CATALOGUE OF THE MECHANICAL ENGINEERING COLLECTION. 81 



Model of the " Grasshopper " Locomotive, 1831. Made in the Museum. 



The " Grasshopper " locomotive is so named from its peculiar 

 motion. It was introduced by the Baltimore and Ohio Railroad in 

 1831, and remained in use on its line for many years. 



The "Grasshopper" locomotive, more particularly called the 

 "Atlantic " type, and which became for a time the standard form 

 of engine on the Baltimore and Ohio Railroad, was designed by 

 Phineas Davis, aided by Ross Winans, then assistant engineer of 

 machinery of the Baltimore and Ohio Railroad. The "Atlantic" 



FIG. 37. MATTHIAS BALDWIN ■'OLD IltO.NSlUKs" L(iLc).\IOTI\ Ej IbSJ. 



had a vertical boiler with a fan driven by the exhaust steam for 

 stimulating the fire. 



There were two vertical cylinders 10 inches by 12 inches, whose 

 power was transmitted to the supplementary driving shaft by means 

 of a spur and pinion, which was geared up to make the wheels 

 revolve twice for every turn of the crank. In this way wheels 3 

 feet in diameter were made equivalent to driving wheels 6 feet in 

 diameter. About twenty engines of the "Atlantic " type were built 

 and they worked very successfully in developing railroad traffic, 

 o-oinor out of favor only when engines with a longer wheel base be- 

 came^ecessary. Cat. No. 233,511 U.S.N.M. 



Model of the Locomotive " Old Ironsides " and Tender, 1832. Gift of the 

 Baldwin Locomotive Works." 



This locomotive was the first built by Matthias Baldwin, the 

 founder of the Baldwin Locomotive Works, in Philadelphia, and 



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