PERPETUAL OR EVER-BURNING LAMPS 103 



liquid to the flame without being itself destroyed. Dr. 

 Plott suggested naphtha for the fluid and asbestos for the 

 wick, but since kerosene oil, naphtha, gasolene, and other 

 liquids of the kind have become common, every housewife 

 knows that as her lamp burns, the oil, of whatever kind it 

 may be, disappears. 



Under present conditions the construction of a perpetual 

 lamp is not a severely felt want ; for constancy and bril- 

 liancy our present means of illumination are sufficient for 

 almost all our requirements. Whether or not it would be 

 possible to gather up those natural currents of electricity, 

 which are suspected to flow through and over the earth, and 

 utilize them for purposes of illumination, however feeble, 

 it might be difficult to decide. But such means of perpet- 

 ual electric lighting would be similar to a perpetual motion 

 derived from a mountain stream. Such natural means of 

 illumination already exist, and have existed for ages in the 

 fire-giving wells of naphtha which are found on the shores 

 of the Caspian sea, and in other parts of the east, and 

 which have long been objects of adoration to the fire- 

 worshippers. 



As for the outcome of present researches into the prop- 

 erties of radium, polonium, and similar substances, and 

 their possible applications, it is too early to form even a 

 surmise. 



