By 1885, W. R. Eynon was making machine tools. He had a half dozen employees. In 1887 W. R. Eynon & Co. of Cleveland was manufacturing milling machines, die sinkers and feed grinders. The principal was William R. Eynon, and Judge Jonathan Ingersoll was an investor on behalf of his son Winthrop. In 1887 or '88 Winthrop Ingersoll, a young mechanical engineer, assumed control of the business. Eynon died in March 1888 at age 51. Very close to the time of Eynon's death, Ingersoll changed the business name to Eynon & Ingersoll; the titular Eynon was Thomas Eynon, whose relationship to William is unclear but was perhaps a brother or nephew.

In March of 1890, the partnership between Thomas Eynon and Winthrop Ingersoll was dissolved, with Ingersoll assuming control of the business. At this time the name changed to the Ingersoll Milling Machine Co.

In 1891, Ingersoll accepted attractive financing terms to relocate the business to Rockford, IL, which was aggressively—and successfully—promoting itself as a major new manufacturing center.

Information Sources

• The 1885 Second Annual Report of the Chief State Inspector of Workshops and Factories to the General Assembly of the State of Ohio lists "W. R. Eynon—Machinist Tools; No. 59-63 Centre str.; employs 6 mailes; 1 minor." The premises were found in good condition and no changes were ordered.
• Ad in 1887-03-15 The Mechanical News: "W. R. Eynon & Co. / Winter St., Cleveland, O / Manufacturers of Universal Milling Machines, Die-Sinking Machines, and Special Machinery. / Send for catalog and price list." A small illustration depicts a vertical milling machine.
• The Cleveland Directory for the Year Ending July, 1888, published by the Cleveland Directory Co., lists "Eynon William R. (W. R. Eynon & Co.), r. 21 Jennings av." and "Ingersol Winthrop (W. R. Eynon & Co.), r. 1045 Prospect". The company listing is "Eynon W. R. & Co., (Wm. R. Eynon and Winthrop Ingersoll), Machinists' Tools, Leonard, cor. Winter".
• A RootsWeb page on Cuyahoga County Probate Court Cases lists William R. Eynon's estate settlement, dated 1888.
• A genealogy page for William R. Eynon says that he was born in 1837 and died in 1888 in Cleveland, leaving behind wife Margaret, daughter Anna and two grandchildren. A gravestone photograph provides the exact death date: 1888-03-03.
• 1890-05-07 The American Engineer.

  SPECIAL NOTICE.-The partnership heretofore existing between the undersigned, under the name of Eynon & Ingersoll, is this day dissolved. All the business of the late firm will be settled by Winthrop Ingersoll, who succeeds to and will continue the manufacture of milling machines, under the name of The Ingersoll Milling Machine Co., at the corner of Kirtland and Lake streets. Signed: Thomas Eynon, Winthrop Ingersoll, Cleveland, O., April 14, 1890.

• American Milling Machine Builders: 1820-1920 by Kenneth L. Cope, 2007.
• According to a company history for Ingersoll Production Systems, "Judge Jonathan Ingersoll purchased an interest in W.R. Eynon & Co., a local machine tool company in Cleveland, Ohio. In 1887, his son Winthrop Ingersoll took over the business and in 1891, he moved the company to Rockford, Illinois. Ingersoll was born. The first shop was only 50 x 150 feet and employeed 19 people."