592 Transactions of tee American Institute. 



is like the attraction of mountains for clouds. A group of trees has a 

 tendency to cause the rain to fall there. 



The President — May that not be because the atmosphere around 

 the trees is saturated with moisture from the perspiration constantly 

 going on ? 



Prof. Phin> — The subject of the influence of forests upon rain is 

 one of the most interesting now before the public. I think that there 

 is an agent at work here, to which a great many effects are attributed 

 without reason — electricity. I do not think it probable that the 

 vapor given off in a particular locality is returned to that locality in 

 the form of rain. A spire of grass is just as efficient in drawing off' 

 electricity as a needle point. In a forest of trees, with its numerous 

 points discharging electricity from the clouds, we see a powerful 

 influence at work, which, I think, has more to do with the result 

 than evaporation. Further, the amount of vapor produced by a plant 

 will be largely increased by its being placed in .a dry atmosphere. 



Prof. James A. "Whitney — This is a cpiestion of practical impor- 

 tance, as well as of scientific interest. These experiments seem to me 

 a repetition of experiments made many years ago. The proportion 

 of water to the mineral matter has been shown to be 2,000 to 1 ; 

 so. that the amount of water passed off must be, to a certain extent, 

 independent of the atmosphere around it. It has been stated by a 

 German chemist that the amount of dilution of the mineral elements 

 can never exceed in strength one grain to 1,000 of water. It hardly 

 seems necessary to attribute to electricity the climatic results from 

 the planting of forests. The water passing into the air will furnish 

 it with moisture tending to the deposition of dew and the falling of 

 rain. In my journey across the plains, last summer, it was a matter 

 of consideration how those plains could be made arable, there being 

 no mountains and no great mass of water supplying the necessary 

 moisture. But I presume there are under those burning sands reservoirs 

 of water which can be reached by artesian wells, as in California; and 

 700 artesian wells, scattered over those plains in the great desert, 

 would make the land fertile. Then planting trees there, it is more 

 than likely that we could create oases in the desert which would 

 bring into that arid country the blessing of a more temperate climate. 

 I do not hesitate to express the opinion that in the sinking of those 

 wells will consist one of the greatest triumphs of engineering in the 

 coming century; and in the results which will follow, one of the 

 greatest triumphs of applied science. 



Mr. Becker related the instance of wells in Germany surrounded 



