Abstract
LONDON. Royal Society, February 17.—Prof. C. S. Sherring-ton, president, in the chair.—Dr. C. Chree: A comparison of magnetic declination changes at British observatories. A comparison is made of mean monthly, daily, and hourly values at different stations, and of the relative amplitudes of the oscillatory movements which frequently occur even on comparatively quiet days. Use is made of magnetic curves from Eskdalemuir, Stonyhurst, Falmouth, and Kew observatories.—Prof. H. M. Macdonald: The transmission of electric waves around the earth's surface.—Prof. T. H. Havelock: The stability of fluid motion. The object is to illustrate the use of the criterion, introduced by Reynolds and modified by Orr, as a measure of the degree of stability of various fluid motions under different boundary conditions. Cases examined are the flow of a stream with a free surface, and the flow between fixed planes under different fields of force and boundary conditions of no slip or no tangential stress or constant normal pressure due to the disturbance from the steady state.—Prof. W. H. Young: The transformation of integrals.—Dr. J. L. Haughton and Kathleen E. Bingham: The constitution of the alloys of aluminium, copper, and zinc containing high percentages of zinc. The constitution of aluminium-copper-zinc alloys containing not more than 15 per cent, of aluminium and 10 per cent, of copper is discussed. The investigation has been carried out by the study of the heat absorptions and evolutions which take place in heating and cooling alloys between temperatures at which they are liquid and ordinary temperatures; by the measurement of electrical resistance at various temperatures; and by microscopic study of specimens which have been annealed for prolonged periods and quenched, or very slowly cooled and quenched. From the results obtained a model has been constructed to represent the constitution at temperatures above 250° C. The diagram advanced by Rosenhain and Archbutt has been used as one face of the ternary prism, the other binary system face being somewhat modified from Tafel's diagram.
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Societies and Academies. Nature 107, 29–31 (1921). https://doi.org/10.1038/107029b0
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DOI: https://doi.org/10.1038/107029b0