114 



CONSTRUCTION 



security. No wooden forms are needed unless it is decided to make the 

 ledge for holding earth for bog plants, which, by the way, is an effort 

 that will well repay in added beauty to the pond. 



Concrete mixture should be one part cement, two of sand and four 

 of coarse gravel or small broken stone. Finishing coat a half inch thick, 

 one part cement, two of sand. The concrete pouring and later the fin- 

 ishing coat should, if possible, each be carried on as continuous jobs. 

 There is apt to be a weakness at points where the work is halted from 

 one day to the next, especially where reinforcement is not used. Tamp 

 concrete well. A pool of this style if well constructed will resist frost. 



In winter fill concrete pools to ground level to counteract freezing 

 pressure from the outside. 



The inclusion of a concrete water lily container, as well as the ring 

 of soil around it for other aquatic plants, is optional. If square, it will 

 need board forms. If round, galvanized iron circles not joined at ends, 

 the outside pieces tied around and the inside ones braced across. The 

 lily pot should be 15 to 20 inches wide and about 8 to 10 inches deep. 

 Topping off edges at ground level with a coping of flat, natural stones set 

 in cement is quite a pleasing addition. 





Fig. 91. Simple Form of Concrete Pool 

 This requires no wooden forms unless ledge is made. Hardy water lily flowers 

 float at the surface as indicated. 



This type of pool is well suited to hardy water lilies. If they are 

 used, the top of soil should be about six inches below the freezing line. 

 Arrowheads and most bog plants in the ledge of soil survive freezing. 



Ground-level pools have charming possibilities for artistic planting 

 outside the edges. Their principal disadvantage is that the fishes are 

 open to the attacks of snakes, frogs and rats if these pests are present. 



