Potentiometer

Potentiometer is an instrument used for measurement or comparison of small potential differences in electromotive forces. A wooden box with a clock like mechanism running from 1-100. A small window showing a gauge from 0-30 at the bottom. A metal label on the box reads "Foote Pierson & Co. 160-162 Duane St. New York No." On the surface of the instrument are three gold knobs set above the surface and a black button flush with the surface. Inside the box, there is a paper instruction attached to the lid, including a pencil-drawn diagram of the potentiometer. There is a paper tag on the box written as "#91".