Metals That Build New Worlds 177 



chloride. Then an electric current is used to break the com- 

 pound into magnesium and chlorine. The light magnesium 

 floats to the top and is skimmed off, and the chlorine is uti- 

 lized to make more hydrochloric acid. Eight hundred tons of 

 water are handled during the production of one ton of mag- 

 nesium. Dr. H. H. Harrington, metallurgist in General Elec- 

 tric Research Laboratories, estimated that the 23,000,000 tons 

 of magnesium salts in a cubic mile of ocean could yield 

 4,500,000 tons of magnesium enough to supply 90,000,000 

 pounds of the metal each year for one hundred years. Mag- 

 nesium also is obtained from several ores found in the West- 

 ern states. 



One Pound of Magnesium 



C. L. Mantell, in Sparks from the Electrode, 1 writes: 



"From a pound of magnesium we can make a bar of the 

 metal a half inch square and 64 inches long, while such a bar 

 from a pound of aluminum would be 42 inches long, and 

 from steel only 14 inches long. A beam of magnesium, light 

 enough in itself to be carried by one man, can yet support 

 an automobile! A steel piece of similar size probably could 

 not be lifted by four men. The advantage of magnesium in 

 the matter of weight alone, especially in aviation and build- 

 ing, makes its production worth the effort." 



Magnesium is not quite as strong as aluminum. But as a 

 structural material it always is used as an alloy, usually with 

 aluminum. These alloys are called Dowmetal, and are much 

 stronger and harder than magnesium alone. Magnesium, which 

 burns with an intense white light, also is used in bomb casings, 

 incendiaries, tracer bullets, flares, and star shells. 



Aside from their uses in airplanes, engineers expect mag- 



1 Mantell, Charles Letnam, Sparks from the Electrode. New York, The 

 Century Company, 1933. 



