FLOATING. 355 



When thoroughly dried, all woods indigenous to Northern 

 Europe will float, but heavy, broadleaved species lose this 

 faculty much more quickly than coniferous wood ; so that 

 while the latter may he floated in the round for great 

 distances, this is not possible with the former. [Of 

 coniferous wood, that of pines and cedars rich in turpentine 

 floats much longer than that of spruce and silver-fir. 

 Experience in India has proved this fact. Tr.] Gene- 

 rally water-logged wood floats vertically. The best depth 

 for floating coniferous logs and split pieces of hard- 

 wood is one and a half to three feet, as then the work- 

 men always can wade into the water to secure the sunken 

 wood . 



There is no necessity for any uniform fall in a stream, and 

 most streams used for floating timber vary greatly in this 

 respect. The best fall is ^oo ^ TO> as then ^ ne wood descends 

 rapidly and is guided easily by the workmen ; there is also 

 little wear-and-tear owing to the pieces dashing together or 

 against rocks, that may also cause continual Mocking of the 

 stream and necessitate severe labour to set the logs floating 

 again. Floating, however, has to be undertaken frequently 

 with a fall, less or much greater than the above. In the 

 latter case, cascades have sometimes to be passed, and much 

 timber is lost. 



Eafting can be done with much less fall, and artificially - 

 constructed or improved rafting-streams have falls of only 



^00 tO 400- 



The last point to be considered in the practicability of 

 a stream for floating timber consists in the possibility 

 of damming its tributaries artificially, so as to collect 

 temporarily a much greater head of water than it usually 

 holds. 



There is much periodical variation in the amount of water in 

 a mountain-torrent, and sometimes a formidable, destructive 

 torrent may be seen where a few weeks later there will be 

 merely a little thread of water. In other cases a stream may 

 be always too low for floating, but by collecting the water of 

 its tributaries, enough water may be obtained to float down a 

 sweep of logs. 



A A2 



