‎FRANKLIN, BENJAMIN (+) TIMOTHY LANE.‎
‎Description of an Electrometer Invented by Mr. Lane" with an Account of Some Experiments Made by Him with It: In a Letter to Benjamin Franklin. - [THE DISCHARGING ELECTROMETER]‎

‎London, Lockyer Davis, 1767. 4to. Without wrappers. Extracted from ""Philosophical Transactions"", vol. 61, part 1. Including title-page and advertisement of volume. A fine copy. Pp. (4), 451-60 + 1 folded engraved plate.‎

Reference : 54348

‎First appearance of Timothy Lane's description of his discharging electrometer. He used it to determine the charge given to a Leyden jar by counting the number of sparks it received from the electrometer set at a constant gap. The instrument became popular in electrotherapy and was used to limit the power of the electrical discharge. (Heilbron, Electricity in the 17th & 18th Centuries).‎