74 



POPULAR SCIENCE MONTHLY. 



curve, resuming the normal rate of travel when the dangerous point has 

 been passed. 



The part which cranes of various kinds have played in the solution 

 of the problem of the economical handling of raw material of various 

 kinds is indeed an important one and there has been a steady increase 

 in capabilities until there are now in service in the United States a 

 number of cranes each of which is capable of handling a load of one 

 hundred tons. 



Easily the most remarkable of all the cranes yet constructed are the 

 great balanced cantilevers invented by Alexander Brown, an American. 

 The cantilever crane is applicable to a large range of work and is the 



Cantilever Crane. 



most perfect machine yet devised for use in handling armor plate and 

 other heavy parts in ship-yards and manufacturing establishments 

 generally. The cantilever is divided into two arms, which in some 

 instances have a span of over 350 feet. By means of trolley and hoist 

 block, mounted on the cantilever of the crane, the load can be hoisted 

 from the ground and traversed from one end of the cantilever to the 

 other, the pier or base of the crane being so arranged that the load 

 passes through it. These cantilever cranes have an automatic counter- 

 weight running on a track along the bridge and above the hoisting 

 trolley, and connected by ropes to the latter, so that whatever the 

 position of the hoisting trolley on one arm of the crane, the counter- 



