294 THE UTILISATION OF WOODLAND PRODUCE. 



entirely of woodwork ; but in either case the chief points are 

 (1) the preparation of a good led down which the timber can 

 glide with least friction, and (2) the provision of safeguards to 

 prevent the logs or fuel-billets springing out of the slide. 



Roadway timber-slides are mostly used for extracting Conifer 

 logs in large quantities when the pathways and side-roads in moun- 

 tain tracts have been so projected as to provide large sweeping 

 curves, round which long logs can glide easily. The slides are 

 usually made from 5 to 8 ft. broad, with corduroy cross-pieces con- 

 sisting of round or split poles laid smooth-side uppermost, and 

 fenced in along the outer edge with poles laid lengthways to act 

 as flange-like side-guards. For winter-sliding when snow covers 

 the ground a gradient of from 1 in 12 J to 1 in 8 (or 8 to 12 J 

 per cent) is needed, and for summer-sliding from 1 in 8 to 

 1 in 5J (or 12 J to 17 per cent) ; but in either case the steepest 

 gradient should be at the top, for starting the logs in their 

 descent, and the lowest gradient at the bottom end, where 

 the slide terminates. Such roadways can also be used for 

 sledging, with cross-pieces close enough to allow the sledge 

 to rest always on two. And they are economical, as 100 to 

 120 logs can daily be shot down a slide over 1J mile long. 

 In laying out such a slide, sharp turns and sudden changes 

 of direction have to be avoided ; but where unavoidable, a 

 buffer is made with billets of pole-wood, and when a log in 

 coming down bumps against this, it rolls over into the track 

 below and slowly continues its way in the new direction 

 with assistance, if necessary (Fig. 81). The logs are launched 

 into the slide thick end first, and to make them glide easily the 

 butts are rounded with an adze. To prevent accidents the 

 launching of each log is announced by bugle - call ; and no 

 other log is despatched till the arrival of the previous one is 

 similarly announced from below. When all the timber has 

 been slid down, the slide itself is broken up and extracted 

 in the same way. 



