288 RETENTION OF SNOWS BY WOODLANDS. 



tbe maximum of June, we find a rejjular decrease to September, 

 and then a^rain a second maximum in November, differing but a little 

 from October. From August to October the prevailing winds are east, 

 and in tbe month of November they become southerly, bringing an 

 increase in the amount of rain-fall. After considering in detail the ob- 

 servations made through a series of years, and many cases of excep- 

 tional droughts, the author remarks that there appear grounds for believ- 

 ing that there has been within the time observed a perceptible change 

 of climate, more especially in the diminution of the rain-fall. 



It is well known that the amount of forest area has diminished very 

 considerably within this period, and it is fair to connect the two coinci- 

 dent facts as cause and effect. Admitting this, the conclusion follows, 

 that with increasing forest area, there would be a decrease of drought, 

 inversely proportioned to its amount. 



RETENTION OF SNOWS IN WINTER AND EARLY SPRING. 



The effect of woodlands in retaining the snows where they fall, and in 

 delaying their melting in the spring, has been everywhere observed in 

 snowy countries. In such localities the snow cannot be drifted by the 

 winds, and when it melts it disappears slowly, sinking into the soil, 

 rather than flowing off upon the surface. The effect of this delay in 

 checking a too early appearance of fruit-blossoms cannot be mistaken. 

 The result is in fact quite similar to that of considerable areas of water, 

 such as our Northern Lakes, along the borders of which, and especially 

 on tbe lee-side, fruits are found to flourish with the greatest success. 

 In a country interspersed with clumps and belts of woodlands the snows 

 drift less, and tbeir melting more evenly over tbe surface cannot fail of 

 being beneficial to the interests of agriculture, and more especially to 

 meadows and pastures. 



Itis observed throughout the mountains of Colorado, andtbeterritories 

 to the north and south of that State, that tbe north slopes are, as a gen- 

 eral rule, much more heavily timbered than those that face toward the 

 south. This is apparently due to the fact that the winter snows are 

 there detained the longest, and that tbe soil is by this means kept moist 

 and sheltered, while under the exposure of tbe sun's direct rays tbe soil 

 becomes dry and sterile. To this rule there are, we believe, but few 

 exceptions, unless due to a local circumstance affecting tbe conditions 

 over a limited area. The effect may be partly due to the shelter thus 

 afforded against drying southwest winds. 



The Commissionerof the General Land Office, in his reportforl874-'75, 

 in noticing the effect of excessive and improvident clearing upon the 

 mountainous regions of California, and its effect upon tbe snows and 

 the rain-fall, says : 



Under this state of things timber has, in many instances, wholly disappeared for 

 miles in the vicinity of the large mining centers. Incidentally to this general waste 

 is another result, often disastrous in immediate eflects and threatening in future 

 consequences. The mountain-streams, whose steady flow is important alike to the 

 miner and to the agricultural interests of the valleys and plains below, are fed by the 

 melting snows. The steadiness of the flow of these streams — the preservation of their 

 volume throughout the year — so long as natural conditions prevail, is in a great meas- 

 ure due to the fact that over large areas of the higher levels the rapid melting of the 

 winter's accumulation is prevented by the dense shade of the forests. This removed, 

 destructive floods, in the season of returning warmth, to be followed later by scarcity, 

 become the rule. It may be noted also, as another incident to this total destruction of 

 timber along the canons, that snow-didea are of frequent occurrence in the denuded 

 localities of the mining settlements, and that, during the past winter, some were at- 

 tended with serious loss of life and property. 



