TEANSACTIONS OF SECTION G. 505 



In electric burners, Messrs. Siemens have lately brought out a 'pendulum' 

 lamp, which differs very materially from their previous forms of regulator and 

 from others of the same class, by dispensing with a large amount of the clockwork. 

 In it the separation and approach of the carbons necessary for lighting is effected 

 by the in-and-out movement of a plunger within a solenoid ; the motions of the 

 plunger being communicated by means of a hinged frame to the upper carbon 

 holder. When the motion of the plunger is not sufficient for the feed of the 

 carbons, the holder-rod, which has a rack on one face in its lower portion, becomes 

 detached from the frame, and continues its descent by gravity. The rate of 

 descent is, however, rendered regular by a pendulum fixed on the same shaft as the 

 toothed wheel fitting into the rack ; thus the descent of each tooth of the carbon- 

 holder rack corresponds to a beat of the pendidum. 



Mr. 0. Heinricks has introduced a ' regulator,' which presents many points of 

 difference from the other lamps distinguished by that name. A small case com- 

 pactly encloses the entire of the controlling apparatus, which acts upon a shaft 

 beneath, but entirely outside of it ; upon this shaft are placed the holders of the 

 two semi-circular carbons, which fall by gravity as required to a point immediately 

 beneath. By this arrangement the light is left free and unrestricted for projection 

 away from the lamp ; while the circular form of the carbon pencils permits of a 

 much greater duration of uninterrupted illumination than would be the case with 

 straight carbon-pencils, within the same space. The controlling mechanism 

 includes two distinct magnets and armatures ; one for the feed, the other for the 

 separation of the carbons. By an ingenious arrangement the alternate action of 

 these two magnets is made to control the approach of the carbons, which becomes 

 a step-by-step movement, instead of an unchecked continuous one. To this last are 

 ascribed, by some, many of the interruptions in the light, as well as the subsequent 

 hissings which are found to occur with the ordinary forms of ' regulator.' 



Much attention has of late been directed to the more economical form of burner 

 termed ' candle,' from the two carbon-rods being placed side by side, and both 

 being consumed at the same rate. The only type in use twelve months ago was 

 the Jablochkoff candle. In its original form it possessed the disadvantages of 

 having the carbons rigidly fixed, so preventing any self-adaptation to the variations 

 of the strength of the electric current, and without any power of relighting itself 

 if once extinguished. This last property has since been acquired by the intro- 

 duction of some zinc filings into the insulating substance : an improvement which 

 does not appear, however, to be much made use of. 



The De Meritens candle dispenses altogether with the insulating substance, and 

 its inconvenience of manufacture ; one, or even two, insulated carbon-rods taking 

 its place, and causing induced currents in them during the passage of the current 

 from one outside main carbon to the other. A form of ' candle ' known as the 

 Wilde, but first devised by Rapieff, is superior to the preceding ones in simplicity, 

 efficiency, and economy. In it the carbons are placed in two separate holders, one 

 fixed and the other responding to the movements of the armature of a magnet, 

 through which the current passes. The Jamin candle, about the merits of which 

 much has been said of late, has the two carbons fixed, without any insulating sub- 

 stance between them. The wire from one of the carbon holders, instead of passing 

 directly away, is before doing so wound vertically round the candle in the plane of 

 the two carbons, and at a distance of about f inch from each of them ; about five 

 turns are taken, each insulated from the other, and all formed into a single coil. 

 Heinricks has a candle with two pairs of semi-circular carbons, at right angles to 

 each other, and with an electro-magnet above controlling them. 



To these improvements in the electrical apparatus themselves must be added 

 those in the delicate automatic governing gear of the engine-motors, both steam 

 and gas, in order to insure that extreme regularity of motion which is requisite 

 for electric illumination. Of these, in steam engines, among the most successful 

 are those of Ransomes, Sims, and Head, of Duvergier (of Lyons), of Robey, &c. 

 While in gas engines, the most extensively used, so far, is the ' Otto ' of Crossley 

 Brothers ; though L. Simon and Son, and also Clerk, have each more recently 

 introduced engines which present ingenious and novel features. 



