C6 THE ART AND PRACTICE OF LANDSCAPE GARDENING. 



in. the proportion of i in 6 as it descends. The plastic clay should 

 be carefully rammed. It may be necessary in some cases to 

 form such a puddle-gutter all round a lake, but in falling ground 

 on-ly at the lower end, so as to prevent water escape. Some lakes 

 may be formed by utilising a natural gully, and throwing a strong 

 dam across its lower end. Then it is necessary to construct a well- 

 made and well-based puddle-gutter in the dam. and the clay wall 

 being amply supported by earth, the surface of the dam may be 

 treated for picturesque effect by planting or other means. The puddle- 

 gutter of a dam is best placed in the centre, and the dam itself 

 should be built up in layers, each one being well rammed and con- 

 solidated. It should not have a width less than 3 ft. plus the square 

 of the depth, with slopes on the inside of 2 to r, and on the outside 

 of i '/ a to i. It is well to cover the sides of a lake with gravel, 

 especially during the period of the entry of water, or where there 

 is danger of a wash. In large lakes of considerable depth, and in 

 reservoirs, the inner slope should be pitched to prevent wash, and 

 the water-level should be fully 3 ft below the top of the em- 

 bankment. When water enters from a pipe or from any point 

 above the lake-level, the sides below the inlet should be paved : 

 that is, an apron 4 to 6 ft. wide should be laid down the 

 slope. Both the overflow and the emptying pipe, where practicable, 

 should be preferably built in the solid ground. A type of over- 

 flow is shown (see Plan, jig. B], A grating to prevent the escape 

 of fish or leaves and rubbish through this overflow should be placed 

 at a short distance down the slope, so that it may not be choked 

 by accumulation of leaves, etc. ; as they float at the surface of the 

 water, which rises beneath any such accumulation, and so the desired 

 level is maintained. In lakes receiving the drainage of large areas, 

 a storm overflow should be provided ; it may consist of a paved 

 duct or channel, formed 3 or 4 in. above the level of the normal 



