Siemens, Ernst Werner Von (1816–1892)

views updated

SIEMENS, ERNST WERNER VON (1816–1892)

Werner Siemens, German inventor, engineer, and entrepreneur was born on December 13, 1816, in Lenthe near Hanover, Lower Saxony, as the fourth child of fourteen children. His father was a tenant farmer. Siemens's education was first undertaken by his grandmother Deichmann, and it continued under a series of home tutors. In 1823 the family moved to Mecklenburg where the father took over the running of the estate of Menzendorf. From Easter 1832 until Easter 1834, Siemens attended the Katharineum, a gymnasium (secondary school) in the Hanseatic town of Lübeck, which he left without final examination. Because his interests were mathematics and natural sciences, rather than classical languages, he took some private lessons in mathematics to improve his education.

The family's precarious financial situation prompted Siemens to choose a military career as a way to advance his education in mathematics, physics and chemistry. In 1835 after basic training at the Artillery Corps in Magdeburg, he moved to Berlin where he stayed for three years as an officer candidate and a student of the Prussian Artillery School. There he was able to study under the guidance of the physicist Gustav Magnus. The death of both parents in 1840 put Siemens, as the oldest son, in charge of his nine surviving siblings. He took his brother Wilhelm to Magdeburg, where he continued his service in an artillery regiment. Passing a term of confinement in fortress, because of assisting a duel, Siemens smuggled in chemicals and experimented with galvanoplasty, a procedure discovered by Moriz Hermann Jacobi. He successfully developed a galvanic method of gold and silver plating. His brother Wilhelm went to England, patented and sold the discovery. From Siemens's electrochemical interests originated also a method of production of ozone and of electrolytic production of clean copper.

TELEGRAPHY

Siemens met the precision engineer Johann Georg Halske at Magnus's Institute of Physics in 1846. Together the two men founded "Siemens & Halske Telegraph Construction Co" in 1847 to exploit the new technology of electric telegraphy, which had been established three years earlier with the first public telegraph line of Samuel Morse. Siemens improved the dial-telegraph, invented the method for a seamless insulation of copper wire with guttapercha, and discovered the multiple telegraphic use of copper conductors. The first long-line telegraph line, which was 660 km long and laid by Siemens & Halske between Berlin and Frankfurt was inaugurated on March 28, 1849, the day at which the first German national parliament in Frankfurt passed a constitution. His industrial career ensured, Siemens retired from the army. In 1851 Siemens & Halske commenced installation of a telegraph line between Moscow and St. Petersburg. For the Russian project Siemens put his brother Carl in charge. In 1855 the telegraph network for European Russia was installed, and through a Polish line a crucial link with Western Europe was established.

To compete worldwide, Siemens founded several industry subsidiary companies: in St. Petersburg, in London, in France, and in Vienna. In these endeavors, Siemens placced great trust in family members. After cousin Johann Georg helped to establish the company financially, Siemens incorporated other relatives: brother Friedrich and nephew Georg, later the first director of Deutsche Bank. In 1868 Siemens Brothers Co. of London started a cooperation with the Indo-European Telegraph Co. to lay mainly overhead cables through Southern Russia and Persia, effectively joining London and Calcutta. An improved printer telegraph with a punched tape synchronized with current pulses of an inductor with a double T armature operated from 1870 on this line.

Between 1874 and 1880 Siemens Brothers laid transatlantic cables using their own cable-steamer Faraday.

ELECTRIC GENERATORS AND MACHINES

The only source of electric energy available until the 1830s was in the form of galvanic elements. The situation changed in 1831 with the discovery of the law of electromagnetic induction by Michael Faraday. The law states that an electric current is generated in a conducting circuit if the latter is exposed to a fluctuating magnetic field. As a consequence of Faraday's discovery, numerous engineers—among them Siemens—designed and improved electric generators. The basic idea behind the first generators was to move wire coils into and out of the magnetic field of a permanent magnet, thereby generating an electric current in the coils according to the induction law. A hand-turned generator with magnets revolving around coils was constructed as early as 1832 in Paris. A year later, the reversed principle to rotate the coils in a fixed field of a permanent magnet was realized in a generator constructed in London. Around 1850, industrial production of electric generators was set up in several European countries. In 1856, Siemens developed a double T armature, cylinder magnet constructed on the basis of Faraday's law of induction to provide a source of electricity for telegraphs cheaper than Zinc galvanic batteries. Though more powerful than galvanic elements, the first generators did not yet provide sufficient electric energy for heavy mechanical work. The limitation was imposed through the rather modest size of the available permanent magnets. To overcome this shortcoming Siemens proposed in 1866, almost simultaneously and independently of some others (Soren Hjorth, Anyos Jedlik, Alfred Vaarley, and Charles Wheatstone) to substitute an electromagnetic effective magnet for the permanent magnet. Siemens is credited with having worked out the principle underlying the new type of generator: a rotating coil inside a stationary coil, both forming a single circuit connected to the external consumer circuit. By starting the rotation of the movable coil, a weak current is induced through a residual magnetic field delivered from the iron armature of the apparatus. The current in the stationary coil causes an increase of the magnetic field, which in turn gives rise to an increased current output from the rotating coil. A self-enhancing process of current generation is so initiated. Siemens called this scheme of a self-excited generator the "dynamo electrical principle." Its formulation, presented to the Academy of Science on January 17, 1867, and subsequent demonstration of the electric light from the dynamo-machine moved through a steam-machine at the factory side in Markgrafenstrasse, Berlin, laid the groundwork for the modern technology of electric generators. This discovery is considered Siemens's most important contribution to science and engineering.

Siemens constructed the first electric railway shown at the Berlin Trade Fair of 1879 and the first electrically-operated lift in 1880, and the first electric trams began operating in Berlin in 1881. Siemens received many honors for his work: an 1860 honorary doctorate from the University of Berlin, an 1873 membership in the Royal Academy of Science, and an 1888 knighthood from Emperor Friedrich III. Siemens died in Berlin, Charlottenburg, on December 6, 1892.

Barbara Flume-Gorczyca