THE SHELTER OF FORESTS. 257 



Becquerel, as quoted by Mr. Marsh, says : "In the valley 

 of the Rhone a simple hedge, two metres in height, is suffi- 

 cient protection for a distance of twenty-two metres." "The 

 mechanical shelter" says Mr. Marsh, "acts, no doubt, chiefly 

 as a defence against the mechanical force of the wind ; but 

 its uses are by no means limited to that efi'ect. If the cur- 

 rent of air which it resists moves horizontally, it w^ould pre- 

 vent the access of cold or parching blasts to the ground for a 

 great distance." "Becquerel's views," says the same author, 

 "have been amply confirmed by recent extensive experiments 

 on the bleak, stony, and desolate plain of the Crau in the 

 department of the Bouches du Rhone, which had remained a 

 naked waste from the earliest ages of history. Belts of trees 

 prove a secure protection even against the piercing and chilly 

 blasts of the Mistral, and in their shelter plantations of fruit- 

 trees and vegetables thrive with the greatest luxuriance." 

 Experiments of a similar nature, and on a large scale, have 

 been made in Holland, and lands, which were formerly con-' 

 sidered unimprovable, such was the force of the winds blow- 

 ing from the North Sea, have been rendered almost the most 

 productive in Europe, simply by sheltering them with rows 

 of trees placed at regular intervals, and at right angles to the 

 direction of the wind. 



It appears, then, that in a country in which a due proportion 

 of forest was maintained, it might be expected that local sum- 

 mer showers would probably be attracted ; that extremes of 

 temperature both in summer and winter would be prevented 

 to such an extent that additional crops would be made pos- 

 sible ; and that the annual rainfall, instead of being rapidly 

 wasted by evaporation, or still more rapidly poured into the 

 sea, would be held in the forest-clad ground, from which it 

 would gradually find its way to the water-courses, which 

 would flow regularly throughout the year, bringing summer 

 verdure to pastures, and assured power to the manuflictories 

 along their banks. 



But these are national questions, and can only be treated 

 in a broad, comprehensive manner. Let us consider, how- 

 ever, whether Massachusetts is furnishing her quota to the 

 national forest system which would return to our country 

 much of its lost fertility. It has been estimated, and I think 



33 



