It looks like an Abney Level for measuring vertical angles. I have seen shorter ones, but the idea is to sight through the tube and adjust the protractor needle to vertical. You can do the same thing with a handheld compass with a collumator.
__________________
Terry Warner
- 74-????? M151A2
- 70-08876 M38A1
- 53-71233 M100CDN trailer
Beware! The Green Disease walks among us!
|