These cookies are absolutely essential for our website to function properly.
We use Google Analytics to measure how you use the website so we can improve it based on user needs.
These cookies may be set by third party websites and do things like measure how you view YouTube videos.
Amgueddfa Cymru – Museum Wales
Typed in black ink on off-white paper, with details handwritten in pencil and blue ink. National Coal Board South Western Division headed paper. A letter addressed to I. Williams of Powell Duffryn Ltd. containing figures relating to the maximum demand and electrical units generated during 1948 at Powell Duffryn Ltd. Loose within pink/peach card file with other documents relating to Middle Duffryn and Bargoed High Pressure Station.