Michael Faraday, his life and work / by Silvanus P. Thompson.

  • Silvanus P. Thompson
Date:
1901
Catalogue details

Licence: In copyright

Credit: Michael Faraday, his life and work / by Silvanus P. Thompson. Source: Wellcome Collection.

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    difference in their amount. Obliquity of intersection caused no difference, provided the same lines of force were cut. If a wire was moving in a held of equal intensity, and with a uniform motion, then the current produced was proportional to the velocity of motion. The “quantity of electricity thrown into a current ” was, ceteris paribus, “ directly as the amount of curves intersected.” Within the magnet, running through its substance, existed lines of force of the same nature as those without, exactly equal in amount to those without, and were, indeed, con- tinuous with them. The conclusion must logically be that every line of force is a closed circuit. Having thus established the exact quantitative laws of magneto-electric induction, he then advanced to make use of the induced current as a means of investigating the presence, direction, and amount of magnetic forces—in other words, to explore and measure magnetic fields. He constructed revolving rectangles and rings furnished with a simple commu- tator, to measure inductively the magnetic forces of the earth. Then he employed the induced current to test the constancy of magnets when placed near to other magnets in ways that might affect their power. Next he considers the fields of magnetic force of two or more associated magnets, and notes how their magnetic lines may coalesce when they are so placed as to constitute parts of a common magnetic circuit. The twenty-ninth series is brought to a close by a discussion of the experimental way of delineating lines of magnetic force by means of iron filings. The paper on the “ Physical Character of the