Harper's Electricity Book for Boys

For the use of the cuts in this chapter, the Publishers desire to acknowledge the courtesy of the General Electric Company, the Thomson Electric Welding Company, and the Cooper...

To adequately treat of dynamos and motors, a good-sized book rather than this single chapter would be necessary, and only a general survey of the subject is possible. Its import...

To the average boy experimenter, electro-plating is one of the most fascinating of the uses to which electricity may be put. In scientific language the process is known as elect...

The science of controlling forces is so well understood and figured out that it becomes a simple mechanical proposition to adapt the various types of controllers to any form of...

Every boy has a horseshoe magnet among his collection of useful odds and ends, and whether it is a large or small one its working principle is the same. If large enough it will...

A unique electric sounder that is sure to attract attention is in the shape of an electric-bell apparatus, with a drum sounder in place of a bell, or knockerless buzzer. Fig. 1.

For direct communication over short or moderately long distances, nothing has been invented as yet that will take the place of the telephone. A few years ago, when this instrume...

Push-buttons and switches are a necessity in every home where electric bells, lights, or fans are used, for with them connections are made or broken. The telegraph-key and the c...

In order to generate electricity it is necessary to employ cells, batteries, or dynamos. Since the construction and operation of a dynamo is somewhat intricate, it will be bette...

The field of applied electricity is such a wide one as to preclude any exhaustive handling of the subject in a book of this size. The aim has been to acquaint the young student...

When a wire or a number of them are brought near a magnetic needle or a small compass, the needle will be deflected from its north and south line and will point east and west, o...

Nearly every boy is interested in telegraphy, and it is a fascinating field for study and experimental work, to say nothing of the amusement to be gotten out of it. The instrume...

The sending apparatus is practically the same in all outfits, and consists of a source of electrical energy, such as a battery, or dynamo, the essential induction-coil and adjus...

Frictional electricity is high potential, current alternating, and of high voltage but very low amperage. Apart from certain uses in laboratory and medical practice, it is value...

We are living in the age of electricity, just as our fathers lived in the age of steam. Electricity is the world-power, the most powerful and terrible of nature’s hidden forces....

In the construction of electrical apparatus there are many things, such as paint, cement, non-conducting compounds, and acid-proof substances, that are necessary in assembling t...

long-distance circuits is made on a wooden spool turned from a piece of wood three inches and a half long and one inch square, as shown at Fig. 19. The core-sheath is turned dow...

The indicator-needle may be cut from stiff paper, thin sheet-fibre, or very thin cold-rolled brass or copper, the latter being commonly known as hard or spring-brass. Only one p...

THE WORK OF THE DYNAMO -- THE ELECTRIC LIGHT -- USES OF THE ARC-LIGHT -- INCANDESCENT AND OTHER LAMPS -- ELECTRIC HEAT -- ELECTRIC FURNACES -- WELDING METALS -- ELECTRIC CAR-HEA...

In the sending apparatus (Fig. 33) S C are the storage-cells, K the key, and I C the induction-coil. T T are the terminals and balls, S G the spark-gap, and P P the posts that h...

DEPENDENCE OF MODERN ELECTRICITY UPON THE DYNAMO -- A FIELD OF FORCE CUTTING ANOTHER FIELD OF FORCE -- VARIETIES OF DYNAMOS -- SIMPLER FORMS OF GENERATORS AND MOTORS -- HOW TO M...

A GROUND TELEGRAPH -- HOW TO TALK FROM HOUSE TO HOUSE -- THE MORSE TELEGRAPH CODE -- A STORY OF EDISON -- HOW DETECTIVES USED THE CODE -- WIRELESS TELEGRAPHY -- ITS TRUE CHARACT...

of which, however, are within the reach of intelligent boys who have followed the chapters carefully from the first. In a final chapter we have simple explanations of the great...

A FASCINATING USE OF ELECTRICITY -- A SIMPLE ELECTRO-PLATING OUTFIT -- THE SULPHATE OF COPPER BATH -- HOW TO MAKE THE TANK AND OTHER APPARATUS -- A VARIETY OF BEAUTIFUL AND USEF...

GOVERNING THE ELECTRIC CURRENT -- OHM’S LAW -- RESISTANCE-COILS AND RHEOSTATS -- HOW TO MAKE SIMPLE APPARATUS -- LIQUID RESISTANCE -- IMPORTANCE OF SWITCHES -- USES OF A HOUSE-C...

VIBRATORY WAVES -- A BLADDER TELEPHONE -- A SINGLE (RECEIVER) LINE -- PLAN OF INSTALLATION -- A DOUBLE-POLE RECEIVER -- THE TRANSMITTER -- ANOTHER FORM OF TRANSMITTER -- THE WIR...

MAKING A ROTARY GLASS-CUTTER -- TO SMOOTH GLASS EDGES -- CUTTING HOLES IN GLASS -- ANTI-HUM DEVICE FOR METALLIC LINES -- A REEL-CAR FOR WIRE -- INSULATORS -- JOINTS AND SPLICES...