ClipArt ETC
"The coil is of flat, rectangular shape, with a narrow central opening just large enough to allow one of the magnets of the astatic system to swing freely. The other magnet swings over a graduated circle placed on the top of the coil, and serves also as an index. Sometimes a mirror and scale are substituted for the index and graduated circle. The sole on which the coil stands is movable on a fixed piece which can be levelled by means of three screws." &mdash Encyclopedia Britannica, 1893

Astatic Multiplier

"The coil is of flat, rectangular shape, with a narrow central opening just large enough to allow one…

"At sea the declination is generally observed by means of an azimuth compass invented by Kater. It consists of a magnet with a graduated compass card attached to it. At the side of the instrument opposite the eye there is a frame which projects upwards from the plane of the instrument in a nearly vertical direction, and this frame contains a wide rectangular slit cut into two parts by a wire extending lengthwise. The eye-piece is opposite this frame, and the observer is supposed to point the instrument in such a manner that the wire above mentioned shall bisect the sun's visible disk. There is a totally reflecting glass prism which throws into the eye-piece an image of the scale of the graduated card, so that the observer, having first bisected the sun's disk by the wire, must next read the division of the scale which is in the middle of the field of view." —The Encyclopedia Britannica, 1903

Azimuth Compass

"At sea the declination is generally observed by means of an azimuth compass invented by Kater. It consists…

"An electric bell consists mainly of an electromagnet, E, and a vibrating armature that carries a hammer, H, that strikes a bell. One terminal of the magnet coils is connected to the binding-post, and the other terminal to the flexible support of the armature. The armature carries a spring that rests lightly against the tip of an adjustable screw at C. This screw is connected to the other binding-post. The bell is connected to a battery of 2 or 3 cells in series, a key, a push-button, P, or some other device for closing the circuit being placed in the line." -Avery 1895

Electric Bell

"An electric bell consists mainly of an electromagnet, E, and a vibrating armature that carries a hammer,…

This illustration shows rays attracted to a magnet, and exerting force upon the object against which they are striking.

Cathode

This illustration shows rays attracted to a magnet, and exerting force upon the object against which…

"A rude form of the compass used by early Chinese sailors. The little wooden figure was set on a pivot, and in the outstretched arm was placed a bar of magnetized iron."—Myers, 1905

Chinese Magnet Figure

"A rude form of the compass used by early Chinese sailors. The little wooden figure was set on a pivot,…

A rod with a slender wire coiled loosely around it.

Coil around rod

A rod with a slender wire coiled loosely around it.

"The dynamo has its field mangets F F magnetized by means of a small current flowing around a shunt circuit." — Hawkins, 1917

Dynamo

"The dynamo has its field mangets F F magnetized by means of a small current flowing around a shunt…

"...in which is shown as electromagnet mounted with its poles in proximity to those of a steel magnet, and connected with a driving-wheel and belt, by which it can be given a rapid rotary motion, so that its poles alternately rotate past those of the steel magnet, producing an alternate reversal of polarity in its core by which an alternating current is generated in its coils." -Atkinson 1903

Dynamo

"...in which is shown as electromagnet mounted with its poles in proximity to those of a steel magnet,…

"The electromagnet that supplies the flux of force must have a current to excite it. This current is sometimes supplied from an outside source. Such a dynamo is said to be seperately excited. Often all of the current from the armature is carried around the coils of the field magnet, thus forming a series dynamo." — Avery, 1895

Series dynamo

"The electromagnet that supplies the flux of force must have a current to excite it. This current is…

"The shunt wound dynamo differes from the series wound machine, in that an independent circuit is used for exciting its field magnet." — Hawkins, 1917

Shunt dynamo

"The shunt wound dynamo differes from the series wound machine, in that an independent circuit is used…

The magnet produced by an electric current is called an electro-magnet.

Electro-Magnet

The magnet produced by an electric current is called an electro-magnet.

"An electromagnet is a bar of iron magnetized by an electric current, substantial as just shown." — Avery, 1895

Electromagnet

"An electromagnet is a bar of iron magnetized by an electric current, substantial as just shown." —…

"When an electromagnet is U-shaped, the coils around the two ends of the bent iron core are so wound that if the coil should be straightened either coil would appear as a continuation of the other, i.e., the current would circle around the core in the same direction in the two coils. Such magnets are often made by connecting an end of the core of one spool-shaped magnet, by a straight soft iron bar called a yoke." — Avery, 1895

Electromagnet

"When an electromagnet is U-shaped, the coils around the two ends of the bent iron core are so wound…

"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…

"This apparatus shows the rotation at once of a magnet and of a movable conductor. The rotating pieces are the magnet sn, which is tied to the copper peg at the bottom of G by means of a piece of string, and swims round the vertical current buoyed up by the mercury in G, and the wire DE, which is hinged to D by a thin flexible wire, and swims round the pole of the vertical magnet n's'." — Encyclopedia Britannica, 1893

Faraday Apparatus

"This apparatus shows the rotation at once of a magnet and of a movable conductor. The rotating pieces…

A hand holding a U-shaped tuning fork.

Hand with tuning fork

A hand holding a U-shaped tuning fork.

A magnet that is the shape of a 'U' or a horseshoe type shape. Wires wound around the core must be wound as shown, with a bridge between the two poles.

