Frederick Augustus Heisely, a son of Frederick Heisely instrument maker, was born July 3, 1792 in Frederick, Maryland.  About 1811, the Heisely family moved to Harrisburg, Pennsylvania.  "It is assumed that Frederick A. served an apprenticeship with his father.  He is first listed in the 1837 Pittsburgh, Pennsylvania Directory.  He has an advertisement in that directory which illustrates a surveyor's compass stating that he also makes clocks and watches.  The 1839 directory lists:  Heisely, F. A., Watch and Instrument Mfg., 6 St. Clair, between Penn. and Liberty.  From 1844 on, he is listed intermittently until 1872-3 when the listings cease.  His name is among the first to be recorded of the members of the First Lutheran Church of Pittsburgh as he was elected an Elder of the congregation on the date of its organization January 15, 1837.  Frederick Augustus Heisely died May 21, 1875.  He is interred in the Allegheny Cemetery in Pittsburgh."

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