32 WATER-LILIES 



maintaining a lower level of the water during 

 the cold season of the year." 



SIMPLE CLAY PUDDLING 



While puddled ponds are the most econom- 

 ical to construct they probably require most 

 in the way of repairs. Besides, they are 

 possible only where the necessary material — 

 a heavy clay — is ready at hand. The first 

 steps of their construction are the same as 

 for all other ponds, at least as far as locating 

 and excavating are concerned; but from there 

 onward the methods of procedure differ. For 

 while both in natural ponds and in ponds 

 built of concrete there is no trouble about 

 their ability to hold water, an artificial pond, 

 where no concrete has been used, must be 

 made wat'er-tight by special means. For 

 such a purpose hydraulic engineering knows 

 of no better material than puddled clay, clay 

 which by a mechanical process has been made 

 homogeneous and very plastic. Unless you 

 absolutely feel the need of exercising your 



