676 
Journal of Agricultural Research 
Vol. XXVII, No. » 
less variable, but in putting down the wells it was found that coarse 
water-bearing sand could be reached, though in some places the clay was 
several feet thick. Although the wells all penetrated to the water¬ 
bearing sand it will be seen from the diagrams 'that the height of the ground 
water was not the same in all the wells and that its quality was very 
different. The range in salt content in the north line of wells was from 
2.68 per cent to 0.037. The irrigation water contained about o.o - ? per 
cent of dissolved material. 
The diagrams show that the water from some of the wells contained 
only very little more dissolved material than the irrigation water. The 
implication is that these wells are located in soil that is readily permeable 
to water and m consequence has long since given up any excess of soluble 
material. The immediate elfect of irrigation on the height of the ground 
water m this series of plats is shown in figures 7 and 8. These diagrams 
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GfiOO/VO SUffFACC - 
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Fig. 12.— Series Y ground waters in wells No. a N to 4 N and the intermediate wells on the 
Newlands project, October 19,1922. 
show that following an irrigation the water stood much higher in some 
wells than in others and also settled away much faster. Even in the 
more permeable areas the rate of subsidence was slow, averaging not more 
than 2 or 3 inches a day for the first week after the irrigation. During 
the period of frequent irrigations in this leaching experiment when the 
water was applied as often as once each week the ground water remained 
about 1 foot higher than it had been before or than it subsided to after 
the close of the irrigation period. 
The condition of height and salt content of the water one month after 
the final irrigation of the season is shown in the second diagram of figure 
10, and figure n. Although these plats had been copiously irrigated 
since the first of August and the drain had been discharging water con¬ 
tinuously there is seen to be very little difference in the salt content of 
