ZOOLOGICAL PARKS AND AQUARIUMS 933 



The reservoir may be constructed with two or more compartments to 

 facilitate periodical cleaning and to give the body of water not in use a 

 period of rest, such treatment having a clarifying effect. All equipment 

 tending to facilitate the distribution of stored water and to preserve its 

 purity is desirable, as its vitiation, even in small degree, may result in 

 serious losses of animal life. The living occupants of the aquarium have 

 no choice but to remain in the tanks where they are placed. Lack of food 

 can be long endured, but the impairment of their natural element is imme- 

 diately fatal, whether from actual fouling or mere lack of oxygen. They 

 may long survive cramped quarters and overcrowding if the supply of water 

 is abundant. Pure water is the life blood of the aquarium, and the loss of 

 all living exhibits may prove less expensive to an aquarium than the restora- 

 tion of a damaged water supply. 



There need be no deterioration of stored water if it is properly managed; 

 circulation, filtration and periods of rest for the precipitation of sediment 

 will keep it in good condition indefinitely. Additions to the supply will be 

 necessary occasionally to replace losses from leakage and evaporation. Even 

 after years of use, the increase in salinity from evaporation is negligible, 

 and this could be corrected by the addition of fresh water. Aeration is 

 automatic, as the surface of the water is exposed to air both in the reservoir 

 and exhibition tanks, and the water is further aerated in falling from the 

 different levels to which it is pumped. Stored sea water must be protected 

 against discoloration from iron rust, but this is not difficult if the pumps 

 and piping are made of non-rusting materials. Its action on iron pumps 

 and piping is very destructive, and galvanizing affords only temporary 

 protection. 



The care of the water supply of any large aquarium is an ever-present 

 responsibility that must be kept in mind by each employee of the institu- 

 tion during his hours of duty. While many of the operations relative to it 

 are accomplished by mechanical means, the feeling of personal responsi- 

 bility cannot be relaxed. The life-sustaining water of the aquarium must 

 flow in purity and abundance at all hours of the day and night. All other 

 features of aquarium management are of secondary importance. Pure water 

 being the life blood of the aquarium organism, the mechanical means for 

 securing its circulation and preservation are next in importance. The cir- 

 culating pump, piping and filters might be compared to heart, arteries and 

 lungs. The mechanical department of the institution is responsible for the 

 continuous flow of water, its temperature, aeration and filtration. A con- 

 siderable amount of machinery is necessary in a large aquarium, the prin- 

 cipal features of which are pump, air compressor, filter and refrigerating 

 machine. 



