Casgliadau Arlein

Chart, compiled of several pages glued together, forming a pull-out chart. Contains a piece of explanatory text above the chart, handwritten in black ink on cream paper. Underneath this is a chart illustrating the order of the coal seams, fireclays, productive shales and fireproof shales on the Northern outcrop of the basin of the coal area of South Wales- from Aberdare to Merthyr, also Dowlais, Beaufort, Brynmawr, Blaenavon and Pwll Du. The chart is colour coded in black, pink, blue and lilac.