Volume 1

A manual of electricity, magnetism, and meteorology / [D. Lardner].

  • Dionysius Lardner
Date:
1841-1844
Catalogue details

Licence: Public Domain Mark

Credit: A manual of electricity, magnetism, and meteorology / [D. Lardner]. Source: Wellcome Collection.

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    to prevent this on the one hand, while the facility to accumulation offered by the conducting power of the spherical surface M is counteracted by the property of that surface in virtue of which it favours the uniform. distribution of electricity on the other. That the con- ductor may become charged with free electricity, either of two effects must be produced. The depth, of elec- tricity on the cylinder must be so increased as to over- come the restraining power of the air, so that it may force its way to the spherical surface M, and thus the conductor may become charged with the positive elec- tricity which passes to it from the cylinder; or the depth of the negative fluid on the surface M must be so increased as to surpass the restraining power of the air, so that a portion of the negative fluid shall pass from the conductor to the cylinder. In this latter case the quantity of positive fluid remaining on the con- ductor would exceed the quantity of negative fluid, and if the conductor were removed from the cylinder it would be found charged with positive electricity. The negative fluid, which would in this case pass from the extremity M of the conductor to the cylinder, would there combine with an equal portion of the positive fluid diffused upon the cylinder, and would, to a proportionate extent, restore the cylinder to its natural state. If the quantity of negative fluid thus supplied by the conductor to the cylinder were exactly equal to the quantity of negative fluid which escaped through the rubber and the chain KL to the earth, then it would necessarily be equal to the quantity of positive fluid developed on the cylin- der, and the cylinder would be obviously restored to its natural state. The electricities which would thus bé combined as the cylinder passes before the conductor would be again decomposed as it passes under the rubber, and the negative fluid which was just received from the conductor would be dismissed through the rubber and the chain KL to the earth. Now it is evident that, consistently with the principles of this theory, either of these two methods of charging