492 



AUXILIARY FOREST INDUSTRIES. 



improvements are introduced to increase their efficiency and 



reduce the motive power required to drive them. 



Figs. 300 and 301 represent one of the numerous kinds of 



multiple saws from the 

 catalogue of Kircher & Co., 

 of Leipzig. The frame, 

 which is generally driven 

 from below (A), runs very 

 smoothly in simple bear- 

 ings (a a) and may support 

 10 to 20 blades at suitable 

 distances. The blades are 

 usually fixed in the frame 

 by wedges. The butt to 

 be sawn is supported on 

 carriages (m m), one on 

 either side of the saw and 

 both running on a light 

 tramway, on which it is 

 firmly secured by iron dogs 

 (n n). Two pairs of remov- 

 able grooved iron rollers 

 (z z) above and below the 

 butt press it forwards 

 against the saw. As soon 

 as the butt has been sawn 

 through it is removed by 

 butt-carriages in front of 

 the saw, another butt is 

 then brought up from 

 behind into contact i with 

 the saw. No time is lost, 

 , , as in forest sawmills, in 



reversing the butt-carriage 

 while butts and logs of any 



length may be sawn. Fig. 301 shows the same saw in 



perspective. 



In order to save time in sharpening the saws (which must 



generally be done every 6 or 7 hours) the frame with the saws 



