In 1845, Birdsill Holly moved to Seneca Falls and joined forces with Horace C. Silsby and Washburn Race, as Silsby, Race & Holly. Early products included a metal bench plane and a sash mortising machine. At some point this firm became Silsby & Holly, makers of pumps, water wheels, a door and blind mortiser, and other machinery.

Probably because of Holly's inventive successes, some wealthy investors lured Holly to Lockport, NY, where in 1859 he founded the Holly Manufacturing Co.

In 1845, at the same time that Silsby, Race & Holly was founded, the firm of Silsby, Mynderse & Co. was established in Seneca Falls by Horace C. Silsby, Edward Mynderse and John Shoemaker. They manufactured agricultural implements, firefighting equipment, and, beginning in 1856, pumps and steam engines. Their pumps and engines were of a then-novel rotary type that had been patented by Birdsill Holly. Mynderse left the firm around 1857 or '58; for a time it operated as H. C. Silsby but soon re-organized as the Silsby Manufacturing Co. This name was active until 1891, when Silsby merged with several other fire engine makers to form the American Fire Engine Co.

Information Sources

• 1852-04-17 Scientific American, front-page article (with engraving) of Holly's patent plane, manufactured by Silsby, Race & Holly.
• 1852-04-24 Scientific American, article (with engraving) of a drill press manufactured by Silsby, Race & Holly.
• 1852-11-20 Scientific American, article (with engraving) of Holly's patent railroad-car brake; for more information, contact Silsby, Race & Holly.
• 1856 Transactions of the American Institute of the City of New-York lists award winners at that year's Fair of the American Institute, including "Silsby Mynderse & Co., Seneca Falls, N. Y., for the second best steam fire engine. Silver medal." First place was won by Lee & Larned of 18 Greenwich street, NYC. Silsby, Mynderse & Co. also won a silver medeal for "specimens of pumps, &c."
• 1859-05-14 and 1859-05-21 Scientific American ad: SUCCESSFUL DURABLE AND ECONOMICAL ROTARY ENGINE---The Holly Patent Rotary Engine and Rotary Pump have now become well-known, and are in use for a variety of purposes in almost every State in the Union. They are regarded by engineers and practical men to be among the most valuable improvements of the age. The patents has now run a little over four years, and has gained for itself a reputation unprecedented in the history of any patented article. The subscriber will dispose of exclusive State rights either to vend or to manufacture and vend the same. Full descriptions of the improvements, with certificates, &c., and any further information, can he obtained by addressing H. C. SILSBY, Seneca Falls, N. Y., who is also sole owner of the Holly Patent Turbine Water-wheel (the cheapest and best turbine wheel in use), rights of which are offered as above.
• 1860-02-25 Scientific American, article on Silsby, Mynderse & Co.'s improved steam fire engine.
• 1872 catalog from Silsby Manufacturing Co.
• 1879 catalog from Silsby Manufacturing Co. The title page says, "Established 1845 / H. C. Silsby, Horace Silsby, Chas. T. Silsby."
• 1896 book, History of the American Steam Fire-Engine, by William T. King, gives a history of Silsby Manufacturing Co., including a critique of their engine and pump designs.
• 2009 book History of Seneca Falls, by Frances T. Barbieri and Kathy Jans-Duffy, has a portrait and brief biography of Edward Mynderse.
• Stan Pratt's Silsby website provides a history page. Note that this page consistently misspells "Mynderse" as "Myndersen".
• The Life and Times of Birdsill Holly by Madelynn P. Fredrickson, Dec. 1996