IRRIGATION BY THE USE OF WINDMILLS. 



19 



to the capacity, cost, etc., of wind-mills and pumps. 

 From the pump company I learned that one horse 

 power will raise a 5-inch column of water 100 feet; a 

 6-inch column seventy feet, and an 8-inch column 

 forty feet; additional horse power will elevate the 

 water in direct proportion. A 10-foot mill will de- 

 velop one-half of one horse power; a 12-foot mill 

 three-fourths horse power; a 14-foot mill two horse 

 power, and each additional two feet in diameter of 

 mill develops practically an additional horse power 

 up to a 30-foot mill which develops eight horse power. 

 The cost of the mills range from $40 for the smallest 

 size up to $400 for the largest. 



In response to an inquiry as to the estimated num- 

 ber of days a wind-mill will run during the year, the 

 company replies as follows: "It depends on locality. 

 Here in Illinois total output one-third or eight hours 

 per day. Kansas and Nebraska will average^double 

 this amount." I think the estimated average for 

 Kansas and Nebraska, as compared with Illinois, will 

 be accepted without question. 



I further ascertained from the pump company that 

 a 5-inch pump geared to run forty-eight 8-inch strokes 

 per second will discharge 1860 gallons of water per 

 hour; a 6-inch pump geared in the same way will dis- 

 charge 2,760 gallons per hour, and an 8-inch pump 

 will discharge 4,860 gallons per hour. 



THE DTJTY OP WATER. 



From the printed report of the Colorado State 

 Agricultural College at Fort Collins, Colo., I 

 learned that the duty of water, as determined by actual 

 measurement is one cubic foot per second running 

 continuously for sixty to sixty-five acres of ground. 

 This during the month of June when the greatest 

 amount of water is needed for irrigation. During the 

 entire irrigation season one cubic foot per second, if 

 reservoired, is sufficient for 175 to 300 acres. The 

 same report shows that by actual measurement the 

 amount of water required for various crops ranges 

 from 1.67 feet to 2.53 feet in depth. That is, if the en- 

 tire amount of water necessary for the perfect irri- 

 gation of the land was applied to the land at one time, 

 it would be necessary to cover the ground to the 

 depth named, according to the crop to be irrigated. 

 The report shows also that this measured depth _in- 

 cludes the measured rainfall during the same season. 

 For the purpose of estimates given in this paper, I 

 will assume that the average depth required for crops 

 is two feet. 



WHAT A WINDMILL WILL DO. 



From the statements made by the pump company 

 as to the capacity of a pump, I learn that a 5-inch 

 pump will discharge 1,860 gallons of water per hour. 

 This is thirty-one gallons per minute or five-tenths 

 gallons per second, and is equal to .06% cubic feet per 

 second. On the Colorado basis as before given, a 



stream running .06% cubic feet per second would irri- 

 gate about six acres of land; but the pump is only 

 estimated to run about one third of the time, conse- 

 quently one-third of the water would be secured and 

 about two acres could be irrigated direct fram the 

 pump. 



I have a large number of reports from farmers who 

 apparently put in their wind-mills originally for the 

 sole purpose of securing water for stock, but have 

 since been successfully irrigating orchards, garden 

 patches, etc., from the surplus water without making 

 any attempt to reservoir it. These reports show that 

 such surplus water is sufficient to irrigate from one 

 to three acres of land. 



RESERVOIR POSSIBILITIES. 



Now suppose a farmer expends a few dollars in 

 constructing a reservoir 100 feet square by four feet 

 deep, what would be the result? Such a reservoir 

 will contain 40,000 cubic feet, or about 300,000 gallons 

 of water, a 5-inch pump discharging 1,860 gallons of 

 water per hour, will in one-third of a day, or eight 

 hours, discharge 14,880 gallons. In twenty days of 

 eight hours each (this is assuming that the wind-mill 

 runs one-third of the time) 297,600 gallons of water 

 will be secured, practically filling our 300,000 gallon 

 reservoir. During the six months from April to Sep- 

 tember inclusive, there are nine periods of twenty 

 days each, therefore the reservoir can be emptied 

 and filled nine times during the six months, result- 

 ing in an aggregate of 2,700,000 gallons of water for 

 irrigation purposes, equal to 360,000 cubic feet. 



IRRIGATION AND RAINFALL. 



The report of the Kansas State Board of Agricult- 

 ure, for last year, shows that at Wallace, Kan., during 

 the six months from April to September, the rainfall 

 aggregated over fifteen inches. We have before found 

 that an average of two feet in depth, including the 

 rainfall, is required for practical irrigation; or in 

 other words, two cubic feet of water per square foot 

 of land. An acre of land contains 43,560 square feet, 

 therefore, to irrigate one acre of land requires 87,120 

 cubic feet of water; of this | or % may be estimated 

 as being the rainfall, leaving % to be supplied from 

 the reservoir. Therefore to irrigate one acre of land, 

 during the season, requires 32,670 cubic feet of water; 

 but our pump and reservoir will supply, during the 

 season, 360,000 cubic feet or water enough to irrigate 

 about eleven acres. 



THINGS ACTUALLY DONE. 



Now, we have seen what in theory ought to be' 

 accomplished with a pump and reservoir of the ca- 

 pacity named, let us see what our farmer's reports 

 show as actually being accomplished. John Simon, 

 of Garden City, Kan., reports a wind-mill pumping a 

 5 inch stream of water into a reservoir 100 feet square 



