A "Control Compass" patented by Liet. Joseph von Peichl of the Austro-Hungarian Navy in 1879. Patent No.5045.
The instrument consists of a double needle with a mirror mounted on agate bearings so as to form a dipping needle. The frame in which this is mounted carries a cover with a lens on one side. There are two sighting vanes, one carrying a wire and other a V and a small hole for sighting the mirror through the lens; the whole being mounted in gimbals in one direction only. The frame carrying the gimbals is a horizontal disc capable of being rotated and fitted with a locking screw; this in turn is carried in a rotatable graduated ring which is also fitted with a locking screw. Thw whole is mounted in a wooden box. Dims. 13" x 13" x 6.25" (33 x 33 x 15.9cm)