176 BULLETIN 173, U. S. NATIONAL MUSEUM 



cylinders, each with 6-foot stroke. This vessel made a successful 

 trip from New York to Washington, D. C, and return, only to 

 founder in a sudden tornadolike squall in New York Bay. Ericsson 

 then returned to the construction of smaller engines, and in the 

 following two years he built over a thousand of them. He em- 

 ployed large hot-air engines to drive air compressors and distributed 

 compressed air to drive small individual air motors on sewing 

 machines in clothing- factory buildings. Later he developed small 

 hot-air engines that operated over gas burners to furnish individual 

 drives to machines and machine tools. 



Between 1855 and 1875 there were about 80 different hot-air en- 

 gines introduced and manufactured. Descriptions of those of Still- 

 man (1860), Roper (1863), Baldwin (1865), Messer (1865), Wilcox 

 (1865), Lauberan (1849), Schwartz (1864), Peters (1862), Bickford 

 (1865), and Kritzer (1862) are given in the article "Air Engines" 

 in the American Mechanical Dictionary ^ by Edward H. Knight, 

 New York, 1874. 



Hot-air engines in large sizes have not proved generally practical. 

 The maximum permissible temperature is rather low, owing to lubri- 

 cation difficulties and the characteristics of the common metals, with 

 the result that the capacities of hot-air engines are extremely low for 

 their size as compared to steam and internal combustion engines. 

 The result has been that few engines of more tlian 1 horsepower have 

 been built. 



The value and popularity of hot-air engines are due to the fact 

 that they are safe and dependable and can be operated by the least 

 skilled of attendants. They are clieap, and their economy compares 

 favorably with other prime movers of the same power. In farm in- 

 stallations, particularly for pumping water, many are still in use. 

 At one time they were regularly installed to pump water in school 

 and office buildings in New York City, where they were also used 

 extensively for driving such machines as sewing machines (in cloth- 

 ing factories) and printing presses. Because of their dependability 

 many were purchased by the Bureau of Lighthouses and installed to 

 generate power in isolated houses. Since 1900 the increasing con- 

 venience of electric power has diminished the demand for hot-air 

 engines, though they are still being built and sold. 



LYMAN AIR ENGINE, 1854 



U.S.N.M. no. 311371; original patent model; transferred from the United States 

 Patent OfBce; not illustrated. 



This model was submitted w^ith the application for the patent 

 issued to A. S. Lyman, of New York. N. Y., February 28, 1854, 

 no. 10576. 



