Gases in street manholes
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S.H. Katz; E.G. Meiter; J.J. Bloomfield
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Article
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1925
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Elsevier Science
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English
โ 112 KB
Nov.. I9z5.] U.S. BUREAU OF MryES NOTES. 683 footage obtained per bit by more than 50 per cent. and reduce the drilling time per foot by a third of that obtained when bits are treated in an open fire without temperature control and quenched under conditions that vary from time to time. Further detai