384 LOGGING 
(2) It is dependent on an abundant rainfall to flood the 
streams. During seasons of drought it may be impossible or 
very expensive to move logs by water. This results in a short 
log supply and the closing down or short-time operation of saw- 
mill plants. Sawmills in the northern regions that are dependent 
on water transportation for a log supply can only run for six or 
seven months, unless special provisions are made for keeping the 
log pond open during freezing weather. During the remainder 
of the year the plant is idle and during this period the owner 
does not realize on his investment. 
(3) There is a heavy loss in driving logs for long distances. 
Logs of all species that have much sapwood suffer a heavy loss in 
merchantable volume between the bank and the mill, if they do 
not reach their destination during the season in which they were 
logged, because the sapwood is attacked by insects and fungi. 
Basswood logs which have floated for a short period in water 
containing vegetable matter acquire a peculiar and unpleasant 
odor that renders the lumber from them unfit for sugar barrel 
cooperage and packages for other commodities that are easily 
tainted. 
A very appreciable loss in driving timber is due to sunken and 
stranded logs. The extent of this loss is depedent on the species 
driven, and the character of the stream. 
The heartwood of stranded logs, especially of hardwoods, 
suffers from checks and splits when exposed to the weather. 
Where timber is brought down rough streams, over water- 
falls, and past obstructions it is often badly battered and broken, 
gravel and sand become iml^edded in a large per cent of the 
logs and occasionally iron and spikes are present, especially 
where iron dogs are used in rafting. Much of this foreign matter 
is not readily detected, and mills suffer a monetary loss due to 
damaged saws and time lost by the sawmill crew. 
Strict laws are now in force in most states providing adequate 
penalties for the theft of logs so that this evil has been largely 
remedied. 
The actual loss in log scale from all causes on the Mississippi 
river drives average about 10 per cent; on the Cumberland and 
Tennessee rivers in Kentucky, 10 per cent; in Montana, 10 per 
cent; spruce, from 5 to 10 per cent and birch, from 25 to 75 per 
cent on short drives in the Northeast; hardwoods in'Pennsyl- 
