- Patent 3,051,138. Sheet 1 of 2. Hydraulic governors.
- From the vintage advertisement collection.
- A vintage Caterpillar Company advertisement.
- An Allis-Chalmer Company's Plate Steel Spiral Casting for 70,000 hourse-powered Niagara Falls hydraulic turbine unit.
- The Allis-Chalmer Manufacturing Company in West Allis, Wisconsin, circa 1930.
- Allis-Chalmers office in Wisconsin, circa 1925.
- The Allis-Chalmer Manufacturing Company in West Allis, Wisconsin, circa 1920.
- A schematic drawing showing the Woodward Airbleed type turboprop engine governor.
- A vintage Gardner Governor Company advertisment.
- A vintage Gardner Governor Company advertisment.
- The Woodward Governor Company's Mill Street factory assembly floor in the 1930's.
- The Woodward Governor Company's factory down by the Rock River in the Water Power District in Rockford, Illinois.