THE CONQUEST OF TIME AND SPACE 



Even before the invention of the Janney coupling a 

 semi-automatic coupling device had been used exten- 

 sively on passenger cars. But this device which in 

 effect was that of two crooked fingers hooked together, 

 allowed the ends of the coaches to swing and roll in a 

 manner most disagreeable to many passengers. The 

 Janney couplings corrected this, since these couplings 

 in their improved form hold the ends of the cars as in 

 a vice. 



A COMPARISON — THE OLD AND THE NEW 



Stephenson's locomotive and its tender, when loaded 

 to full capacity with fuel and water, weighed seven 

 and three-quarter tons. The locomotive itself was a 

 trifle over seven feet long. In 1909 the Southern Pacific 

 Railway purchased a Mallet Compound locomotive 

 which, with its tender, weighs three hundred tons, or 

 approximately forty times the weight of the little 

 Rocket. This great locomotive is over sixty-seven feet 

 long, or some nine times the length of the Rocket^ and 

 will haul more than twelve hundred tons back of the 

 tender. 



The cylinders of the Rocket were eight inches in di- 

 ameter, with a seventeen inch stroke ; the high-pressure 

 cylinders of this Mallet locomotive are twenty-six 

 inches in diameter, and the low-pressure cylinders are 

 forty inches. But curiously enough the driving wheels 

 of the two engines show little discrepancy, those of 

 the Rocket being fifty-six inches in diameter, as against 

 fifty-seven for those of the larger engine. The total 



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