On Physical Lines of Force/Figures
On Physical Lines of Force → Figures
Nineteen drawings prepared for this edition. Those marked after Maxwell follow the composition of his Plate V; the rest are explanatory and have no counterpart in the printed paper.
Part I — magnetic phenomena
Fig. A. Lines of force about a bar magnet. The iron-filings experiment, and Maxwell's definition of a line of force. → The introductory discussion
Fig. B. The centrifugal force of one vortex. Pressure at the axis, at the circumference, and the mean parallel to the axis. → Prop. I
Fig. C. Tension along the lines, pressure across them. Why unlike poles attract and like poles repel on one state of stress. → Why spinning makes a pull
Fig. K. A bundle of parallel vortices. The medium spreads sideways and shortens along the axes. → Prop. I
Fig. S. The stress on a cube of the medium. Hydrostatic pressure plus a tension along the vortex axis, projected on the coordinate planes. → Prop. II · modern form
Part II — electric currents
Fig. D. Vortex cells and the particles between them. After Maxwell, Plate V. fig. 2. The current AB, the rows of cells turning oppositely above and below it, and the idle-wheel particles at every cell corner. → The mechanism
Fig. E. Circuit, line of force, and vortices. After Maxwell, Plate V. fig. 1. Fixes the handedness relating current direction to the sense of rotation. → The mechanism
Fig. F. The anchor ring. After Maxwell, Plate V. fig. 3. Induction with no external magnetic field anywhere. → Induced currents · the vector potential
Fig. G. The idle wheel. Two vortices in direct contact cannot both turn the same way; a particle between them can make them. → Prop. IV
Fig. L. How an induced current arises. Three stages: the current starts, the neighbouring vortices resist being spun up, and the next layer of particles is driven backwards. → Induced currents
Part III — statical electricity
Fig. M. The porous membrane and the elastic one. Conduction and induction as two independent qualities of bodies. → Conduction and induction
Fig. H. The cell yields, and pushes back. Electromotive force distorts a cell; the elastic reaction balances it; the particles come to rest displaced. → Prop. XIII
Fig. I. The displacement current closes the circuit. The charging capacitor, and the two surfaces spanning one loop. → Prop. XIV
Fig. J. A transverse undulation. Displacement and magnetic force at right angles to each other and to the direction of travel. → Prop. XVI · the wave equation
Fig. R. The two measures of electricity. Their ratio is a velocity; Weber and Kohlrausch measured it; Fizeau had measured the speed of light. → The unit ratio
Part IV — polarized light
Fig. N. Magnetic rotation of the plane of polarization. The two circular components travel at different speeds in a medium whose vortices are already turning. → Why magnetism must be rotatory
Reference figures
Fig. O. Circulation and the curl. Maxwell's verbal statement of the current law, and what it becomes when the loop shrinks to a point. → Ampère–Maxwell
Fig. Q. A concordance of notation. Maxwell's 1861 symbols and their modern equivalents. → Notation
Fig. P. Chronology, 1820 to 1873. → Chronology
A note on the figures
These are original drawings, not reproductions of the 1862 plate. No page image of Maxwell's Plate V was available for this edition, so the three marked after Maxwell were reconstructed from his textual descriptions of them — which are detailed enough to fix the composition but not the draughtsmanship. His fig. 2 in particular is drawn here as a regular hexagonal tiling with a particle at every vertex; the printed figure may differ in the number of rows and in the exact packing. See Sources and editorial method.
All figures are SVG and will scale without loss. If they do not display, they were probably not uploaded — an XML import carries page text only. See On Physical Lines of Force/Rendering test.