SOME RECENT TRIUMPHS 



All these experimenters had adopted the same agent 

 as the means of, so to say, forcing the transformation 

 namely, electricity. The American investigators 

 employed a current of ten thousand volts; the German 

 workers carried the current to fifty thousand volts. 

 The flame of the electric arc thus produced ignited 

 the nitrogen with which it came in contact readily 

 enough; but the difficulty was that it came in contact 

 with so little. Despite ingenious arrangements of 

 multiple poles, the burning-surface of the multiple 

 arc remained so small in proportion to the expenditure 

 of energy that the cost of the operation far exceeded 

 the commercial value of the product. Such, at least, 

 must be the inference from the fact that the establish- 

 ments in question did not attain commercial success. 



The peculiarity of Professor Birkeland's method is 

 based upon the curious fact that when the electric arc 

 is made to pass through a magnetic field, its line of 

 flame spreads out into a large disk "like a flaming 

 sun." The sheet of flame thus produced represents no 

 greater expenditure of energy than the lightning flash 

 of light that the same current would produce outside 

 the magnetic field; but it obviously adds enormously 

 to the arc-light surface that comes in contact with the 

 air, and hence in like proportion to the amount 

 of nitrogen that will be ignited. In point of fact, 

 this burning of nitrogen takes place so rapidly in lab- 

 oratory experiments as to vitiate the air of the room 

 very quickly. In the commercial operation, with 

 powerful electro-magnets and a current of five thousand 

 volts, operating, of course, in closed chambers, the ratio 



[307] 



