English, c.1900, signed to the base 'BECKER, HATTON WALL, LONDON', on three adjustable screw feet, base with single spirit level, vertical dial with scale to one side, removable glass window, with steel needle on knife rests with a needle support arm operated vai a screw, instrument height 20.5cm

Note: Dip circles (sometimes referred to as dip needles) were used to measure the angle between the horizon and the Earth's magnetic field (the dip angle). They were used in surveying, mining and prospecting as well as for the demonstration and study of magnetism.