Printed photographic reproduction illustrating two wiring plans for a doorbell: one bell and two push buttons with either button ringing the bell, the other showing two bells and two push buttons with each button…
Portrait of American chemist Edward Goodrich Acheson (1856-1931), inventor of the Acheson process to synthesize graphite and silicon carbide and later a manufacturer of carborundum and graphite.
Edward Goodrich Acheson…
This engraving shows Dutch mathematician and physicist Jean Henri van Swinden (1746–1823) demonstrating the generation of electricity to the Felix Meritis Society in Amsterdam. The Felix Meritis Society was founded in…
Black finished cylindrical casing with three copper electrodes in a line next to product inscription; nickel knob is raised above the cylinder; outer dial goes from 0-15 (but only three digits are visible through its…