Chapter I: Front Matter

WARNING: This book of one hundred years ago describes experiments which are too dangerous to attempt by either adults or children. It is published for historical interest only.

THE "HOW-TO-DO-IT" BOOKS

ELECTRICITY FOR BOYS

THE "HOW-TO-DO-IT" BOOKS

ELECTRICITY FOR BOYS

A working guide, in the successive steps of electricity, described in simple terms

WITH MANY ORIGINAL ILLUSTRATIONS

By J. S. ZERBE, M.E.

AUTHOR OF CARPENTRY FOR BOYS PRACTICAL MECHANICS FOR BOYS

THE NEW YORK BOOK COMPANY NEW YORK

COPYRIGHT, 1914, BY THE NEW YORK BOOK COMPANY

CONTENTS

INTRODUCTORY Page 1

I. ELECTRICITY CONSIDERED. BRIEF HISTORICAL EVENTS Page 5

The Study of Electricity. First Historical Accounts. Bottling Electricity. Discovery of Galvanic Electricity. Electro-motive Force. Measuring Instruments. Rapidity of Modern Progress. How to Acquire the Vast Knowledge. The Means Employed.

II. WHAT TOOLS AND APPARATUS ARE NEEDED Page 11

Preparing the Workshop. Uses of Our Workshop. What to Build. What to Learn. Uses of the Electrical Devices. Tools. Magnet-winding Reel.

III. MAGNETS, COILS, ARMATURES, ETC. Page 18

The Two Kinds of Magnets. Permanent Magnets. Electro-Magnets. Magnetism. Materials for Magnets. Non-magnetic Material. Action of a _Second_ Magnet. What North and South Pole Mean. Repulsion and Attraction. Positives and Negatives. Magnetic Lines of Force. The Earth as a Magnet. Why the Compass Points North and South. Peculiarity of a Magnet. Action of the Electro-Magnet. Exterior Magnetic Influence Around a Wires Carrying a Current. Parallel Wires.

IV. FRICTIONAL, VOLTAIC OR GALVANIC AND ELECTRO-MAGNETIC ELECTRICITY Page 29

Three Electrical Sources. Frictional Electricity. Leyden Jar. Voltaic or Galvanic Electricity. Voltaic Pile; How Made. Plus and Minus Signs. The Common Primary Cell. Battery Resistance. Electrolyte and Current. Electro-magnetic Electricity. Magnetic Radiation. Different Kinds of Dynamos. Direct Current Dynamos. Simple Magnet Construction. How to Wind. The Dynamo Fields. The Armature. Armature Windings. Mounting the Armature. The Commutator. Commutator Brushes. Dynamo Windings. The Field. Series-wound Field. Shunt-wound. Compound-wound.

V. HOW TO DETECT AND MEASURE ELECTRICITY Page 49

Measuring Instruments. The Detector. Direction of Current. Simple Current Detector. How to Place the Detector. Different Ways to Measure a Current. The Sulphuric Acid Voltameter. The Copper Voltameter. The Galvanoscope Electro-magnetic Method. The Calorimeter. The Light Method. The Preferred Method. How to Make a Sulphuric Acid Voltameter. How to Make a Copper Voltameter. Objections to the Calorimeter.

VI. VOLTS, AMPERES, OHMS AND WATTS Page 60

Understanding Terms. Intensity and Quantity. Voltage. Amperage Meaning of Watts and Kilowatt. A Standard of Measurement. The Ampere Standard. The Voltage Standard. The Ohm. Calculating the Voltage.

VII. PUSH BUTTONS, SWITCHES, ANNUNCIATORS, BELLS AND LIKE APPARATUS Page 65

Simple Switches. A Two-Pole Switch. Double-Pole Switch. Sliding Switch. Reversing Switch. Push Buttons. Electric Bells. How Made. How Operated. Annunciators. Burglar Alarm. Wire Circuiting. Circuiting System with Two Bells and Push Buttons. The Push Buttons, Annunciators and Bells. Wiring Up a House.

VIII. ACCUMULATORS, STORAGE OR SECONDARY BATTERIES Page 82

Storing Up Electricity. The Accumulator. Accumulator Plates. The Grid. The Negative Pole. Connecting Up the Plates. Charging the Cells. The Initial Charge. The Charging Current.

IX. THE TELEGRAPH Page 90

Mechanism in Telegraph Circuit. The Sending Key. The Sounder. Connecting Up the Key and Sounder. Two Stations in Circuit. The Double Click. Illustrating the Dot and the Dash. The Morse Telegraph Code. Example in Use.

X. HIGH-TENSION APPARATUS, CONDENSERS, ETC. Page 98

Induction. Low and High Tension. Elastic Property of Electricity. The Condenser. Connecting up a Condenser. The Interrupter. Uses of High-tension Coils.

XI. WIRELESS TELEGRAPHY Page 104

Telegraphing Without Wires. Surging Character of High-tension Currents. The Coherer. How Made. The Decoherer. The Sending Apparatus. The Receiving Apparatus. How the Circuits are Formed.

