The Ferrier Machine Works (aka Philo Ferrier & Son, aka Ypsilanti Machine Works) was a foundry and machining business that specialized in mill parts, particularly corn-shellers. Philo Ferrier began the business around 1860 in the Millworks Building, at 308-312 N. River Street, a building now appropriately home to the River Street Bakery (though Mann notes that the building dates to 1840, and the millworks was not its original use).

Chapman describes the Machine Works as "one of the great industrial establishments of the city" in 1881, employing a large number of skilled workers and featuring a 10 horsepower motor.

Ferrier's son Charles joined the business in 1870, and continued to run it after Philo's death in 1912.

Sources:

• Mann, Ypsilanti: A History in Pictures, pg. 34.
• Ypsilanti Gleanings, March 1990, Philo Ferrier.
• Chapman, 1881, pg. 1137:
  • The foundry and machine shops of Ferrier & Son, located on River street, near the M. C. R. R. depot, form one of the great industrial establishments of the city. The foundry is principally devoted to the construction of mill machinery and corn-shellers. The buildings of the firm are extensive and substantial; the main building is 60x130 feet, two-stories high, with return house containing foundry and machine shop. A 10-horse power engine is the motive power used. The firm employs a large number of skilled workmen.