The London, Edinburgh and Dublin philosophical magazine and journal of science . of the whole distance betweenthe legs reckoned from the negative leg. Imagine the middle plate therefore connected through agalvanometer with the positive electrode of the lamp, and letthe middle plate be first placed close to the positive leg andthen moved continuously nearer towards the negative current through the galvanometer would first fall off asthe plate receded from the positive leg, and after reachinga minimum at a point about \ of the whole distance betweenthe legs reckoned from the positive leg
The London, Edinburgh and Dublin philosophical magazine and journal of science . of the whole distance betweenthe legs reckoned from the negative leg. Imagine the middle plate therefore connected through agalvanometer with the positive electrode of the lamp, and letthe middle plate be first placed close to the positive leg andthen moved continuously nearer towards the negative current through the galvanometer would first fall off asthe plate receded from the positive leg, and after reachinga minimum at a point about \ of the whole distance betweenthe legs reckoned from the positive leg, would rise up to amaximum when the middle plate was as nearly in contact withthe negative leg as possible without actually touching it. § 6. Experiment 3.—In order to explore more thoroughlythe action of the different portions of the incandescence carbonconductor in producing this effect, a lamp was taken havinga horse-shoe shaped carbon, and a pair of small platinum cylin- Fig. ders, held on platinum wires sealed through the glass, soplaced as to embrace without touching the carbon of these cylinders, X, was placed so as to embrace thecarbon near the bottom of the leg, and the other, Y, near thespring of the arch (see fig. 5). These small cylinders had a 64 Prof. J. A. Fleming on the length of about 12 millims. and a diameter of about 8 that the distance from the carbon filament to the innersurface of the cylinder was about 3 or 4 millims. The lamphad a rather thick carbon, and at an electromotive force of48 volts took a current of 132 amperes to raise it to itsnormal incandescence of 18*8 candles, corresponding to 3*3watts per candle-power. This lamp will be alluded to asLamp No. 3. It is obvious that there are four possible arrangements inwhich a current can be obtained between an embracingcylinder and a positive electrode of the lamp. These areillustrated in fig. 6, in which the horse-shoe shaped line stands Fig. 6. Position Posit
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Keywords: ., bookcentury1800, bookdecade1840, bookidlondon, booksubjectscience