XII. THE TELEPHONE Page 110

Vibrations. The Acoustic Telephone. Sound Waves. Hearing Electricity. The Diaphragm in a Magnetic Field. A Simple Telephone Circuit. How to Make a Telephone. Telephone Connections. Complete Installation. The Microphone. Light Contact Points. How to Make a Microphone. Microphone, the Father of the Transmitter. Automatic Cut-outs for Telephones. Complete Circuiting with Transmitters.

XIII. ELECTROLYSIS, WATER PURIFICATION, ELECTROPLATING Page 123

Decomposing Liquids. Making Hydrogen and Oxygen. Purifying Water. Rust. Oxygen as a Purifier. Composition of Water. Common Air Not a Good Purifier. Pure Oxygen a Water Purifier. The Use of Hydrogen in Purification. Aluminum Electrodes. Electric Hand Purifier. Purification and Separation of Metals. Electroplating. Plating Iron with Copper. Direction of Current.

XIV. ELECTRIC HEATING. THERMO-ELECTRICITY Page 135

Generating Heat in a Wire. Resistance of Substances. Signs of Connectors. Comparison of Metals. A Simple Electric Heater. How to Arrange for Quantity of Current Used. An Electric Iron. Thermo-Electricity Converting Heat Directly into Electricity Metals. Electric, Positive, Negative. Thermo-electric Coupler.

XV. ALTERNATING CURRENTS, CHOKING COIL, TRANSFORMER Page 145

Direct Current. Alternating Current. The Magnetic Field. Action of a Magnetized Wire. The Movement of a Current in a Charged Wire. Current Reversing Itself. Self-Induction. Brushes in a Direct Current Dynamo: Alternating, Positive and Negative Poles. How an Alternating Current Dynamo is Made. The Windings. The Armature Wires. Choking Coils. The Transformer. How the Voltage is Determined. Voltage and Amperage in Transformers.

XVI. ELECTRIC LIGHTING Page 161

Early conditions. Fuels. Reversibility of Dynamo. Electric arc. Mechanism to maintain the arc. Resistance coil. Parallel carbons for making arc. Series current. Incandescent system. Multiple circuit. Subdivision of electric light. The filament. The glass bulb. Metallic filaments. Vapor lamps. Directions for improvements. Heat in electric lighting. Curious superstitions concerning electricity. Magnetism. Amber. Discovery of the properties of a magnet. Electricity in mountain regions. Early beliefs as to magnetism and electricity. The lightning rod. Protests against using it. Pliny's explanation of electricity.

XVII. POWER, AND VARIOUS OTHER ELECTRICAL MANIFESTATIONS Page 175

Early beliefs concerning the dynamo. Experiments with magnets. Physical action of dynamo and motor. Electrical influence in windings. Comparing motor and dynamo. How the current acts in a dynamo. Its force in a motor. Loss in power transmission. The four ways in which power is dissipated. Disadvantages of electric power. Its advantages. Transmission of energy. High voltages. The transformer. Step-down transformers. Electric furnaces. Welding by electricity. Merging the particles of the joined ends.

XVIII. X-RAY, RADIUM AND THE LIKE Page 184

The camera and the eye. Actinic rays. Hertzian waves. High-tension apparatus. Vacuum tubes. Character of the ultra-violet rays. How distinguished. The infra-red rays. Their uses. X-rays not capable of reflection. Not subject to refraction. Transmission through opaque substances. Reducing rates of vibration. Radium. Radio-activity. Radio-active materials. Pitchblende. A new form of energy. Electrical source. Healing power. Problems for scientists.

LIST OF ILLUSTRATIONS

FIG.

