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29-±
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MOLESWOBTh’s POCKET-BOOK
Irrigation—continued.
„ _ , I»on S1.UICE&
H = Head of water in feet.
A. = Area of sluice in inches.
v = Theoretical velocity due to head of water in feet per
minute — 482 H. For Table of value of v, see
‘Theoretical velocity of water.”
y = Quantity of acres irrigated.
( =-0033 Av.
This is calculated on the assumption that the coefficient of
discharge = -6, and that f an inch of water including waste is
supplied m 24 hours, and that the sluice-pipe is circular.
Head of Water. 1 6 Diameter of Sinice-pipe in inches.
1 8 ' 9 12 f 10 ! 18 24 13-55*
—
feet. acres. acres. acres. acres. acres. acres.
2 63 113 143 254 452 572 1016 323
4 90 160 202 360 640 809 1439 45S
6 110 195 248 440 783 991 1761 561
8 127 226 286 509 904 1156 2035 648
10 142 252 320 569 1011 1280 2275 723
15 174 309 391 696 1238 1567 27S5 887
20 201 357 452 804 1430 1809 3222 1024
30 246 437 554 985 1751 2217 3941 1254
40 284 505 640 1037 2022 2558 4550 144 A
50 । A- 318 565 715 1272 2261 2861 5088 J619
vr one SQimrc foot, 13*55 crivps mt> qroa
foot. Area in square feet X 4751L Q *"* °f °De square
Press pre on Sluices
1) __ Mean depth of sluice below surface in feet.
A __ Area of sluice in square feet.
P = Pressure on sluice in lbs.
K — Coefficient of friction.
X = Power required to work the sluice in lbs.
X = K x P. ’
K = 0 • 68 when the sluice is of wood.
Kz=0’31 „ n metal
tor other coefficients of friction, see ° Friction.”