142 



THE IRKIGATION AGE. 



stand by a right-angled elbow, as shown in Plate V, 

 Fig. 1, or the connection ma}' be made by a short piece 

 of canvas hose from six to ten feet in length. Many 

 prefer this latter method, as it gives greater freedom 

 of movement to the first two or three sections of pipe 

 and also protects the cement stand from disturbance 

 by careless handling. When the sections of pipe are 

 jointed and extend nearly to the lower end of the 

 field, the water is turned in and the irrigation of the 

 first strip begun. Many irrigators distribute the 

 stream from the metal pipe directly. Others distribute 

 by means of one or two lengths of metal pipe, which 

 are attached to the main pipe either by a short piece 

 of hose or by a metal elbow (Plate V, Fig. 2), while 

 still others use one, two or three 50-foot lengths of 

 canvas hose at the end of the metal pipe, with which 

 the stream can be conveyed to every part of the strip 

 within the radius of the hose. It is common practice, 



side by canvas sections. This system might be em- 

 ployed on very rough ground with but little prepara- 

 tion of the surface and with but little modification of 

 the method just described. The only requisite is that 

 a head be maintained on the pipes sufficient to carry 

 the stream to the top of the highest knolls without 

 much diminution of its flow. The use of pipes is not 

 confined to tracts where flooding is the method of irri- 

 gation employed, but they are also used to some ex- 

 tent with basin and contour check irrigation. The 

 pipes convey the water to the various checks without 

 the losses which would occur if the common method of 

 filling one check through a serious of others were em- 

 ployed. 



CONSTRUCTION OF PIPE, HOSE AND STANDS. 



The thin iron pipe commonly used varies from 

 seven to nine inches in diameter and is made in sec- 





Distributing Water From Sections ol Metal Pipe Attached to Main Pipe by Canvas Elbows. 



after having sufficiently irrigated the lower five or six 

 rods of the strip, to disconnect several lengths of the 

 metal pipe, reattach the distributing hose and proceed 

 with the irrigation of a second and higher portion of 

 the strip. While the water is running there the dis- 

 connected pipes are placed in the adjoining strip in 

 much the same manner as that in which they were 

 originally strung out in the first strip, beginning, how- 

 ever, at the lower end of the strip and proceeding up- 

 ward in reverse order. When the second portion of 

 the first strip is watered, more metal pipe is discon- 

 nected and placed in the adjoining strip, the hose is 

 moved up to the third portion of the strip and the 

 stream handled in the same manner as in the two 

 lower portions just irrigated. This method of pro- 

 cedure is continued until all of the first strip has been 

 watered. Then the metal pipe is jointed up and the 

 connection made with the second stand and the irri- 

 gation of the second strip accomplished by repeating the 

 operation as in the first strip. 



This method is used to the best advantage on land 

 having a fairly even slope. Where the land is uneven 

 and broken the metal pipes give better results if laid 

 along the ridges and the water distributed on either 



tions of varying lengths. The most common length is 

 twelve feet, formed of four 36-inch sections. All joints 

 and seams are riveted and soldered, and the end of 

 each section is crimped to give it rigidity. Some 16- 

 foot sections are used, but these are rather long, and, 

 although there are fewer joints where leakage may 

 occur, their length makes them bulky and awkward to 

 handle. The roughness of the land on which the pipes 

 are used governs to some extent the best length of sec- 

 tion. On some rough land 10-foot sections are used 

 with the best success, while on smooth land some pre- 

 fer 15-foot sections. 



Various weights of galvanized iron may be used, 

 ranging from No. 20 to No. 26 B. W. G. No. 26 

 iron is too light for most work ; it makes a fragile pipe 

 which is easily damaged, especially at the ends. The 

 most serviceable pipe, where price and durability are 

 considered, seems to be that made from No. 22 or 

 No. 24 iron. No. 20 is heavy for all ordinary pur- 

 poses, but makes a very strong and lasting pipe. No. 

 22 iron is the grade most commonly used. It makes a 

 good, serviceable pipe that is light but at the same 

 time quite strong. The effect of water pressure on 

 these metal pipes, as governing the weights of iron 



