  | PART I.—Magnetism. | | Page. | | CHAPTER I. Iron and Steel | 3 | | Introduction.—Kinds of iron and steel.—Exp. 1, To study steel.—Discussion.—Exp. 2, To find whether a piece of hard steel can be made softer.—Annealing.—Exp. 3, To find whether a piece of annealed steel can be hardened.—Hardening; Tempering.—Exp. 4, To test the hardening properties of soft iron.—Discussion. | | | CHAPTER II. Magnets | 7 | | Kinds of magnets.—Exp. 5, To study the horseshoe magnet.—Poles; Equator.—Exp. 6, To ascertain the nature of substances attracted by a magnet.—Magnetic Bodies; Diamagnetic Bodies.—Practical Uses of Magnets.—Exp. 7, To study the action of magnetism through various substances.—Magnetic Transparency; Magnetic Screens.—Exp. 8, To find whether a magnet can give magnetism to a piece of steel.—Discussion; Bar Magnets.—Exp. 9, To make small magnets.—Exp. 10, To find whether a freely-swinging bar magnet tends to point in any particular direction.—North-seeking Poles; South-seeking Poles; Pointing Power.—The Magnetic Needle; The Compass.—Exp. 11, To study the action of magnets upon each other.—Exp. 12, To study the action of a magnet upon soft iron.—Laws of Attraction and Repulsion.—Exp. 13, To learn how to produce a desired pole at a given end of a piece of steel.—Rule for Poles.—Our Compass.—Review; Magnetic Problems.—Exp. 14, To find whether the poles of a magnet can be reversed.—Discussion; Reversal of Poles.—Exp. 15, To find whether we can make a magnet with two N poles.—Exp. 16, To study the bar magnet with two N poles.—Discussion; Consequent Poles.—Exp. 17, To study consequent poles. Exp. 18, To study the theory of magnetism.—Theory of Magnetism; Magnetic Saturation.—Exp. 19, To find whether soft iron will permanently retain magnetism.—Retentivity or Coercive Force; Residual Magnetism.—Exp. 20, To test the retentivity of soft steel.—Discussion.—Exp. 21, To test the retentivity of hard steel.—Exp. 22, To test the effect of heat upon a magnet.—Discussion.—Exp. 23, To test the effect of breaking a magnet.—Discussion. | | | CHAPTER III. Induced Magnetism | 20 | | Exp. 24, To find whether we can magnetize a piece of iron without touching it with a magnet.—Temporary Magnetism; Induced Magnetism.—Exp. 25, To find whether a piece of steel can be permanently magnetized by induction.—Exp. 26, To study the inductive action of a magnet upon a piece of soft iron.—Polarization; Pole Pieces.—Exps. 27–30, To study pole pieces. | | | CHAPTER IV. The Magnetic Field | 23 | | Exp. 31, To study the space around the magnet, in which pieces of iron become temporary magnets by induction.—Discussion; The Magnetic Field.—Exp. 32, To study the magnetic field of a bar magnet.—Magnetic Figures; Lines of Magnetic Force.—Exps. 33–37, To study the magnetic fields of various combinations of bar magnets.—Exps. 38–39, To study the lifting power of combinations of bar magnets.—Discussion; Compound Magnets.—Exps. 40–42, To study the magnetic field of the horseshoe magnet.—Discussion; Resistance to Lines of Force.—Exp. 43, To show that lines of force are on all sides of a magnet.—Discussion.—Exp. 44, To study a horseshoe magnet with movable poles.—Discussion; Advantages of Horseshoe Magnets. | | | CHAPTER V. Terrestrial Magnetism | 31 | | The Magnetism of the Earth.—Declination.—Exp. 45, To study the lines of force above and below a bar magnet placed horizontally.—
| PART III.—Current Electricity. | | CHAPTER XIV. Construction and Use of Apparatus | 89 | | Exp. 101, To study the effect of the electric current upon the magnetic needle.—Electrical Connections.—Current Detectors.—Exp. 102, To study the construction and use of a simple "key."—Exp. 103, To study the construction and use of a simple "current reverser."—Exp. 104, To study the simple current detector.—Exp. 105, To study the construction and use of the simple galvanoscope.—Discussion; True Readings.—Exp. 106, To study the construction and use of a simple astatic needle.—Astatic Needles.—Exp. 107, To study the construction and use of a simple astatic galvanoscope.—Astatic Galvanoscopes. | | | CHAPTER XV. Galvanic Cells and Batteries | 102 | | Exp. 108, To study the effect of dilute sulphuric acid upon carbon and various metals.—To amalgamate.—Dilute sulphuric acid.—Discussion.—Exp. 109, To study the effect of dilute sulphuric acid upon various combinations of metals.—Discussion.—Exp. 110, To study the construction of a simple Voltaic or Galvanic cell.—The Electric Current.—Source of the Electrification.—The Electric Circuit; Open and Closed Circuits.