148 PILdtCliGHh AR BORTCULT URE 
sive. This condition can be changed by the systematic planting of trees in 
belts to break the continuity of the currents and prevent such an accumula- 
tion of heat by the surface currents. At each successive obstruction 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 vallevs, the high rolling prairies 
having no wood, while the trees in the valley are all below the average surface. 
Were this 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 equalized by the obstructions. 
Opponents will say that hot air always rises directly and does not pass 
horizontally along the surface. 
But water traverses a thousand miles of underground strata, enters the 
porous sandstone at the Great Falls of the Missouri and reappears in the 
valley of the 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 current does traverse the region named each season, and 
these truths are well known to every resident of the territory described. The 
pressure of the overlying atmosphere, which is colder than the sirocco, so 
long as there are no mountains, forests or obstruction to divert the sirocco, 
hold the hot current close to the surface. 
The force of the wind at the surface of the earth is what concerns us, 
and not its velocity at points of greater elevation, 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 currents to a 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 result. 
To construct levees, dams and engineering works for the improvement 
of navigable rivers, requires the authority and control of the government, 
and aid of each state benefited. And this work, which would ameliorate the 
condition of millions of our people, cannot be accomplished without the co- 
operation of the national government, each state interested, and whole communities 
of land owners. It will require patriotism and a high order of statesmanship 
among legislators to prepare and enact laws releasing from taxation the 
lands occupied by timber, and which will not be productive of an income for 
the owner for several years, but it is worthy the effort. 
