168 



THE ELECTRIC LIGHT. 



earnestly and carefully in favour of the electric 

 light. 



I am going to show you the effect that will 

 take place with that large lens when we throw 

 the oil lamp out of action, and put the electric 

 light into use. It is astonishing to find how 

 little the eye can compare the relative inten- 

 sities of two lights ; look at that screen and try 

 to recollect the amount of light thrown upon it 

 from the 3| inch lamp of Fresnel, and now, 

 when we shift the lens sideways, look at the 

 glorious light arising from that small carbon 

 point (fig. 58) ; see how beautifully it shines in 



Fig. 58. 



the focus of that lens and throws the rays for- 

 ward. At present the electric light is put at 

 just the same distance as the oil light, and 

 therefore, being in the focus of the lens, we 



