File:Our country and its resources; (1917) (14760428026).jpg

Identifier: ourcountryitsres00hopk (find matches)
Title: Our country and its resources;
Year: 1917 (1910s)
Authors: Hopkins, Albert A. (Albert Allis), 1869-1939
Subjects: United States. (from old catalog)
Publisher: New York, Munn & co., inc.
Contributing Library: The Library of Congress
Digitizing Sponsor: Sloan Foundation

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use-fulness proved to be a limited oneon account of their inability to standup in a strong wind. The defects of the ordinary cap-tive balloon were overcome by twoGerman army officers. Captains Par-seval and Sigsfeld, who produced in1898 the so-called kite-balloon—acraft which has proven so success-ful that it is now recognized to bean indispensable auxiliary of everyup-to-date army and navy. The kite-balloon consists essen-tially of an elongated gas-bag whichis divided into two unequal portions,the larger of which (Comprisingabout four-lift lis the total volume i istilled with hydrogen; the remainingone-fifth constitutes the ballonnet, orair-cell, and this is automatically in-flated by the wind through a con-venient aperture. The ballonnet ful-fills two purposes: first, it createswithin the gas-bag a sur-pressureequal to the pressure of the windplus the static pressure of the hydro-gen, thus enabling the balloon tomaintain its shape regardless of anywind the mooring cables can with-
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368 OUK COI NTR1 AND lis RESOURCES stand: and secondly, air being muchheavier than hydrogen, the air-cellcauses the balloon to assume an in-clined position, which is particularlyfavorable for counter-acting the de-pressing tendency of the wind. Inorder to keep the crafl alv aj s bead-on to the wind a sausage-shaped airbag rudder is fitted to the rear ofthe envelope, which is inflated thesame way as the air-cell: longitudi-nal stability is further insured bya number of sails and a device simi-lar t a kites tail. The standard type of kite-balloonhas a volume of from 25,000 to 35,000CUbiC feet, and it carries one or twoobservers who are connected by trie-phone with the artillery unit theyare attached to. As a fire-controlstation for military, and even navaloperations of a stationary character(siege, blockade, etc.), the kite-balloon far surpasses the aeroplane, af-fording, as it does, a steady platformwherefrom held glasses or telescopes can he used to irreat advantage. In the Gr

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