File:Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous (14596779900).jpg

Identifier: triumphswonderso01boyd (find matches)
Title: Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress ..
Year: 1899 (1890s)
Authors: Boyd, James Penny, 1836-1910
Subjects: Progress Inventions
Publisher: Philadelphia, Pa., A. J. Holman & Co
Contributing Library: The Library of Congress
Digitizing Sponsor: Sloan Foundation

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iple was based on the fact that every dynamo carried within thecores of its magnets enough of unused or residual magnetism to render themagnets self-exciting the moment the machine started. So the outside meansof magnetizing the fields of force of the dynamo passed away. The dynamo speedily grew in size and importance. The electro-magnets WONDERS OF ELECTRICITY 37 or fields of force were greatly increased in number, size, and power. Therewere great improvements in the construction and efficiency of the wireor armatures which cut the fields of force, and a corresponding increasein their number. Commutators and brushes underwent like improvement.So, at last, the well-nigh perfect and all-powerful dynamo of the end of thecentury was evolved, with a capacity for delivering, in the form of electricity,ninety per cent of the mechanical energy which set it in motion. In theapplication of steam to machinery, eighty per cent, and sometimes more, ofthe energy supplied by a ton of coal is lost..
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A DYNAMO. With the perfection of the dynamo, its uses multiplied. It became a primefactor in electric lighting. Trolley systems sprang up in city, town, andvillage, taking the place of horse and traction cars. In certain places, as in theBaltimore tunnel, the dynamo superseded the engine for hauling freight andpassenger cars. The mighty dynamos which convert the inexhaustible energyof Niagara Falls into electricity send it many miles away to Buffalo, to beapplied to lighting and to every form of machinery. The end of the centurysees a power plant in operation in New York city capable of furnishingone hundred thousand horse-power, or enough to supply the lighting, rapidtransit, and thousand and one mechanical needs of the entire municipality.The essential parts of an ordinary dynamo are: (1.) The electro-magnets, which, 38 TRIUMPHS AND WONDERS OF THE XIX™ CENTURY however numerous, are arranged in circular form upon part of the frameworkof the machine. (2.) The iron coils or armatures

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