This volume has been prepared in response to a general demand created by a series of articles which appeared in Electrician and Mechanic, Popular Electricity and Modern Mechanics, and The World's Advance. The articles covered briefly the apparatus employed in an experimental study of high frequency current phenomena over a period of several years.
In this work, I have spared no effort to produce a treatise of practical value. Theory has been ignored chiefly because it would serve merely to confuse the non-technical reader. The designs offered are more than theoretical—they are the result of actual construction and experiment. In many cases, the entire oscillation transformer has been rebuilt and rewound many times before satisfactory results were obtained.
The work has been divided into six basic parts. The first two chapters tell the uninitiated reader what the high frequency current is, what it is used for, and how it is produced. The second section comprising four chapters describes in detail the principles of the transformer, condenser, spark gap, and oscillation transformer, and covers the main points in the design and construction of these devices as applied to the work in hand. The third section covers the construction of small high frequency outfits designed for experimental work in the home laboratory or in the class room. The fourth section is devoted to electro-therapeutic and X-Ray apparatus. The fifth describes apparatus for the cultivation of plants and vegetables. The sixth section is devoted to a comprehensive discussion of apparatus of large size for use upon the stage in spectacular productions.
An appendix giving the current prices of the parts and materials required for the construction of the apparatus described has been added with a view to expediting the purchase of the necessary goods.
I wish to acknowledge my indebtedness to the following concerns and individuals for assistance rendered in the preparation of this volume: Victor Electric Company for illustrations of standard electro-therapeutic apparatus; Clapp-Eastham Company for illustrations and the list of parts and materials; Mr. Melville Eastham for a practical working knowledge of magnetic leakage transformer design and construction; and, last, but not by any means least, Prof. Wm. C. Houghton, for many ideas and suggestions, and much unselfish manual labor during the course of experiments which made this treatise possible.