PRACTICAL BOOK OF GARDEN ARCHITECTURE 



the desired level, and no swamp or marsh land to be 

 dredged, the only alternative is to excavate the 

 ground, and thus create a depression sufficient to 

 hold the required amount of water. 



The artificial lake should be from two to three 

 feet in depth, at least, to allow for the growth of 

 water plants; to avoid injury by freezing, when 

 cement is used in constructing the basin ; and to keep 

 the water from becoming stagnant because of shal- 

 lowness. Any sort of still water will have a tendency 

 to breed mosquitoes unless precautions are taken to 

 guard against the pests. The precautions are so 

 simple, however, that no one should forego the pleas- 

 ure of a; garden lake on this account. For the 

 small lake, a few gold fish will be all that is required 

 to keep the water free from larvae and wrigglers. 

 For the large lake, covering a wide area, and of con- 

 siderable depth, it may be necessary to have fish 

 that are both surface and bottom feeders. Top min- 

 nows and stickle-backs have been suggested for this 

 purpose; but any lake fish that will flourish in the 

 artificial water supply will be useful for keeping the 

 place free from mosquitoes. Trout and fish of a 

 similar nature will not live in the still water lakes, 

 as they flourish only in the clear cold water of spring- 

 fed streams. 



The formation of green scum on the water is a 



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