Contributions to Terrestrial Magnetism Volume 1

Contributions to Terrestrial Magnetism Volume 1

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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. 1840 edition. Excerpt: ... prescribed in the magnetic Instructions which have received the sanction of the Royal Society. Experiments made by Lieutenants Lefroy and Riddell in the Royal Military Repository at Woolwich in May 1842, with magnets of four inches in length, gave 372 as the approximate value of the horizontal force at Woolwich at that period, agreeably to the following memorandum: --"The number 372, given as the approximate value of the horizontal intensity at Woolwich, expressed in English units of feet, seconds, and grains, was determined from experiments of deflection and vibration made with on of Weber's transportable magnetometers. "The experiments of deflection were made after the method of M. Gauss, with the axis of the deflecting magnet perpendicular to the magnetic meridian, the angles being measured on the scale fixed over the reading telescope. The deflecting and suspended magnets were of the same dimensions, about four inches in length and four-tenths in diameter. "The values of were calculated from the several pairs of observations by the formula m r5 tan vl--r5 tan u X--2 (r--r2) "The partial results, distances, and angles of deflection are given in the accompanying abstracts. "The moment of inertia of the vibrating magnet was determined by observing a "The number obtained for the force of the earth's magnetism expresses the ratio which that force bears to the unit of force, the unit of force being that which, acting on the unit of mass, through the unit of time, generates in it the unit of velocity. These units are entirely arbitrary; but for the sake of convenience in comparison, it is desirable that they should be the same in all the observations which shall be made according to this system. For the more

Product details

  • Paperback | 60 pages
  • 189 x 246 x 3mm | 127g
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236612183
  • 9781236612182