AQUARIUM CONSTRUCTION 



In the construction of an aquarium the first consideration should be 

 the comfort of the animal inmates, then the production of a pleasing form, 

 with sufficient strength to insure against leaks or breaking of the glass by 

 the water pressure. This latter, as previously mentioned, frequently 

 occurs with all-glass aquaria, and has led to the more general adoption of 

 brass and iron-framed aquarium tanks. 



Aquarium Proportions. Surface aeration being necessary to the 

 survival of all forms of aquatic life, the aquarium should be constructed to 

 have large surface dimensions, greater than the depth of the water; even 



JP^ 



FIG. 235. 



though its appearance may not be quite as pleasing as the usual high and 

 narrow forms, designed to offer the largest field of view, to occupy the 

 least space, and to restrict the weight of both the aquarium and its con- 

 tents. To test the importance of surface aeration, a few freshwater fishes 

 may be placed into a shallow dish of water and the same number into a 

 high and narrow jar containing the same quantity of water, when it will 

 be observed how soon those in the latter receptacle will come to the 

 surface gasping for air. The diagram. Fig. 235, shows three vessels, 

 each containing 1000 cubic inches of water, the first having a surface 

 area of 50 square inches, the second 100 square inches, and the third 

 200 square inches. No. 3 will support at least twice as many fishes as 

 No. 2 and four times as many as No. i. 



The length of an aquarium may be proportioned to the available 

 space, but the breadth should not exceed 24 inches; when greater than 

 this the contents will be somewhat obscured. The depth of water 

 should not exceed 20 inches, because the pressure of the water would cause 

 discomfort to the inmates and tend to confine their movements to the 

 upper part of the aquarium. Large shallow tanks always give the best re- 

 sults. When space is available and the light is on the surface, a nearly 



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