WINlJMlLr. lliinCATIUN. 451 



will hold water four or five- feet deep, ;iiid a larjjer rcHervoir is 

 preferable. Where a Hiuall reservoir is used, a correspondingly 

 small piece of jifround must be Hooded each time, and the flood- 

 ing' must be done ofteiier. 



The best form of reservoir is round. A round reservoir exposes 

 less wall throuj^h which the water can seep, and from which it 

 can dry out, and is easier to build. In a round reservoir fifty feet 

 in diameter and four feet deep, there is thirteeen per cent less wall 

 surface than in a reservoir of etiual capacity built uj} scjuare, and 

 if the reservoir were built lony; and narrow the amount of wall 

 surface in proportion to its holding- cai)acity would be vastly in- 

 creased However, in the opinion of some, reservoirs should be 

 built oblono, say fifty feet wide and one hundred feet long-, or one 

 hundred feet wide and two hundred feet long, etc., and extending 

 at right angles to the prevailing wind, as the momentum of the 

 waves in traveling a considerable distance will be likely to injure 

 the banks. 



A location should be -ecured, if possible, with hardpan or tough 

 clay subsoil. If possible, place it on the highest part of the plot to 

 be irrigated and as near as possible to the source of the water. If 

 there is any slope whatever, let it be away frorn the reservoir. It 

 should be borne in mind that hillside, as well as level ground, can 

 be profitably irrigated if proper care is taken in the location of the 

 reservoir. Occasionally good results are obtained by building a 

 dam across some depression, thus necessitating an artificial bank 

 only on two sides of the reservoir. Sometimes, also, a sloping de- 

 pression on a hillside is enclosed at the lowest part by a substantial 

 daiti. Most reservoirs are made by simply scraping up from the 

 the outside of the reservoir a ridge of dirt sufficiently high to give 

 four, five or six feet of water on the inside. No dirt should be 

 thrown up from the inside of the reservoir, because it is desirable 

 to keep the bottom of the reservoir as high as the surrounding land, 

 and because the surface of the ground holds water much better than 

 the strata further down. However, if there is any sod upon the 

 ground where the embankments are to be made, the ground under 

 the locality of the embankment should be thoroughly ploughed, 

 and the sods removed, as sod is not a proper material for the con- 

 struction of embankments, and there would always remain a pos. 

 sibility of water seeping through at the bottom of the euibank- 

 ment. 



Now, with an ordinary scraper commence scraping up soil from 

 the outside of the reservoir to form the embankment. The earth 

 should be thoroughly leveled, pounded and packed as it is thrown 

 in place. No attempt should be made to mix rock or other ma- 

 terial with the dirt composing the walls. The embankment should 

 be very wide at the bottom sloping up very gradually from the 

 inside, as the waves would destroy perpendicular embankments. 

 Walls from four to six feet in height are usually to be preferred. 



When the embankments are constructed, it is well to fill the tank 

 partly full with water and allow it to seep out. While the bottom is 

 still muddy, turn into the reservoir horses and cattle and drive them 



