TIMBER-SLIDES. 



321 



various sizes, of which there are 4 6 in a cross- section, and 

 generally they are embedded in boulder ballast ; when the 

 present working of the forest-block has been completed these 

 logs will be removed and exported as timber. Where the line 

 is above the ground-level, the slide is supported on piles made 

 as follows : 



Two logs, about 8 feet long, are placed 10 feet apart in 

 line with the slide, cross-wise on these are placed two others 

 12 feet long, notches in their ends fitting into corresponding 

 notches in the others, then two more longitudinally and so on, 



i !>'.. 



till the required height is reached. The middle space is filled 

 with boulders, and the outer frame-work is packed with dry 

 stone-masonry to give solidity to the piles. 



The largest log sent down was 48 feet long and it descended 

 for 2,500 feet, at the rate of 20 miles an hour. Vide Plate 

 III. Tr.] 



(b) Plank- Slides. In plank-slides, as shown in Fig. 200, 

 the base and walls are made of planks, which are let into the 

 block-sleepers and nailed firmly to them. 



[In the Lambatatch Forest in Tihri-Garhwal in the north- 

 west Himalayas, a slide of this kind, 2J miles long, was made by 



F.U. Y 



