Description:
A telephone receiver design without a diaphragm, by French inventor Clement Ader. Device consists of a frame made of four brass bars which supports a dish-shaped rubber earpiece and brass tapered cylinder at one end and a pair of flat brass disks with a tapered cylinder at the other end. A brown jacket of material surrounding the tapered cylinder furthest from the earpiece is cracked and partially missing.
Connecting the two ends is a thin iron rod; a small spool wound with wire, which should sit on the rod and attach with two coils of wire to two brass binding posts, is missing. The binding posts, each with a knurled-edge thumb adjustment screw, are mounted on one of the brass bars, and protrude out of the frame.