The first volume of a manuscript written by William John Roberts, giving a comprehensive account of the history, management and social life of Penrhyn Quarry near Bethesda, Gwynedd.

W. J. Roberts worked in the slate quarry between 1920 and 1954 (with the exception of the war years of 1939-45), the memories of which he documented in two large volumes of manuscript, including accounts both in Welsh and English, in addition to various sketches illustrating machinery, process and quarry buildings.

Both volumes of the manuscript and their full transcriptions are available here: https://www.peoplescollection.wales/collections/1981021