Abstract
IN a paper on “A Metallographic Description of Some Ancient Peruvian Bronzes from Machu Picchu,” Mr. C. H. Matthewson, in the American Journal of Science (No. 240, December, 1915), gives an interesting account of the detailed application of modern metallographic methods to the study of ancient metal objects with the view of arriving at an insight into the methods of working employed by those who fashioned the various objects. Some work of this kind has already been done by Garland, Hadfield, and Rosenhain, but the present paper carries the matter further, for the author has carried out a somewhat extensive series of experiments on the behaviour of the tin-copper alloys under cold and hot working and annealing, in order to arrive as closely as possible at the precise mode of treatment which each of the thirty-three objects examined had undergone. While in general terms it has always been possible to determine from a microscopic examination of such an object whether it has been cast or wrought,Matthewson endeavours to carry the “matter further and to, establish with some degree of accuracy at what temperature working has been carried out and what ranges and durations of annealing have been employed. For this purpose he makes use of measurements of grain-size, of a classification of the degree of “coring” or of “homgenisation “which has been produced, and also of the various indications of cold work or overstrain. Quite apart from its archaeological interest, the paper represents a valuable study of the behaviour of the tin-copper alloys ranging in tin-content from about 2 to 14 per cent, under mechanical deformation and annealing. Less happy are the author's excursions into the domain of theories of plastic strain and of annealing in metals generally; they burden a lengthy paper with much additional matter scarcely relevant to the subject.
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Metallographic Methods in America . Nature 97, 388–389 (1916). https://doi.org/10.1038/097388b0
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DOI: https://doi.org/10.1038/097388b0