54 



THE POPULAR SCIENCE MONTHLY. 



make the trip from St. Louis to New Orleans about 1,200 miles in 

 four days, and can make, in still water, more than twenty miles an 

 hour. 



In the East, we have a form of engine which is distinctively known 

 as the American steamboat-engine. It is shown in Fig. 62. 



. n n i i \m m i o l nrM i :i i a a i a 1 I 1 " 



Fig. 62. The American Beam-Engine. 



This engine is recognized throughout the engineering world as 

 one of the most complete and thoroughly perfected of known types of 

 steam-engine. 



106. This peculiarly effective and easy-working engine, and the 

 equally peculiar vessel (Fig. 63) which is usually impelled by it, are, 

 in all their peculiarities, characteristically American. 



The " skeleton-beam," which is one of the prominent features, was 

 first used by Robert L. Stevens on the ferry-boat Hoboken, in 1822. 



The valve-gear is usually that known as the " Stevens valve- 

 gear." It was invented by Messrs. Robert L. and Francis B. Stevens, 

 in 1841. The "gallows-frame" took its present form in the hands of 



