From William Henly
ALS: American Philosophical Society
Sunday Evening Apl 18. 1773
Dear Sir

I am much pleased that I went to the Society last [night?] I am now sensible what the crown is, which Mr. [Wilson?] informed me he had prepared for you. As you [are to?] wear it on horseback on Salisbury plain, and a [chain?] is to hang dangling from behind; when you next experiment permit me to request the honour of [being] your trainbearer. I think it will add a little [to the] state with which you’l take your ride. B[ut for?] the greater pomp I could wish to recommend a person to precede you on foot, equip’d as follows. He should have a cap of metal, furnished with a pair of ears of a very considerable length standing upright, and terminated by large round balls; which besides making a handsome appearance upon the cap, would (as I learn from a curious paper read last night,) make so great a resistance to a stroke of lightning, as effectually to preserve the head (suppose Mr. W—s) within it from harm. On second thoughts I believe it will be scarce worth our while to take this trouble, for I recollect a building called the monument whose head is adorned with much such a kind of hoop as my friend W— has proposed, and the hoop is surrounded by 1000 points to represent flames of fire. The Iron twist rail (which is carried to the bottom,) may very well serve to represent your dangling chain: but this building which hath stood very near a century, happens never to have been struck by lightning at all; I think therefore we may as well content [us;] were I to conclude by inference from the experiments [I] have already made; it would be thus. Supposing such a force used as would strike the Knob in contact with the coatings at 4½ Inches from the insulated body. In that case I suspect that the point could not be struck at more than 2 Inches, for I cannot help thinking that the point lessens the force of explosion as the distance increases to a certain quantity, and after that hath no more influence than Knobs. I should imagine this experiment (which I own to me, seems demonstration,) must convince every one who repeats it (except those who are determined not to be convinced,) of the preference due to pointed Conductors, rather than those terminated by a Knob.

I beg your indulgence in the liberty I now take, and that you would believe me to be with real regard Dear Sir your obliged and obedient Servant

W Henly

Addressed: To / Dr. Franklin / Craven-street / Strand
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