Identifier: radiomiracleof2000drin (find matches)
Title: Radio, miracle of the 20th century ... a story of human achievement that stands unrivalled in the history of humanity, together with a colorful portrayal, giving a broad, general view of the whole subject of wireless telegraph and telephone and its marvelous development
Year: 1922 (1920s)
Authors: Drinker, Frederick E. (from old catalog) Lewis, James G., (from old catalog) joint author
Subjects: Radio
Publisher: (Philadelphia, Printed by National publishing co.)
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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MIRACLE OF THE AGE 145 Glands along the tube or canal secrete wax which guardsthe approach to the drum and protects it. As frequentlyhappens, through injury or illness there is an inflamma-tion which interferes with the flow of the secretion andthere is an excess of wax which hinders or prevents hear-ing and we send for an expert to remedy the condition—the physician or surgeon. The middle ear is called the tympanum, and is sepa-rated from the outer ear by the drum. The tympanum isa small cavity in the temporal bone of the skull communi-cating with the throat by the Eustachian tube. This tubeis in reality a valve which controls the air pressure on theinside of the drum, which is exactly equal to the pressureon the external or outside under normal conditions. ALL SOUNDS ARE VIBRATIONS. The structures of the inner ear lie in the temporal boneon the side of the tympanum directly opposite the drum.They are made up of a system of small bony spaces andtubes called the bony labyrinth, insi

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