—Plates or Elements.—Direction of Current.—Poles or Electrodes.—Chemical Action in the Simple Galvanic Cell.—Action in Cell Using Impure Zinc; Action Using Pure Zinc.—Exp. 111, To see what is meant by "local currents" in the cell.—Local Action; Local Currents.—Reasons for Amalgamating Zinc Plates.—Exp. 112, To study the "single-fluid" Galvanic Cell.—The Simple Cell.—Polarization of Cells.—Effects of Polarization.—Remedies for Polarization; Depolarizers.—Exp. 113, To study the "two-fluid" Galvanic Cell.—Setting Up the Two-Fluid Cell.—Care of Two-Fluid Cell.—Copper Sulphate Solution.—Chemical Action in the Two-Fluid Cell.—Various Galvanic Cells; Open and Closed Circuit Cells.—The LeclanchÉ Cell—Dry Cells.—The Bichromate of Potash Cell.—The Daniell Cell.—The Gravity Cell. | | | CHAPTER XVI. The Electric Circuit | 115 | | Exp. 114, To see what is meant by "divided circuits" and "shunts."—Divided Circuits; Shunts.—Exp. 115, To see what is meant by "short circuits." | | | CHAPTER XVII. Electromotive Force | 117 | | Electromotive Force.—Unit of E. M. F.; The Volt.—Exp. 116, To see whether the E. M. F. of a cell depends upon the materials used in its construction.—Discussion.—Electromotive Series.—Exp. 117, To see whether the E. M. F. of a cell depends upon its size.—Discussion. | | | CHAPTER XVIII. Electrical Resistance | 120 | | Resistance.—Exp. 118, To study the general effect of "resistance" upon a current.—External Resistance; Internal Resistance; Unit of Resistance; The Ohm.—Resistance Coils; Resistance Boxes.—Simple Resistance Coil.—Exp. 119, To test the power of various substances to conduct galvanic electricity.—Conductors and Nonconductors.—Exp. 120, To find the effect of sulphuric acid upon the conductivity of water.—Internal Resistance.—Exp. 121, To find what effect the length of a wire has upon its electrical resistance.—Discussion.—Exp. 122, To find what effect the size (area of cross-section) of a wire has upon its electrical resistance.—Discussion.—Exp. 123, To compare the resistance of a divided circuit with the resistance of one of its branches. Discussion.—Exp. 124, To study the effect of decreasing the resistance in one branch of a divided circuit.—Current in Divided Circuits. | | | CHAPTER XIX. Measurement of Resistance | 130 | | Exp. 125, To study the construction and use of a simple Wheatstone's Bridge.—The Simple Bridge.—Equipotential Points.—Example.—Exp. 126, To measure the resistance of a wire by means of Wheatstone's Bridge; the "bridge method."—Allowances for Connections.—Exps. 127–137, To measure the resistances of various wires, coils, etc., by the "bridge method."—Table.—Exp. 138, To study the effect of heat upon the resistance of metals.—Effect of Heat upon Resistance.—Exp. 139, To measure the resistance of a wire by the "method of substitution."—Simple Rheostat.—Exp. 140, To measure the E. M. F. of a cell by comparison with the two-fluid cell.—Exp. 141, To measure the internal resistance of a cell by the "method of opposition." | | | CHAPTER XX. Current Strength | 142 | | Strength of Current.—Unit of Current Strength; The Ampere.—Measurement of Current Strength.—The Tangent Galvanometer.—The Ammeter.—The Voltameter.—Unit of Quantity; The Coulomb.—Electrical Horse-power; The Watt.—Ohm's Law.—Internal Resistance and Current Strength.—Exp. 142, Having a cell with large plates, to find how the strength of the current is affected by changes in the position of the plates, the external resistance being small.—Exp. 143, Same as Exp. 142, but with small plates.—Exp. 144, To find whether the changes in current strength, due to changes in internal resistance, are as great when the external resistance is large, as they are when the external resistance is small.—Discussion, with examples.—Arrangement of Cells and Current Strength.—Cells in Series.—Cells Abreast.—Exp. 145, To find the best way to join two similar cells when the external resistance is small.—Exp. 146, To find the best way to join two similar cells when the external resistance is large.—Best Arrangement of Cells. | | | CHAPTER XXI. Chemical Effects of the Electric Current | 151 | | Chemical Action and Electricity.—Electrolysis.—Exp. 147, To study the electrolysis of water.—Composition of Water.—Electromotive Force of Polarization.—Exp. 148, To coat iron with copper.—Exp. 149, To study the electrolysis of a solution of copper sulphate.—Electroplating.—Exp. 150, To study the chemistry of electroplating.—Discussion.—Electrotyping.—Voltameters.—Exp. 151, To study the construction and action of a simple "storage" cell.