Benson, John fl. 1793-1797 * Optical Biddle, Owen 1737-1799 Philadelphia (practitioner) Biggs, Thomas fl. 1792-1795 New York and Surveying Philadelphia Blakslee, Ziba 1768-1834 Newtown, Conn. Surveying Blundy, Charles fl. 1753 Charleston, S. C. Thermometric; watches Bowles, Thomas S. c. 1765-1821 Portsmouth, N. H. Surveying Breed, Aaron 1791-1861 Boston Surveying Brokaw, Isaac fl. 1771 Philadelphia * Bulmain & Dennies fl. 1799 New York Nautical Burges, Bartholomew fl. 1789 Boston Scientific Burnap, Daniel 1759-1838 East Windsor and Surveying; clocks Coventry, Conn. Caritat, H. fl. 1799 New York Astronomical Chandlee, Benjamin, 1723-1791 Nottingham, Md. Surveying; clocks Jr. Chandlee & Bros. fl. 1790-1791 Nottingham, Md. Clocks; surveying Chandlee, Ellis 1755-1816 Nottingham, Md. Surveying; clocks Chandlee, Ellis & fl. 1791-1797 Nottingham, Md. Clocks; surveying Bros. Chandlee, Goldsmith c. 1751-1821 Winchester, Va. Surveying; astronomical; clocks Chandlee, Isaac 1760-1813 Nottingham, Md. Surveying; clocks Clark, Robert fl. 1785 Charleston, S.C. Nautical; surveying optical Clough, Jere 18th century Boston Surveying Condy, Benjamin fl. 1756-1798, Philadelphia Mathematical; sand d. 1798 glasses Crow, George c. 1726-1772 Wilmington, Del. Surveying; clocks Dabney, John, Jr. fl. 1739 Boston Mathematical Dakin, Jonathan fl. 1745 Boston Mathematical; balances Davenport, William 1778-1829 Philadelphia Mathematical; surveying Dean, William (?-1797) Philadelphia Surveying; nautical Devacht, Joseph and fl. 1792 Gallipolis, Ohio Watches; compasses; Francois sundials Donegan (or fl. 1787 New York Glass; Denegan), John philosophical Donegany, John (see Donegan) Doolittle, Enos 1751-1806 Hartford, Conn. Surveying; clocks nautical; Doolittle, Isaac 1721-1800 New Haven, Conn. Clocks; scientific Doolittle, Isaac, 1759-1821 New Haven, Conn. Surveying; clocks Jr.