328 



LAND-TRANSPORT. 



Arrangements have sometimes to be made to reduce the 

 velocity of logs when sliding, and a mode of break for the 

 purpose is shewn in fig. 172 ; as the log coming down strikes 



Fig. 172. 



__J^-^ '-"-".- 



and lifts the break, its velocity is naturally reduced. Another 

 plan is to lead an intermediate section of the slide upwards, and 

 allow the piece to fall into a side-bifurcation by which the slide 

 is continued. The piece of wood loses all its acquired velocity in 

 this change of direction, and then descends again, until it meets 

 with another break. 



[The largest slide of this nature liithcrto ni;ulc in India is tlio 

 Bakani shde, near Chamba, in tlie Punjab. It is 12,539 feet long, 

 with a vertical fall of 1,G50 feet, or an average gradient of 13^ per 

 cent. It is formed of 4,000 deodar -logs of various sizes, of wliich 

 there are 4-6 in a cross section, anil tliey are genei'ally embedded in 

 boulder l)allast, and when the pi'esent working of the forest-block 

 has been comi)lcted these logs will be removed and exported as 

 timber. Where the line is above the ground-level, tlie slide is 

 supported on piles made as folhjws : — 



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

 the slide, cross-wise on these are placed 2 others 12 feet long, notches 

 in their ends fitting into corresponding notches in the others, then 

 2 more longitudinally and so on, till the reipiired height is reached 



