NOTES AND COMMENTS 933 



unchanged. The presence of a steam-pipe running along a mill roof 

 would have exactly the opposite effect. This would raise the tempera- 

 ture of the air and hence lower the relative humidity, thus preventing 

 condensation on the roof in its vicinity simply because the air would 

 not reach the dew point." 



R. C. B. 



A New Record of Growth of Pacific Coast Douglas Fir 



About a year ago in the Proceedings^ there was an account of some 

 Douglas fir sample plots in the Pacific Northwest which had been grow- 

 ing at the rate of 1,259 board feet per acre per year. Those plots were 

 located on the lower western foothills of the Cascade Range in Oregon. 

 Recently some plots, located on the west side of the Coast Range in 

 Oregon, Siuslaw National Forest, a region of supposedly more rapid 

 growth, have been remeasured and they show an even more rapid rate 

 of growth. 



These two plots (each a half acre in area), when fifty years old, 

 averaged in 191 1 32,680 board feet per acre in trees 12 inches and 

 over in diameter gross scale, or 9,216 cubic feet per acre in all the trees. 

 In 1916, when they were remeasured, there were 41,451 board feet per 

 acre, or 10,560 cubic feet. That indicated an average annual growth 

 per acre of 1,754 board feet, or 269 cubic feet. Most of the trees had 

 grown about an inch and a third in diameter in the five years ; one of 

 them had grown 3 inches. The average number of living Douglas-fir 

 trees per acre had dropped from 291 to 266, because of the death of 

 some suppressed trees; of this latter number 128 were over 12 inches 

 in diameter. 



This is a record which, so far as the writer knows, has not been 

 equaled in any other natural coniferous forest in the world where the 

 same intensity of utilization is assumed. 



Slash Disposal Experiments in Canada 



Specific experiments in slash disposal on the Western Forest Re- 

 serves have been so successful that the Dominion Forestry Branch has 

 decided to continue this work and, by means of investigations on larger 

 areas and areas of varied conditions in timber, soil, etc., to develop a 

 policy which will render Canadian forests as free from fire danger, due 



*Five Years' Growth on Douglas Fir Sample Plots, by Thornton T. Munger, 

 Proceedings of the Society of American Foresters, Vol. X, No. 4. 



