AQUARIUS 306 



ately, usually near the corners of the aquarium. 

 If the fish move about quietly below the 



AQUEDUCT 



An aquarium any mother can easily provide 

 for the children at home. 



surface they are comfortable, but if they come 

 to the surface and gasp, the water does not 

 contain enough oxygen and some animals must 

 be taken out or more plants must be put in. 

 The second illustration shows what may be 

 accomplished in any home in the study of 

 small water life and what may result from it. 



The following is a reliable recipe for making 

 a cement that will render an aquarium water- 

 tight. Mix one-third litharge to two-thirds red 

 lead (powdered) with raw linseed oil to the 

 consistency of putty. The litharge and red 

 lead should be thoroughly mixed and freed 

 from all lumps before mixing the oil. 



Public Aquariums. Many large cities now 

 have large aquariums where aquatic life may 

 be studied and which attract large numbers of 

 visitors. One of the largest aquariums in the 

 world is in New York, in the famous building 

 on the Battery, formerly known as Castle 

 Garden, where millions of emigrants to the 

 United States have landed. It contains 150 

 tanks for small fish and a number of big pools 

 for sharks and other large and dangerous fish. 

 The aquariums of the American Fish Com- 

 mission at Washington, and those at Naples, 

 Petrograd, Paris, Hamburg and Brighton (Eng- 

 land), are also of great educational value. The 

 one at Petrograd has been maintained for more 

 than 150 years. G.W. 



AQUARIUS, akwa'rius, meaning water 

 bearer, is the name given in astronomy to a 

 constellation and the original eleventh sign of 

 the zodiac, which now occupies the position of 

 the twelfth sign, owing to the forward motion 

 of the equinoxes (see PRECESSION OF THE EQUI- 

 NOXES). The sun is in the zodiacal sign Aqua- 

 rius during parts of January and February. 

 The name was given on account of the rains 

 that fall so plentifully in Italy during that 



season. The symbol of Aquarius is , signi- 

 fying running water. See ZODIAC, for illustra- 

 tion. 



AQUATIC, a kwai ' ic, PLANTS. See WATER 

 PLANTS. 



AQUEDUCT, ak' wedukt, an artificial chan- 

 nel for the conveyance of water from one 

 place to another. In general use, however, thr 

 term is restricted to a system for supplying a 

 city with water from a distance, and to a stoiu , 

 concrete or metal channel in which the down- 

 ward grade is sufficient to cause the water to 

 flow by gravity. Modern aqueducts frequent ly 

 combine such gravity channels with other sec- 

 tions in which water is pumped or forced 

 through other pressure. 



Aqueducts were in use among the ancient 

 Egyptians, Phoenicians, Persians and Greeks, 

 but they were most common in the Roman 

 Empire, where they reached astonishing pro- 

 portions. Ancient Rome was supplied with 

 water by eleven great aqueducts, parts of which 

 were carried on high bridges which still stand 

 as monuments of Roman art and engineering. 

 Two of these are used to-day to supply water 

 to the modern city of Rome. In many other 

 parts of Europe, from Constantinople to 

 Nimes, France, are ruins of aqueducts built 



AT NIMES 



by the Romans. The Pont du Gard, fourteen 

 miles from Nimes, is unrivalled for boldness 

 of design. It is built of huge blocks of stone, 

 and consists of three tiers of arches across the 

 valley of the River Gardon. Each large arch 

 in the two lower tiers has a span of sixty and 

 seventy-five feet, respectively, and the height 

 of the structure is 160 feet. The aqueduct at 

 Segovia, Spain, built by the Romans in the 

 first century after Christ, has two tiers of 

 arcades, which reach a height of 102 feet. It 

 is 2,400 feet long, and is one of the most 

 admired works of antiquity. 

 The Story of Modern Aqueducts. During 



