HEALTHFOLNESS. 151 



Reserve and Now Wasted Forces ix Nebraska. 



Owing to the almost constant movements of the atmosphere it 

 can be much more extensively employed as a motive power than 

 has yet been attempted. Wind mills are in general use now' for 

 pumping water and for motive power where little force is required. 

 That it has capacity to do much more than this is evident when we 

 formulate its force. A wind, for example, of three miles an hour 

 move< 4.40 feet per second. and produces a pressure of about thirty- 

 eight pounds for every square foot directly exposed to it. But 

 winds that constitute a stiff breeze, traveling at the rate of twenty- 

 five miles an hour, are not uncommon in Nebraska. This rate of 

 motion equals 39.67 feet per second and produces a pressure of 

 about 2,641 pounds for every square foot exposed to its action. 

 Between these two velocities lie the movements of winds that could 

 be depended on to propel machinery. Xow, remembering that the 

 movement of the winds is almost constant, and is felt in all situa- 

 tions, the amount of its wasted force is seen to be prodigious. Its 

 use already, all over the west on farms and railroad stations for 

 pumping water is a prophecy of its far more extensive employment 

 as a propelling agent in the near future. Mechanical ingenuity 

 will contrive a method by which the effect of the irregularitv of the 

 winds can be better overcome. The wind mills now used are al- 

 ready immeasurably better than those contrived only a few years 

 ago. Tbis improvement no doubt will continue until, like water in 

 a mill dam, the wind itself can be stored up for future use. The 

 mechanical engineer is already familiar with similar contrivances. 

 Its intermittant character cannot always be an obstacle to its exten- 

 sive use for driving machinery. It has one prime recommendation. 

 It is cheap. Each year will therefore see a great multiplication of 

 them. 



A still greater source of force and energy and the the fountain of 

 all the complicated movements on the earth is the sun. All the ex- 

 hibitions of force, organic and inorganic, chemical or physical, the 

 production of winds, currents, rainfall, the intricate causes that 

 operate to produce varieties of climate — all these are dependent on 

 solar radiation. Pouillet calculated that the earth received every 

 minute from the sun 2,247 billion units of heat, which quantity, if 

 transformed into mechanical force, "would raise 2,247 billions x 774 

 pounds to the height of ore foot." 



