408 AMERICAN FORESTRY 



furnishes water for irrigation. The areas most subject to erosion are the 

 steep, south slopes where the gradient is frequently as much as 35 degrees 

 and where the trees are far apart. 



"At several points on the watersheds there are small areas of "slide rock," 

 and other areas where a soil has only recently been created. Outcrops of 

 rock in place are few in number and represent an extremely small area. 

 Throughout, the fine black loamy soil is interspersed with small stones, yet 

 the depth of soil in most cases is considerable. The streambeds are littered 

 with boulders which have rolled down the steep slopes, and with trunks of 

 aspen trees which are plentiful and of good size along the streams. The 

 debris shows no evidence of erosion and it may be assumed that powerful 

 floods have not occurred in either watersheds for many years. In many 

 places the streams are invisible, flowing under the loose boulaers. This 

 feature is more marked in Watershed B than in A. A notable feature is the 

 short branch stream coming in from the north about 400 feet above the dam 

 on Watershed B. This comes from a spring, the water having apparently 

 been carried on the lava substream from higher portions of the watershed, 

 breaking out where the lava outcrops. There is, however, no reason to 

 suppose that the water comes from without the watershed." 



Mr. Bates goes on to exjilain that the primary work of the streamflow 

 study is the accurate measurement of the two streams involved, continuously 

 and without error through all seasons for a number of years. The secondary 

 work of the study includes the measurement of precipitation, temperature and 

 other meteorological factors which may affect the flow of these streams. He 

 then describes at length and very interestingly tlie dikes, basins, weirs and 

 still-wells by which the flow of the streams can be regulated and measured. 



In conclusion Mr. Bates says that the experiment which he has described 

 is the only one of its kind that has ever been instituted, excepted the Emmen- 

 thal experiment in Switzerland near Zurich, and he adds that in his belief it 

 must "always stand a.s an example of the scientific thoroughness in the 

 solution of forestry problems, which can only be obtained by concentrating 

 the efforts of experts at permanent experiment stations, on the ground. The 

 length of time involved in this experiment must be determined entirely by 

 the occurrence of a variety of climatic conditions. Whether it be ten years 

 or twenty, its results must aft'ect a large number of people, and I believe that 

 it has a claim to recognition by all those who are interested in the problem, 

 whether they be foresters, meteorologists, engineers, irrigators, or merely 

 farmers on river bottoms subject to inundation." 



