124 Miracles Ahead! 



induces heat in the wood or plastic, just as the current flow 

 in the metal induces heat. 



In any type of induction heating, the speed with which 

 the current changes direction increases the speed with which 

 the heat can be developed in the material being heated. We 

 can comprehend the speed-up which results when induction 

 heating is applied, not at the typical sixty cycles per second of 

 our standard A.C. but at perhaps sixty million cycles per sec- 

 ond of R.F. heating. 



When Malaya and the Netherlands East Indies fell into 

 Japanese hands, more than half the world's supply of tin fell 

 into their hands too. When our precious supply of tin was so 

 sharply curtailed, R.F. heating saved the day. R.F. heating 

 tripled our supply of tin overnight, by making it possible to 

 coat our tin cans with a coating one-third as thick as the coat- 

 ing formerly used. And resistance welding, which likewise 

 uses heat at R.F. speeds of control, has eliminated the use of 

 soldering in many places where it was heretofore used, free- 

 ing solder, which contains tin, for uses where it is still impera- 

 tive. 



When it became more and more desirable to use plastics 

 and bonded plywoods in the construction of planes, both to 

 save metal and to cut weight, R.F. heating again came to the 

 rescue. The bottleneck in plywoods and plastics was the slow 

 drying time. And R.F. heating has broken this bottleneck, 

 giving us next year's production of propellers by tomorrow 

 afternoon! 



X-Raying Steel 



The industrial use of X ray is speeding production as 

 efficiently as the widespread use of R.F. heating. A three- 

 hundred-thousand-volt X-ray machine is used to "see" through 

 four inches of steel, finding flaws in casts and weldings while 



