66 THE DESTRUCTIVE AGENTS OF FORESTS. 



Date. , Approximate number of hand saw 



mills that will he running. 



1915 41 



1920 23 



1925 9 



1930 5 



1935 3 



1940 0 



There are three or four band saw mills being erected at this 

 date, and it is probable that a few others will be built within 

 the next 5 years. The number, however, will be small, as nearly- 

 all the large tracts of available timber are in the hands of 

 operators. 



The amount of timber cut in the various operations con- 

 nected with the lumber industry could not be accurately esti- 

 mated. The cut of saw mills during the past 30 years has been 

 about 18 billion feet. It is not known how much was cut before 

 that time, nor how much was rafted out in the log, nor how 

 much was cut for hoop-poles, cross ties, tan-bark, pulp wood, 

 poles, etc., but the quantity was very large. 



Such facts in detail as have been learned regarding the 

 various phases of the lumber industry in the state are given in 

 the county discussions. A further inquiry into this subject 

 would bring out many additional and interesting facts of com- 

 mercial history. 



DISEASES OF FOREST TREES AND WOOD-DE- 

 STROYING FUNGI. 



Extent and General Results of Disease. 



The life of trees, like the life of animals, is shortened by 

 disease. Some species resist disease more readily than others 

 but not one has been found that is wholly free from it through 

 all the stages of its life. Some trees, it would seem, are subject 

 to many kinds of diseases. These are constantly struggling 

 against conditions which interfere with their normal growth 



