Metals That Build New Worlds 175 



electric plants in the Tennessee Valley and on the Columbia 

 River are helping to solve this problem. 



Most of the world's warplanes are made of an alloy con- 

 sisting of aluminum, copper, magnesium, and manganese, and 

 called duralumin. A new secret aluminum alloy has been de- 

 veloped for war use. It is said to add 10 to 25 per cent to the 

 strength of the metal. 



R. L. Duffus, in the New York Times Magazine, sums 

 up past advances and future prospects of aluminum: 



"Cheap and abundant aluminum is here, cheaper and far 

 more abundant aluminum just around the corner. One picks 

 up a handful of bauxite from a stockpile. It wouldn't look 

 well in the middle of the parlor rug. Apply the magic of mod- 

 ern chemistry and metallurgy to it and suddenly it shines; 

 and in the glitter one can see not only the flames of war but 

 the glow of cleaner, more beautiful homes, public buildings, 

 motor cars, railroad equipment in fact, a more splendid mate- 

 rial civilization." 



Much of the bauxite comes from Surinam (Dutch Guiana), 

 although smaller amounts are obtained in Arkansas. Alunite, 

 an ore found in Utah and other Western states, also is used in 

 place of bauxite, while TVA engineers believe that abundant 

 aluminum can be obtained from a clay called kaolin. 



The Ocean as a Treasure Chest 



The ocean is the world's greatest storehouse of minerals. 

 A cubic mile of ocean weighs about 4,500,000,000 tons and 

 contains about 3% per cent of dissolved salts, weighing 

 around 155,000,000 tons. Sodium chloride (ordinary table 

 salt) and other sodium salts make up about 117,000,000 tons 

 of this total; magnesium salts, 23,000,000 tons; calcium salts, 

 6,000,000 tons; and the remainder is made up of salts of other 

 metals. 



