358 \vatek-ti;ansi'( »ht. 



1. Conditiiins nicc.'isarij for St renins to he Utilisaltlr. 



Indcpeudently of artificial improvements which may l)e effected, 

 a watercourse used for tioating timber must possess certain 

 natural peculiarities, depending on the direction, power and 

 fall of the stream. The direction must eventually lead to the 

 timber-markets, however much the stream may wind on the way 

 there. Not unfrequently artificial channels are cut in order to 

 shorten the course of the stream. 



The minimum width admissible is the length of the logs 

 to be floated, as, unless they have room to turn, constant 

 blocks will occur during floating. Only in the case of artificial 

 floating-channels, where the banks are quite smooth, and butts 

 for saw-mills are floated, may the width of the stream be less 

 than the length of the logs. 



The maximum width of a stream used for floating depends on 

 the possibility of securing and extracting all sunken wood by 

 means of ordinary appliances. Even with the best management 

 some of the heaviest logs will sink, and this sunken wood is 

 either carried along the bottom of the stream, or sticks in holes 

 in its undermined banks. In very broad streams, sunken wood 

 cannot be guided to the shore or otherwise secured. Hence, 

 unless the logs are being rafted, the breadth of streams used 

 should not exceed that of a large brook, or small river. 



The depth of the water is also an important point ; this 

 should be suflicient to float water-logged timber which will not 

 quite sink, without danger of its grounding on the bottom of the 

 stream. Long and slowly running streams should be deeper than 

 rapid streams, which carry the timber better where the distance 

 for floating is short, and there is, therefore, less chance of the 

 wood becoming water-logged. "When large, round timber is 

 floated, a greater depth is necessary than for poles and split wood, 

 which is easier to float. 



When thoroughly dried, all woods indigenous to Northern 

 Europe will float, but heavy, broad-leaved species lose this 

 faculty much more quickly than coniferous wood ; so that while 

 the latter may be floated in the round for great distances, it is 

 not possible to do so with the former. Water-logged wood 

 generally floats vertically. The best dcptli for floating coniferous 



