I received this “Marsch-Zirkel” from an old woman. She told me her husband got it from his grandfather.
Its an instrument to see the marching and riding (cavalry) time on a map for a certain distance.
One side is for 1:100000, the other side for 1:80000 map scale.
The inscription in it is:
Prm. Lieut. Brenske
D.R.P. No 61509
Does anybody know something about this item? What is its value?
All I found out was that it was invented in 1891