178 BOARD OF AGRICULTURE. 



alike injurious to agriculture, to navigation and to health. 

 The eflfect of this change may he seen on a small scale, even 

 in my own town of West Newbury. Three difierent streams 

 within our borders formerly afforded useful mill privileges. 

 Now at midsummer one can walk along their beds dryshod. 



The disastrous effects of forest destruction have of late 

 been attracting much attention. New York is much con- 

 cerned for the preservation of the forests of the Adirondack 

 region, the great reservoir for the waters of the Hudson 

 River. The State of Connecticut is waking up to the im- 

 portance to her of the forests along the head-waters of the 

 Connecticut River in the States of New Hampshire and Ver- 

 mont, and the dwellers along the valley of the Ohio are 

 looking at the destruction of the forests of the Alleghany re- 

 gion as the cause of the devastating floods of 1882 and 1883. 



These disastrous effects are evoking a great deal of discus- 

 sion. I think we may take it for granted that the amount 

 of rain-fall, in all forms, that comes to the earth from the 

 air, is just equal to the amount of moisture evaporated from 

 the earth, including, of course, its whole surface, — land and 

 water. As rain-fall depends on evaporation, and is just equal 

 to it, it follows that increase or decrease of evaporation will 

 be followed by a corresponding increase or decrease of rain- 

 fall. 



It is a mistaken opinion that, other things being equal, the 

 soil a few inches below the surface is more moist where shaded 

 by luxuriant vegetation than where exposed to the direct rays 

 of the sun. I was once standing with several others in a 

 potato field where one-half the crop had been dug for early 

 market, while the other half had been left to mature. The 

 weather had been warm and dry, and the question came up, 

 where shall we find most moisture, — where the potatoes 

 have been dug and the bare earth is exposed to the sun, or 

 where the potatoes are still growing? The answer, almost in 

 concert, was, " We shall find most moisture where the 

 ground is shaded by the vines." Investigation proved the 

 contrary, beyond all dispute. Where nothing was growing, 

 three inches below the surface revealed moist earth ; while 

 among the growing potatoes the soil was dry to twice that 

 depth, the roots having absorbed the moisture, and the 

 leaves and stems exhaled it into the atmosphere. 



