UPAS 



6003 



URANUS 



palace of the former emperor, the University 

 of Berlin, the Arsenal, the French and British 

 embassies, and other important buildings. 

 Through the Brandenburg Gate are five passage- 

 ways; the center one was long reserved by 

 courtesy for use of the royal family only. 



For additional details and setting of this ave- 

 nue in the scheme of city building, see BERLIN. 

 The Brandenburg Gate is shown in illustration 

 opposite page I' 173. 



U ' PAS , one of the largest forest trees of the 

 island of Java, a tree whose poisonous, milky 

 juice has been the subject of various fables. 

 It belongs to the nettle family. In 1844 speci- 

 mens were transported to Europe, where sev- 

 eral varieties are now grown in gardens and 

 hothouses. The white-barked trunk, free of 

 branches half or three-quarters of its height, is 

 often more than a hundred feet tall. When 

 the bark is bruised or cut a sticky, white fluid 

 runs out, and with this the natives poison their 

 arrowheads. It was formerly, but incorrectly, 

 believed that the tree exhaled a substance 

 which caused skin eruptions and was dangerous, 

 if not fatal, to plants, men and beasts even at 

 a distance of fifteen miles. The inner bark of 

 the upas is used by natives for making bags and 

 clothing. 



U'RAL MOUNTAINS (in Russia pronounced 

 oorahl'y'), a mountain system extending along 

 the eastern boundary of Russia from the Arctic 

 Ocean to the vicinity of the Caspian Sea. 

 These mountains are remarkable for their min- 

 eral wealth, for they contain rich deposits of 

 platinum, the best in the world, and valuable 

 mines of gold, copper, silver, mercury, nickel, 

 cobalt and coal (see RUSSIA, subhead Minerals 

 and Mining). Diamonds, sapphires, emeralds, 

 amethysts and other precious stones also occur. 

 The Urals are not a lofty system, as the aver- 

 age elevation is between 1,000 and 1,500 feet, 

 but there are several peaks that rise over 5,000 

 feet above the sea. The highest, Mount Tel- 

 pos, has an altitude of 5,433 feet. In the ex- 

 treme northern part the mountains form a nar- 

 row, treeless ridge, but farther south th\ 

 broaden out considerably, attaining a width of 

 about 200 miles. Here the lower slopes are 

 <! with dense forests. Through a pass in 

 tin- e. nf nil section the Trans-Siberian Railway 

 in ikes its way into Siberia. 



URAL RIVER, a river of Russia which rises 



on the eastern slopes of the Ural Mountains, 



and after a course of 1,485 miles enters the 



Caspian Sea through several mouths (see col- 



; map. following page 2092). On \\< hank-- 



are the towns of Orsk, Orenburg, Uralsk and 

 Guriev. Owing to the shallow water, its navi- 

 gation is limited except during periods of high 

 water. It has extensive salmon and sturgeon 

 fisheries. 



URANIA, ura'nia, the one of the nine 

 Muses who was known as the patron of 

 tronomy. In one hand she holds a globe and 

 in the other a rod with which she traces out 

 some figure. See MUSES. 



URANIUM, ura'nium, a rare metallic ele- 

 ment related chemically to chromium, molyb- 

 denum and tungsten. It is a heavy, white. 

 moderately-hard metal, softer than steel, and 

 having a specific gravity of 18.7. Uranium is 

 never found native, but occurs in several ores, 

 notably in pitchblende. The salts of uranium 

 are used as pigments in glass and porcelain 

 manufacture. Uranium received its name in 

 honor of the discovery of the planet Uranus 

 (1781) by Sir William Herschel. The metal 

 possesses marked radioactivity. See RADI 

 RADIOACTIVITY. 



URANUS, u'ranus, one of the planets, sev- 

 enth in distance from the sun, was discovered 

 accidentally by Sir William Herschel in 1781. 

 The astronomer at first thought it to be a 

 comet, and it was not until a year later that it 

 was clearly established as a planet. It is named 

 after the mythological Uranus, lord of the 

 heavens, husband of Gaea, the Karth. Uranus 

 is visible to the naked eye and appears as a star 

 of the sixth magnitude, and is about 1,750.000.- 

 000 miles distant from the sun, around which it 

 revolves in eighty-four of our years. Peculiari- 



in the motion of Uranus led to the disco 

 of another planet, Neptune, in 1846. 



The diameter of Uranus is believed to be 

 about 32,000 miles, nearly four times that of the 

 earth, but it is stated by some an then ties as 

 being only 28,500 miles. In hulk. Uranus is 

 about sixty-six times greater than the earth; 

 its mass is about fourteen nn<l one-half times 

 that of the earth, and its !>out the 



same as that of the sun, or one-fourth 

 density of the earth. It is thought that Uranus 

 rotates very rapidly on its axis, but no exact 

 time can be stated, though the length of its day 

 is probably between nine and ten hours. 

 light-reflecting power of Uranus is very great, 

 probably :i little greater than that of Juj 

 The gravity on the surface of Uranus, due to 

 its great mass, is so much greater than on tin 

 earth that if a man rould possibly go to Uranus 

 he would be unable to lift hand or foot, and 

 h> life would be crushed out by his own weight. 



