i OUTLOOK AND ENDEAVOUR 7 



certain stage of his career, he was forced definitely to 

 ask himself, and finally to decide whether he would 

 make wealth or science the pursuit of his life. He could 

 not serve two masters, and he chose science. After the 

 discovery of magneto-electricity, his fame was so well 

 recognised that the commercial world would not have 

 considered any fees too high for the aid of abilities like 

 his. Tyndall says he might with ease have realised an 

 income of 10,000 a year during the last thirty years of his 

 life, yet he earned almost nothing by professional services. 



Taking the duration of his life into account, this son of a black- 

 smith, and apprentice to a bookbinder, had to decide between a 

 fortune of 150,000 on one side, and his undowered science on 

 the other. He chose the latter and died a poor man. But his 

 was the glory of holding aloft among the nations the scientific 

 name of England for a period of forty years. Tyndall. 



The invention of the miner's safety-lamp by Sir 

 Humphry Davy was based upon scientific researches 

 described by him to the Royal Society between 1815 

 and 1817. The investigations were undertaken at the 

 request of a " Society for Preventing Accidents in 

 Mines," formed in 1813 in consequence of the increase 

 of colliery explosions as pits of greater depth were worked. 

 The Society looked to scientific men to provide " a 

 cheap and effectual " remedy for these calamities, and 

 Davy's assistance was secured in 1815, after a number 

 of impracticable suggestions had been considered. 



As the result of experiments, Davy discovered the 

 principle upon which safety-lamps are constructed, 

 namely, " that explosive mixtures of mine-damp will 

 not pass through small apertures or tubes ; and that if 

 a lamp or lanthorn be made air-tight on the sides, 

 and furnished with apertures to admit the air. it will 

 not communicate flame to the outward atmosphere." 



