IQOI.] FORESTRY. 3 



false alarm. But whatever else was uncertain there was one 

 thing to which practical men had pinned their faith, namely, 

 that from some cause or another there was a change in the 

 water power, and that it was associated with rernoving the 

 forest cover from the land. They could trace it from where 

 never-failing springs became wet weather springs only, down 

 the channels of the streams to where in late summer and early 

 autumn the wheels of mills and factories that, in former days, 

 ran throughout the year, now halted and waited because there 

 was not water enough to turn them. This was all true 

 enough, but we were still far from the full solution of the prob- 

 lem. It was quite sure that the rainfall was as great as ever, 

 but it remained to be shown that the quantity of water which 

 ran off through these channels, when we considered the whole 

 year, was probably as great as when the entire country was 

 timbered. At least such seems to be the verdict of the most 

 recent investigators. The whole truth boiled down seemed 

 to be this. Forests conserve what rain does fall, and by 

 preventing excessive freshets through increasing the absorb- 

 ing power of the earth's surface they distribute the water more 

 evenly throughout the year. What subsequent modifications 

 this truth may receive, it is probably substantially correct as 

 stated. 



But this brings with it a train of events which is of immense 

 importance. So long as water remains in the soil there is a 

 reserve power upon which we may count in time of need. 



When it becomes aqueous vapor and flies to the sky its 

 usefulness to us is in doubt, and when it rushes out of the 

 country in a flood not only is its usefulness uncertain, but 

 its destructiveness is sure. In other words, forests enable us 

 to retain the rainfall in a useful condition for gradual distribu- 

 tion throughout the entire year. Not only do they lead the 

 rainfall into the earth where it is safe against immediate run-off 

 and evaporation, but they do more than this: they actually, 

 out of the surplus which they have saved, return more aqueous 

 vapor to the atmosphere during the growing season than a like 

 area of cleared ground in any ordinary farm crop could do. 

 How important this vapor is does not appear at first sight. 

 It is well known that, coming from above, the heat of the sun 

 can, in a great measure, penetrate through the moisture in the 

 air, and reach the earth to be absorbed by it. On the other 

 hand this same heat when radiated back during the night can- 



