Transactions Of The Academy Of Science Of Saint Louis Volume 2 Primary Source Edition

Author : St. Louis Academy of Science
Publisher : Forgotten Books
ISBN 13 : 9781333264789
Total Pages : 648 pages
Book Rating : 4.2/5 (647 download)

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Download or read book The Transactions of the Academy of Science of St. Louis, 1861-1868, Vol. 2 written by St. Louis Academy of Science and published by Forgotten Books. This book was released on 2016-08-19 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from The Transactions of the Academy of Science of St. Louis, 1861-1868, Vol. 2: With Plates Illustrating Papers Since glass threads, however fine they may be, are never quite equal, and a slight difference in the glass threads may cause Slight variations in the instrument, it is needed, for comparative observations on different instruments, to deter mine the sensitiveness of each instrument by the tension of a zinc-oopper column of a certain size, the tension of one ele ment to be used as unity for the table of calculation. For collecting atmospheric electricity, Prof. Dellmann uses also a peculiar apparatus. He believes, with many others, that a fixed apparatus does not answer the purpose, because it can never be sufficiently isolated, is charged but Slowly and gradually, and does not indicate the actual electricity of the surrounding atmosphere. He therefore makes use Of a movable apparatus, that is, a hollow ball of copper or brass, six inches in diameter, with a metallic stem; the latter rest ing in a metallic tube, from which it is perfectly isolated by shellac. This collecting apparatus is fixed to a pole about thirty feet long, which is, by a Windlass, drawn up along the wall of the house to the height of the roof, where the air circulates freely; the observer then touches, by means of a thin wire, the stem Of the ball with a half-moon-shaped piece of brass; the ball is thus charged with electricity, the pole let down again quickly, and the collecting apparatus is, at Once, brought into contact with the measuring instrument. 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.