THE IRRIGATION AGE. 



295 



the turnout and see by the turning of the wheel that 

 water is sitll coming. When users realize that every 

 turn of the wheel means so much water charged to 

 them they will be more liable to economize in its use. 

 The Grant-Mitchell meter is shown in figures 21 

 and 22. It consists of a wheel turning in a horizontal 

 circular opening through which the water is made to 

 pass. This opening sets a little below the bottom of 

 the ditch. The water in entering drops into a box set 

 below the ditch bottom, passes 

 under a cross wall, rises through 

 the circular opening in which the 

 meter is set, and passes on down 

 the ditch. The meter consists of 

 four flat blades set so that the 

 water in flowing through the cir- 

 cular opening strikes against 

 them at an angle. In this way the 

 wheel is turned similarly to a wind 

 mill. On the upper end of the 

 shaft carrying the wheel is a coun- 

 ter which records the number of 

 revolutions of the wheel. 



This meter is made in 4 sizes, 

 12-inch, 18-inch, 21-inch, and 39- 

 inch. The size to be used is de- 

 termined by the size of the circu- 

 lar opening. The rated capacities 

 for these sizes given by the makers 

 are 1.66, 3.75, 5.83 

 and 16.66 cubic 

 feet per second, re- 

 s p e c t i vely. The 

 wheel, counter, and 

 standard for hold- 

 ing the wheel are 

 sold and controlled 

 by the patentees or 

 their licensed 

 agents. The prices 

 quoted for Pacific 

 Coast delivery, in 

 lots of not less 

 than 6, with freight 

 but not duty paid, 

 are $52.25, $66.75, 

 $ 7 4 . 2 a n d 

 $170.30, respective- 

 ly for the four 

 sizes. The meter 

 was invented by the two Australian 

 engineers for whom it is named 

 and has been used to some extent in 

 that country, but it has been but lit- 

 tle used in the United States. The 

 box for the meter can be built of 

 either wood or concrete : that in- 

 stalled at Davis is of wood. The 

 standard for holding the meter is 

 arranger! so that the meter can be re- 

 moved when not in use. On systems 

 where the flow through each meter 

 is not continuous, the meter can be 

 used on more than one ditch, being 

 moved around as water is turned out. 



Fig. 32 The Grant-Mitchell meter measuring 

 water. 



r 



material used thro. 

 Clear width of open 



SKETCH OF BOX USED IN TESTS OF 

 12" HILL METER 



Fig. 23 Sectional elevation of a 12-inch Hill meter. 



Fig. 24 A Hill meter in operation. 



The tests made at Davis of a 21-inch Grant- 

 Michell meter showed that for discharges of over 2 

 cubic feet per second and up to 6.5 cubic feet per sec- 

 ond, the meter makes one revolution for every 6.1 

 cubic feet of water passed. More water is passed per 

 revolution on lower rates of discharge. The 24 tests 

 made show that the meter will probably register within 

 2.5 per cent of the true quantity. The fall required 

 in the ditch to get the water through the meter varies 

 with the rate of flow. It is 

 about 1 inch when the discharge 

 is 3 cubic feet per second and 

 rises to 4 inches with a flow of 5 

 cubic feet per second. 



This meter is not as much 

 affected by changing the depths 

 of water on the lower side as 

 some others. The tests at Davis 

 were made with varying depths 

 but showed no regular differ- 

 ences. This is an advantage 

 when used on a ditch which is 

 sometimes checked up. Its high 

 cost, however, is against its 

 general use. 



The Hill meter is shown in 

 figures 23 and 24. It consists of 

 a circular opening set hori- 

 zontally in the floor of a box 

 through which 

 the water to be 

 measured is made 

 to pass. The meter 

 consists of curved 

 vanes set on a 

 central drum. It 

 sets in the center 

 of the opening 

 and is turned by 

 the water as it 

 strikes against the 

 vanes on rising 

 through the open- 

 ing. The turning 

 of the meter 

 drives the gears 

 of a counting de- 

 vice which records 

 the water passed 

 in acre-feet. Dif- 

 ferent sized openings and meters 

 are used for different sized quan- 

 tities of water. The box in which 

 the meter is set resembles a siphon. 

 The Hill meter is patented and 

 must be bought of the patentee or 

 his licensed agents. While it has 

 not been used to any extent as 

 yet, and has not been pushed com- 

 mercially, it is estimated that the 

 meter alone, when manufactured 

 in quantities, should cost about $10 

 each for the 12-inch size and about 

 from $12 to $15 for the larger size, 

 with a probable reduction with 

 (Continued on page 302) 



Sect. Elev 



