Fig. 2: Alessandro Volta’s electrophorus
“Volta employed two metal discs, the one of zinc, the other of copper, two, or two and one-half inches of breadth, very plane, not varnished, and having in their centres insulating handles perpendicular to their surfaces, by means of which he could bring them into contact with each other without actually touching any of them with the hand. In this manner he made these discs approach until they touched each other, as in fig. 2 and then separated them, keeping them parallel as he drew them back; but as the electricity developed by a single contact is always extremely feeble, he did not immediately try it with the electrometer” (p. 430).
