WOOD TRANSPORT BY LAND. 



in place by props (w) ; d d, when used, are similarly sup- 

 ported. 



The construction of slides in the Black Forest is somewhat 

 different, as shown in Fig. 19(5, where all the poles, except the 

 two lowest, are bored by augers, and kept in position by strong 

 beech trenails. In some cases a plank is used for the bottom 

 of the slide. 



The trestles supporting the block-sleepers vary in height, 

 according to the nature of the ground, or the block-sleepers 

 may rest directly on the ground. 



In the Black Forest and the Tyrol, the block-sleepers 

 rest usually on round billets. 



Fig. 197 shows the mode of construction of the end-section 



Ki<jf. 11)4. MH liod of joiiiiiiir pieces of a slide. 



Fig. 1 !)">. r.lock-sloeper. 



of a slide, m being a plate of wrought iron, over which the 

 descending pieces slide, and which, owing to its elasticity, 

 propels them upwards before they fall. 



Slides intended for the transport of logs must be constructed 

 in a much stronger manner than those for firewood, and it is 

 then chiefly the side-pieces (b and c) which must be strongly 

 supported; logs measuring one foot and one foot two inches 

 in diameter and 50 to GO feet long may be used. 



The slide shown in Fig. 198 is used for logs in the Pril'tcn- 

 thal, in N. Tyrol. It is sub-divided above into two branches, 

 and is chiefly used for bringing down bulls ; its strength of 

 construction ni;iy bo judged from the plate. 



\Yb<'ii sliding logs JJO to (>() foot long, it must bo 

 hored that wlioro the slide is of any considerable longth 



