Christian Hülsmeyer

Christian Hülsmeyer (Huelsmeyer) (25 December 1881 – 31 January 1957) was a German inventor, physicist and entrepreneur. He is often credited with the invention of radar, but his apparatus, called the "Telemobiloscope," could not directly measure distance to a target and thus does not merit this full distinction. The Telemobiloscope was, however, the first patented device using radio waves for detecting the presence of distant objects.

Hülsmeyer was born at Eydelstedt, a village in Lower Saxony, Germany. He was the youngest of five children of Johann Heinrich Ernst Meyer and Elisabeth Wilhelmine Brenning. His birth name was Johann Christel, but after early childhood the name Christian was used. Following completion of the local Volksschule (elementary school), he attended Grundschule (primary school) in nearby Donstorf. A teacher there recognized his capabilities and, in 1896, assisted him in gaining admission to the Lehrerseminare (Teacher Training College) in Bremen. At the school, his major interest was in physics, and, after classroom hours, he was allowed to use the physics laboratory for his own experimenting. His interest was more with the potential applications of physics than with the academic side.

In June 1900, Hülsmeyer left college without completing his studies and obtained a job as an electrical trainee in the Siemens & Halske factory in Bremen. There he learned how concepts of devices were turned into commercial applications, intensifying his inventive nature. In April 1902, he left employment with Siemens to live with his brother Wilhelm in Düsseldorf and pursue his ideas for electrical and optical products. His brother initially funded him in setting up a shop where, a number of ideas were quickly turned into working items. These included a device (called a Telephonogram) that telegraphed sounds; an electro-optical system for turning a truck into a mobile, multi-faced billboard; and a wireless apparatus for remotely igniting explosives. Within a year, he filed several patent applications on these and other inventions.

In developing the wireless apparatus, Hülsmeyer read of Heinrich Hertz’s discovery that electromagnetic waves were reflected from metallic surfaces. He then turned his full attention to using the Hertz phenomenon in a system for preventing collisions between ships. Giving the name Telemobiloskop (Telemobiloscope) to the system, he made a patent application on 21 November 1903, and also advertised for a financial backer. Henry Mannheim, a leather merchant in Cologne, responded, and in March 1904, invested 2,000 Marks for 20 percent of future profits from the apparatus. The firm Telemobiloskop–Gesellschaft Hülsmeyer & Mannheim was opened the following May and officially registered in Cologne on 7 July 1904.

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