Abstract
LONDON.Optical Society, May 14.—F. W. Preston: (I) The fundamental law of annealing. The fundamental law of annealing, that the rate of decrease of stress varies as the square of the stress present, is deduced from first principles by means of dimensional analysis, assuming that the rate of decrease of stress depends, (I) only on the stress present and the viscosity; (2) on the stress present, the viscosity, and the rigidity of the material. The law suggested as an empirical relation by Adams and Williamson is true dimensionally.— (2) The dimensional accuracy of Mr. Hampton's paper on “The Annealing of Glass.” No corrections are made in Mr. Hampton's results, which are based on sound reasoning. The practical conclusions of Mr. Hampton's paper are justified in every way.—T. Smith: Note on the cosine law. Objections raised to the statement that rays selected by a cosine relation determine caustic surfaces in the object and image spaces, and to some points in the proof of the cosine law, are considered, and the adoption of the original enunciation of the theorem justified as opposed to the modified form suggested by Hertzberger and approved by Boegehold. A direct derivation of the analytical form of the law of refraction from the cosine law is given.
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Societies and Academies. Nature 116, 66–68 (1925). https://doi.org/10.1038/116066a0
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DOI: https://doi.org/10.1038/116066a0