Horseshoe Electromagnet

A magnet that is the shape of a 'U' or a horseshoe type shape. Wires wound around the core must be wound…

"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…

"The coils of wire may begin near one pole of the magnet and terminate near the other, or the wire may consist of shorter pieces wound over each other, on any part of the magnet. In either case, the ends of the wire, where several pieces are used, must be soldered to two strips of tinned sheet copper, for the combined positive and negative poles of the wires. To form the magnet, these pieces of copper are made to commnicate with the poles of the battery, by means of cups containing mercury, as shown in the figure, or by any other method." —Comstock, 1850

Magnet

"The coils of wire may begin near one pole of the magnet and terminate near the other, or the wire may…

Design for magnet recharger.

Magnet Recharger

Design for magnet recharger.

Diagram of connections of magnet recharger.

Magnet Recharger

Diagram of connections of magnet recharger.

"Salient pole, bipolar field magnet with single coil wound around the yoke." — Hawkins, 1917

Bipolar field magnet

"Salient pole, bipolar field magnet with single coil wound around the yoke." — Hawkins, 1917

"Consequent pole bipolar field magnet with two coils on the core." — Hawkins, 1917

Bipolar field magnet

"Consequent pole bipolar field magnet with two coils on the core." — Hawkins, 1917

"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…

A type of magnet whose magnetic field is produced by the flow of electric current. The magnetic field disappears when the current ceases.

Electro Magnet

A type of magnet whose magnetic field is produced by the flow of electric current. The magnetic field…

"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.

"Modern dynamo with four consequent pole field magnets. In this construction the ring shaped yoke also serves as a frame; the circular form of yoke gives the least chance of magnetic leakage." — Hawkins, 1917

Multi-polar field magnet

"Modern dynamo with four consequent pole field magnets. In this construction the ring shaped yoke also…

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

"Effect of breaking a magnet into several parts. If a magnetized needle be broken, each part will be found to be a complete magnet having a N and S pole." -Hawkins, 1917

Separating a magnet

"Effect of breaking a magnet into several parts. If a magnetized needle be broken, each part will be…

"The polarity of the solenoidal magnet may be determined by holding it in the right hand so that the fingers point in the direction of the current; then the extended thumb will point toward the marked or north-seeking pole of the magnet." — Avery, 1895

Solenoidal magnet

"The polarity of the solenoidal magnet may be determined by holding it in the right hand so that the…

"The region about a magnet in which its magnetic forces can be detected is called the magnetic field. This can be graphically represented by placing a piece of cardboard over the magnet and sprinkling ironn fillings on the paper, gently tapping at the same time." -Hawkins, 1917

Magnetic Field

"The region about a magnet in which its magnetic forces can be detected is called the magnetic field.…

"Tracing lines of force with a suspended magnet." -Hawkins, 1917

Tracing magnetic field lines

"Tracing lines of force with a suspended magnet." -Hawkins, 1917

"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…

Figure showing magnetic lines of force from a magnet, as well as both north and south poles.

Magnetic Field

Figure showing magnetic lines of force from a magnet, as well as both north and south poles.

A magnetic locator.

Magnetic Locator

A magnetic locator.

"A bar of steel which is a magnet, suspended in such a way that it can freely turn to the north or south." —Wells, 1857

Magnetic Needle

"A bar of steel which is a magnet, suspended in such a way that it can freely turn to the north or south."…

"In a magneto the field magnets are permanently magnetized. The strength of the magnet field of a magneto is constant while that of a dynamo varies with the output." — Hawkins, 1917

Magneto

"In a magneto the field magnets are permanently magnetized. The strength of the magnet field of a magneto…

"...consists of a circular, multipolar field magnet, inclusing a cylinder armature with coils wound back and forth in grooces on its face." -Atkinson 1903

Altenating Current Motor

"...consists of a circular, multipolar field magnet, inclusing a cylinder armature with coils wound…

"Bring the two ends of the wire into contact, and thus close the circuit. The needle instantly flies around as though it was trying to place itself at right angles to the wire. Break the circuit, and the needle swings back to its north and south position. Twist the wires together, and bend the conductor into a loop so that the current passes above the needle in one direction and beneath the needle in the other direction. The deflection of the needle will be greater than before." — Avery, 1895

Needle, compass

"Bring the two ends of the wire into contact, and thus close the circuit. The needle instantly flies…

"A small bar magnet suspended in such a manner as to allow it to assume its chosen position relative to the earth is a magnetic needle. The needle may turn in a horizontal plane, it is a horizontal needle; e.g., the mariner's or the surveyor's compass. If it turns freely in a vertical plane, it constitutes a dipping-needle." — Avery, 1895

Dipping needle

"A small bar magnet suspended in such a manner as to allow it to assume its chosen position relative…

A pair of opposite poles attracting, the magnetic force shown by iron filings.

Attractive poles

A pair of opposite poles attracting, the magnetic force shown by iron filings.

The outline of a bar magnet, and the influence of its poles on a surface covered with iron filings.

Magnetic polse

The outline of a bar magnet, and the influence of its poles on a surface covered with iron filings.

A pair of similar magnetic poles repelling, the magnetic forces shown by iron filings.

Repelling poles

A pair of similar magnetic poles repelling, the magnetic forces shown by iron filings.

"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…

Device for separating, by means of an electromagnet, magnetic particles in a slurry from the remainder of the particles in the mixture. Used in the recovery of medium in heavy-media separation.

Magnetic Separator

Device for separating, by means of an electromagnet, magnetic particles in a slurry from the remainder…

"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…