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THE POPULAR SCIENCE MONTHLY. 



ter, turning, carries the engines about with it. It is an ingenious and 

 curious device. 



49. " To Oliver Evans," says Dr. Ernest Alban, 1 the learned Ger- 

 man engineer, "was it reserved to show the true value of a long-known 

 principle, and to establish thereon a new and more simple method of 

 applying the power of steam a method that will remain an eternal 

 memorial to its introducers." Dr. Alban here refers to the earliest 

 successful introduction of the non-condensing high-pressure steam- 



enarine. 



Oliver Evans, one of the most ingenious mechanics that America 

 has ever produced, was born at Newport, Delaware, in 1755 or 1756, 

 the son of people in very humble circumstances. 



He was, in his youth, apprenticed to a wheelwright, and soon 

 exhibited great mechanical talent and a strong desire to acquire 

 knowledge. 



His attention was at an early period drawn to this possible appli- 

 cation of the power of steam to useful purposes by a boyish prank. 

 Placing a small quantity of water in a gun-barrel, and ramming down 

 a tight wad, he put the barrel in the fire of a blacksmith's forge. 

 The loud report which accompanied the expulsion of the wad was an 

 evidence to young Evans of the great, and, as he supposed, previously 

 undiscovered power of steam. 



Subsequently, meeting with a description of a Newcomen engine, 

 he at once noticed that the elastic force of confined steam was not 

 there utilized. 



Fig. 27. Oliver Evans's Engine, 1800. 



He then designed the non-condensing engine, in which the power 

 was derived exclusively from the tension of high-pressure steam, and 

 proposed its application to the propulsion of carriages. 



50. About the year 1780 Evans joined his brothers, who were 

 millers by occupation, and at once employed his inventive talent in 



1 " The High-Pressure Engine investigated," Dr. Ernest Alban, London, 1847. 



