Universal Pattern Wheatstone Bridge
This bridge (by Kohlrausch) was designed to measure the resistance of wires, objects containing electrolytes such as the human body, and contact resistances  of earth plates and lightning arresters. It consists of  a bank of resistors, a non-linear scale , and a small induction coil .  This particular piece came to UVM in 1896 through James G. Biddle as a result of a gift from Edward H. Williams to the university of a new science building - including equipment and furniture. More here. 
Diagram showing external connections.  The resistance to be measured is connected to terminals at the left. The telephone is used in place of a galvanometer when the induction coil is being used for electrolytic resistance measurements. 
Diagram from Elekrizitat, Graetz, 1906, pg 93-95.
Various models of this device claim to measure resistances from .05 - 20,0000 ohms.  The resistance is read directly from the scale.

For more information go to A Manual of Practical Medical Electricity, Turner, 1904. , Electro-Medical Instruments and Their Managment, Schall, 1902, or Price List 50, Physical Apparatus Vol III, Max Kohl, 191_. (Thanks to the person who sent me the first two references - due to a hard drive failure I've lost your name/email. Please send me another email so I can credit your contribution to this page)

"Made By Hartmann & Braun Frankfurt A/M. Germany No. 582" 


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