FORESTS AND RAINFALL. 251 



conductors, without undergoing and producing some change of 

 electrical condition." 



The following interesting illustrations are not without value 

 as vasuelv indicatinsj in what direction we must turn for an 

 explanation of the summer droughts, which in certain portions 

 of the country have increased of late to an alarming extent. 

 lu Massachusetts, however, some cause outside the destruc- 

 tion of the forests must be sought for ; as in the earliest 

 history of the Colony, and long before land enough had been 

 cleared to induce any climatic change, the country was nearly 

 devastated by severe summer droughts, which, if less frequent, 

 were no less violent than those of the present day. 



Mr. Calvin Chamberlain, in an able memorial on the subject 

 of forests,* presented to the house of representatives of the 

 State of Maine in 1869, says : "There is a portion of Hancock 

 County (Maine) , along the coast, that is now nearly denuded 

 of trees. During the heat of summer, the radiation from the 

 parched surface aftects the atmosphere to excessive drj'uess. 

 The electrical and rain-bearing clouds that approach from the 

 westward, as they come within this dry atmosphere, are 

 absorbed and dissipated before their watery contents can 

 reach the earth ; while the clouds just north of them float on 

 over a better wooded district and yield a copious rainfall ; and, 

 on the other hand, the showers continue abmidant in the more 

 humid atmosphere of the contiguous bays and ocean." 



Dr. Lapham j observes that " in the hot and dry plains of 

 our South-western Territories we often see clouds passing 

 overhead that reserve their contents until they have passed 

 from these almost desert regions. These clouds frequently 

 present all the actual appearance of rain in the higher region 

 of the atmosphere, and the fertile-giving drops are seen to fall 

 far down towards the earth, only to be dissolved and dissi- 

 pated in the lower strata of air, heated by the reflection from 

 the parched earth, which these raindrops do not reach." 



As moderators of the extremes of heat and cold, the bene- 

 fits derived from extensive forests are undoubted, and that 

 our climate is gradually changing through their destruction is 



* Agriculture of Maine. Second Series. 1869. 



t Report of the Disastrous EtFects of the Destruction of Forest Trees now going 

 on so rapidly in the State of Wisconsin. 1867. 



