A dictionary of electrical words, terms and phrases

Front matter

Ctass_QC SOS~ Book - n g5"

COPYRIGHT DEPOSIT

ONE COPY REC'D MAY 23 1898

Preface To The First Edition

THE rapid growth of electrical science, and the almost daily addition to it of new words, terms and phrases, coined, as they too frequently are, in ignorance of t-hose already existing, have led to the production of an electrical vocabulary that is already beSvildering in its extent. This multiplicity of words is extremely discouraging to the student, and acts as a serious obstacle to a general dissemination of electrical knowledge, for the following reasons :

i. Because, in general, these new terms are not to be found eve*", in the unabridged editions of dictionaries.

2. The books or magazines, in which they were first proposed, are either inaccessible to the ordinary reader, or, if accessible, are often written in phraseology unintelligible except to the expert.

3. The same terms are used by different writers in conflicting senses.

4. The same terms are used with entirely different meanings.

5. Nearly all the explanations in the technical dictionaries are extremely brief as regards the words, terms and phrases of the rapidly growing and comparatively new science of electricity.

In this era of extended newspaper and periodical publication, new words are often coined, although others, already in existence, are far better suited to express the same ideas. The new terms are used for a while and then abandoned ; or, if retained, having been imperfectly defined, their exact meaning is capable of no little ambiguity; and, subsequently, they are often unfortunately adopted by different writers with such varying shades of meaning, fti&t it is difficult to understand their true and exact significance.

Then again, old terms buried away many decades ago and long since forgotten, are dug up and presented in such new garb that their creators would most certainly fail to recognize them.

It has been with a hope of removing these difficulties to some extent that the author has ventured to present this Dictionary of Electrical Words, Terms and Phrases to his brother electricians and the public generally.

He trusts that this dictionary will be of use to electricians, not only by showing the wonderful extent and richness of the vocabulary of the science, but also by giving the general consensus of opinion as to the significance of its different words, terms or phrases. It is, however, to the general public, to whom it is not only a matter of interest but also one of necessity to fully understand the e^act meaning of electrical literature, that the author believes the book will be of the greatest value.

In order to leave no doubt concerning the precise meaning of the words, terms and phrases thus defined, the following plan has been adopted of giving :

(1.) A concise definition of the word, term or phrase.

(2.) A brief statement of the principles of the science involved in the definition.

(3 ) Where possible and advisable, a cut of the apparatus described or employed in connection with the word, term or phrase denned.

It will be noticed that the second item of the plan makes the Dictionary approach to some extent the nature of an Encyclopedia. It differs, however, from an Encyclopedia in its scope, as well as in the fact that its definitions in all cases are concise.

Considerable labor has been expended in the collection of the vocabulary, for which purpose electrical literature generally has been explored. In the alphabetical arrangement of the terms and phrases defin -d, much perplexity has arisen as to the proper catch-word under which to place them. It is believed that part of the difficulty in this respect has been avoided by the free use of cross references.

In elucidating the exact meaning of terms by a brief statement of the principles of the science involved therein, the author has freely referred to standard textbooks on electricity, and to periodical literature generally. He is especially indebted to works or treatises by the following authors, viz. : S. P. Thompson, Larden, Cumming, Hering, Prescott, Ayrton, Ayron and Perry, Pope, Lockwood, Sir William Thomson, Fleming, Martin and Wetzler, Preece, Preece and Sivewright, Forbes, Maxwell, De Watteville, J. T. Sprague, Culley, Mascart and Joubert, Schwendler, Fontaine, Noad, Smee, Depretz, De la Rive, Harris, Franklin, Cavallo, Grove,. Hare, Daniell, Faraday and very many others.

The author ofL-rs his Dictionary to his fellow electricians as a starting point only. He does not doubt that his book will be found to contain many inaccuracies, ambiguous statements, and possibly doubtful definitions. Pioneer work of this character must, almost of necessity, be marked by incompleteness. He, therefore, invites the friendly criticisms of electricians generally, as to errors of omission and commission, hoping in this way to be able finally to crystallize a complete vocabulary of electrical words, terms and phrases.

The author desires in conclusion to acknowledge his indebtedness to his friends, Mr. Carl Henng, Mr. Joseph Wetzler and Mr. T. C. Martin, for critical examination of the proof sheets ; to Dr. G. G. Faught for examination of the proofs of the parts relating to the medical applications of electricity, and to Mr. C. E. Stump for valuable aid in the illustration of the book ; also to Mr. George D. Fowle, Engineer of Signals of the Pennsylvania Railroad Company, for information concerning their System of Block Signaling, and to many others.

EDWIN J. HOUSTON.

Central High School, Philadelphia, Pa., September, 1889.

Preface To The Second Edition

THE first edition of the "Dictionary of Electrical Words, Terms and Phrases" met with so favorable a reception that the entire issue was soon exhausted. ' Although but a comparatively short time has elapsed since its publication, electrical progress has been so marked, and so many new words, terms and phrases have been introduced into the electrical nomenclature, that the preparation of a new edition has been determined on rather than a mere reprint from the old plates.

The wonderful growth of electrical science may be judged from the fact that the present work contains more than double the matter and about twice the number of definitions that appeared in the earlier work. Although some of this increase has been due to words which should have been in the first edition, yet in greater part it has resulted from an actual multiplication of the words used in electrical literature.

To a certain extent this increase has been warranted either by new applications of electricity or by the discovery of new principles of the science. In some cases, however, new words, terms or phrases have been introduced notwithstanding the fact that other words, terms or phrases were already in general use to express the same ideas.

