Isaac Chandlee was born in Nottingham, Maryland in 1760 and died there in 1813.  He was one of three sons of Benjamin Chandlee, Jr. and characterized as one of the "Six Quaker Clockmakers" of the Chandlee family.   Isaac was in partnership with his brother Ellis from 1792 until 1804.

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