Related Object Info
dip circle
This instrument is made of a brass circle mounted on vertically on a round brass circular base. The base has a copper level and is supported by three feet, which have each a leveling screw. The whole instrument can rotate on its base with the help of a tangent screw.
There is an engraved scale around the vertical circle, marked by single degrees and subdivided every 30'. It is numbered by tens in the following way: 30°-0°- 90°-0°-30°, the zeros matching up at horizontal diameter. The index arm with vernier pivots on center of circle. The magnetic needle is mounted on knife-edge pivots and is enclosed in a rectangular brass box with copper edges, silvered base and glass cover.
A small copper magnifying glass is attached at the upper end of the box to assist in aligning the needle. Some screws have small pre-determined punched dots for dismantling purposes. A very uncommon instrument by Nairne.