CATALOG OF THE MECHANICAL COLLECTIONS I57 



ATKINSON "CYCLE" GAS ENGINE, 1889-90 

 U.S.N.M. no. 310371; original; gift of the heirs of Samuel Powel ; not illustrated. 



This is a 2-liorsepower, 4-stroke cycle, illuminating-gas engine, 

 built in 1889-90 by Henry Warden, of Philadelphia, licensee under 

 patents of James Atkinson, of Hampstead, England, Patent no. 

 367496, August 2, 1887. 



The feature of the engine is the vibrating toggle linkage between 

 the piston rod and crankshaft by which four piston strokes of dif- 

 ferent lengths are produced in each revolution of the crank. This 

 arrangement gives one explosion stroke per revolution and permits 

 the use of an explosion stroke considerably longer than the suction 

 or compression strokes with a resulting degree of expansion greater 

 than is obtained with the usual four strokes of equal lengths. 



The cylinder of the engine is horizontal, the crankshaft is well 

 above the center of the cylinder, and the connecting rod from the 

 crank has a short T-head to one pin of which is attached the piston 

 rod, to the other a vibrating arm pivoted to the engine frame slightly 

 below tlie center of the cylinder and beyond the center of the 

 crankshaft. 



This arm swings through an arc of approximately 90°, and the 

 crank is the only revolving part of the system. Valves for exhaust, 

 air intake, and fuel intake are located in the head of the cylinder and 

 are operated by a short cam shaft, which, in turn, is driven by a 

 bevel gear from a long inclined lay shaft to the crankshaft of the 

 engine. The lay shaft carries a small centrifugal governor, which 

 moves the fuel valve follower away from its actuating cam when 

 the speed of the engine increases. Ignition is by means of a hot tube 

 located on the top of the cylinder and heated by a gas burner and 

 refractory lined chimney. The ignition port is uncovered by the 

 piston. The cylinder diameter is 5 inches, suction stroke 4^ inches, 

 compression stroke Syo inches, explosion stroke 5 inches, and exhaust 

 stroke 6 inches. 



The engine was built for Samuel Powel, of Newport, R. I., who 

 used the engine to power a small experimental machine shop there. 



HORNSBY-AKROYD OIL ENGINE, 1893-1895 

 Pl.\te 33, FiGuiiE 1 



U.S.N.M. no. 309637; original; from Robert McReady; photograph no. 6092. 



This engine was the first one built by the De La Vergne Refrig- 

 erating Machine Co. after acquiring the American license to the 

 inventions of IT. Akroyd Stuart and C. R. Binney in 1893. It was 

 the first 4-stroke, heavy-oil engine including a hot-bulb vaporizer 

 and igniter built in the United States. Built as an experimental 

 engine in 1893, it was run for test purpo.scs at the factory until 1895, 



