Dupee, John fl. after 1761 Boston Surveying Ellicott, Andrew 1754-1820 Baltimore Surveying; (also practitioner) astronomical Emery, Samuel 1787-1882 Salem, Mass. Mathematical Evans, George fl. 1796; d. Philadelphia Mathematical 1798 Fairman, Gideon 1774-1827 Newburyport, Mathematical (See Hooker and Mass. Fairman) Fisher, Martin fl. 1790 Philadelphia Glass Folger, Peter 1617-1690 Nantucket (practitioner?) Folger, Walter, Jr. 1765-1849 Nantucket Astronomical; surveying Ford, George fl. late 18th Lancaster, Pa. Surveying; nautical century to 1842 Ford, George, II fl. 1842 Lancaster, Pa. Surveying; nautical Fosbrook, W. fl. 1786 or New York Surgical; dental earlier Gatty, Joseph fl. 1794 New York and Glass; Philadelphia philosophical Gilman, Benjamin C. 1763-1835 Exeter, N.H. Mathematical; clocks Gilmur, Bryan fl. end of Philadelphia Mathematical; 18th century clocks Godfrey, Thomas 1704-1749 Philadelphia Improved reflecting backstaff Gould, John fl. 1794 Philadelphia Nautical; surgical; optical Grainger, Samuel fl. 1719 Boston (practitioner) Greenleaf, Stephen 1704-1795 Boston Mathematical Greenough, Thomas 1710-1785 Boston Mathematical; surveying; nautical; astronomical Greenough, William fl. 1785 Boston Surveying Greenwood, Isaac, fl. 1726 Boston Surveying Sr. (practitioner) Greenwood, Isaac, 1730-1803 Boston Mathematical Jr. Grew, Theophilus fl. 1753 Philadelphia (practitioner) Hagger, Benjamin c. 1769-1834 Boston and Mathematical; King Baltimore surveying Hagger, William c. 1744-1830? Newport, R.I. Nautical Guyse Halsie, James, I fl. 1674 Boston (practitioner) Halsy, James, II 1695-1767 Boston Mathematical; surveying Halsy, John fl. 1700 Boston Mathematical Halsy, Joseph fl. 1697-1762 Boston Surveying; nautical