APPLICATIONS OF THE ELECTRIC LIGHT. 275 



45 degrees, a semi-transparent platinized plate of glass. This 

 glass is mounted in a frame so arranged that it can be 

 turned a little to the right or left, while still inclined at the 

 same angle. Further, a frame containing three coloured 

 glasses, red, white, and green, is placed in front of the 

 reflector, and serves at the same time to protect the lantern 

 from wind and rain. 



A jointed rod proceeds from the frame of the inclined 

 glass, and another from the frame carrying the coloured 

 glasses, and these rods are connected with two small levers 

 within reach of the engine-driver. The lamp is connected 

 with the magneto-electric machine by two cables, and when 

 the current passes in the lamp the luminous rays are thrown 

 forward by the reflector, but, as the glass is slightly platinized, 

 only a portion of the beam proceeds straight forwards, whilst 

 the other is projected upwards towards the sky in the form of 

 a cone. By means of the first lever this cone can be turned 

 obliquely either to the right or to the left, while the forward 

 illumination still continues, and by means of the second 

 lever the rays can be coloured either red or green. Now, by 

 giving a certain meaning to each combination, a considerable 

 number of signals may be formed. Besides this, although a 

 train may be passing through a deep cutting or be hidden 

 from sight by curves and inclines, or although the direct view 

 of it may be intercepted by bridges or other objects, the 

 beam projected vertically indicates its position at a great 

 distance. 



Application of the Electric Light to the Lighting 

 of the Drifts in Mines, &c. Several men of science, and 

 among the rest De la Rive, Boussingault, and Louyet, have 

 laid claim to having thrown out the first suggestion of the 

 use of the electric light in mines. The idea originated, as 

 seems to me to have been proved, with Louyet; but the 

 application of it was certainly not made until 1845 by 

 Boussingault. 



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