On the lines of magnetic force / Professor Faraday.

  • Faraday, Michael, 1791-1867.
Date:
1852
Catalogue details

Licence: Public Domain Mark

Credit: On the lines of magnetic force / Professor Faraday. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    4/4 (page 108)
    have these axes adjusted perpendicular to the line of dip and then be revolved. A commutator was employed and associated, both with the galvanometer and the parallelograms, so that the upper part of the revolving wire always sent the current induced in it in the same direction. Here it was found that rotation in one direction gave one electric current; that rotation in the reverse direction gave the contrary current; that the effect at the gal- vanometer was proportionate to the number of rotations with the same rectangle ; that with different sized rectangles of the same wire the effect was proportionate to the area of the rectangle, i. e. the num- ber of curves intersected, &c. &c. The vicinity of other magnets to this magnet made no difference in the effect provided they were not moved during the experiments ; and in this manner the non-interference of such magnets with that under investigation was fully established. All these and other results are more fully stated and proved in papers now before the Royal Society. The general conclusions are, that the magnetic lines of force may be easily recognized and taken account of by the moving wire, both as to direction and intensity, within metals, iron or magnets, as well as in the space around ; and that the wire sums up the action of many lines in one result: That the lines of force wrell represent the nature, condition, direction, and amount of the magnetic forces : That the effect is directly as the number of lines of force intersected, whether the intersection be direct or oblique : That in a field of equal force, it is directly as the velocity ; or as the length of the moving wire; or as the mass of the wire: That the external power of an unchangeable magnet is definite yet illimitable in extent; and that any section of all the lines of force is equal to any other section : That the lines of force within the magnet are equal to those without: and that they are con- tinuous with those without, the lines of force being closed curves. [M.F.] In the Library, were exhibited :— Portrait of Shakspeare (fac-simile in all but colour of the remains of a Portrait on Panel by his partner, Richard Burbage, 1597). [Presented by W. Nicol, Esq. M.R.I.] Whitworth's Surfaces : — i.e. Two Iron Plates, the surfaces made so true by scraping, not grinding, that when one is placed on the other, they will not touch until the film of air between them becomes displaced by the weight of the upper plate. [Exhibited by Mr. J. G. Appold.] Model of Appold’s Centrifugal Pump. [Exhibited by Messrs. Watkins and Hill.] Hodges’ Power-Accumulators. [Exhibited by Mr. Hodges.]