"Adolph Wissler was born in St. Louis Missouri in 1866 and died there in 1926.  He is first listed in the 1881 St. Louis City Directory as a machinist.  Then in 1900 as Adolph Wissler Surveying Instruments, and in 1905 as Wissler Instrument Works."

Reference:  Smart, Charles E.   The Makers Of Surveying Instruments In America Since 1700  Troy, New York:  Regal Art Press.  1962