Abstract
LONDON. Physical Society, Mar. 8.—Ezer Griffiths and J. H. Awbery: The dependence of the mobility of ions in air on the relative humidity. The apparatus employed was a modification of Zeleny's original method, the end of a wind channel being closed by a disc of gauze fitted with a guard ring through which a steady stream of air of definite humidity was pumped. The motion of the negative ions due to the action of the air stream was balanced by a counter potential gradient, and the mobility deduced from the critical potential required to produce a balance. The rate of air flow was measured by means of an Ewing ball and tube flowmeter, using a hollow glass sphere to make it suitable for low air rates. Efforts were made to construct a direct indicating instrument.—A. M. Tyndall, with a note by C. F. Powell: Some unsolved problems relating to the mobilities of gaseous ions. The address dealt with:—(1) Established results and proposed theories; (2) the difference between positive and negative mobilities; (3) the effect of vapours; (4) mobility in pure gases; (5) positive ions of short age; (6) suggestions as to future progress. Note by Mr. C. F. Powell: An apparatus of the ‘four gauze’ type has been designed for experiments with highly purified gases.
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Societies and Academies. Nature 123, 665–667 (1929). https://doi.org/10.1038/123665b0
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DOI: https://doi.org/10.1038/123665b0