00754cam a22002171  4500001001300000003000400013005001700017008004100034010001700075035002000092040004600112050002300158100003100181245012900212260004200341300004000383490006200423650001700485650001700502999001700519gs 27000056 DLC20260227111331.0920604s1926    enkaf        f000 0 eng c  ags 27000056   a(OCoLC)25937148  aLibrary, U.S. Geological SurveycCStdDLC00aTN295b.G65 no. 231 aHay, Peter Stewart,d1884-12aA method of trapping the dust produced by pneumatic rock drills,cby P.S. Hay. With a preface, by Professor J.S. Haldane ...  aLondon,bH.M. Stationery Off.,c1926.  a18 p.b2 fold. pl., diagrs.c25 cm.0 a[Gt. Brit.] Safety in Mines Research Board. Papervno. 23 0aMine safety. 0aRock-drills.  c26539d26539