204 FELLING AND CONVERSION OF TIMBER. 



car supporting the pole is moved forward by means of a winch, 

 and he states that this gives 8 to 10 times the pressure of the 

 original arrangement. 



Ordinary screw-jacks (Fig. 141), are used also with advan- 

 tage, as in the Schwarzwald, for uprooting trees and stumps. 

 Eecently, in Wiirttemberg, a portable windlass has been used 

 with good results both for uprooting trees and stumps, and for 

 dragging loads of timber up steep inclines. Provided that 

 the cost of working it is not too great, its use is to be recom- 

 mended on account of its great power and adaptability. 



[The Deracineuse Lobo used for extracting trees by the 

 roots in Belgium is a gear of three legs on slides, by which it 

 can be moved from tree to tree ; also a system of pulleys and 

 chains with toothed apparatus to be driven into the base of 

 each tree. It is worked by six men and not only saves about 

 ,7 per acre in wood, and labour, including ploughing up the 

 ground at <2 per acre, but enables the land to be planted up 

 at once without any fear of the pine-weevil.* Tr.] 



SECTION III. SEASON FOR FELLING. 



The proper season for felling depends on several circum- 

 stances, of which the most important are, the climatic con- 

 ditions, available labour force, mode of felling, technical 

 quality of the outturn, and species of tree, besides some other 

 special points depending on particular cases. 



1. Climatic Conditions. 



These are in many regions the most important of all the cir- 

 cumstances which determine the season for felling ; for where 

 the winter is severe and the fall of snow heavy and lasting, so 

 that outdoor work has to stop, as in most high mountain dis- 

 tricts and in many localities only moderately elevated, forest 

 work during winter may be impossible. In case fellings 

 cannot be carried on during winter, transport by means of 

 sledges, which is facilitated by the snow, may be effected. In 

 high mountain regions, therefore, transport of timber an<l 

 firewood is the chief occupation during winter. In plains and 



* Cf. Report of proceedings of 11. K. Alb. Society for 1110(5. 



