Mining and Ore-Dressing Machinery: A Comprehensive Treatise Dealing With the Modern Practice of Winning Both Metalliferous and Non-Metalliferous Minerals (Classic Reprint) - Softcover

Lock, C. G. Warnford

Softcover

ISBN 10: 1333180411 ISBN 13: 9781333180416

Verlag: Forgotten Books, 2019

Inhaltsangabe

Excerpt from Mining and Ore-Dressing Machinery: A Comprehensive Treatise Dealing With the Modern Practice of Winning Both Metalliferous and Non-Metalliferous Minerals

Wind. - For giving motion to machinery, windmills have been and still are very extensively used. Engineers of the last generation devoted much attention to the construction of windmills, and brought them to great perfection. The introduction of steam-power - manageable, and always to be depended ou - has, in a great measure, superseded that of wind. True, after the first cost of a windmill, the power is comparatively inexpensive; but it is so variable in intensity - sometimes, when it is not required, exerting great force, and sometimes, when it may be most wanted, totally ineffective - that it is generally preferable to apply a force, perhaps considerably more expensive in its production, but constant, steady, and completely under control. The intervention of electric storage batteries, however, is an obvious method of reducing this evil to a minimum.

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Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com

This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

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Excerpt from Mining and Ore-Dressing Machinery: A Comprehensive Treatise Dealing With the Modern Practice of Winning Both Metalliferous and Non-Metalliferous Minerals

Were we to divide the radius 30 ft. Into six equal parts, and calculate the angles at each point, we should find them correspond nearly with the means of those given by Smeaton and others.

Mills are generally made with four strong wooden arms or radii, fixed firmly in a central socket, and steadied and stiffened by tie-rods, connecting their extremities together, and with a projecting strut on the central boss. The width of each sail at the extreme should be about half of the radius, so that in a mill 60 ft. Diameter, or 30 ft. Radius, each sail would be 15 ft. Wide at the extreme. The part of the arm next the centre for about 71; of the radius, that is, 5 ft. In the case supposed, is not fitted with sails because the surface there is so little effective, as well from its short leverage as from its obstructing the wind reflected from the head of the turret behind it. The width at the inner end should be of the radius, or 10 ft. The surface of each sail is therefore 312% sq. Ft., and the total of the four is 312% X 4 1250 sq. Ft.

The total area of the circle 60 ft. In diameter is somewhat above 2800 sq. Ft., so that not half the surface of the circle is clothed with sails. There would be no disadvantage in extending the surface by making the sails broader or more numerous, until it became of the whole surface. Beyond this additional sail-surface is disadvantageous, for it appears to obstruct the free passage of the currents reflected from the sails, and thus clogs their motions. It is found advantageous to arrange the surface of the sail somewhat in the proportions of Fig. 2, which represents the front View of one sail.

About the Publisher

Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com

This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Details zur Ausgabe

• Verlag: Forgotten Books
• Erscheinungsdatum: 2019
• Sprache: Englisch
• ISBN 10: 1333180411
• ISBN 13: 9781333180416
• Einband: Tapa blanda
• Anzahl der Seiten: 478
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: Nicht verfügbar