ELECTKIC LIGHT APPLIED TO LANTERNS. 



been ilhiminated by the oxy-hydrogen light. The manner in 

 which this illumination is produced will be explained more fully 

 in another part of the MUSEUM. Meanwhile, we may briefly 

 state here, that the light proceeds from a ball or cylinder of lime, 

 which is rendered incandescent, or white-hot, by the name of a 

 blow-pipe, from which a mixture of oxygen and hydrogen gases, 

 in the proportion in which these gases produce water, issues. 



It might be imagined that the light produced by a piece of 

 solid matter like lime, however intensely heated, could never be 

 brilliant enough to produce a strong illumination ; nevertheless, 

 the light radiated from the lime in this case was the most intense 

 artificial light Avhich had ever been produced until the invention 

 of another, which we shall presently notice. 



In the oxy-hydrogen lanterns, the cylinder of lime is mounted, 

 so as to occupy the place of the flame of the lamp in the axis of 

 the lenses. The flame of the blow-pipe is projected upon that 

 side of it which is presented towards the lenses, and since the 

 lime, though it does not undergo combustion, is gradually wasted 

 by the action of the flame, it is kept in slow revolution by clock- 

 work, connected with the axis upon which it is supported, so as 

 to present to the flame successively different parts of its surface. 



21. This method of illumination, though still continued, is 

 greatly surpassed in splendour by that of the electric light, which 

 has recently been applied to the magic lantern by Mr. Dubosc, 

 the successor of Mr. Soleil, the celebrated Paris optician. 



The electric light, which will be more fully described in 

 another part of this series, is produced by bringing two pieces of 

 charcoal, previously put in connection with the poles of a Voltaic 

 battery, nearly into contact ; the Voltaic current will then pass from 

 one to the other, the ends of the charcoal thus nearly in contact 

 becoming incandescent, and emitting the most brilliant artificial 

 light which has ever yet been produced. 



The method of mounting this illuminating apparatus in the 

 lantern is shown in fig. 3. 



The wires H K, being connected with the poles of the battery, 

 are attached to two pieces of metal, the negative wire H com- 

 municating with the upper pencil of charcoal c, and the positive 

 wire K with the lower charcoal pencil a. The points of the 

 pencils being nearly in contact, the light will be produced in the 

 manner just explained. 



Although the charcoal does not, properly speaking, undergo 

 much combustion, it is gradually wasted, and when the points 

 would thus become separated, the current would be suspended, 

 and, therefore, the light would cease. To prevent this, and to 

 maintain the illumination, an apparatus consisting of clock- 



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