33 !• LAN D-TKANSPURT. 



(1) Maintenance of Wooden Slides. — Wooden slides are either 

 permanent or temporary, the i\nmer serving a certain forest tract 

 for a series of years, or counectin<,' a collectiuf,' depot hi<,'h up in 

 the mountains, to which the wood is brought in sledges, with a 

 lower depot in the valley. Such a slide must be most carefully 

 and strongly constructed, and the site for it well chosen, and the 

 gradients very carefully arranged. 



Temporary slides are used in bringing-down wood from the 

 upper to the lower part of a felling-area, or to a road, and are 

 constructed in a much lighter and less expensive way than 

 permanent slides. 



The construction of slides requires a large quantity of wood, 

 and this is further increased by the slight durability of the latter, 

 for although slides may last longer in damp, shady places, and 

 shorter on sunny aspects, yet they rarely last more than 7 years, 

 and usually repairs are required after 3 or 4 years. 



[In tlic Himalayas, deodar-wood i« so saturated with oil, that its 

 heartwood is practically imperishable in mountain districts, and 

 timbers in bridges in Kashmir exposed to alternations of damp and 

 dryness have lasted for hundreds of years, so that very durable 

 timber-slides may be made of deodar. — Tk.] 



As progress is made in the construction of roads, slides become 

 less important ; at any rate, this applies to slides several miles 

 long, which were formerly so prevalent on the southern declivity 

 of the Alps, where the best constructors of slides are to be found. 



Shorter slides, however, intended to complete communications 

 over steep ground, are still extensively used in the Alps and 

 other mountain-ranges, and their use is being extended. 



2. (in)iiN(I-sli(h's. 



Ground-slides arc tracks often fcmnd on mountain-sides, and 

 are either made on the l)are ground by the repeated sliding of 

 logs, or artificially improved in various ways, so as to be fit for 

 sliding. As a rule, a depression on a steep slope is selected, and 

 a line for sliding dug along it, and pieces of wood placed on it 

 transversely on which the logs may slide, and other pieces placed 



