Here's one to figure out. It has a patent date that I haven't looked up yet. I thought that I'd give the diggers a chance here. Oh the things we bring home.[]
Here's a look at the other side. On the above is: PAT. APRIL 23d 1878 / MADE IN THE / UNITED STATES OF AMERICA . Above all this is an old looking arrow and under that is the word: WINDING. Any ideas???
It's a winding cap from a clock. The clock it came from must have had functions other than just telling time because it's a secondary cap not a main spring cap.
Some military clocks had this feature so several functions could be set and wound independently. Several manufacturers used them.
Thanks Towhead (that was fast) & Capsoda -
After looking at the link below, the clock pictured shows a different back, but I get the idea. Case closed..... Thanks again.