"When Jacob Blattner retired in 1872, his son Henry Blattner took over the business together with his brother-in-law, Frank Adam.  The 1874 St. Louis directory lists them as 'Blattner & Adam mathematical and optical instrument makers.'    The instrument business was continued until 1891.  Henry Blattner continued the optical business and Frank Adam became further involved in the electrical construction work of the Western Electric Company.  Adolph Wissler, who had been a workman and foreman for Blattner & Adam took over the instrument business, which he continued until 1926.   

Henry Blattner was born in St. Louis, Missouri in 1848 and died there in 1922.  Frank Adam was born in Frieburg, Alsace-Loraine in 1838 and died in St. Louis in 1922." 

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