A composite volume in three parts, dated to the late-fifteenth century (pp. 1-32), 1650 (pp. 33-48) and the eighteenth century (pp. 49-102), containing astrological material (pp. 2, 15-16, 95-98, 26-32); names of plants in Latin and Welsh (p. 3); charms (pp. 4-6); the Paternoster, with every sentence explained (p. 7b); theological tracts (pp. 10-14); a commentary on the Prophecies, dated 5 May 1650 (pp. 33-48); fragments of Bruts (pp. 49-64, 71-74, 83-94); a list of the hundreds and commotes of Wales (pp. 99-100) and of the parishes of Carmarthenshire (pp. 101-102); etc.
On p. 6 is the note 'Gruff: llwyd ap Madoc Dd. a wnaeth y llyvyr hwnn i T. ap howel'.

The letters, 1894-1913, refer to the writer's academic work, researches and publications on the Welsh manuscripts. He refers to his research trips to a number of libraries and archival repositories. There are also a few passing references to contemporary events in Wales and to developments at the University College of Wales, Aberystwyth.

Papers of Timothy Lewis, 1853-1955, including works by him, transcripts of manuscripts of Welsh literature and Welsh law, and correspondence. The archive also comprises substantial groups of the papers of his friend, J. Gwenogvryn Evans (1852-1930), which mainly consist of transcripts of manuscripts and correspondence; and of his father-in-law, Beriah Gwynfe Evans (1848-1927), including works by him, and letters.