Ericsson’s Patent Model of a Marine Steam Engine – ca 1858

Ericsson’s Patent Model of a Marine Steam Engine – ca 1858

<< >>
Usage conditions apply
This model was filed with the application to the U.S. Patent Office for Patent Number 20,782 issued to John Ericsson of New York, New York on July 6, 1858. The patent was for improvements in marine steam engines for powering a screw propeller. Mr. Ericsson’s goal was to maximize the power and compactness of the engine so that it could be located transversely and very low within a boat.
His design consisted of two compact steam cylinders which were bolted together and mounted horizontally across the beam of the ship. They drove a single propeller shaft via a system of push rods and rocker arms. The design allowed for even application of power with reduced vibration and wear on engine parts and the frame of the ship.
Mr. Ericsson was a prolific inventor; his inventions included many types of steam engines and associated apparatus as well as air engines. He was the designer of the USS Monitor for the North during the Civil War, and the engine for the Monitor was based on this patent.
The patent model is made of brass and is mounted on a wood base representing a section of the hull of a ship. A brass plate on the base of the model is engraved “Screw Propeller Engine, J. Ericsson, Inventor.” All of the key elements of the patent are illustrated by the model which was provided with a crank on the propeller shaft to allow operation for demonstration. A full description of the operation of the engine along with complete diagrams can be found in the patent document online at the United States Patent and Trademark Office website,
Object Name
engine, steam, marine, model
patent model, engine, steam
date made
patent date
Ericsson, John
place made
United States: New York, New York City
associated place
United States: New York, New York City
overall: 9 in x 11 1/2 in x 11 1/2 in; 22.86 cm x 29.21 cm x 29.21 cm
ID Number
catalog number
patent number
accession number
Patent Models
Steam Engines
See more items in
Work and Industry: Mechanical and Civil Engineering
Patent Models
Engineering, Building, and Architecture
Power Machinery
Exhibition Location
National Museum of American History
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object