Theodore Drury to Faraday   17 December 1838¹

My Dear Sir,

Permit to describe an extraordinary electrifying machine which I yesterday witnessed, and which I think will be new even to you.

It is no other than a leather strap, which connects twodrums in a large worsted mill in the town of Keighley.

Thedimensions and particulars of the strap are as follows:

It is in length. .......... 24 feet

Breadth. .................. 6 inches

Thickness. ................ 1/8 do.

It makes 100 revolutions in a minute.

The drums, over which it passes at both ends, are two feet in diameter, made of wood fastened to iron hoops and turning on iron axles; these drums are placed at 10 feet distance from each other, and the strap crosses in the middle between the drums, where there is some friction; the strap forming a figure of eight. There is no metal in connexion with the strap, but it is oiled. If you present your knuckle to the strap above the point of crossing, brushes of electrical light are given off in abundance, and when the points of a prime conductor are held near the strap, most pungent sparks are given off to a knuckle at about two inches; I charged a Leyden jar of considerable size in a few seconds by presenting it to the prime conductor. The gentleman who told me of this curious strap has frequent‑ly charged his electrical battery in a very short time from it, and he informed me that it is always the same, generating electricity from morning to night without any abatement or alteration. If this strap had the advantage of silk flaps and a little amalgam, it would rival the machine in the lecture room in Albemarle- street.

Pray excuse the earnestness of

Your most faithful Servant, | Theodore Drury.

Keighley Rectory, Yorkshire, | Dec. 17, 1838.