UTILITIES FOR HANDLING RAW MATERIAL. 



73 



.also used for transferring coal from mine to storage pile or cars. For 

 such utilization there is selected apparatus of great simplicity of design, 

 namely, a scraper conveyor with steel nights of proper shape attached 

 to the chain and drawing the material along in a steel trough. Some 

 installations of this character have a length of about 300 feet and a 

 capacity of four tons of coal per minute. 



Modifications of the belt conveyor are now to be found in use in 

 .almost every branch of the industrial domain, being put to a variety 



Car Dumping Machine. 



of uses ranging all the way from the movement of grain to the carriage 

 of logs and stone. Moving platforms, constructed on the endless chain 

 plan, also have an important place among the utilities for handling 

 bulk commodities. Likewise is there extensive employment of traveling 

 cableways and aerial ropeways wherein either the impetus of gravity 

 or hauling ropes are depended upon for propulsive power. Some of 

 the recently installed traveling cableways have a span exceeding 700 

 feet and are adapted for handling loads of from five to ten tons. The 

 most modern of all of these aerial transportation systems is that 

 designated 'telpherage,' whereby electricity is relied upon as an opera- 

 tive force. In this class of installations the overhead trolley system of 

 the ordinary electric railway has simply been adapted to the rope rail- 

 ways, and by the provision of an ingenious device the electric car or 

 telpher is enabled automatically to slacken speed when approaching a 



