Page:A Treatise on Electricity and Magnetism - Volume 2.djvu/16

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CONTENTS

Art.	Page
480. Potential function due to a straight current. It is a function of many values	130
481. The action of this current compared with that of a magnetic shell having an infinite straight edge and extending on one side of this edge to infinity	131
482. A small circuit acts at a great distance like a magnet	131
483. Deduction from this of the action of a closed circuit of any form and size on any point not in the current itself	131
484. Comparison between the circuit and a magnetic shell	132
485. Magnetic potential of a closed circuit	133
486. Conditions of continuous rotation of a magnet about a current	133
487. Form of the magnetic equipotential surfaces due to a closed circuit. Fig. XVIII	134
488. Mutual action between any system of magnets and a closed current	135
489. Reaction on the circuit	135
490. Force acting on a wire carrying a current and placed in the magnetic field	136
491. Theory of electromagnetic rotations	138
492. Action of one electric circuit on the whole or any portion of another	139
493. Our method of investigation is that of Faraday	140
494. Illustration of the method applied to parallel currents	140
495. Dimensions of the unit of current	141
496. The wire is urged from the side on which its magnetic action strengthens the magnetic force and towards the side on which it opposes it	141
497. Action of an infinite straight current on any current in its plane	142
498. Statement of the laws of electromagnetic force. Magnetic force due to a current	142
499. Generality of these laws	143
500. Force acting on a circuit placed in the magnetic field	144
501. Electromagnetic force is a mechanical force acting on the conductor, not on the electric current itself	144

Chapter II.

Mutual Action of Electric Currents.

502. Ampère's investigation of the law of force between the elements of electric currents

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