Ernst von Siemens. Portrait of German electrical engineer (Ernst) Werner von Siemens (1816-92). He was born in Lenthe, Hanover, and was the most versatile of four engineer brothers. In 1834 he entered the Prussian Artillery, and later took charge of the artillery workshops in Berlin. While in Prussia he developed the telegraphic system. He realised the insulating property of gutta-percha. However, his main achievements were in designing electrical generators, electric traction and electrolytic systems. The SI unit of electrical conductance is named after him. Ernst von Siemens was also the founder of the important Siemens and Halske engineering company.