24 BULLETIN" 115, U. S. DEPARTMENT OF AGRICULTURE. 



laterals are very small, the velocity low, and the possible pressure 

 head not more than 2 feet an " L '•' structure of a simple wall of 

 concrete might be used, with one leg of the " L " at right angles to 

 each of the smaller laterals with slots in the ends of the walls where 

 the water openings occur. 



COMBINATION DELIVERY GATE, DIVISION BOX, AND MEASURING WEIR, CONSOLI- 

 DATED LOWER BOULDER RESERVOIR & DITCH CO., COLORADO. 



There has been designed and installed for the Consolidated Lower 

 Boulder Reservoir & Ditch Co., of Longmont, a small concrete and 

 iron structure which takes the place of a delivery gate, with an ad- 

 justable shutter, lockable at the various positions of the gate shutter. 

 This shutter is shaped and placed under conditions approximately 

 correct for the Cipolletti weir, which gives a very close measuring 

 device through the orifice of the gate. 



The j)lans shown in figure 4 are for a box to be placed at the lower 

 end of a small lateral, the water to enter the structure as shown by 

 the arrow. The three weir openings allow water to be delivered to 

 any one or more of these farmer's ditches, one leading from the box 

 in the same direction as the flow of water toward the box in the 

 lateral and the other two leading off to either side. 



A modification of this structure allows a delivery to one side only, 

 the continuation of the lateral leading off from the structure either 

 at the other side or at the end opposite that through which the water 

 entered. 



The construction where a delivery is to be made to either side and 

 the lateral continued from the box is similar to the first case taken 

 above. Each of the openings leading from the box is provided with 

 an adjustable cast and wrought iron Cipolletti weir, as shown in the 

 details of the drawings. There are two equal and symmetrical cast- 

 iron plates each three-eighths inch in thickness, sliding between 

 wrought-iron guides. The inside edges of these plates have a slope 

 of \ to 1, and give the correct conditions for the Cipolletti weir, 

 aside from any velocity of approach, which must be guarded 

 against. When the plates are wide open the weir is 3 feet long 

 on the cast-iron crest. The latter is stationary, and set 15 inches 

 above the bottom of the box. On the assumption that the depth of 

 water over a weir should neither exceed one-half the distance from 

 the weir crest to the bottom of the supply channel nor one-half the 

 distance from the ends of the weir crest to the sides of the supply 

 channel the maximum allowable depth over the weir is 7-| inches. 



A delivery to the maximum of 5 second-feet may be made to any 

 one of the branches and still use the measuring device. As the slides 

 are closed the weir condition changes from that of a Cipolletti weir 



