"Frederick Heisely was born in Lancaster County, Pennsylvania in 1759.  In 1778 he enlisted in Captain Joseph Howell's Company, 2nd Pa. Regiment, Colonel Stewart in command, and was in service during the Jersey campaign of 1778.  It is assumed that when he was discharged from the Army, he became an apprentice to George Hoff of Lancaster, a clock and instrument maker.  He married George Hoff's daughter, Catherine, in 1783 and moved to Frederick, Maryland.  While there he made the town clock.  His two sons were born in Frederick:  George Jacob in 1789, and Frederick Augustus in 1792.  In 1793 the Heisely family moved back to Lancaster, Pennsylvania and Frederick became a partner with this father-in-law, George Hoff.   They were in partnership for about eight years, making surveyor's instruments, land compasses and projectors.  About 1811 the family moved to Harrisburg, Pennsylvania.  Frederick became a prominent citizen of Harrisburg, being Treasurer of Dauphin County from 1827 to 1829.  He was in business with his son George J. from 1811 until Frederick retired.  The firm was known as Heisely & Son.  Frederick died in Harrisburg, Pennsylvania in 1843."

Instrument shown is from the collection of the National Museum of American History, a division of the Smithsonian Institution