NATURAL PHILOSOPHY. 151 



was conducted to the lamp placed in a reflector at one end of the 

 room, and an intensely brilliant electric light flashed in the eyes 

 ot all beholders, dazzling them as the noon-day sun, illuminating 

 the nooks and corners of the spacious apartment with a clearness 

 beyond that of sunshine, and deadening the vivid flame of the sun- 

 burner in the centre of the ceiling until it appeared of a dull 

 brown. When tried once at Wilde's factory, in Manchester, it 

 threw the flames of the street-lamps into shadow at a quarter-mile 

 distance. Dazzling though it was, the light fascinated all within 

 its influence, and they who had provided themselves with colored 

 glasses gazed on it with wonder and admiration. Some, placing 

 a lens in the path of the raj 7 , burned holes through sheets of 

 paper; others held out their hands to intercept the heat, which 

 could be distinctly felt at a distance of 50 yards. Then the lamp 

 was turned off, and the light blazed for a while in the middle of 

 the experiment stand, more dazzling than before; then a long 

 loop of wire was screwed into 'the terminals, and held up on a hook 

 by an attendant; in a few seconds it smoked, assumed a dull red 

 color which brightened to a glowing white, under which the wire 

 melted and fell in glittering fragments to the floor. Short lengths 

 of thick iron rod were similarly fused ; but the crowning experi- 

 ment was the melting of a rod of platinum. To those who know 

 what is meant by the fusing of this very refractory metal, this ex- 

 periment will be the most convincing of all of the enormous power 

 of this machine. 



It was interesting to watch the steam engine during these ex- 

 periments, for, in every instance, it slackened speed when the 

 wires or rods were growing hot. The resistance is then great, 

 and becomes greater as the metal increases in heat ; and it was 

 only by constant care on the part of the driver that a uniform rate 

 of motion was maintained. 



By and by arose the question, what practical use can be made 

 of this surpassing light ? To which the answer was : it can be 

 used instead of oil for lighthouses. The Commissioners of North- 

 ern Lights have had a small machine made to be tried at one of 

 the lighthouses under their charge ; a French company have 

 bought the right to use it in France, intending to apply it first at 

 the lighthouse on Cape Grisnez, whence, as is declared, the light 

 will be seen across the whole breadth of the Channel. The cost 

 of the light, as computed by a competent authority, will not be 

 more than Gel. or 8d. an hour, including coal, carbon-rods for the 

 lamps, expense of maintenance, and interest on the price of the 

 machine. This must be considered cheap for alight which makes 

 the sun look pale. 



Beside the production of light, the machine is susceptible of 

 mechanical and chemical applications. An electro-plating firm in 

 Birmingham are about to use it instead of a battery for the depo- 

 sition of copper ; the cost will be less than that of the zinc and 

 acid of the galvanic batteiy at present employed in the process ; 

 and a firm in Whitechapel are setting up one of the machines for 

 the production of ozone in large quantities, to be applied in the 

 bleaching of sugar. With such a promising commencement, we 



