This is an antique German surveying equipment, used for angle reading within a fraction of a second of arc. This was made by the well known German Firm Fennel Kassel.
In 1852, the French physicist Léon Foucault discovered a gyro with two degrees of freedom points north. This principle was adapted by Max Schuler in 1921 to build the first surveying gyro. In 1949, the gyro-theodolite – at that time called a “meridian pointer” or “meridian indicator” – was first used by the Clausthal Mining Academy underground. Several years later it was improved with the addition of autocollimation telescopes. In 1960, the Fennel Kassel company produced the first of the KT1 series of gyro-theodolites. Fennel Kassel and others later produced gyro attachments that can be mounted on normal theodolites.
Still in working condition.