Edmund March Blunt opened a chart and instrument store in New York in 1811. His sons, Edmund and George William Blunt, trading as E. & G. W. Blunt, opened a similar store in 1824. In the early days, most of these instruments were imported. An advertisement from 1837 states: “One of the firm is now in England superintending the manufacture of Theodolites, Transit Instruments, etc.,–and any orders for Instruments not now on hand, will be forwarded to him, and executed promptly.” In the mid-1850s, after having built a dividing engine, the Blunts advertised that they could “divide Astronomical and Nautical Instruments to a degree of precision which they will guarantee to be equal to the best of foreign make.” The firm, with its dividing engine, became Blunt & Nichols (in 1866), Blunt & Co. (in 1868), Eckel & Imhoff (in 1872), and H. A. Kolesch (in 1885).
Ref: Harold Burstyn, At the Sign of the Quadrant (Mystic, Ct., 1957).
Description of E. & G. W. Blunt’s Dividing Engine (New York, 1857).