TransactionsPublished under the care of the General Secretary and the Treasurer . g, separated from eachother by 2 cms of air. The moving sectors M (Fig. 2) pass be-tween two fixed charged sectors S, touching at the same time abrush A connected to earth. The sectors are thus charged bv PENDER: MOVING CHARGES. 453 indiiction. They tlien leave the brush A and the sectors S andpass under an astatic system E. Leaving E, they touch a secondbrush B, also connected to earth, by which they are placing a galvanometer between A ot B and the earth, one canmeasure the quantity of charge take
TransactionsPublished under the care of the General Secretary and the Treasurer . g, separated from eachother by 2 cms of air. The moving sectors M (Fig. 2) pass be-tween two fixed charged sectors S, touching at the same time abrush A connected to earth. The sectors are thus charged bv PENDER: MOVING CHARGES. 453 indiiction. They tlien leave the brush A and the sectors S andpass under an astatic system E. Leaving E, they touch a secondbrush B, also connected to earth, by which they are placing a galvanometer between A ot B and the earth, one canmeasure the quantity of charge taken by the sectors when they arecharged, or the quantity given up when they are discharged; or,to avoid circumlocution, the charging current or the dischargingcurrent. The astatic system is suspended in a metallic tube con-nected to earth. Between the tube and the moving sectors a sheetof ebonite is placed to prevent the sectors discharging to the quantitative measurements this method possesses two dis-advantages. First, it is impossible to calculate the distribution of. the charge on the sectors, and, therefore, the magnetic field pro-duced at the astatic system. Second, it is impossible, with thesectors moving in the open air, to shield the tube containing thesystem from the violent air currents produced by the rotatingsectors. However, in spite of these difficulties, M. Cremieu and the au-thor, in their joint researches, obtained readily the effect pre-dicted by Faraday, which effect also agrees quantitatively, to arough approximation, with that calculated. We have now to account for M. Cremieus inability, in his orig-inal experiments, to obtain any of these effects we have just de- 454 PENDER: MOVING CHARGED. scribed. Let me call attention here to the fact that so far we havealways spoken of a moving metallic surface. A simple metallic sur-face M. Cremieu never employed. To make the supposed effect aslarge as possible, M. Cremieu desired to obtain a large surfacedens
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Keywords: ., bookcentury1900, bookdecade1900, bookidtr, booksubjectelectricity
