Check the listing for details. Keuffel & Esser Dip Circle Inclination Compass, Scientific Instrument. 1900. Condition: Used, Made in United States. Listed at 282.72 USD. Old scientific magnetic measuring instrument manufactured by Keuffel & Esser Co. New York between 1900 and 1930. This is a tilt compass, also called a dip circle, used to measure the tilt angle of the Earth's magnetic field. This type of instrument was intended for geologists, engineers, cartographers, scientific expeditions and physics laboratories. The object is made of brass, with its original cover and a metal ring allowing free suspension for precise measurement. The magnetic needle is mobile and functional. The brass has an authentic patina, consistent with age. Function: Measurement of the earth's magnetic inclination Condition: Good general condition, functional needle, normal traces of use Beautiful collector's item, cabinet of curiosities, vintage decoration Historical piece from.