ClipArt ETC
"The alternator is a dynamo designed for the generation of alternating currents. It has collecting rings instead of a communtator so that the current is delivered just as it is generated, and a small direct current dynamo for engergizing its field magnets, the pole-pieces of which are generally very numerous." -Avery 1895

Alternator

"The alternator is a dynamo designed for the generation of alternating currents. It has collecting rings…

"The arc lamp is essentially a device for automatically separating the carbons when the current is turned on, for 'feeding' the carbons together as they are burned away at their tips, and, in some cases, for short-circuiting the lamp in case of irregularity or accident." -Avery 1895

Arc Lamp

"The arc lamp is essentially a device for automatically separating the carbons when the current is turned…

"Galvanism is the branch of electric science to which an experiment by Galvani gave birth. His wife, who was making soup from frogs, put them in proximity to a charged electrical machine. On touching them with a scalpel their legs became greatly convulsed. He came to the erroneous conclusion that animal electricity existed in the nerves and muscles of frogs, etc. His contemporary Volta inferred that the metals took the active part in producing the contraction, and the electricity was due to their contact. In 1800 he first described and constructed what has since been called the Voltaic pile."—(Charles Leonard-Stuart, 1911)

Galvanic Battery

"Galvanism is the branch of electric science to which an experiment by Galvani gave birth. His wife,…

"A heavy-current (2000 amp.) 650-volt, single-pole overload circuit breaker (General Electric Company, type C, form K2)." —Croft 1920

Circuit Breaker

"A heavy-current (2000 amp.) 650-volt, single-pole overload circuit breaker (General Electric Company,…

A device used to transform electricity into different voltages and amperages.

Induction Coil

A device used to transform electricity into different voltages and amperages.

Diagram showing the stronger meandering of the current as compared with the river as a whole.

Current

Diagram showing the stronger meandering of the current as compared with the river as a whole.

"Take the zinc from the tumbler of acid and, while it is yet wet, rub thereon a few drops of mercury...replace the zinc in the acid, and notice that no bubbles are given off. Place a copper strip in the solution...bring the strips together at their upper ends as shown. Connect the metals and observe the result." -Avery 1895

Current Electricity

"Take the zinc from the tumbler of acid and, while it is yet wet, rub thereon a few drops of mercury...replace…

An AC motor is an electric motor that is driven by an alternating current. It consists of two basic parts, an outside stationary stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft that is given a torque by the rotating field. There are two types of AC motors, depending on the type of rotor used. The first is the synchronous motor, which rotates exactly at the supply frequency or a sub multiple of the supply frequency. The magnetic field on the rotor is either generated by current delivered through slip rings or by a permanent magnet.The second type is the induction motor, which turns slightly slower than the supply frequency. The magnetic field on the rotor of this motor is created by an induced current.

Current Motor

An AC motor is an electric motor that is driven by an alternating current. It consists of two basic…

"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…

"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,…

"If an electromagnet be subsituted for the steel magnet as shown...and the terminals of its coils connected with the brushs as shown each magnet will generate a current in the coils of the other magnet." -Atkinson 1903

Dynamo

"If an electromagnet be subsituted for the steel magnet as shown...and the terminals of its coils connected…

"Thus, if we suppose the conducting wire be placed in a vertical situation, as shown, and p, n, the current of positive electricity to be descending through it, from p to n, and if throught the point c in the wire in the plane NN be taken, perpendicular to p, n, that is in the present case a horiczontal plane, then if any number of circles be described in that plane, having c for thier common centre, the action of the current on the wire on upon the north pole of the magnet, will be to move it in a direction corresponding to the motion of the hands of a watch, having the dial towards the positive pole of the battery." -Comstock 1850

Circular Motion of the [Electric] Fluid

"Thus, if we suppose the conducting wire be placed in a vertical situation, as shown, and p, n, the…

"Around a vertical conductor carrying a heavy current, place a peice of paper and sprinkle iron filling on the paper. Notice that the iron particles arrange themselves in distinct circular whirls around the wire, as shown." -Avery 1895

Magnetic Field Due to Current

"Around a vertical conductor carrying a heavy current, place a peice of paper and sprinkle iron filling…

"If the conducting wire is bent into the form shown, the lines of force will pas around the wire from one face of the loop to the other, and in the direction indicated by the 'rule of thumb' just given." -Avery 1895

