Humboldt State University ® Department of Chemistry
Robert A. Paselk Scientific Instrument Museum
L &N Wheatstone Bridge
Leeds & Northrup Co.
HSU Physics Department, 1960
Used in physics to determine the value of an unknown resistance. This instrument represents L&N’s final version.
From WikiPedia: "A Wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component.
Its operation is similar to the original potentiometer. It was invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843. One of the Wheatstone bridge's initial uses was for the purpose of soils analysis and comparison." (http://en.wikipedia.org/wiki/Wheatstone_bridge; downloaded from Wikipedia 06/27/2012)
Early descriptions of the Wheatstone Bridge are provided below:
The instrument is described in the catalog scan available above. The case measures 9 1/2" x 6" x 1/4" x 3 7/8". The catalog scan is from Cenco, Cat J- 150 General Catalog Laboratory Apparatus & Scientific Instruments, Chicago. (1950).
Operating directions are available via this link: Directions: 4760 Wheatstone Bridge