Jack Device Used for Lifting Objects
A jack is mechanical device used to lift heavy loads or apply great forces. Jacks employ a screw thread or hydraulic cylinder to apply very high linear forces. A mechanical jack is a device which lifts heavy equipment. The most common form is a car jack, floor jack, or garage jack which lifts vehicles so that maintenance can be performed.
Government Printing Office The Official Gazette of the United States Patent Office (Washington, DC: Government Printing Office, 1895)
Courtesy the private collection of Roy Winkelman