THE WATER GARDEN 137 



may be planted out in open pools when the nights 

 are warm — early in June, usually. 



The simplest way to construct an artificial pool is 

 to mark out the circumference on the ground and 

 then to dig a trench two and a half feet deep and as 

 narrow as can be handled, making the sides as smooth 

 and even as possible. Concrete will then be poured 

 into this, using rather small gravel in the mixture and 

 paddling it away from the sides so that in setting the 

 concrete may have a smooth, firm surface. After 

 the concrete has become perfectly hard (and sufficient 

 time must be allowed for this part of the work) the 

 inside of the pool may be dug out down to the bottom 

 of the concrete wall and a cement floor laid, great 

 care being given to the joining of the floor and wall, 

 for it is at the angle of floor and wall that trouble 

 from leakage usually occurs. It is better to cove this 

 angle and leave the work as smooth as possible. If 

 this is done, both in the rough and in the finishing 

 coat which is applied over all, any cracks which occur 

 in future will be easily located and repaired. Rough- 

 ness here frustrates all attempts to locate the trouble 

 and necessitates the going over the whole angle if re- 

 pairs are needed. 



As the top of the pool should be a few inches above 

 the ground — ^just how high being a matter of taste — 

 forms will be required for this part of the work or 

 concrete blocks shaped to the curve of the circle can 



