Ericsson Air Engine, Patent Model

eThis model was submitted to the U.S. Patent Office with the application for Patent no. 22281, issued to John Ericsson, December 14, 1858.
This is one of the earliest hot-air engines in which cold air is drawn into, compressed, heated, and expanded within the same cylinder. This and the Ericsson engine of 1855 were the basis of design for most of the later commercial hot-air engines introduced in the United States.
The model is of an engine having a very large horizontal cylinder, one end of which is occupied by the grate and flue of a furnace. In the cylinder beyond the furnace are two pistons, one of which is a transfer or pump piston, the other the working piston. The two pistons complete their outward stroke (away from the furnace) at about the same time, but the transfer piston, which is nearer the furnace, moves inward faster than the work piston and draws in a supply of cold air through a self-acting valve in the working piston. Upon the outward stroke the transfer piston closes up on the work piston and compresses the charge between the two and transfers it through valves to the space around the heater. The pressure produced by the increase of temperature during this transfer propels the working piston through the outward stroke and supplies the motive force. The return stroke is affected by means of a flywheel.
This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.
Currently not on view
Object Name
engine, air, model
patent model, engine, hot air
date made
patent date
Ericsson, John
Physical Description
brass (overall material)
iron (overall material)
brass base - from catalog card: 6 in x 8 in; 15.24 cm x 20.32 cm
overall: 5 3/4 in x 8 1/2 in x 6 1/8 in; 14.605 cm x 21.59 cm x 15.5575 cm
place made
United States: New York
associated place
United States: New York, New York
ID Number
accession number
catalog number
patent number
Patent Models
See more items in
Work and Industry: Mechanical and Civil Engineering
Industry & Manufacturing
Bulletin 173
Patent Models
Engineering, Building, and Architecture
Data Source
National Museum of American History, Kenneth E. Behring Center
Related Publication
Frank A. Taylor. Catalog of the Mechanical Collections of the Division of Engineering United States National Museum, Bulletin 173
Additional Media

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