Magnetic Field Around a Current Carrying Wire

"If the conducting wire is bent into the form shown, the lines of force will pas around the wire from…

"Fuse protection on instrument circuit of an alternating-current switchboard." —Croft 1920

Fuse Protection on Alternating Current Switchboard

"Fuse protection on instrument circuit of an alternating-current switchboard." —Croft 1920

"Illustrating fuse protection for voltmeter and ground detector and ground detector on a direct-current switchboard." —Croft 1920

Fuse Protection on Direct Current Swtichboard

"Illustrating fuse protection for voltmeter and ground detector and ground detector on a direct-current…

"The galvanometer is an instrument for determining the strength of an electric current by means of the deflection of a magnetic needle around which the current flows. When a galvanoscope is provided with a scale so that the deflections of its needle may be measured, it becomes a galvanometer." — Avery, 1895

Astatic galvanometer

"The galvanometer is an instrument for determining the strength of an electric current by means of the…

"The galvanometer is an instrument for determining the strength of an electric current by means of the deflection of a magnetic needle around which the current flows. When a galvanoscope is provided with a scale so that the deflections of its needle may be measured, it becomes a galvanometer." — Avery, 1895

Tangent galvanometer

"The galvanometer is an instrument for determining the strength of an electric current by means of the…

"Apparatus used to detect current and its direction." -Avery 1895

Galvanoscope

"Apparatus used to detect current and its direction." -Avery 1895

"Illustration showing the path of leakage current caused by ground due to damp insulation." —Croft 1920

Current Leakage Around Generator

"Illustration showing the path of leakage current caused by ground due to damp insulation." —Croft…

"Illustration showing current leakage through the rame of a machine which is insulated from the ground." —Croft 1920

Current Leakage Around Generator

"Illustration showing current leakage through the rame of a machine which is insulated from the ground."…

"Incandescence lamps operate essentially on the principle...[that] the current being sent through some substance that, because of its high resistance, becomes intensely heated and brilliantly incandescent. The only suitable substance known for such a resistance filament is carbon, which, carefully prepared and bent into a loop, is enclosed in a glass bulb from which the air is exhausted to prevent oxidation, i.e., combustion." -Avery 1895

Incandescence Lamp

"Incandescence lamps operate essentially on the principle...[that] the current being sent through some…

"The induction coil is...often called the Rhumkorff coil. Receiving a large current of small electromotive force, it delievers a small current at a high pressure, sometimes hundreds of thousands of volts, i.e., it is a 'step up' transformer." -Avery 1895

Induction Coil

"The induction coil is...often called the Rhumkorff coil. Receiving a large current of small electromotive…

"The induction coil is...often called the Rhumkorff coil. Receiving a large current of small electromotive force, it delievers a small current at a high pressure, sometimes hundreds of thousands of volts, i.e., it is a 'step up' transformer." -Avery 1895

Induction Coil

"The induction coil is...often called the Rhumkorff coil. Receiving a large current of small electromotive…

"With a lamp chimney or other large glass tube, a perforated cork, two pieces of glass tubing 4 and 15 inches long respectively, a bit of rubber tubing, a small lamp or candle, and two coverless crayon boxes, arrange apparatus as shown." — Avery, 1895

Lamp chimney and candle

"With a lamp chimney or other large glass tube, a perforated cork, two pieces of glass tubing 4 and…

"Alternating current self starting Cooper-Hewit mercury-vapor lamp." —Croft 1917

Cooper-Hewit Mercury Vapor Lamp

"Alternating current self starting Cooper-Hewit mercury-vapor lamp." —Croft 1917

"Direct current self starting Cooper-Hewit mercury-vapor lamp." —Croft 1917

Cooper-Hewit Mercury Vapor Lamp

"Direct current self starting Cooper-Hewit mercury-vapor lamp." —Croft 1917

"Lenz's apparatus for measuring the heat given off by an electric current." -Hawkins, 1917

Lenz's Apparatus

"Lenz's apparatus for measuring the heat given off by an electric current." -Hawkins, 1917

"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 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…

"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…

"Magnetic field of a solenoid. This is best observed by cutting a piece of cardboard and fitting it around the solenoid, as shown." -Hawkins, 1917

Magnetic field, solenoid

"Magnetic field of a solenoid. This is best observed by cutting a piece of cardboard and fitting it…

