SAWMILLS. 491 



the large mills are superior, owing to their smooth cut. [The 

 maintenance of State sawmills in French coniferous forests 

 depends on the wish of the Government to enable small timber 

 purchasers to compete with large sawmill owners, who would 

 otherwise have a monopoly. The State gives the use of a 

 conveniently situated sawmill as one of the conditions in the 

 sale of a lot of trees. The purchaser pays to the State a fixed 

 rate per square meter of wood sawn. Tr.] 



(b) Steam Sawmills.* 



1. Frame-saws. 



Although most of the sawmills which will be now described 

 are driven by steam, the use of water-power is not excluded ; 

 it must then be strong and steady so as to be suitable for 

 powerful turbines. Whilst forest sawmills usually work with 

 only one saw 7 , or at most two saws, steam sawmills are supplied 

 with a number of saws and other wood-working machines, so 

 that they can turn out wood completely ready for use in 

 buildings, etc. They differ chiefly from forest sawmills by 

 their enormous outturn and its better quality. 



Besides differing from forest sawmills in these points and in 

 their motive power, steam sawmills also are constructed differ- 

 ently ; being formed completely of iron they are mora com- 

 pact, stronger, possess greater stability and work more evenly ; 

 friction is reduced to a minimum and they are much more 

 powerful. This greater power is utilised specially in steam 

 sawmills by there being several saws, up to 10, in the same 

 frame, all of which work at once ; a butt is thus sawn into 

 planks in one operation. These are termed multiple saws. 

 As regards the power required to drive multiple saws, it is 

 estimated that three horse-power is required for the empty 

 frame alone, one horse-power for the first four blades and for 

 every other blade half a horse-power. These saws are con- 

 structed on the same principle as ordinary saws, but mechanical 



* An excellent account is given of modern American sawmills by Hotchkiss 

 in " Encyc. Brit.." issii, vol. xxi. Also see Worssam & Co.'s catalogue (King's 

 I load, Chelsea). Mathey, ' Exploitation Commerciale dcs Bois," vol. ii., 1906, 

 MI excellent detailed account of steam and water sawmills. 



