Casgliadau Arlein

Graphs drawn in pencil, with handwritten details in pencil, on off-white, grey lined graph paper. Three graphs on one piece of graph paper. One graph (the smaller graph at the top of the document) is entitled 'Electrical + CA. units generated + costs', another (the larger graph below) is entitled 'Unit Costs and Coal Per Unit'. The other graph is on the reverse and is entitled 'PD system + others Unit Costs'. There are also details handwritten in pencil alongside the graphs. Dated April 1952. Also attatched to the graph is a piece of off-white, blue ruled paper with details handwritten in pencil. Contains a table of figures containing the dates 1939-1946. Loose within peach card file with other documents relating to Powell Duffryn Electrical System.