THE THOUGHT IS IN THE QUESTION THE INFORMATION IS IN THE ANSWER HAWKINS
ELECTRICAL GUIDE NUMBER
ONE QUESTIONS ANSWERS
& ILLUSTRATIONS
A PROGRESSIVE COURSE OF STUDY
FOR ENGINEERS, ELECTRICIANS, STUDENTS AND THOSE DESIRING TO ACQUIRE A WORKING KNOWLEDGE OF
ELECTRICITY AND ITS APPLICATIONS A PRACTICAL TREATISE
by
HAWKINS AND STAFF
THEO. AUDEL & CO. 72 FIFTH AVE. NEW YORK. COPYRIGHTED, 1914,
BY
THEO. AUDEL & CO., New York.
Printed in the United States. PREFACE
The word "guide" is defined as:
One who leads another in any path or direction; a person who shows or points out the way, especially by accompanying or going before; more particularly, one who shows strangers or tourists about; a conductor; leader, as "let us follow our guide."
This book, or "Guide," is so called because it leads or points out the way to the acquirement of a theoretical and practical knowledge of Electricity.
There are several guides, each covering in detail a certain phase of the broad subject of Electricity and leading the reader progressively, and in such a way, that he easily grasps, not only the simple fundamental facts, but the more complex problems, encountered
in the study of Electricity. This is accomplished by the aid of a very large number of illustrations, together with specific explanations,
worded in concise and simple language.
The Guides are written partly in the question and answer form, as this style of presentation has met with hearty approval, not only from those of limited education, but also from the better informed.
Where recourse is had to the question and answer form, the special aim of the author has been to give short and direct answers, in such plain language as to preclude a misconception of the meaning. With this in view, the answer gives simply the information sought by the question.
The answer is limited to one paragraph so that the reader may concentrate upon the fact or facts demanded by the question.
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Any enlargement of the answer or specific explanations of items contained therein, are presented in separate paragraphs printed, in
smaller type.
With this plan of separating the answer, as it were, from items of secondary importance, and making it short and simple, its content is more forcibly impressed upon the mind of the reader.
In a text book, it is necessary to illustrate and explain the various species of commercial apparatus met with in practice, and in this connection the Publishers desire to call attention to the manner in which the author has treated what may be classed as the "descriptive matter." Contrary to the usual custom of giving descriptions of commercial machines in the main text, where they would occupy considerable space, to the exclusion of the more important matter, all such descriptions are placed in small type directly under the illustrations, leaving space for an adequate presentation of the underlying principles, theories, and for the large amount of practical information that is essential to obtain a general knowledge of Electricity and its numerous applications.
Credit is largely due to Frank D. Graham, B.S., M.S. (Princeton University), and M.E. (Stevens Institute), practical engineer, for the authorship of the Guides, and for original sketches illustrating electrical principles and construction.
TABLE OF CONTENTS GUIDE NO. 1.
INTRODUCTORY CHAPTER SIGNS AND SYMBOLS ELECTRICITY 1 to 4
Nature and source--kinds of electricity: static, current, dynamic, radiated, positive, negative, atmospheric, frictional, resinous, vitre-ous.
STATIC ELECTRICITY 5 to 26
Electrical attraction and repulsion--the charge--distribution of the charge--free and bound electricity--conductors and insulators--electroscopes--gold leaf electroscope--electric screens--electrification by induction--nature of the induced charge--the electrophorus--condensers; Leyden jar--electric machines--action of Toepler-Holtz machine--Wimshurst machines.
THE ELECTRIC CURRENT 27 to 34
Volt--ampere--ohm--Ohm's law--production of the electric current--current strength--voltage drop in an electric current. PRIMARY CELLS 35 to 67
The word "battery"--action of cell--chemical changes; polarization--effects of polarization--methods of depolarization--depolarizers--depolarizer bag--Volta's contact law--contact series of metals--laws of chemical action in cell--requirements of a good cell--single and two fluid cells--the Leclanche cell--Fuller bichromate cell--the Edison cell--Grenet bichromate cell--Daniell cell--directions for making a Daniell cell--gravity cells--Daniell gravity cell--so-called "dry" cells--points relating to dry cells-- care of cells--cleanliness--separating the elements--creeping--amalgamated zinc--battery connections.
CONDUCTORS AND INSULATORS 68 to 74
The so-called "non-conductors"--table of conductors and insulators--mode of transmission--effect of heat--heating effect of the current--insulators--impregnating compounds--water as a conductor.
RESISTANCE AND CONDUCTIVITY 75 to 82
Standard of resistance--conductivity of metals and liquids--effect of heat--laws of electrical resistance--conductivity--specific
conductivity--divided circuits.
ELECTRICAL AND MECHANICAL ENERGY 83 to 92
Definitions: energy, matter, molecule, work, foot-pound, volt-coulomb, ampere-hour, power, horse power, watt, kilowatt, watt-
hour--mechanical equivalent of heat--British thermal unit--electrical horse power--the farad.
EFFECTS OF THE CURRENT 93 to 104
Thermal effect--use of heat from the current--magnetic effect--chemical effect--electrolysis--electro-chemical series--electric osmose--electric distillation--muscular contractions--electroplating--electrotyping.
MAGNETISM 105 to 124
Two kinds of magnetism--nature of each--poles--magnetic field--magnetic force--magnetic circuit--magnetic flux--the Maxwell--the Gauss--magnetic effect of the current--corkscrew rule--solenoids--permeability--magnetic saturation--magnetomotive force--reluctance--analogy between electric and magnetic circuits--hystereses--residual magnetism.
ELECTROMAGNETIC INDUCTION 125 to 136
Faraday's discovery--Faraday's machine--Faraday's principle--line of force--induction of current--laws of electromagnetic induction--rules for direction of induced current--Fleming's rule--Ampere's rule--the palm rule--self-induction.
INDUCTION COILS 137 to 154
Self-induction--mutual induction--primary induction coils--secondary induction coils--plain secondary induction coils--secondary induction coils with vibrator and condenser; cycle of action--magnetic vibrators--vibrator adjustment--table of induction coil dimensions--table of sparking distances in air--points relating to induction coils--wiring diagram.
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THE DYNAMO 155 to 160
Operation--essential parts--field magnets--armature--construction of dynamos--parts; bed plate, field magnets, armature, commutator, brushes.
THE DYNAMO: BASIC PRINCIPLES 161 to 170
Definitions--essential parts--elementary alternator--operation--direction of induced current--application of Fleming's rule--cy-
cle of operation--the sine curve; its construction and application.
THE DYNAMO: CURRENT COMMUTATION 171 to 180
How the current is produced--how direct current is obtained--the commutator--inductors--"continuous current"--action of four
coil elementary dynamo--conditions for steadiness of the current. CLASSES OF DYNAMO 181 to 198