THE HIGHWAY OF THE WATERS 



Stevens also invented what he called a "rotary 

 engine" which was really an engine constructed on the 

 same principle as the modem turbine engine. It was a 

 small affair which he placed in a skiff, and used for 

 turning the screw-propeller of a boat which was able 

 to travel at a rate of three or four miles an hour on the 

 North River, during the fall of 1802. But Stevens 

 found so much difficulty in packing the blades of this 

 engine without causing too much friction that he finally 

 abandoned it for the more common type of reciprocat- 

 ing engine. But if this httle steamboat had its defects, 

 it nevertheless contained the germs of two great features 

 of steam navigation — ^the screw propeller and the tur- 

 bine engine, the advantage of the first of which was 

 not recognized for nearly half a century, and the other 

 not until almost a full century later. 



In 1804 Stevens produced another propeller steam- 

 boat, this one using the ordinary type of reciprocating 

 engine, and being notable for having twin screws of a 

 pattern practically identical with the screws now in 

 use. This boat was able to steam at a rate of four 

 miles an hour on many occasions, and at times almost 

 double this rate, according to some observers. The 

 engines of this boat are still in existence, and on several 

 occasions since 1804 have been placed in hulls corre- 

 sponding as nearly as possible to the original, and have 

 demonstrated that they could force the boat through 

 the water at six or eight miles an hour. These engines 

 in a modem hull were exhibited at the Columbian Ex- 

 position at Chicago, in 1893. They supply irrefutable 

 evidence that the practical steamboat had been in- 



[69] 



