THE CONQUEST OF NATURE 



was formed, and within the next five years gas street- 

 lamps had become familiar objects in the streets of 

 London, and house illumination by this means a com- 

 mon thing among the wealthier classes. 



In the early days of gas-lighting the results were 

 frequently disappointing, because no suitable and 

 efficient type of burner had been devised; but in 1820 

 Neilson of Glasgow discovered the principle of the 

 now familiar flat burner, of which more examples still 

 remain in use the world over than of all other kinds 

 combined. Indeed, this simple, but as we now regard 

 it, inefficient burner, would probably have remained the 

 best-known type for many years longer than it did had 

 not the possibilities of lighting by electricity aroused 

 persons interested in the great gas-plants to the fact 

 that the new illuminant was jeopardizing their enormous 

 investments; making it clear that they must bestir 

 themselves and improve their flat burners if they would 

 arrest disaster. To be sure, several modifications of the 

 round Argand burner had been introduced from time 

 to time, some of them being a distinct improvement 

 over the flat burner, but these did not by any means 

 seriously compete with electric light. And it was not un- 

 til the incandescent mantle was perfected that gas as a 

 brilliant illuminant was able to make a stand against 

 its new competitor. 



THE INCANDESCENT GAS MANTLE 



It has been known almost since the beginnings of 

 civilization that all solids can be made to emit light 



[208] 



