The "Robert L. Shaw 222 Water St. N.Y." signature refers to Robert Ludlow Shaw (1813-1876). Shaw originally worked with John H. Wheeler, who boasted that he was a "real Manufacturer" of mathematical instruments. In 1836, when Wheeler withdrew from business, Shaw and Addington Frye took over the shop. They showed their surveying and navigational instruments at several exhibitions, and won several prizes. In 1845, now in business on his own, Shaw announced that "Having had many years experience in the Manufacturing Line, he feels confident that he can produce as good an article of his own manufacture, and at as low prices, as has ever been made in any part of the world." He went on to say that in manufacturing instruments, "no time or expense has been spared to enable him to compete, in point of accuracy, with the best manufacturers in Europe." Moreover, he had imported a large dividing engine based on the designs of Jesse Ramsden, "the same as is used by the London manufacturers, the accuracy of which has been subjected to the severest test, and proved to be correct." Shaw's product line included "Quadrants, Octants, Sextants, Circles, Astronomical Transits, Telescopes, Theodolites, Levels, and Surveyor's Compasses." In 1850 Shaw had $3,000 capital invested in his business; employed 11 workmen at $120 per month, spent $1,000 on materials, and produced goods worth $10,000. Despite Shaw's claims, in design and production this instrument is less successful than those made by William J. Young. The horizontal circle is graduated every 30 minutes of arc, and read by opposite verniers to single minutes. The vertical arc is graduated every 30 minutes of arc, and read by vernier to single minutes. This transit belonged to John Ferris, a surveyor of Dutchess County, N. Y., who probably bought it around 1848. Ref: Anne Preuss and Don Treworgy, "Robert Ludlow Shaw,"Rittenhouse 2 (1988): 65-69. R. L. Shaw's Edition of the Nautical Almanac and Astronomical Ephemeris for the Year 1848 (New York, 1845). Conrad Ham, "A Family History of a Group of Surveying Instruments, 1750 to the Present Year 1954," Annual Report of Proceedings of the Connecticut Society of Civil Engineers 70 (1954): 134-138.

National Museum of American History - Transit