ARBORICULTURE 



219 



struction the whirls or counter currents 

 would mingle the cold air of the upper 

 strata with the hot surface current, 

 equalizing the temperature by reducing 

 the heat at the surface. 



In all the region traversed by these 

 siroccos, as well as the entire prairie 

 country, the scant timber lies in the low 

 valleys, the high rolling prairies having 

 no wood, while the trees in the valley are 

 all below the average surface. Were this 



The force of the wind at the surface 

 of the earth is what concerns us, and not 

 its velocity at points of greater eleva- 

 tion, hence we may consider how best to 

 increase the height of the current. 



Sage brush deflects the wind from one 

 to six feet, and prevents the sand motions, 

 enabling seeds of grasses and trees to 

 germinate ; wild plum and similar bushes 

 raise it to a height of six to fifteen feet. 

 An osage hedge not cut back controls the 



WIND GURREN-T8— THE AMERICAN SIROCCO. 



reversed, and the trees placed upon the 

 highest lands the effect would be very 

 different from what it now is, as the cold 

 and hot currents would be ecpialized by 

 the obstructions. 



Oponents will say that hot air always 

 rises directly and does not pass horizon- 

 tally along the surface. 



But water traverses a thousand miles 

 of underground strata, enters the porous 

 sandstone at the Great Falls of the Mis- 

 souri and reappears in the valley of the 



currents to height of twenty to thirty 

 feet, while a belt of catalpa speciosa, 

 properly grown will influence the wind to 

 a height of from fifty to one hundred 

 feet. Eucalyptus, a hundred and fifty 

 feet. But these belts must be at frequent 

 intervals to accomplish the desired re- 

 sult. 



To construct levees, dams and engi- 

 neering works for the improvement of 

 navigable rivers, requires the authority 

 and control of the government, and aid 



CONTROL OF WIND BY MOUNTAINS AND TREES. 



James, in Dakota, rising two hundred 

 feet above the surface. Years of actual 

 experiences, with the facts before us, it 

 is self-evident that this hot surface cur- 

 rent does traverse the region named each 

 season, and these truths are well known 

 to every resident of the territory de- 

 scribed. The pressure of the overlying 

 atmosphere, which is colder than the sir- 

 occo, so long as there are no mountains, 

 forests or obstructions to divert the sir- 

 occo, hold the hot current close to the 

 surface. 



of each state benefited. And this work, 

 which would ameliorate the condition of 

 millions of our people, cannot be accom- 

 plished without the co-operation of the 

 national government, each state inter- 

 ested, and whole communities of land 

 owners. It will require patriotism and 

 a high order of statesmanship among 

 legislators to prepare and enact laws re- 

 leasing from taxation the lands occupied 

 by timber, and which will not be produc- 

 tive of an income for the owner for sev- 

 eral vears, but it is worthv the effort. 



