The typical telegraph galvanometer from Ericsson. 3

A didactical coherer receiver with bell. 4

View of the coherer/decoherer. 4

A single needle block telegraph. 4

A double needle block telegraph. 3

The Batavia (now Jakarta)-Singapore cable from 1859. 8

A variable resistance for telegraph measurements. 1

A big Wheatstone bridge by Siemens & Halske. 3

A very early high voltage dry-cell battery by Zamboni. 3

Fire or police remote alarm box with an automatic code generator and a Morse key. 3

Detail of the code generator wheel. 3

Typical Belgian drum sounder. 2

Single needle telegraph, was in use by the Midland Railway in England. 4

Dial telegraph transmitter by Breguet-d'Arlincourt. 7

Inside of the Breguet-d'Arlincourt transmitter. 7

A unique telephone by Mildé (FR) ca. 1895. 4