1. Work bench Frontispiece

PAGE 2. Top of magnet-winding reel 14 3. Side of magnet-winding reel 14 4. Journal block 15 5. Plain magnet bar 19 6. Severed magnet 20 7. Reversed magnets 21 8. Horseshoe magnet 22 9. Earth's magnetic lines 23 10. Two permanent magnets 24 11. Magnets in earth's magnetic field 24 12. Armatures for magnets 25 13. Magnetized field 26 14. Magnetized bar 26 15. Direction of current 27 16. Direction of induction current 28 17. Frictional-electricity machine 30 18. Leyden jar 32 19. Galvanic electricity. Crown of cups 33 20. Voltaic electricity 34 21. Primary battery 36 22. Dynamo field and pole piece 39 23. Base and fields assembled 41 24. Details of the armature, core 42 25. Details of the armature, body 42 26. Armature Journals 43 27. Commutator 43 28. End view of armature, mounted 44 29. Top view of armature on base 45 30. Field winding 47 31. Series-wound 47 32. Shunt-wound 48 33. Compound-wound 48 34. Compass magnet, swing to the right 50 35. Magnetic compass 50 36. Magnet, swing to the left 50 37. Indicating direction of current 51 38. The bridge of the detector 52 39. Details of detector 53 40. Cross-section of detector 54 41. Acid voltameter 56 42. Copper voltameter 56 43. Two-pole switch 66 44. Double-pole switch 66 45. Sliding switch 67 46. Rheostat form of switch 68 47. Reversing switch 69 48. Push button 70 49. Electric bell 71 50. Armature of electric bell 72 51. Vertical section of annunciator 72 52. Front view of annunciator 72 53. Horizontal section of annunciator 72 54. Front plate of annunciator 72 55. Alarm switch on window 76 56. Burglar alarm on window 76 57. Burglar alarm contact 77 58. Neutral position of contact 78 59. Circuiting for electric bell 79 60. Annunciators in circuit 80 61. Wiring system for a house 80 62. Accumulator grids 83 63. Assemblage of accumulator grids 85 64. Connecting up storage battery in series 87 65. Parallel series 88 66. Charging circuit 88 67. Telegraph sending key 91 68. Telegraph sounder 92 69. A telegraph circuit 94 70. Induction coil and circuit 99 71. Illustrating elasticity 100 72. Condenser 101 73. High-tension circuit 102 74. Current interrupter 103 75. Wireless-telegraphy coherer 105 76. Wireless sending-apparatus 107 77. Wireless receiving-apparatus 108 78. Acoustic telephone 111 79. Illustrating vibrations 111 80. The magnetic field 112 81. Section of telephone receiver 114 82. The magnet and receiver head 115 83. Simple telephone connection 116 84. Telephone stations in circuit 117 85. Illustrating light contact points 118 86. The microphone 119 87. The transmitter 119 88. Complete telephone circuit 121 89. Device for making hydrogen and oxygen 124 90. Electric-water purifier 127 91. Portable electric purifier 129 92. Section of positive plate 130 93. Section of negative plate 130 94. Positive and negative in position 130 95. Form of the insulator 130 96. Simple electric heater 137 97. Side view of resistance device 139 98. Top view of resistance device 139 99. Plan view of electric iron 140 100. Section of electric iron 141 101. Thermo-electric couple 143 102. Cutting a magnetic field 146 103. Alternations, first position 148 104. Alternations, second position 148 105. Alternations, third position 148 106. Alternations, fourth position 148 107. Increasing alternations, first view 149 108. Increasing alternations, second view 149 109. Connection of alternating dynamo armature 150 110. Direct current dynamo 151 111. Circuit wires in direct current dynamo 152 112. Alternating polarity lines 154 113. Alternating current dynamo 155 114. Choking coil 157 115. A transformer 158 116. Parallel carbons 164 117. Arc-lighting circuit 165 118. Interrupted conductor 166 119. Incandescent circuit 167 120. Magnetic action in dynamo, 1st 177 121. Magnetic action in dynamo, 2d 177 122. Magnetic action in dynamo, 3d 178 123. Magnetic action in dynamo, 4th 178 124. Magnetic action in motor, 1st 179 125. Magnetic action in motor, 2d 179 126. Magnetic action in motor, 3d 180 127. Magnetic action in motor, 4th 180

INTRODUCTORY

Electricity, like every science, presents two phases to the student, one belonging to a theoretical knowledge, and the other which pertains to the practical application of that knowledge. The boy is directly interested in the practical use which he can make of this wonderful phenomenon in nature.

It is, in reality, the most successful avenue by which he may obtain the theory, for he learns the abstract more readily from concrete examples.

It is an art in which shop practice is a greater educator than can be possible with books. Boys are not, generally, inclined to speculate or theorize on phenomena apart from the work itself; but once put them into contact with the mechanism itself, let them become a living part of it, and they will commence to reason and think for themselves.

It would be a dry, dull and uninteresting thing to tell a boy that electricity can be generated by riveting together two pieces of dissimilar metals, and applying heat to the juncture. But put into his hands the metals, and set him to perform the actual work of riveting the metals together, then wiring up the ends of the metals, heating them, and, with a galvanometer, watching for results, it will at once make him see something in the experiment which never occurred when the abstract theory was propounded.

He will inquire first what metals should be used to get the best results, and finally, he will speculate as to the reasons for the phenomena. When he learns that all metals are positive-negative or negative-positive to each other, he has grasped a new idea in the realm of knowledge, which he unconsciously traces back still further, only to learn that he has entered a field which relates to the constitution of matter itself. As he follows the subject through its various channels he will learn that there is a common source of all things; a manifestation common to all matter, and that all substances in nature are linked together in a most wonderful way.

An impulse must be given to a boy's training. The time is past for the rule-and-rote method. The rule can be learned better by a manual application than by committing a sentence to memory.

In the preparation of this book, therefore, I have made practice and work the predominating factors. It has been my aim to suggest the best form in which to do the things in a practical way, and from that work, as the boy carries it out, to deduce certain laws and develop the principles which underlie them. Wherever it is deemed possible to do so, it is planned to have the boy make these discoveries for himself, so as to encourage him to become a thinker and a reasoner instead of a mere machine.

A boy does not develop into a philosopher or a scientist through being told he must learn the principles of this teaching, or the fundamentals of that school of reasoning. He will unconsciously imbibe the spirit and the willingness if we but place before him the tools by which he may build even the simple machinery that displays the various electrical manifestations.