John Halsy (fl. 1700); mathematical instruments. Joseph Halsy (fl. 1697-1762); surveying instruments. Rowland Houghton (1678-1744); surveying instruments. Andrew Newell (1749-1798); surveying instruments. Joseph Newell (fl. 1800-1813); surveying instruments. Joseph Pope (1750-1826); scientific instruments and clocks. Nathan Prince (fl. 1743), practitioner; scientific instruments. Paul Revere (1735-1818); gunnery instruments. Charles Thacher (18th century); surveying instruments. Samuel Thaxter (1769-1842); surveying, nautical, and mathematical instruments. William Williams (1737/8-1792); mathematical and nautical instruments. Brookfield: John Potter (1746-1818); surveying instruments. Hanover: John Bailey II (1752-1823); surveying instruments. Lanesboro: Benjamin Platt (1757-1833); surveying instruments, clocks, and compasses. Lynn: John Bailey II (1752-1823); surveying instruments. Nantucket: Peter Folger (1617-1690), practitioner(?). Walter Folger (1765-1849), practitioner; clocks and astronomical instruments. Newburyport: Gideon Fairman (1774-1827); mathematical instruments. Hooker & Fairman (before 1810); mathematical instruments. Northampton: Jedidiah Baldwin (c.1777-1829); surveying instruments. Stiles & Baldwin (fl.1791); surveying instruments. Stiles & Storrs (fl.1792); surveying instruments. Plymouth: Benjamin Warren (fl.1740-1790); surveying and nautical instruments. Salem: Jedidiah Baldwin (c.1777-1829); surveying instruments. Samuel Emery (1787-1882); mathematical instruments. John Jayne (late 18th century); mathematical instruments. Benjamin King (1740-1804); nautical instruments. Daniel King (1704-1790); mathematical instruments. John Prince (1751-1836), practitioner; scientific instruments. Southwick: Amasa Holcomb (1787-1875); surveying and mathematical instruments. NEW HAMPSHIRE Exeter: Benjamin C. Gilman (1763-1835); mathematical instruments and clocks. Hanover: Jedidiah Baldwin (c.1777-1829); surveying instruments. Newmarket: John Kennard (1782-1861); surveying instruments. Portsmouth: Thomas S. Bowles (c.1765-1821); surveying instruments.