Mine timber in Pennsylvania coal mines
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Harry E. Tufft
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Article
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1924
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Elsevier Science
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English
โ 102 KB
PREVIOUS tests on bond clays by the bureau had determined that American clays can be used successfully in graphite crucible manufacture and service. The next step was to determine the value of American graphites as compared with the foreign. The final tests were carried out at the plant of the Detro