SAWING MACHINES. 



767 



replaced by a saw. The cylinder is small, and works at high pressure ; a 

 piston moves the saw in a guide-frame. The machine is firmly fixed against 

 the tree, and the support is fastened by a chain. 



A rack arrangement provides for the turning of the machine as the saw 

 continues to cut its way through the trunk of the tree. 



The weight is not excessive, and the necessary steam is supplied by a 

 portable furnace and boiler, which communicates with the saw-motion by 

 a flexible tube. The saw can cut through a horizontal as well as through a 

 perpendicular trunk thus timber can be rapidly cut up. 



Another ingenious sawing machine is that invented by Mr. W. W. Giles, 



Fig. 897 Sawing machine. 



of Chicago, United States, America. This apparatus is about eight feet 

 long, and one extremity is fixed to the trunk of the tree to be operated on. 

 The operator sits upon a ledge or saddle at the opposite end, and 

 putting his feet upon the treadles, pushes them and the saw forward ; 

 this movement is assisted by the weight of the hands on the lever. The 

 saw, under these circumstances, cuts into the wood with great force, and 

 when the operator pushes tJie lever forward he brings the force of his legs to 

 bear at the same time, and carries the saw back again. So feet, hands, 

 dead weight with the saw itself, combine at once upon the tree, and the 



