"Samuel Thaxter was born in Hingham, Massachusetts in 1769 and died in Boston in 1842.  He is first listed in the 1796 Boston Directory as a mathematical instrument maker.  In the 1822-23 edition, the business is listed as Samuel Thaxter & Son (Joseph H. 1801-1835).  Samuel Thaxter's grandson, Samuel Thaxter Cushing (1821-1882), took over the business around 1843. Upon the death of Samuel Thaxter Cushing, his widow, Abby C. Cushing took over management of the business until 1905 at which time Herbert Risteen Starratt became manager.  The last entry of the company (Samuel Thaxter & Son) in the Boston Directory is 1916."  

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