"Illustrating Maxwell's 'corkscrew rule' for relative directions of current and lines of force...a current flow through the wire ab in the direction from a to b, the magnetic lines will encircle the wire in the direction of the curved arrow ro which shows the direction in which the corkscrew must be turned to advance in the direction of the arrow n." -Hawkins, 1917

Maxwell's Corkscrew Rule

"Illustrating Maxwell's 'corkscrew rule' for relative directions of current and lines of force...a current…

"...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…

"Illustration showing the installation of an alternating current motor." —Croft 1920

Alternating Current Motor Installed

"Illustration showing the installation of an alternating current motor." —Croft 1920

"Tesla's oscillator is a combined prime motor and electric generator, and produces alternating currents without rotary motion of the generting coils. the motive force may be that of steam or of compressed air." -Avery 1895

Tesla's Oscillator

"Tesla's oscillator is a combined prime motor and electric generator, and produces alternating currents…

Oscillograph diagram of primary and secondary currents.

Oscillograph

Oscillograph diagram of primary and secondary currents.

Heinze-Springfield current regulator and battery cut-out.

Regulator

Heinze-Springfield current regulator and battery cut-out.

"When the brass plugs are inserted...the coils are short-circuited, i.e., practically, the whole of a current passing from block to block goes through the plug, but when a plug is withdrawn the current passes through the corresponding coil...By withdrawing the proper plugs, one may throw into the circuit and resistance desired, from a single ohm up to the full capacity of the box." -Avery 1895

Resistance Box

"When the brass plugs are inserted...the coils are short-circuited, i.e., practically, the whole of…

"The rheostat is an apparatus for admitting the current to the motor gradually, so as not to heat and injure the coils and insulating material by admitting the full current before the armature has attained its full rotary speed..." -Atkinson 1903

Rheostat

"The rheostat is an apparatus for admitting the current to the motor gradually, so as not to heat and…

"A typical direct-current starting rheostat is illustrated [here]." —Croft 1920

Rheostat

"A typical direct-current starting rheostat is illustrated [here]." —Croft 1920

"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…

"A rule for direction of induced current which in some cases, is more conveniently applied than Fleming's rule." -Hawkins, 1917

Right Hand Rule

"A rule for direction of induced current which in some cases, is more conveniently applied than Fleming's…

"Fleming's rule for direction of induced current. Extend the thumb, forefinger and middle finger of the right hand [as shown]. Place the hand [so that] the thumb will point in the direction in which the conductor moves, the forefinger in the direction of the lines of force (N to S), then will the middle finger point in the direction in which the induced current flows." -Hawkins, 1917

Right Hand Rule of Induced Current

"Fleming's rule for direction of induced current. Extend the thumb, forefinger and middle finger of…

"The palm rule for direction of induced current: If the palm of the right hand be held against the direction of the lines of force, the thumb in the direction of the motion, then the fingers will point in the direction of the induced current." -Hawkins, 1917

Right Hand Rule, Palm

"The palm rule for direction of induced current: If the palm of the right hand be held against the direction…

"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 shunt, in electricity, is a conductor placed between two points in closed circuit, to divert or shunt part of the current."—Finley, 1917

Shunt

"A shunt, in electricity, is a conductor placed between two points in closed circuit, to divert or shunt…

"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…

"Coil some No. 12 copper wire throuh holes in a board, as shown, and pass a strong current through it. Sprinkle iron filling as before and note the effect. Such a coil of conducting wire, wound so as to afford a number of equal and parallel circular electric circuits arranged upon a common axis, is called a solenoid." -Avery 1895

Solenoid

"Coil some No. 12 copper wire throuh holes in a board, as shown, and pass a strong current through it.…

"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…

"A transmitter or key is a current interrupter manipulated by the operator. It consists essentially of a metal layer, L, pivoted at aa, and conneted to the line by the screw at m which is insultated from the base, and the screw at n which is connected to the base and lever." -Avery 1895

Telegraph Transmitter

"A transmitter or key is a current interrupter manipulated by the operator. It consists essentially…

"We may compare currents by the quantities of a given electrolyte which they decompose in a given time. Faraday's voltameter is intended for this purpose. As compared with a galvanometer, the voltameter has the obvious disadvantage that it cannot measure a current at once, but only after the current has been flowing for some time." -Hazeltine, 1894

Faraday's Voltameter

"We may compare currents by the quantities of a given electrolyte which they decompose in a given time.…