Tangent Galvanometer Magnetometer supported on brass tube fitted on bakelite plate free to revolve in the base of the instrument. Magnetometer and bakelite ring both can rotate independently of the base, fitted with levelling screws. Compass box consists of a bakelite case with metal dial graduated in degrees and anti-parallax mirror. Cobalt steel magnet and aluminium pointer mounted on special synthetic saphire, needle moves on hardened steel pivot. Ring dia 162mm. Winding 2, 50, 500 turns. Qty :