Rare! Type One G.L. CHAMBERLIN Patent 1867 Inclinometer

Patented Jan. 1, 1867 by G.L. Chamberlin of Marietta, OH.  Manufactured by W.S. Batchelder of Pittsburgh, PA.  The rare type 1 features the knurled locking mechanism on the inside of the frame. Vial is full and working and appears original. There are only a handful of type 1 examples known. The early locking mechanism was prone to breaking and the design was quickly changed to the more common wingnut on the outside of the frame. This one has survived undamaged and in very nice original condition.