This small instrument, only about 7 inches across, made by the A. Kruss company in Hamburg, Germany, was brought to Hawaii by Emil Louis Kruss sometime soon after the Hawaiian "revolution" of 1893. I believe that Emil Kruss was the son of William Kruss, one of two brothers who inherited control of the company when their father died in 1851.

Emil Kruss left Hamburg in 1889, became a naturalized U.S. citizen in San Francisco in 1893, and later set off for Hawaii. He became the proprietor of Hotel Wahiawa, where he met and became friends with my grandfather. When Kruss died shortly after WWII, my grandfather served as executor of his estate, and the barmoter passed into his hands. At that time, there was communication with members of the Kruss family in Hamburg, and my parents sent several care packages to them during the Marshall Plan period, only to subsequently lose track of them.

But a quick Google check found the firm A. Kruss Optronic alive and well, and still headed by a member of the Kruss family. So I just fired off an email with these photos and a long version of this history, and am waiting to see what, if anything, comes back in reply.