|Friedrich Wilhelm Georg Kohlrausch (1840-1910) was a professor
of physics at Göttingen, Zürich, Würtzburg, Strasbourg and
Berlin during his career. He wrote a widely-used book on methods
of experimental physics, and developed improved measurement
techniques in electricity and magnetism.| || The Catalogue and
Price-List of Electrical Testing Apparatus, issued by James W.
Queen & Co. of Philadelphia in 1887, shows the upper version of
the Kohlrausch Universal Bridge (from the Denison University
Collection). The catalogue description is: "Professor
Kohlrausch's Universal Rheometer, or Bridge and Rheometer
combined; with induction coil, for measuring the resistance of
solid and fluid conductors, batteries, etc., by means of
galvanometer or telephone ... $52.00." The telephone receiver
was an extra $6.00. The prefix rheo, introduced by Wheatstone in
1837, refers to resistance. The second piece of apparatus, from
Washington and Lee University, can be found in the 1921
catalogue of E. Leybold's Nachfolger [Successo