Papers of Rev. Canon Henry Thomas, 1871-1946, including notes relating to Merioneth, with special reference to local history and antiquities and gentry families; notes on Welsh literature, the development of the eisteddfod, and theology; an address given on the centenary of the National School at Dolgellau, 1946; various printed material and a report on local charities, 1895.

'Hanes Eisteddfodau y Ganrif Bresennol', i.e. the nineteenth century, written for the National Eisteddfod held at Cardiff, 1883.

'Llawlyfr Hanesyddol o'r prif Eisteddfodau o Eisteddfod Caerfyrddin ... yn y 15fed ganrif hyd y flwyddyn 1892 gyda chofnodiad cryno o'u defodau, beirdd, llenorion, cerddorion, telynorion, prif destynau, beirniaid, a buddugwyr', written for the Chicago eisteddfod, 1893.

A manuscript of Owain Llewelyn Owain's essay 'Hanes yr Eisteddfod yng Nghymru 1880-1944', for which he was awarded a prize at the National Eisteddfod of Wales, Llandybïe, 1944, under the pseudonym 'Llion', adapted and edited by the author for proposed publication, [c. 1949].