THE IKRIGATION AGE. 



299 



CURRENT WHEELS ; THEIR USE IN LIFTING 

 WATER FOR IRRIGATION.* 



CONSTEUCTION OF CURRENT WHEELS. 

 CONSTRUCTION FOR A SWIFT CURRENT IN IDAHO. 



(Continued.) 



The wheel shown in Fig. 12 has been in use on Lost 

 Kiver, Idaho. It was built to raise water about ten 

 feet for the irrigation of 2.25 acres in garden and grain. 

 It is fourteen feet in diameter, with paddles six feet 

 in length mounted on a shaft eighteen feet long, span- 

 ning the stream. The shaft is an eight by eight inch 

 square timber. For six inches near each end it is 

 turned round to form a bearing. The spokes are very 

 substantial, being made of two by six inch material. 

 Each paddle carries a 3-gallon pickle keg on one end. 



tween two crib piers at a point where the river channel 

 at high water is only about fifteen feet wide. In low 

 water the channel is only about ten feet wide, the cur- 

 rent being about five feet per second. This narrow 

 channel of the river is only a few years old, and al- 

 though it appears to consist of a hard cemented gravel, 

 still it is by no means certain that in the course of time 

 the wheel may not again be left stranded above the 

 current. 



Four hundred feet of lumber were used in building 

 the wheel and twenty-five pounds of bolts, making the 

 cost of material about $12, not including the buckets. 

 The heavy construction of the wheel would be unwise 

 under most conditions; but in a current as swift as 

 five feet per second in low water and much swifter when 

 the water is high, any but the most substantial construe- 





Wheel Operating a Rotary Pump, Yakima River, Washington. 



The kegs are set on a bevel, as shown in the figure. 

 The device for raising and lowering the wheel is very 

 simple, consisting of two uprights which support a 

 pulley, beneath which a wooden bearing is hung by 

 a %-inch rope. A piece of gas pipe is used as a wind- 

 lass (Fig. 13). 



When the wheel was built it was set between two 

 supports at a point where the river is about forty feet 

 wide, the supporting posts being driven into the bed of 

 the stream at either side of the deeper current. The 

 swift current .in the center of the stream turned the 

 wheel very satisfactorily for a time, but owing to the 

 soft nature of the bed, which at this point is composed 

 of coarse gravel, during the high water the current 

 washed out a- deep channel directly under the wheel and 

 left it high and dry when the flood subsided. To ob- 

 viate this difficulty, the wheel is to be remounted be- 



*Courtesy U. S. Dept. of Agriculture. 



tion would prove unsatisfactory. The notching of the 

 main arms where they cross at the center of the wheel 

 weakens them seriously. Were this avoided by placing 

 one set nearer the middle of the shaft, leaving space 

 enough so that the rim of 1-inch boards could be nailed 

 on the inside of one set and on the outside of the other, 

 two by four inch material would be strong enough. 

 While the eight by eight inch shaft would sustain a 

 weight at the center of over 10,000 pounds, still it is 

 none too heavy for the wheel weighing 1,600 pounds; 

 since it is evident that the friction in the bearings is 

 greatly increased by a comparatively slight bending of 

 the shaft. 



The wheel raised sufficient water to irrigate the 

 2.25 acres in forty-eight hours, the water being applied 

 four of five times in the season. It should then raise 

 sufficient water for the successful irrigation of forty 

 acres using the water for 160 days. 



