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Amgueddfa Cymru
Printed in black ink on off-white paper. Full Title: 'Steam Production at Collieries: Where the life of a steam-driven pit does not justify electrification, it is often possible to effect considerable economies by improved boiler plant, steam storage and similar modifications' by E.Ivor David. There is also a cover slip pinned to the front of the article. Typed in black ink on white 'Colliery Engineering' headed paper, containing the note 'with the editors compliments.' Loose within a green card file with all other documents with accession number 83.184I/67. The file is labelled 'Colliery Boiler Plant B31', 'Cefn Coed Data' and 'Colliery Engineering'.