The editor's own set of Cymru (O. M. Edwards), Vols. 1-44, 1891-1913 containing manuscript notes, some original manuscripts of contributions and letters by correspondents.
Twelve letters, 1900-1902, from Edward Thomas to Sir Owen M. Edwards, his erstwhile tutor at Lincoln College, Oxford, written shortly after Thomas had left university, their main purpose being to ask for guidance in seeking employment; they also reflect his attachment to Wales and his interest in the Welsh language.
Letters, 1895-1918, relating mainly to William Thomas (Islwyn) (1832-1878), to manuscripts and to books, written to Sir Owen Morgan Edwards (1858-1920) by M. Jenkyns (sister to Islwyn), R. E. Roberts (Cwmfelinfach, Ynysddu), Daniel Davies (Ton, Ystrad, Glamorgan) (1840-1916) and John Kyrle Fletcher (1872-1942).