CLIMATIC. 77 



the polar winds have direct action. Owing to vacuous air over our heated 

 prairies these winds, moisture-laden, tend to blow inland, precipitating 

 snow, hoar-frost or rain upon our highlands. 



Prof. M. W. Harrington, chief of the Weather Bureau at Washington, 

 D. C, says: "As the interior air of the forest is generally cooler, in the 

 warm season, it must be heavier, and the difference of temperature must 

 be often so great that the heavier air will overcome the obstacles to its 

 flow and gradually pour out near the ground. Its place will be taken by 

 the air above, which will settle, and thus there may be set up a forest 

 circulation, exactly corresponding to such a system of winds as is found in 

 land or sea breezes, or may be found over a lake at night." 



Thus our water area, together with the vast body of trees - co-acting in 

 unison, engender what answers to a sea breeze blowing inland upon the 

 open, heated regions by day, and these land exposures, cooling off quicker 

 at night than the water and forest, send the air waves back in cool 

 refreshment. 



DO FORESTS PROflOTE RAINFALL? 



Because a drouth affects a forest, it does not follow that it is not a factor 



in the promotion of rainfall. We can and do rob the forest of its power to 



perform its natural functions. Break down its roofy foliage, burn up its 



leafy floor, and the dry conditions of the forest atmosphere, arising from 



rapid evaporation, forestall precipitation. This forest unbalance reacts 



disastrously upon our vast agriculture, whose hungry mouths devour what 



rain descends, thus largely preventing flowage to the woodlands, and our 



lakes and rivers recede, trending to a general desert in land and atmosphere. 

 i 



HUMAN INTERFERENCE. 



The following extract, occurring in "Outlines of Forestry," is from 

 Geikie's "Text Book of Geology," page 471: "Human interference affects 

 meteorological conditions, 1. By removing forests and laying bare to the 

 sun areas which were previously kept cool and damp under trees. * * * 

 2. By drainage, the effect of this operation being to remove rapidly the 

 discharged rainfall, to raise the temperature of the soil, to lessen the 

 evaporation and thereby to diminish the rainfall." 



TESTIMONY OF FORESTERS. 



Collating the facts of history, a majority of scientific foresters maintain 

 that, where great forests have been removed, the rainfall has lessened, and 

 where great forests have been restored, the rainfall has increased. Among 

 the many testimonies are those of eminent professors who have given the 

 matter the closest possible consideration. In his "Report Upon Forestry," 

 1877, Franklin B. Hough cites the testimony of the distinguished French 

 forester, Prof. Becquerel: "St. Helena fully forested when discovered 

 in 1502. The introduction of goats and other causes led to the removal of 



