Circa 1895 English Dip Circle - Rare Sciencetific Item.The Dip Needle is a compass (can act as a standard compass too) pivoted to move in the plane containing the magnetic field vector of the earth. It will then show the angle which the magnetic field makes with the vertical. It can also be used to detect Metal deposits. The needle must be accurately balanced so that only magnetic torques are exerted on it. Some texts suggest that the dip angle be measured twice, with the poles of the needle reversed by remagetization between trials, and the results averaged. Some instruments allow the needle and circle to be rotated to allow use as a compass. Condition Good.
Diam Closed 4.5" (11.5cm) €295