3 6 



FORESTRY AND IRRIGATION 



March 



On the great plains west of the Mis- 

 sissippi the most available power is the 

 force of the wind. On account of the 

 flatness of the country the winds are 

 almost incessant and rather more forci- 

 ble than is agreeable. Fortunately, the 

 people in these regions have been able 

 to make a servant of the nuisance which 

 blows the soil off their fields, and set it 

 to make them more productive by in- 

 creasing the water supply. 



Various unique machines have been 

 employed to take advantage of the 

 measureless power afforded by the winds. 

 Among the more ingenious home-made 



use them, considering the gain in effi- 

 ciency. 



Mounted on scientifically braced steel 

 towers, they catch every breath of air, 

 face the wind automatically, and shut 

 themselves off when their work is done. 

 If the wind rises to violence which 

 makes the exposure of much surface 

 dangerous, they present only the edge 

 of the wheel to the increasing pressure. 



In much of the great plains country 

 there is just enough rainfall to render 

 a crop dubious. The cattle industry 

 does not demand nearly as much water 

 as does farming. Hence it follows that 



AN OVERSHOT WINDMILL. 



affairs is the wind engine, which is like 

 an old-fashioned over-shot water-wheel 

 in construction and action. The lower 

 half is shielded by a simple screen of 

 boards surrounding it on all sides, so 

 that the wind can act only on the upper 

 half. 



Wooden mills on wooden towers have 

 also had their day, as well as wind 

 wheels without towers, and wheels 

 made with sails of cloth. The modern 

 facility of metal construction and exact 

 engineering calculation have produced 

 stiff, light-running windmills made en- 

 tirely of steel at a price so low that no 

 one who needs them can afford not to 



a few efficient mills can supply from the 

 widely extended artesian basins the 

 comparatively small extra amount of 

 water necessary to insure successful 

 operations in a country where there are 

 no streams available. 



But the wind sometimes proves a poor 

 reliance. Some hot August, when cat- 

 tle and crops alike are parching with 

 thirst, a dead calm occurs, and the 

 broad fans of the mills are motionless 

 and useless for several days at a time. 

 Then it is that the foresighted hus- 

 bandman runs out the traction engine 

 or gasoline engine, previously adapted 

 and adjusted for such emergencies, and 



