152 ANNUAL OF SCIENTIFIC DISCOVERY. 



may bo sure that many other useful applications of Wilde's ma- 

 chine will be discovered. London Athenaeum. 



THE ELECTRIC LIGHT. 



Our ideas of the electric light are almost invariably associated 

 with the recollections of trouble and difficulty often experienced 

 in the management of a large galvanic battery, with its accom- 

 panying fittings, acids, and fumes, detrimental alike to the clothes, 

 hands, and olfactory organs of the operator. How different it 

 would be if, instead of the cumbrous paraphernalia, we had but to 

 turn a wheel, and lo ! our sun would send forth his brilliant 

 beams ! This is not now a matter of mere theoretical speculation, 

 but is really im fait accompli. 



In the new machine no magnetism, no electricity, is required to 

 commence the action. Nothing but motion is needed to convert 

 a mass of iron and covered wire into a magazine of intense elec- 

 tric power. 



The new machine consists essential!} 7 of a bar of iron bent in 

 horseshoe fashion; around this is coiled covered wire, as in an 

 ordinary electro-magnet. Between the poles revolves a spindle 

 carrying covered wire, insulated, but so arranged that either end 

 will be alternately brought into contact with each terminal of tho 



*/ O 



wire surrounding tho iron bar. Again ; the spindle is so placed 

 that, during its revolution on its long axis, it is made to present 

 each side in succession to either limb of the horseshoe. The spin- 

 dle is driven by an endless band, which passes around the circum- 

 ference of a tolerably large fly-wheel. This is the general 

 construction. When the spindle is rapidly revolved the horseshoe 

 becomes magnetized, a powerful electric current being induced in 

 the wire helix at the same time; and, as the motion is continued, 

 the forces go on acting and reacting until a very high degree of 

 intensity is obtained. The electricity can be taken between two 

 terminals placed in proper position. In this respect an important 

 point of difference exists between Mr. Wilde's machine and Pro- 

 fessor Wheatstone's, inasmuch as in the former any body which we 

 wish to su limit to the action of the electric current must form the 

 terminals of the complete circuit, whereas in the new apparatus 

 the substance to be operated upon forms a bridge or short cut for 

 the electricity, in order to complete the circuit. 



The power of this apparatus is so great that, even when of small 

 size and easily turned by the hand, it is capable of burning a piece 

 of iron wire 30 inches long and one-sixteenth or more in diameter. 

 In this experiment, at the moment of separation of the fused and 

 glowing iron, the metal scintillates in a very beautiful manner. 

 The same result is also obtained by approaching one terminal, 

 consisting of iron wire, to the second end ; the iron immediately 

 takes lire and burns with brilliant coruscations. When the cur- 

 rent is made to pass between charcoal points a beautiful and steady 

 light can be obtained. This is the point which elneily interests 

 us, and we have little doubt that before long \ve shall have a ma- 

 chine which will be practically available, ami en aide us to realize 



