

ELECTRICITY. 



IM 



B year :tn<l live UK. nth-. 

 u To r. 'apitulate : the gas made from one 

 pound of coal would yield a candle-li^ht l'i.r tif- 

 teen hour-; die potind <>t' the gas would yield 

 a IL'ht. ri|ii:il tn oiii- candle fur -.-vent \ -live 

 hour-; hut could all tho energy in a pound 



!">ti In- converted into light, it would bo 



1 1. 'lit to the burning of a caudle for 12,410 

 boon 



' rir. Light Regulator. A simple ap- 

 paratus has been devised by Mr. Highley, of 

 L mdiiii, for the regulation of the distance of 

 the carbon points used for the electric light. 

 Tho prime regulator is an electro-magnet, but 

 no clock-work is employed. The whole mechjm- 

 Nm is contained in a box or case, which serves 

 as a base to tho apparatus. The only parts vis- 

 ible above the box are two tubes standing at a 

 littlo distance apart, into which the carbons are 



d and fastened by binding screws. One 

 <>f the tubes is straight, and the other bent over 

 or hooked at the top, so that its end stands ex- 

 actly over the top of the straight tube. The 

 principle of the contrivance is the regulation 

 of the sliding of these tubes, the straight one 

 up and the bent one down, so that the carbons 

 shall be kept at a constant distance. One-half 

 of the case is occupied by an air-reservoir, 

 which can be filled by means of an India-rubber 

 ball syringe or pump. A spiral spring is placed 

 on the top of this reservoir, to cause it to col- 

 lapse and expel tho air, and the foot of the 

 bent tube is fixed to that top inside of the 

 spiral spring; consequently, as the reservoir 

 collapses, the top descends, and the bent tube 

 descends with it. Also to the top of the reser- 

 voir is attached the end of a lever, which, at 

 the other end is connected with the bottom of a 

 straight tube, and, as the reservoir descends 

 the other end rises, and so raises the straight 

 tube to meet the descending bent tube, both 

 motions being produced by the collapsing res- 

 ervoir of air. From the reservoir there is an 

 emission tube or stop-cock, to let out the air 

 as required. This stop-cock is connected by 

 the keeper to an electro- magnet, around which 

 is coiled the electric conductor in its passage to 

 one of the carbons, the other pole of the bat- 

 tery being connected direct to the other car- 

 bon. The battery being connected to the reg- 

 ulator, tho electro-magnet attracts to itself the 

 keeper and shuts tho stop-cock ; then the air- 

 reservoir is pumped full, and the light is in full 

 operation ; but, the carbon being consumed, the 

 current gradually slackens by means of the in- 



1 resistance. The magnetism consequent- 

 ly lessens, and the keeper is released, and its 

 fall opens the stop-cock a little and lets out a 

 putt' of air ; tho top of the reservoir descends 

 and takes with it the bent tube and the end of 

 the lever, the other end of which raises the 

 straight tube. The carbons then approach, and 

 tho current is reestablished in its full strength ; 

 the electro-magnet again attracts to itself the 



keeper, which shuts tho stop-cock, and t 

 are replaced in the former portion, BO to re- 

 main until tho ends of UK; carbon are again 

 consumed. A second spiral spring is attached 

 to the keeper of the electro-magnet to 

 late tho fall of the keeper, and so regulate the 

 strength of the current. 



The Electric Light for fluoy. An ingenious 

 apparatus has been contrived by M. Adolpho 

 Mironde, of Rouen, for the purpose of lighting 

 buoys by the electric light. He places in the 

 buoy to bo lighted, arranged, so as to keep in 

 equilibrium, a receiver or battery (of a size 

 and weight in proportion to the size of tho 

 buoy), producing an electric current, then a 

 Ruhmkorff induction-bobbin, and lastly, at its 

 upper part, he places a lamp furnished with 

 glasses, in which lamp he sets one or several 

 glass tubes or spheres known as Geissler's 

 tubes. A plate or roofing of metal or other 

 suitable material may be placed above as shel- 

 ter for the apparatus. The main object of tho 

 invention is to render the production of light 

 independent of any communication between 

 the buoy and the shore. When the battery 

 requires replenishing, which will be perceived 

 by the diminished intensity of the light, it will 

 only be necessary to raise it through the man- 

 hole, and replace the battery by another, and 

 to charge, if required, the Geissler's tubes : for 

 experience shows that after working a certain 

 time, the gas, whatever it may be, is more or 

 less decomposed according to its nature (nitro- 

 gen gas has been found to be the best). By fit- 

 ting out buoys with these lights, ships will be 

 prevented from striking them at night, while 

 reefs, banks, and other objects which are to be 

 avoided will be made visible by night almost 

 as clearly as by day. 



Engraving by Electricity. The method of 

 engraving by electricity, recently discovered 

 by M. Dulos, may be briefly described as fol- 

 lows: A plate of copper is prepared, and upon 

 it is sketched tho figure to be represented, in 

 varnish. This having been perfectly dried, is 

 then immersed in a bath of chloride of iron and 

 chloride of ammonium. A small electric cur- 

 rent is passed through it from an iron electrode, 

 and iron is deposited from the solution on the 

 copper plate, on the parts not covered by the 

 varnish lines. When this deposit is of sufficient 

 thickness, the copper plate is taken out of tho 

 bath and thoroughly washed and dried. When 

 the varnish, in which the design was made, is 

 dissolved off and the parts made clean, then 

 the design appears in has relief of copper on an 

 iron ground. The plate is then dipped for an 

 instant in a solution of cyanide of silver, in 

 cyanide of potassium, but without an electric 

 current. By this means the copper parts coat 

 themselves with a film of silver, the iron re- 

 maining free, as it will not coat itself by itn- 

 nier-ion in that solution. The plate is again 

 washed and dried, and then covered with a 

 coating of mercury, which adheres to the sil- 

 ver only, for without sodium-amalgam it will 



