38 THE BOOK OF GARDENING. 



The running water must be led away into ditches, and great 

 care must be taken to prevent the flooding of the work by 

 erecting a strong dam at the deviation of the stream. When 

 the soil has been excavated to the intended depth the 

 bottom of the lake should be smoothed, giving the necessary 

 fall to the ground. It must then be made watertight by 

 using either cement or puddle. In the majority of cases, 

 when a solid foundation is available, concrete is used! The 

 bed, when levelled and well rammed, is covered with a layer 

 of not less than 6in. of concrete at the bottom and 8in. on 

 the sides. 



The concrete used should be composed of a mixture of three 

 parts of broken stones or coarse gravel and two parts of 

 hydraulic mortar and sand. This mortar itself is a mix- 

 ture of two parts of sand and one of hydraulic lime. 

 The concrete should then be well and evenly rammed, the 

 surface made smooth with the back of a shovel, and left to 

 dry for a few days. It should then be covered with a layer 01 

 Portland cement iin. thick. 



When puddle is used, the ground should be excavated to the 

 required depth, allowing ift. thick at the bottom and i8in. on the 

 sides. Puddle is prepared by cutting clay, pouring water on it, 

 and treading it until it is plastic enough for use. When it has 

 been applied on the surface, it must be well trodden and rammed. 

 The shores can be solidified, if the ground should happen to 

 require it, by driving in a few pegs at the edges with branches 

 and interlacing them. If there is any fear of the shores, getting 

 washed away, the side can be covered under the water-line 

 with coarse stones. 



A lake may also be formed by utilising a stream and erecting 

 across its lower end a ' strong dam of one and a half to 

 three of base to one of height. This dam should be built 

 up in layers of clay, well rammed, and supported by earth. The 

 surface could be planted with grass and shrubs, but not with 

 trees, as the roots of the latter, when shaken by the winds, would 

 loosen the soil, and allow the water to run through. The top 

 of the dam must be at least 5 yds. or 6yds. wide, according to the 

 nature of the soil employed and the volume of water to be kept 

 back, and 5ft. above the water-line. Rocks can be scattered 

 about the shores, especially close to the inlet and the over- 

 flow, which can be hidden by the aid of plants. The sides 

 below the inlet must be paved to a width of about 6ft. The 



