THE CONQUEST OF NATURE 



be fed automatically into the water in proportion to the 

 gas consumed." 



Perhaps the most significant thing, showing the stage 

 of progress that has been made in overcoming the danger 

 of explosions from acetylene gas, is that the use of 

 generators meeting some such requirements as the above 

 is not prohibited by fire underwriters. This in itself is 

 very convincing evidence of their safety. 



THE TRIUMPH OF ELECTRICITY 



Throughout the ages primitive man had had con- 

 stantly before him two sources of light other than that 

 of the sun, moon, and stars. One of these, the fire of 

 ordinary combustion, he could understand and utilize; 

 the other, more powerful and more terrible, which flashed 

 across the heavens at times, he could not even vaguely 

 understand, and, naturally, did not attempt to utilize. 

 But early in the seventeenth century some scientific 

 discoveries were made which, although their destination 

 was not even imagined at the time, pointed the way 

 that eventually led to man's imitating in the most strik- 

 ing manner Nature's electrical illumination. 



About this time Otto von Guericke, the burgomaster- 

 philosopher of Magdeburg, in the course of his numerous 

 experiments, had discovered some of the properties of 

 electricity, by rubbing a sulphur ball, and among other 

 things had noticed that when the ball was rubbed in a 

 darkened room, a faint glow of light was produced. He 

 was aware, also, that in some way this was connected 

 with the generation of electricity, but in what manner he 



