Essex Patented Engine

Description (Brief)
Henry Essex of Buffalo, New York received patent number 723,660 in 1903 for this design of a caloric engine. The engine is a “hot air” or caloric engine, where heated air powers the piston before being cooled and returning to be heated, continuously producing work. The engine consists of a flywheel at one end with displacing rod, a heating element in the center with two piston inside, and cool air pockets on either side of the center.
Currently not on view
Object Name
engine, hot air
date made
overall - from catalog card: 8 in x 18 1/2 in x 7 in; 20.32 cm x 46.99 cm x 17.78 cm
flywheel - from catalog card: 6 in; x 15.24 cm
overall: 8 1/4 in x 7 in x 19 in; 20.955 cm x 17.78 cm x 48.26 cm
ID Number
catalog number
accession number
Engineering Steam Toys and Models
Engineering, Building, and Architecture
Family & Social Life
See more items in
Work and Industry: Mechanical and Civil Engineering
Engineering Steam Toys and Models
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Bequest of the Estate of Greville I. Bathe
maker referenced
Maass, Eleanor A.. Greville Bathe's "Theatre of Machines": The Evolution of a Scholar and His Collection

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.