No:  842

This Artillery compass was produced by C.P.Goerz on the  20-10-1915. Inside the cover, you can  see a map of the isogons  ( Lines having equal declination are connected by lines known as ISOGONS ) for Central Europe in German dated Jan. 1, 1915

Markings: M.15 Richt-Bussole (aiming compass), Wien u. Pozsony (names of Goerz' plants in Vienna, Austria and Pozsony, former Hungarian designation of Bratislava, today's capital of Slovakia, which was a part of the Austro-Hungarian Empire until 1918).