Casgliadau Arlein

Report contained within a light brown card file. Report is typed in black ink on white paper. The file also contains 13 plans and graphs of various sizes relating to the report, printed in brown ink on cream paper. A report on compressed air tests at Windsor Colliery March/April 1941, by B.L. Metcalf. Dated 29th April 1941. Also contained within the file are four other documents: A document typed in black ink on white paper, containing figures relating to compressed air consumption at Taff Merthyr Colliery. A graph handwritten in brown ink on cream graph paper, entitled 'curves showing compressed air generated at various electric collieries and total electricity consumed' (dated 10/1/47). A graph typed and drawn in black ink, 'Nett H.P. taken for Isothermal Compression of Air or Gas from N.T.P. per 100 cu. ft. and total B.H.P from test results on B & M Compressors'. Notes handwritten in pencil on off-white paper, containing a list of figures for Windsor Colliery (Dated February 1953).