Peter Cooper and Phineos Davis 



No original parts remain of one of the best known early 

 locomotives, the Tom Thumb. A full sized operable leplica 

 (figure 15), however, was made in 1926 by the Baltimore and 

 Ohio Railroad Go. for use in their exhibit that year at the 

 Philadelphia Sesqui-Centennial International Exposition. It 

 has since appeared at the Fair of the Iron Horse, held at 

 Halethorpe, near Baltimore, in the fall of 1927, the Chicago 

 World's Fair in 1933 and 1934, the New York World's Fair 

 in 1939 and 1940, and the Chicago Railroad Fair in 1948 

 and 1949. Its permanent home is in Baltimore, at the Balti- 

 more and Ohio Transportation Museum. 



A small nonoperable model of the Tom Thumb, about 2 feet 

 long (figure 16), made in the National Museum in 1890 

 (USNM 204581), is exhibited in the collection of the Mu- 

 seum. Other small models of it appear in the B & O 

 Museum. One of these, a y4-inch-scale model recently made 

 under the direction of Lawrence W. Sagle of the B & O 

 Museum, differs somewhat from the usually accepted idea of 

 the Tom Thumb. 



Notably, the smokestack is not straight, but has an elbow 

 at its upper end, and the belt-driven blower is located there 

 rather than on the floor of the machine as in the replica and 

 the other models. Peter Cooper, the New York engineer and 

 inventor who constructed the original Tom Thumb as an ex- 

 periment in the winter of 1829-1830, mentioned this upper 

 location of the blower in a speech delivered many years later, 

 in 1875, and quoted in Bulletin 73 of the Railway and 

 Locomotive Historical Society (1948, pp. 50-52). 



The little locomotive, with its vertical boiler made of rifle 

 barrels, looked rather like the larger locomotive of John 

 Stevens of only several years earlier but had considerably 

 smaller wheels, these being only 30 inches in diameter. 



Although a 3V4-inch bore for its vertical 1 -cylinder engine 

 is given by most writers, Jonathan Knight, chief engineer of 

 the Baltimore and Ohio, in the fourth annual report of the 

 company (for 1830, p. 35) gives the figure as 3^2. Unfortu- 

 nately, he does not mention the stroke, which is usually 

 given elsewhere as either 14y4 or 14^2 inches. The bore and 



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