—Secondary or Storage Cells. | | | CHAPTER XXII. Electromagnetism | 158 | | Electromagnetism.—Exp. 152, To study the lines of force about a straight wire carrying a current.—Ampere's Rule.—Lines of Force About Parallel Wires.—Exp. 153, To study the lines of force about a coil of wire like that upon the galvanoscope.—Exp. 154, To study the magnetic field about a small coil of wire.—Coils.—Polarity of Coils.—Exp. 155, To test the attracting and "sucking" power of a magnetized coil or helix.—Exp. 156, To find whether a piece of steel can be permanently magnetized by an electric current.—Exp. 157, To study the effect of a piece of iron placed inside of a magnetized coil of wire. | | | CHAPTER XXIII. Electromagnets | 165 | | Electromagnets.—Cores of Electromagnets.—Exps. 158–163, To study straight electromagnets; Lifting power; Residual magnetism of core; Magnetic tick; Magnetic figures; Magnetic field.—Horseshoe Electromagnets.—Use of Yoke.—Experimental Magnets.—Method of Joining Coils.—Exps. 164–173, To study horseshoe electromagnets; To test the poles; To study the inductive action of one core upon the other; Magnetic figures; Permanent Magnetic Figures; Lifting power; Residual magnetism when magnetic circuit is closed.—Closed Magnetic Circuits. | | | CHAPTER XXIV. Thermoelectricity | 175 | | Exp. 174, To find whether electricity can be produced by heat.—Home-made Thermopile.—Thermoelectricity.—Peltier Effect.—Thermopiles. | | | CHAPTER XXV. Induced Currents | 178 | | Electromagnetic Induction.—Exp. 175, To find whether a current can be generated with a bar magnet and a hollow coil of wire.—Discussion.—Induced Currents and Work.—Exp. 176, To find whether a current can be generated with a bar magnet and a coil of wire having an iron core.—Exp. 177, To find whether a current can be generated with a horseshoe magnet and a coil of wire having an iron core.—Induced Currents and Lines of Force.—Exp. 178, To find whether a current can be generated with an electromagnet and a hollow coil of wire.—Exp. 179, To find whether a current can be generated with an electromagnet and a coil of wire having an iron core.—Discussion of Exps. 178–179.—Exp. 180, To study the effect of starting or stopping a current near a coil of wire or other closed circuit.—Exp. 181, To study the effect of starting or stopping a current in a coil placed inside of another coil.—Discussion of Exps. 180–181.—Direction of Induced Current.—Laws of Induction.—Primary and Secondary Currents.—Exp. 182, To see what is meant by alternating currents.—Direct and Alternating Currents.—Self-induction; Extra Currents. | | | CHAPTER XXVI. The Production of Motion by Currents | 187 | | Currents and Motion.—Exp. 183, Motion produced with a hollow coil and a piece of iron.—Exp. 184, Motion with hollow coil and bar magnet.—Exp. 185, Motion with electromagnet and piece of iron.—Exp. 186, Motion with electromagnet and bar magnet.—Exp. 187, Motion with electromagnet and horseshoe magnet.—Exp. 188, Motion with two electromagnets.—Discussion of Exps. 183–188.—Exp. 189, Rotary motion with a hollow coil of wire and a permanent magnet.—Exp. 190, Rotary motion with an electromagnet and a permanent magnet.—Discussion of Exps. 189–190. | | | CHAPTER XXVII. Applications of Electricity | 192 | | Things Electricity Can Do.—Exp. 191, To study the action of a simple telegraph sounder.—Discussion.—Telegraph Line; Connections.—Operation of Line.—Exp. 192, To study the action of the "relay" on telegraph lines.—The Relay.—Exp. 193, To study the action of a two-pole telegraph instrument.—Exp. 194, To study the action of a simple "single needle telegraph instrument."—Exp. 195, To study the action of a simple automatic contact breaker, or current interrupter.—Automatic Current Interrupters.—Exp. 196, To study the action of a simple electric bell, or a "buzzer."—Electric Bells and Buzzers.—Exp. 197, To study the action of a simple telegraph "recorder."—Exp. 198, To study the action of a simple "annunciator."—Discussion.—Exp. 199, To study the shocking effects of the "extra current." Induction Coils.—Action of Induction Coils.—Transformers.—The Dynamo.—The Electric Motor.—Exp. 200, To study the action of the telephone.—The Telephone.—The Bell, or Magneto-transmitter.—The Receiver.—The Carbon Transmitter.—Induction Coils in Telephone Work.—Electric Lighting and Heating.—Arc Lamps.—The Incandescent Lamp. | | | CHAPTER XXVIII. Wire Tables | 208 | | APPARATUS LIST | 210 | | INDEX | 215 |
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