Transit, Engineers Precise Level c 1912 (OPTIC10)

According to collector George Fulford's notes:

Bausch & Lomb was famous in the early part of the last century for the high quality optics in their microscopes, and it’s understandable why the War Department chose them to design and manufacture their famed aircraft bubble sextants in WW2. I’ve had this transit for decades, and it did not just sit on a shelf, I had it on a tripod and delighted in using it as a telescope. The clarity of the viewing was why I originally bought it and the more I used it the more I appreciated the extraordinary high quality of the instrument. It is a very heavy all brass mechanical work of art with any number of alignment knobs, and I’ve yet to see another for sale anywhere. In fact this transit appears to be the only one Bausch & Lomb ever built, and the only reference I’ve been able to Google has a picture of it and that being only on loan to a museum.