WOODWORKERS' TOOLS AND EQUIPMENT 79 



Among the devices invented in Europe was one consisting of 

 a platinum wire stretched in a frame fitted with insulated 

 handles. The wire was heated to white heat by an electric 

 current and then applied to the bole of the tree through which 

 it was designed to burn its way. It has never been introduced 

 in this country. 



Another device that was patented consisted of a chisel-like tool 

 actuated by a power machine, which was intended to cut a 

 channel through the tree. 



Other devices such as drag saws and cross-cut saws operated 

 by steam or gasoline power have been devised, but they have 

 all been too heavy and bulky for transportation in the forest. 

 Their weight is not only a handicap in getting the machine around 

 through brushy woods and over rough bottom, but also pre- 

 vents their rapid removal from the vicinity of falling timber 

 where they are continually subject to damage. 



POWER LOG-MAKING MACHINES^ 



On comparatively level land in an open forest composed of 

 large trees, air-driven drag saws, called "steam dagos" have 

 been used successfully for "bucking-up" logs. 



The equipment consists of a traction engine with an air 

 compressor and an air storage tank. The saws which may be 

 attached readily to a log of any size are of the drag-saw type, 

 driven by a piston working from a small cylinder, mounted on 

 a metal frame weighing from 60 to 75 pounds. The cylinder is 

 connected with the air chamber on the engine by a line of hose 

 of sufficient length to give a working radius of 300 feet. Three 

 frames and one saw are the usual equipment for an outfit. 



Another type of log-making machine, patented in 1907, is 

 known as the Endless Chain Saw. The essential features of the 

 machine are an endless chain in which the links, represented by 

 saw teeth shaped like those of a cross-cut saw, are riveted to- 

 gether. The backs of the teeth fit into sprockets. The chain is 

 supported by a steel arm from 6 to 9 feet long, one end of which is 

 pivoted to the frame carrying the machinery. This arm carries 



1 See page 100. 



