made to appear in proper relationship. This tends to remove the 

 effect of artificiaHty, especially if rocks, shells, and similar objects 

 are judiciously placed. It makes the display more closely resemble 

 natural surroundings and undoubtedly results in healthier fish. 



In displaying fishes it has been found that there is less refraction 

 of light to annoy the visitor if the back wall, with its covering of 

 rocks, is set at an angle of about 45 degrees. The bottom should con- 

 tain small gravel, or coarse white or gray sand. The introduction of 

 compressed air in each aquarium is of great value in keeping the 

 water fresh, especially if stored water is used. 



The surface of the water should be at least one-half inch above 

 the upper edge of the frame in front of the aquarium so there will be 

 no refraction of light. A very important feature is the proper light- 

 ing of an aquarium. In most places it is necessary to provide arti- 

 ficial illumination ; a shaded electric light suspended a short distance 

 above the center of each tank usually suffices. Care should be exer- 

 cised to deflect the light rays from the line of vision. 



Different sizes of aquariums may be used for various species of 

 fish, but ordinarily those about 5 feet in length, 4 feet in depth, and 3 

 feet wide at the bottom increasing to 5 feet at the top are most satis- 

 factory. Aquariums with sloping rear walls are generally most de- 

 sirable, thus affording a close view of the fish as they approach the 

 bottom. Smaller aquariums, however, are generally made with per- 

 pendicular sides all around. 



Transparent labels giving the name, both common and scientific, 

 of specimens in each aquarium should be posted conveniently for the 

 visitor. The labels should also briefly describe their habits, range, 

 and any particularly interesting features. 



COXCLUSIOX 



A public aquarium in a city may speedily become one of its most 

 popular and useful institutions. As compared with other public 

 enterprises, it can be constructed at moderate cost, while the upkeep is 

 not particularly great, especially if it is operated in conjunction with 

 parks or other municipal institutions. 



Of course these notes and suggestions do not pretend to include 

 a complete description of methods and appliances, but are offered 

 rather as a basis for discussion and to emphasize the importance of 

 public aquariums as an educational influence leading ultimately to far 

 greater appreciation and utilization of the enormous resources of the 

 sea. It is hoped that there may be deeply impressed upon all the 

 thought that a public aquarium is or should be a vivid presentation 



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