ClipArt ETC
"Magnetic hysteresis in armature core. Unlike poles are induced in the core opposte the poles of the field magnet. Since on account of the rotation of the core the induced poles are reversed a thousand or more times a minute, considerable energy is required to change the positions of the molecules f the iron for each reversal, resulting in the generation of heat at the expense of a portion of the energy required to drive the armature." -Hawkins, 1917

Magnetic Hysteresis in Armature Core

"Magnetic hysteresis in armature core. Unlike poles are induced in the core opposte the poles of the…

"Action of current on solenoids. To demonstrate this fact experimentally, a solenoid is constructed as shown...Te solenoid is then moveable about a vertical axis, and if a rectilinear current QP be passed beneath it, which at the same time traverses the wires of the solenoid, the latter is seem to turn and set at right angles to the lower current..." -Hawkins, 1917

Current on Solenoids

"Action of current on solenoids. To demonstrate this fact experimentally, a solenoid is constructed…

"Magnets so construted as to be temporarily magnetized in this way are called electromagnets" -Atkinson 1903

Electromagnet

"Magnets so construted as to be temporarily magnetized in this way are called electromagnets" -Atkinson…

A pair of hands, each holding a narrow bit of wire over a compass needle.

Hands with wires

A pair of hands, each holding a narrow bit of wire over a compass needle.

"Experiment illustrating Lenz's Law. If a copper ring be held in front of an ordinary elecromagnet, and the current circulating through the coil of the magnet be in such a direction as to magnetize the core as indicated b the letters S N, then as the current increases in the coil more and more of the lines of force proceeeding from N pass through the ring OO from left to right." -Hawkins, 1917

Lenz's Law

"Experiment illustrating Lenz's Law. If a copper ring be held in front of an ordinary elecromagnet,…

"Lines of force of a circular loop. If a current flow through the loop in the direction indicated, the lines of force both inside and outside the loop, will cross the plane of the loop at right angles, and all those which cross the loop on the inside will pass through the plane in one direction...while all on the outside will return through the plane in the opposite direction." -Hawkins, 1917

Lines of Force

"Lines of force of a circular loop. If a current flow through the loop in the direction indicated, the…

"Lines of force in a circular loop. If the loop pass through a piece of cardboard at right angles to its plane, and the curent flow as indicated, the dotted lines on the cardboard will represent the direction of the lines of force in the plane of the cardboard." -Hawkins, 1917

Lines of Force

"Lines of force in a circular loop. If the loop pass through a piece of cardboard at right angles to…

"If a magnet is cut or broken into two or more pieces, each piece becomes a separate magnet, with north and south poles in the same relative positions as in the original magnet...But if the pieces be pressed closely together, their poles dissapear leaving only the two original poles." -Atkinson 1903

Effect of Breaking a Magnet

"If a magnet is cut or broken into two or more pieces, each piece becomes a separate magnet, with north…

"The two most common forms of artificial magnets are the bar magnet and the horseshoe magnet. The first of these is a straight bar of iron and steel; the second is U-shaped." — Avery, 1895

Horseshoe magnet

"The two most common forms of artificial magnets are the bar magnet and the horseshoe magnet. The first…

An illustration of a horseshoe shaped magnet.

Horseshoe Magnet

An illustration of a horseshoe shaped magnet.

An illustration of a rectangle shaped steel magnet with "consequent poles at a and b." -Century, 1889

Rectangle Shaped Steel Magnet

An illustration of a rectangle shaped steel magnet with "consequent poles at a and b." -Century, 1889

An illustration of magnetic curves, "the name given to those curves in which an infinite number of very needles would arrange themselves when placed round a magnet and at liberty to move round an axis." -Century, 1886

Magnetic Curves

An illustration of magnetic curves, "the name given to those curves in which an infinite number of very…

"Experiment showing lines of force in the magnetic field surrounding a conductor carrying an electric current." -Hawkins, 1917

Magnetic Field

"Experiment showing lines of force in the magnetic field surrounding a conductor carrying an electric…

"Oersted's experiements are illustrated...which shows, at A, B, C and D, the four different positions which a balanced magnetic needle tends to assume when placed parallel to a wire through wich an electric current is flowing in the different directions indicated by the arrows..." -Atkinson 1903

Deflection of te Magnetic Needle by the Electric Current

"Oersted's experiements are illustrated...which shows, at A, B, C and D, the four different positions…

"Experiment illustrating the molecular theory of magnetism. Coarse steel filings are placed inside a small glass tube and the contents magnetized. It will be found that filing which at first had no definite arrangement will rearrange themselves under the influence of magnetic force, and assume symmetrical position, each one lying in line with, or parallel to its neighbor, as shown in the lower figure." -Hawkins, 1917

Magnetism

"Experiment illustrating the molecular theory of magnetism. Coarse steel filings are placed inside a…

"Right hand palm rule to determine the direction of the magnetic field around a conductor carrying a current." -Hawkins, 1917

Right Hand Rule

"Right hand palm rule to determine the direction of the magnetic field around a conductor carrying a…

"Right hand rule for polarity of a solenoid: If the solenoid be grasped in the right hand, so that the fingers point in the direction in which the current is flowing in the wires, the thumb extended will point in the direction of the north pole [of the solenoid]." Hawkins, 1917

Right Hand Rule, Solenoid

"Right hand rule for polarity of a solenoid: If the solenoid be grasped in the right hand, so that the…

"A coil of wire through which an elecric current is flowing shows magnetic properties similar to those of an electromagnet, b much weaker than those of a similar coil having a soft iron core. Such a coil, if suspended...will assume a north and south position..." -Atkinson 1903

Solenoid

"A coil of wire through which an elecric current is flowing shows magnetic properties similar to those…

"Illustrating the effects of introducing an iron core into a solenoid. In the upper firgure, the air space or 'air core' surrounded by the solenoid offers considerable resistance to the passage of magnetic lines, allowing only a small number to pass through. If a pieve of iron be introduced, as in the lower figure, the number of lines will be greatly increased." -Hawkins, 1917

Effect of a metal core in a solenoid

"Illustrating the effects of introducing an iron core into a solenoid. In the upper firgure, the air…

"Mutual action of solenoids. When two solenoids traversed by a current are allows to act on each other...attraction and repulsion will take place just as in the case of two magnets." -Hawkins, 1917

Solenoid, attraction

"Mutual action of solenoids. When two solenoids traversed by a current are allows to act on each other...attraction…