Geological Survey of England and Wales....Bridgend (Pontypridd)
Original Geological Survey on the One-Inch scale by Sir H. De la Beche and others. Published on Sheets 20, 36 & 37, Old Series. Revised up to 1872 by H.W. Bristow and H.B. Woodward. Resurveyed on the six-inch scale by R.H. Tiddeman, M.A., and T.C. Cantrill, B.Sc., (N.E. margin by A. Strahan, M.A). Published with Drift, 1901. Sir Archibald Geikie, D.C.L., F.R.S., Director General. Published in color by the Director General Ordnance Survey at the Ordnance Survey Office, Southampton 1902.
Approx 50cms by 33cms