A copy of Siôn Dafydd Rhys, Cambrobrytannicæ Cymraecæve Lingvae Institvtiones et Rvdimenta... (London: Thomas Orwin, 1592, ESTC S115912), with manuscript additions in a number of seventeenth- and eighteenth-century hands throughout the volume and on the back fly-leaves, including Welsh verse in strict and free metre on pp. 98, 151, 196, 200 and 308-309, and 'pedwar mesir arhigain Cerdd Dant', 'y pedwar mesir arhugain Cerdd dafod' and 'y saith fesur ar hugain, ne'r saith fesurau [Cerdd Dant]' on pp. 305-307, together with a drawing of a Welsh triple harp and a diagram illustrating the tuning of its three sets of strings on p. 308.
The Welsh verses on p. 98 are probably in the hand of Robert Lloyd, whose name occurs on pp. 95, 98 and 157, and those on pp. 196 and 200 in the hand of Ffoulk Edwardes, whose name occurs on p. 156. The eighteenth-century hand which added the dates to poems on pp. 45, 164, 181, 183, 184, 190 and 248 probably also copied the verses on pp. 151, 248 and the texts on pp. 305-309.