Karl Elsener (inventor) Karl Elsener (inventor) Karl Elsener (9 October 1860 - 26 December 1918) was a Swiss cutler, inventor and entrepreneur. Karl Elsener completed an apprenticeship as a knife maker in Zug. After some journeyman years he opened a factory in Ibach, Switzerland in 1884 for the manufacture of knives and surgical instruments. He invented the Swiss army knife in 1891 and developed his knife manufacturing company into what has become Victorinox. From 1912 to 1918 Elsener was a member of the cantonal parliament of the Canton of Schwyz. He was married three times. After him his son, Carl Elsener (1886-1950), and
Karl Weissenberg studied at the Universities of Vienna, Berlin and Jena with Mathematics as his main subject. He published on the theories of Symmetry groups and Tensor and Matrix algebra, then applied mathematics and experimentation to crystallography, rheology and medical science. Karl Weissenberg Karl Weissenberg (11 June 1893, Vienna – 6 April 1976, The Hague) was an Austrian physicist, notable for his contributions to rheology and crystallography. The Weissenberg effect was named after him, as was the Weissenberg number. He invented a Goniometer to study X-ray diffraction of crystals for which he received the Duddell Medal of the Institute of Physics in