Soren Hjorth. Engraving of Soren Hjorth (1801- 70), Danish engineer & inventor, with the electric motor he devised in 1849 and patented in 1851. The base of the motor contained batteries that drew some electromagnets down into others. This recip- rocating, vertical motion was converted into rot- ary motion by a cranked flywheel (at upper right). The machine was displayed at the Great Exhibition in London, UK, during 1851 but was generally unsuccessful as a practical motor. In 1855 Hjorth patented a self-excited electrical dynamo but failed to exploit the idea. He was also Technical Director of the first Danish railway line, between Copenhagen & Roskilde, which opened in 1847.