This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1904 Excerpt: ...quartz shows no elastic fatigue after being twisted. Siemens has shown that the glass of a Leyden jar is sensibly warmed by rapid charging and discharging. The distortion shows a lag behind the electric stress, a phenomenon known as hysteresis when applied to magnetic induction. The result in both cases is the ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1904 Excerpt: ...quartz shows no elastic fatigue after being twisted. Siemens has shown that the glass of a Leyden jar is sensibly warmed by rapid charging and discharging. The distortion shows a lag behind the electric stress, a phenomenon known as hysteresis when applied to magnetic induction. The result in both cases is the absorption of energy and the generation of heat. The quantity of heat generated is proportional to the square of the potential difference to which the condenser is subjected. 161. Dielectric Polarization (B., 573).--Faraday's theory of induction was that it is an action between contiguous parts of the dielectric, resulting in a certain polarized state of its particles. In proof of this polarization he placed bits of dry silk filaments in turpentine contained in a long rectangular glass vessel with pointed conductors entering from opposite ends. When one of these was connected with the earth and the other with a frictional machine, the bits of silk collected together along lines of induction, forming long filaments of considerable tenacity. Matteucci demonstrated that the dielectric is polarized or charged by contiguous particles throughout. He formed a condenser of a large number of thin plates of mica compressed between two terminal metal plates (Fig. 85). After charging it and insulating, it was found on removing the mica plates and examining them that each one was charged positively on one side and negatively on the other, all the positive sides being turned toward the positive electrode, and all the negative ones in the opposite direction. Maxwell explains the residual charge by assuming that the dielectric is not homogeneous, and that it therefore becomes electrified at the surfaces separating the nonhomogeneous parts, like the electrification of...
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