Siemens, Ernst Werner von (1816–1892)

German electrical engineer and inventor who discovered the dynamo principle 1867. He organized in 1870 the construction of the Indo-European telegraph system between London and Kolkata (formerly Calcutta) via Berlin, Odessa, and Tehran.

Siemens was born near Hannover and studied at a military academy in Berlin. In 1847 he founded, with scientific instrumentmaker Johan Halske (1814–1890), the firm of Siemens-Halske to manufacture and construct telegraph systems.

In addition, he cooperated with his brothers who founded Siemens Brothers in the UK. As scientific consultant to the British government, Siemens helped to design the first cable-laying ship. He also helped to establish scientific standards of measurement.

Siemens's inventions include a process for gold- and silver-plating and a method for providing the wire in a telegraph system with seamless insulation, using gutta-percha.

Siemens introduced the double-T armature and succeeded in connecting the armature, the electromagnetic field, and the external load of an electric generator in a single current. His companies became pioneers in the development of electric traction – making trams, for example – and also electricity-generating stations.