Excerpt from A Redetermination of the Coefficient of Viscosity of Air: A Dissertation Submitted to the Faculty of the Ogden School of Graduate Science in Candidacy for the Degree of Doctor of Philosophy, (Department of Physics) N view Of certain results on the Coefficients Of Slip Obtained by him from his study Of the laws of fall of small spheres in gases, Prof. Millikan suggested to me that I attempt to Check these results by making some measurements on the coefficients of viscosity at very low pressures with the constant de ection apparatus designed by himself and Dr. Gilchrist. In the course Of this work the method was so perfected as to make it capable of a precision apparently. Unapproached heretofore in measurements on the viscosity of gases. Since the knowledge of the exact value Of this coefficient for air is of such fundamental importance in many lines Of physical research it seemed worth while to turn aside for the sake of attempting again to fix its value with all the precision possible. This was especially needed since some question1 has been raised recently relative to the reliability Of the estimate made by Prof. Millikan as to the most probable value Of this constant. From determinations made under his direction by gilchrist2 by the constant de ection method, and by Rapp3 by an improved capillary tube method, taken in connection with reliable determinations made elsewhere and by other methods, Prof. Millikan published4 as the most probable value Of this constant, 17, at 2 3 C., 0001824, and estimated its uncertainty at not more than one tenth per cent. 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."