Otto Caloric Engine, Patent Model

This wooden model (incomplete) was submitted to the U.S. Patent Office with the application for Patent no. 145123, issued to Nicolaus Otto, of Deutz, Germany, December 2, 1873.
In this engine hot gases were admitted to the cylinder above the piston during one-third of the down stroke. The remainder of the stroke dilated the confined gasses and rendered a great portion of the heat of the gases latent. The remaining portion of the heat was absorbed by the water-cooled cylinder surfaces and the piston was returned by the pressure of the atmosphere. The piston is so connected to the crankshaft that the upward stroke was much slower than the downward stroke to permit the heat that was rendered latent on the downstroke and that was liberated during the upstroke to be absorbed by the cooled surfaces of the cylinder.
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, hot air, model
patent model, engine, caloric
date made
patent date
Otto, Nicolaus A.
Physical Description
wood (overall material)
overall: 5 1/4 in x 5 1/2 in x 2 3/4 in; 13.335 cm x 13.97 cm x 6.985 cm
place made
associated place
Deutschland: North Rhine-Westphalia, Deutz
ID Number
catalog number
accession number
patent number
See more items in
Work and Industry: Mechanical and Civil Engineering
Industry & Manufacturing
Bulletin 173
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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