Dated 1840-1850. From Scientific apparatus, musical instruments and telegraph equipment, [1834-1875].
ABC automatic telegraph receiver designed by Wheatstone. The mechanism consists of a spring driven clockwork controlled by an electromagnetic escapement and activated by pulses of current from the sender. These pulses rotate the wax disc, printed with the alphabet and numerals, and the required character is indicated by a single needle pointer. The disc or dial on the receiver moves in unison with the dial on the transmitter. Housed in a mahogany box with a glass front decorated with pilasters and pediment, a plate on the mechanism is inscribed 'C. Wheatstone Invt.'.