coming down. In the Stone Gallery Thermometer 29. Balls diverged ½ Inch. The Wind while we were there got round more to the Southward, and the Air grew more hazy, which I believe brought on, or increased the Electricity.9
Monday Evening 5 O Clock Mr. Bell1 went there, and observed that in the Stone Gallery Balls diverged when held at Arms length2 ½ Inch, Thermometer 34. In the Golden Gallery, held in the same manner they diverged ½ Inch Thermometer 33. In all these cases the Mercury had time to subside before observation. I am Dear Sir sincerely yours
3. Henly, when he published these experiments, dated them between Dec. 24 and 29: Phil. Trans., LXIV (1774), 427. His letter mentions Monday (which in that week was the 28th) and “yesterday” as if they were different days; we assume that his experiments were performed on the 29th and that he was writing on the 30th.
4. Our conjecture is that Henly had received part of the material he had requested in his letter above, under Oct. 28, and a promise from BF to send more.
5. The bell is undoubtedly a reference to BF’s first experiment described above, Aug. 18, and therefore the friend is BF. Henly is parodying Benjamin Wilson, whose letter opposing BF’s theories had been read before the Royal Society on Dec. 10; see the headnote above, p. 424, on the Purfleet committee’s letter.
6. For Timothy Lane, F.R.S., the apothecary and electrical experimenter, see above, XIII, 288 n, 459 n.
7. For Henly’s rod, which was in effect an electrometer, see his note above, Sept. 30.
8. The only word that makes sense in context: there was no electricity in the air.
9. Henly was investigating the relationship between altitude, temperature, and electrical charge in the atmosphere; he believed that fog on a frosty day was strongly and positively electrified: Phil. Trans., LXIV (1774), 425–6.
1. Possibly George Bell (1755–85), the Scottish physician and botanist; he and BF had a number of friends in common, through any of whom Bell and Henly might have met; see the Literary and Philosophical Soc. of Manchester Memoirs, II (1785), 381–93. Whoever this Bell may have been, he and Henly often collaborated in electrical experiments: Phil. Trans., LXII (1772), 134; LXIV (1774), 137, 417.
2. [Henly’s note:] from the Ballustrade.