SCIENTIFIC AMERICAN SUPPLEMENT NO. 647
NEW YORK, MAY 26, 1888
Scientific American Supplement. Vol. XXV., No. 647.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
| TABLE OF CONTENTS. |
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PAGE. |
| I. |
ARCHITECTURE.—Elements of Architectural Design.—By H. H. Statham.—Continuation of this important contribution to building art, Gothic, Roman, Romanesque, and Mediæval architecture compared.—26 illustrations. |
10339 |
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The Evolution of the Modern Mill.—By C. J. H. Woodbury.—Sibley College lecture treating of the buildings for mills. |
10329 |
| II. |
CHEMISTRY.—An Automatic Still.—By T. Maben.—An improved apparatus for making distilled water.—1 illustration. |
10335 |
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Testing Indigo Dyes.—Simple and practical chemical tests of indigo products. |
10342 |
| III. |
CIVIL ENGINEERING.—Railway Bridge at Lachine.—Great steel bridge across the St. Lawrence near Montreal.—2 illustrations. |
10333 |
| IV. |
ELECTRICITY.—Influence Machines.—By Mr. James Wimshurst.—A London Royal Institution lecture, of great value as giving a full account of the recent forms of generators of static electricity.—14 illustrations. |
10327 |
| V. |
HYGIENE.—The Care of the Eyes.—By Prof. David Webster, M.D.—A short and thoroughly practical paper on the all important subject of preservation of sight. |
10341 |
| VI. |
MECHANICAL ENGINEERING.—Economy Trials of a Non-condensing Steam Engine.—By Mr. P. W. Winans, M.I.C.E.—Interesting notes on testing steam engines. |
10331 |
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The Mechanical Equivalent of Heat.—By Prof. De Volson Wood.—A review of Mr. Hanssen's recent paper, with interesting discussion of the problem. |
10331 |
| VII. |
METEOROLOGY.—The Meteorological Station on Mt. Santis.—A new observatory recently erected in Switzerland, at an elevation of 8,202 feet above the sea.—1 illustration. |
10341 |
| VIII. |
NAVAL ENGINEERING.—Improved Screw Propeller.—Mr. B. Dickinson's new propeller.—Its form and peculiarities and results.—4 illustrations. |
10333 |
| IX. |
PHOTOGRAPHY.—Manufacture of Photographic Sensitive Plates.—Description of a factory recently erected for manufacturing dry plates.—The arrangement of rooms, machinery, and process.—10 illustrations. |
10336 |
| X. |
TECHNOLOGY.—Cotton Seed Oil.—How cotton seed oil is made, and the cost and profits of the operation. |
10335 |
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Improved Dobby.—An improved weaving apparatus described and illustrated.—1 Illustration. |
10333 |
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Sulphur Mines in Sicily.—By Philip Carroll, U. S. Consul, Florence.—How sulphur is made in Sicily, percentage, composition of the ore, and full details. |
10334 |
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The Use of Ammonia as a Refrigerating Agent.—By Mr. T. B. Lightfoot, M.I.C.E.—An elaborate discussion of the theory and practice of ammonia refrigerating, including the hydrous and anhydrous systems, with conditions of economy. |
10337 |
INFLUENCE MACHINES.1
By Mr. James Wimshurst.
I have the honor this evening of addressing a few remarks to you upon the subject of influence machines, and the manner in which I propose to treat the subject is to state as shortly as possible, first, the historical portion, and afterward to point out the prominent characteristics of the later and the more commonly known machines. The diagrams upon the screen will assist the eye to the general form of the typical machines, but I fear that want of time will prevent me from explaining each of them.
In 1762 Wilcke described a simple apparatus which produced electrical charges by influence, or induction, and following this the great Italian scientist Alexander Volta in 1775 gave the electrophorus the form which it retains to the present day. This apparatus may be viewed as containing the germ of the principle of all influence machines yet constructed.
Another step in the development was the invention of the doubler by
