Georg Butenschön was the proprietor of a workshop for scientific instruments located in Bahrenfeld, near Hamburg, and he showed his wares at the international exhibitions held in Chicago (1893), Berlin (1896), and Paris (1900). His basic pocket level was based on his German patent (#36795 dated 1886), which described an instrument in which the level vial, cross hairs, and distant object were seen together through the eyepiece of the telescope. The lower, angle-measuring part of the instrument is based on another Butenschön patent (#76668 dated 1894). This example has screws for horizontal and vertical fine adjustment. The horizontal circle is graduated to degrees, and read by vernier to single minutes. The base of the instrument is a ball and socket joint that can be screwed into a piece of wood.
Ref: Georg Butenschön, "Beschreibung der Taschen-Nivellir-Instrument" (Bahrenfeld bei Hamburg, 1902).
Deutsche Gesellschaft fur Mechanik und Optik, Special Catalogue of the Collective Exhibition of Scientific Instruments and Appliances (Berlin, 1893), p. 16.