Chapter I

. About Frictional Electricity.--II. About Magnets and Magnetism.--III. How Electricity is Generated by the Voltaic Cell.--IV. Various Voltaic Cells.--V. About Push-Buttons, Switches and Binding-Posts.--VI. Units and Apparatus for Electrical Measurements.--VII. Chemical Effects of the Electric Current.--VIII. How Electroplating and Electrotyping are Done.--IX. The Storage Battery and How it Works.--X. How Electricity is Generated by Heat.--XI. Magnetic Effects of the Electric Current.--XII. How Electricity is Generated by Induction.--XIII. How the Induction Coil Works.--XIV. The Electric Telegraph, and How it Sends Messages.--XV. The Electric Bell and Some of its Uses.--XVI. The Telephone, and How it Transmits Speech.--XVII. How Electricity is Generated by Dynamos.--XVIII. How the Electric Current is Transformed.--XIX. How Electric Currents are Distributed for Use.--XX. How Heat is Produced by the Electric Current.--XXI. How Light is Produced by the Incandescent Lamp.--XXII. How Light is Produced by the Arc Lamp.--XXIII. X-Rays, and How the Bones of the Human Body are Photographed.--XXIV. The Electric Motor and How it Does Work.--XXV. Electric Cars, Boats and Automobiles.--XXVI. A Word About Central Stations.--XXVII. Miscellaneous Uses of Electricity.

This book explains, in simple, straightforward language, many things about electricity; things in which the American boy is intensely interested; things he wants to know; things he should know.

It is free from technical language and rhetorical frills, but it tells how things work, and why they work.

It is brimful of illustrations--the best that can be had--illustrations that are taken directly from apparatus and machinery, and that show what they are intended to show.

This book does not contain experiments, or tell how to make apparatus; our other books do that. After explaining the simple principles of electricity, it shows how these principles are used and combined to make electricity do every-day work.

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_Everyone Should Know About Electricity._

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A VERY APPROPRIATE PRESENT

Things a Boy Should Know About Wireless

By THOMAS M. ST. JOHN, Met. E.

Author of "Things a Boy Should Know about Electricity," "Fun with Electricity," "The Study of Elementary Electricity and Magnetism by Experiment," "The Study of Electric Motors by Experiment," "Electrical Handicraft," Etc., Etc.

126 Pages--109 Illustrations and Diagrams Bound in Cloth--Net $1.00

This book contains much practical and some theoretical information regarding the operation and explanation of wireless outfits. It discusses enough of the theoretical side to make the student sure of himself and to give a well-rounded knowledge of this most practical subject.

The author has explained the various pieces of apparatus needed in a wireless station in such a clear manner that the student can not fail to understand how they work and why they work. The numerous drawings and diagrams simplify the discussions to such an extent that the reader will not want to skip a single paragraph.

"Things a Boy Should Know About Wireless" will be welcomed by thousands of enthusiasts and it should find its way into every library.

From

THOMAS M. ST. JOHN

Cascade Ranch. East Windham,--N.Y.

The Study of Elementary Electricity and Magnetism by Experiment

By THOMAS M. ST. JOHN, Met. E.

FOURTH EDITION Price, postpaid, $1.25.

The book contains 220 pages and 168 illustrations. It measures 5 × 7-1/2 in., and it is bound in green cloth.

CONTENTS: Part I. Magnetism.--