Figure 17.—Brass surveying compass made by Stephen Greenleaf (fl. 1745) of Boston. Photo courtesy New Hampshire Historical Society, Concord.
Following Daniel's death, his business in instruments was inherited by his son Benjamin King (1740-1804), of Salem. Benjamin specialized in producing nautical instruments, and several of his Davis quadrants have survived in public collections. When he died on December 26, 1804, Reverend Bentley wrote that King was " ... a Mathematical Instrument maker, in that branch which immediately regarded practical navigation by quadrant and compass. He supported a very good character through life & was much esteemed."[29]
Another of the very early mathematical instrument makers in Massachusetts was Stephen Greenleaf (see fig. 17), who kept a shop on Queen Street opposite the prison in Boston where
He makes and Mends all Sorts of Mathematical Instruments, as Theodolites, Spirit Levels, Semicircles, Circumferences, and Protractors, Horizontal and Equinoctial Sun Dials, Azimuth and Amplitude Compasses, Elliptical and Triangular Compasses, and all sorts of Common Compasses ... N.B. He sets Load Stones on Silver or Brass, after the best manner.[30]
Jonathan Dakin worked as a mathematical balance-maker "at the Sign of the Hand & Beam, opposite to Dr. Colman's Meeting House" where he made a variety of scale beams in 1745.[31]
An interesting advertisement by Rowland Houghton appeared in the January 17-24, 1737, issue of the Boston Gazette. Houghton announced that he had "lately improv'd on his new Theodolite, by which the Art of Surveying is rendered more plain & easy than heretofore." Houghton was active in the political scene in Boston, as evidenced by the fact that in various issues of the Boston Gazette for January and February 1739 he is listed variously as "Commissioner," "Proprietors' Clerk" and as "Collector."
Isaac Greenwood, Jr. (1730-1803), was born at Cambridge, where he married Mary I'ams in 1757. He maintained a shop where he combined the business of mathematical instrument maker and ivory turner, and also imported hardware. After the Revolution, he engaged in dentistry, specializing in making artificial teeth and in the manufacture of "umbrilloes." Paul Revere apparently did printing for him on five different occasions between 1762 and 1774, and in about 1771 engraved his trade card, which read:
ISAAC GREENWOOD, Ivory Turner Next door to Doctor John Clark's at the North End Boston. Turns all sorts of work in Ivory, Silver, Brass, Iron, Horn, Wood, etc. Such as Billiard Balls, Tea Boards, Scallopd and Plain Salvers, Decanters ...[32]
Isaac's father, Isaac Greenwood, Sr., was "Professor of Mathematicks and Natural and Experimental Philosophy" at Harvard. In the Boston Gazette for February 19-26, 1728, there appeared the following notice of his installation: