Benjamin Platt was the migratory type. In 1817 he migrated from Lanesboro to Columbus, Ohio. His son, Augustus Platt (1793-1886), also made mathematical instruments (see fig. 25) in Columbus. In 1809 a grandson, named William Augustus Platt was born. When the child's mother died, Benjamin and Adah Platt adopted the boy, and when he came of age he went into the watchmaking trade. William Platt married Fanny Hayes, sister of President Hayes.[52] His shop was listed in the 1843 city directory; it was the first jewelry and clock and watch store in the community.
An interesting account of instrument making in Ohio is found in the report of a missionary, John Heckewelder. He mentioned the brothers Joseph and Francois Devacht who worked as watchmakers and instrument makers in Gallipolis, Ohio. Writing in 1792, Heckewelder stated that "the most interesting shops of the Workmen [in Gallipolis] were those of the Goldsmiths and Watchmakers. They showed us work on watches, compasses, sundials finer than I have ever beheld."
Figure 24.—Brass surveying compass made by Benjamin Platt (1757-1833) of New Milford, Connecticut, about 1795-1800. Shown in original wooden case and separately (opposite page). Photos courtesy Ohio State Museum.
New York
There were relatively few makers of mathematical instruments in New York City before the end of the 18th century. Perhaps the earliest was John Bailey, who moved from Fredericksburg, Virginia, to Fishkill, New York, in 1778. He was a cutler by trade, and he made and sold surgical instruments.[53]
"Bulmain & Dennies" at 59 Water Street in New York were the appointed agents to sell the "Perpetual Log or Distance Clock to find a ship's way at sea." The device had been patented in the United States, and one of the instruments was displayed at the bar of the Tontine Coffee House, according to an advertisement in the July 23, 1799, issue of the New York Gazette and General Advertiser.
H. Caritat, at 153 Broadway in New York, imported and sold "The Planispherical Planetarium." This item was described in an advertisement[54] as "a graphic representation of the earth, in twelve particular positions during its revolutionary course around the sun, as also of the Moon's revolution around the earth, together with literal description of parts and motions, etc." The advertisement also stated that Caritat sold "Carey's newly improved Terrestrial and Celestial Globes which omitted the Constellary Configurations."