The Aquameter
Gemini compass was originally manufactured by the Aquameter
Compass Co. of
New Jersey. Aquameter was
sold to
Rule Industries, the maker of Danforth compasses in the 1990's.The Gemini compass was updated and included in the Danforth Constellation line of
instruments as the 4-1/2" Constellation Compass.
Try contacting Danforth for instructions:
Danforth - ITT