In 1879, Siemens & Halske presented the world's first electric passenger train in which power was supplied through the rails. The 150-volt direct current flowed through the two rails to the small locomotive via an insulated flat iron bar mounted between the rails. The little electric locomotive, on which the driver sat, pulled a train of three small carriages, each holding six passengers, around a 300 meter long circular track through the exhibition grounds. Werner von Siemens described the train's success in a letter to his brother Carl: "Our electric railway is quite a spectacle here. In fact, it is working better than expected. For a few hours each day, 1,000 passengers pay 20 pfennigs a ride to benefit a charity. Each train carries 20 to 25 people. The speed is about the same as a horse-drawn railway. Now something can be built on this !" Siemens & Halske AG (or Siemens-Halske) was a German electrical engineering company that later became part of Siemens. It was founded in 1847 as Telegraphen-Bauanstalt von Siemens & Halske by Werner von Siemens and Johann Georg Halske.