1902. 



FORESTRY AND IRRIGATION. 



i73 



should be cut even with the trunk. 

 The best time for pruning is undoubt- 

 edly in the fall or early winter. 



As so many of our eastern white 

 pine woods are seriously affected by the 

 pine weevil, attention should be called 

 to it. The presence of the insect is first 

 manifested by the wilting of the ter- 

 minal shoot, which, if examined care- 

 fully, will be found completely mined 

 by the insect larvae. A tree thus dam- 

 aged will fail for several seasons to send 

 forth a terminal shoot, with the result 

 that the lateral branches strive with one 

 another to gain supremacy. It is at 

 this point that the owner of the wood- 

 lot can materially aid nature in her 

 efforts to again produce a normal tree. 

 A limb should be selected to take the 

 place of the leader, and in making a 

 choice its thriftiness and relation to the 

 tree should be considered. After a 

 choice has been made all the other 

 branches of the whorl should be re- 

 moved, thus giving the newly chosen 

 leader every opportunity to develop. 

 If the work has been judiciously done, 

 the tree may again assume its normal 

 shape in after years. 



A TREE THAT HAS BEEN ATTACKED BY THE 

 PINE WEEVir.. 



THE RESERVOIR IDEA. 



By G. M. Houston. 



THE recent spirited, comprehensive 

 development of systems of irri- 

 gation reservoirs in northern Colorado 

 is in response to several causes, some of 

 them a little complex, but most of them 

 of a very evident nature. In general, 

 it may be said that the snow leaves the 

 eastern slope of the Rocky Mountains too 

 rapidly and too earl}- in the season. For 

 these reasons the irrigator and the irri- 

 gation engineer, even if all the suitable 

 lands within one hundred miles of the 

 foothills were devoted to grains and other 

 so-called early crops, would be put to 

 their wits' ends to make even a wasteful 

 use of the riotous floods that are the re- 

 sult of innumerable rivulets and brooks 

 combining in the stream beds and val- 

 veys. This is notably true of the Cache 



la Poudre and the South Platte Rivers. 

 Too often the flood season is accom- 

 panied by such seasonal rains as make 

 the use of the passing flood unnecessary 

 and impossible. In addition, the com- 

 ing of the rainy term means the more 

 rapid wasting of the snow in the moun- 

 tains. This will be sorely needed after 

 five days of sunshine, even though the 

 soil may be soaked and reeking with 

 the rains of ten days, owing to the ex- 

 treme evaporative powers of the atmos- 

 phere of the Colorado Plateau. 



Additional reasons that may be count- 

 ed among the very evident ones that 

 lend to the great waste of the winter 

 snows are the forest fires and the 

 indiscriminate cutting of timber, that 

 have wasted the forests of the eastern 



