I send you two specimens of tin-foil melted between glass, by the force of two jars only.
I have not heard that any of your European electricians have ever been able to fire gun-powder by the electric flame. We do it here in this manner:—A small cartridge is filled with dry powder, hard rammed, so as to bruise some of the grains; two pointed wires are then thrust in, one at each end, the points approaching each other in the middle of the cartridge till within the distance of half an inch; then, the cartridge being placed in the circuit, when the four jars are discharged, the electric flame leaping from the point of one wire to the point of the other, within the cartridge amongst the powder, fires it, and the explosion of the powder is at the same instant with the crack of the discharge.
Your's, &c.
B. FRANKLIN.
FOOTNOTES:
[56] See the paper entitled, [Farther Experiments], &c.
[57] The cushion being afterwards covered with a long flap of buckskin, which might cling to the globe; and care being taken to keep that flap of a due temperature, between too dry and too moist, we found so much more of the electric fluid was obtained, as that 150 turns were sufficient. 1753.
TO C. C[58]. ESQ. AT NEW-YORK, COMMUNICATED TO MR. COLLINSON.
[Unlimited Nature of the electric Force.]
Philadelphia, 1751.