Engraved portrait of Ernst Werner von Siemens (1816-1892) who co-invented an electroplating proces (1841) and also developed an electric dynamo. He was responsible for both the first telegraph line and the first electric railway in Germany and, together with his brother Sir William Siemens (1823-1883), developed a widely used proces of steelmaking. The standard scientific unit of electrical conductance, the Siemens (S), was named after him. Illustration from 'Die ElektricitAt im Dienste der Menschheit' (Electricity in the service of mankind) by Alfred Ritter von Urbanitzky (b 1852), published in Vienna in 1885.
© Science Museum / Science & Society Picture Library