100 THE AXGLER AXD HUXTSMAX 



"The outlet is a three-sided box extending into the 

 bank. In this position it can be reached easily from the 

 shore by means of a board walk laid from the top of the 

 bank to the top of the overflow box. The size of the box 

 will be determined by the flow r of water. For a pond dis- 

 charging from 200 to 500 gallons per minute it should be 

 24 inches square, its depth being, of course, conditional on 

 the water level and the height of the embankment. The 

 bottom of the box should extend to the deepest part of the 

 pond, and its top should be flush with the top of the em- 

 bankment. At the bottom a terra-cotta pipe is laid with 

 cement joints extending through the earth embankment, 

 and a slotted groove or frame of 2-inch material is fastened 

 12 inches from the rear of the box to hold the dam boards, 

 the latter to be 1 1-2 or 2 inch lumber from 6 to 8 inches 

 wide, each provided w r ith two holes from three-fourths to 

 one inch in diameter and three-fourths of an inch deep on 

 one side to facilitate removal by inserting therein a hook or 

 the teeth of a garden rake. 



"Inserted in front of the dam boards on the outer edge 

 of the box is a screen in either one or two sections. It is 

 made to work up and down in a groove, and, in order that its 

 lower edge may closely fit the bottom of the box, the latter 

 is provided with a floor, and sheet piling is driven down in 

 front of it to prevent undermining. In front of the drain 

 box, and with its bottom sloping toward it, is the "kettle" 

 or basin, made by excavating in front of the drain box, so 

 that in drawing down the pond all the water will flow to 

 this low point. The upper end of the "kettle" should be 

 a foot lower than the bottom of the pond proper. A kettle 

 for a 1-acre pond should be about 75 feet long and 15 or 20 

 feet w r ide. It is preferable to have its bottom and sides of 

 cement or lumber, but if one does not care to go to that ex- 

 pense the unlined pond bottom will suffice. 



"If natural conditions will permit, the water supply 

 should enter the pond through an open ditch or raceway, 