The character of the work is necessarily encyclopedic. The definitions are given in the most concise language. In order, however, to render these definitions intelligible, considerable explanatory matter has been added.

The Dictionary has been practically rewritten, and is now, in reality, a new book based on the general lines of the old book, but considerably changed as to order of arrangement and, to some extent, as to method of treatment.

As expressed in its preface, the author appreciates the fact that the earlier book was tentative and incomplete. Though the wide scope of the second edition, the vast number of details included therein, and the continued growth of the electrical vocabulary must also necessarily make this edition incomplete, yet the author ventures to hope that it is less incomplete than the first edition. He again asks kindly criticisms to aid him in making any subsequent edition more nearly what a dictionary of so important a science should be.

The order of arrangement in the first edition has been considerably changed. The initial letter under which the term or phrase is defined is in all cases that of the noun.

For example, "Electric Light " is defined under the term " Light, Electric " ;

"Diameter of Commutation" under "Commutation, Diameter of ," "Alternating Current Dynamo-Electric Machine" under "Machine, Dynamo-Electric, Alternating Current ." As before, the book has numerous cross references.

Although the arrangement of the words, terms and phrases under the initial letter of the first word, term or phrase, as, for example, " Electric Light" under the letter E, might possess some advantages, yet, in the opinion of the author, the educational value

VI

of the work would be thereby considerably decreased, since to a great extent such an. arrangement would bring together incongruous portions of the science.

Frequent cross references render it possible to use the Dictionary as a text-book in connection with lectures in colleges and universities. With such a book the student need make notes only of the words, terms or phrases used, and afterwards, by the use of the definitions and explanatory matter connected therewith, work up the general subject matter of the lecture. The author has successfully used this method in his teaching.

In order to separate the definitions from the descriptive matter, two sizes of type have been used, the definitions being placed in the larger sized type.

In the descriptive matter the author has not hesitated to quote freely from standard electrical works, electrical magazines, and periodical literature generally. Among the numerous works consulted, besides those to which reference has already been made in the preface to the first edition, he desires to acknowledge his indebtedness especially to "The Alternating Current Transformer," by J. A. Fleming ; to various works of John W. Urquhart ; to "Modern Views of Electricity," by Prof. O. J. Lodge; to "A Text-bojk of Human Physiology," by Landois & Sterling; and to "Practical Application of Electricity in Medicine and Surgery," by Liebig & Rohe.

The cuts or diagrams used in the book have either been drawn especially for the work or have been taken from standard electrical publications.

The chart of standard electrical symbols and diagrams has been taken from Prof. F. B. Crocker's paper on that subject.

The definition of terms used in systems of electric railways have been taken mainly from a paper on " Standards in Electric Railway Practice," by O. T. Crosby.

The author desires especially to express his obligations to Prof. F. B. Crocker of the E ectrical Engineering Department, Columbia College, New York, and to Carl Hering. of Philadelphia, for critical examination of the entire manuscript and for many valuable suggestions ; also to The Electrical World and the Electrical Engineer of New York, and to Prof. Elihu Thomson, Edward Caldwell, T. C. Martin, Dr. Louis Bell, Joseph Wetzler, Nikola Tesla, Wm. H. Wahl, Prof. Wm. D. Marks, Prof. A. E. Dolbear, C. W. Pike, John Hoskin, and numerous others, for aid in connection with new words or phrases. So far as thev relate to the medical applications of electricity, the proof sheets were revised by Dr. G. G. Faught, of Philadelphia.

The author desires to thank critics of the first edition and the electricil fraternity in general for valuable suggestions. He presents this second edition of his Dictionary in the hope that it may to some extent properly represent the vocabulary of electrical science.

Central High School, EDWIN J. HOUSTON.

Philadelphia, May, 1S92.

Preface To The Third Edition

THE second edition of the "Dictionary of Electrical Words, Terms, and Phrases" was exhausted in such a comparatively short time that the publishers believed that what new matter might be required for a third edition could best be added in the form of an appendix.

Although not quite two years have elapsed since the issue of the second edition, yet the growth of electrical science has continued at so rapid a pace, and new words, terms, and phrases have of necessity been introduced so rapidly, that fully twenty per cent., both of new words and new matter, have been found necessary for the third edition. Had this fact been known in time, it might have been better to have developed the additional matter throughout the text, rather than placing it at the end of the book as an appendix.

Should a demand be made for a fourth edition, the author contemplates rewriting and re-arranging the entire volume. He is thoroughly aware of the inaccuracies and incompleteness of many of the definitions in the second edition, and hopes, in the event of a demand for a fourth edition, to produce a volume more nearly approximating to what an electrical dictionary should be. In the meantime, he again asks the kindly criticisms of his fellow laborers in the electrical field to aid him in the work.

In order to facilitate the use of the cross-references, all words, terms, and phrases referred to in the appendix are so marked; i e., (See Appendix — Insulation, Kilometric, of Cable.} All references not so marked will be found in the main text of the dictionary.

The author desires to express his obligations to numerous authors and technical journals for information as to new words, terms, and phrases, and to the significance generally given to them in actual use. He desires especially to acknowledge his obligations to his colleague, Mr. A. E. Kennelly, and to Professors R. A. Fessenden, C. Wellman Park; to Messrs. C. P. Steinmetz, J. F. Kelly, O. B. Shallenberger, Carl Hering, H. W. Frye, W. D. Weaver, W. F. C. Hasson, Townsend Wolcott, J. B. Cahoon, and many others, for reading of proof sheets and suggestions.

The author presents this third edition of the Dictionary with the hope that it may prove of value to the electrical fraternity.

EDWIN J. HOUSTON.

Philadelphia, May, 1894.

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