MANAGEMENT OP THE AQUARIUM. 49 



for, if they do, not only will the growth of the conferva be 

 encouraged, but the temperature of the water wiU quickly rise 

 too high. The higher the temperature of the water, the fewer 

 animals wiU it be able to contain ; besides which, water 

 in this condition very readily becomes impure. The average 

 temperature of an aquarium ought to be about SOdeg., and, if 

 possible, it should never be allowed to vary more than lOdeg. 

 either way. It may be reduced by covering the tank with a 

 woollen cloth, the lower end of which is standing in some 

 water. 



As a rule, aquaria are placed near a window — a position con- 

 ducive to the growth of the plants, but not to the happiness 

 of the fish. Indeed, it is positively cruel to put fish in an all- 

 glass aquarium and allow the sun to shine upon it during the 

 hottest part of the day. Since an aquarium, however, will most 

 likely be put close to a window, let it be one facing the north 

 if possible. An eastern aspect is not at all unsuitable, but it 

 win be advisable to cover the tank at night, so that it will not 

 get the early morning sun. 



There are many ways of shading aquaria so that they shall 

 not be unduly influenced by light and sun. If the aquarium is 

 round, a sheet of green paper or a piece of American cloth, 

 hung by means of small wire hooks to the edge of the glass, 

 will answer the purpose. This can easily be removed for the 

 inspection of the contents of the aquarium. Of course, such a 

 screen cannot be called ornamental, but it is effective. Flowers 

 or ferns placed between the aquarium and the window will 

 supply not a little shade. If the tank is rectangular, and all- 

 four sides made of glass, the same kind of shading will do, or 

 cardboard may be cut to exactly fit three of the sides, instead. 

 A little protection from too much light and sun may be obtained 

 by having three of the sides made of ground-glass, or by 

 covering these sides (externally, of course), with whitening 

 dabbed on with a sponge, in imitation of ground-glass ; or the 

 conferv£e may be allowed to grow upon the three sides, and the 

 fourth kept clear by using, when necessary, a piece of flannel 

 tied to the end of a short cane. A good piece of looking-glass, 

 cut the exact length and depth of the aquarium, and placed 



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