THE CONQUEST OF NATURE 



even dangerous, blast-furnaces. There is no glare 

 and roar of fires; there are no showers of sparks; there 

 is no gush of fiery streams of molten metal. A silent 

 and invisible electric current, generated by the fall 

 of distant waters, does the work more expeditiously, 

 more efficiently, and more cheaply than it could be 

 done by any other method as yet discovered. 



Fully to appreciate the importance of the method 

 just outlined, we must reflect that aluminum is a metal 

 combining in some measure the properties of silver, 

 copper, and iron. It rivals copper as a conductor of 

 electricity; like silver it is white in color and little 

 subject to tarnishing; like iron it has great hardness 

 and tensile strength. True, it does not fully compete 

 with the more familiar metals in their respective fields; 

 but it combines many valuable qualities in fair degree ; 

 and it has an added property of extreme lightness that 

 is all its own. Add to this the fact that aluminum is 

 extremely abundant everywhere in nature it is a 

 constituent of nearly all soils and is computed to form 

 about the twelfth part of the entire crust of the earth 

 whereas the other valuable metals are relatively rare, 

 and it will appear that aluminum must be destined 

 to play an important part in the mechanics of the 

 future. There is every indication that the iron beds 

 will begin to give out at no immeasurably distant day; 

 but the supply of aluminum is absolutely inexhaustible. 

 Until now there has been no means known of extract- 

 ing it cheaply from the clay of which it forms so im- 

 portant a constituent. But at last electro-chemistry 

 has solved the problem; and aluminum is sure to take 



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