You searched for: “circumferentor
circumferentor (s) (noun), circumferentors (pl)
A surveyor's compass with diametral projecting arms is an instrument used to survey or to measure horizontal angles: A circumferentor is used in mines and in wooded or uncleared areas.

Circumferentors were typically mounted on tripods and rotated on ball-and-socket joints.

This entry is located in the following unit: circum- (page 2)