The set of Mendelssohn's op. 44 quartets with manuscript marking of unknown origin once belonging to William Hamilton (about whom nothing is known). It has been in the Bodleian Library, Oxford, shelfmark: Mus. 177 c. 120 (1-3), since 1969. The set contains detailed performance markings in at least two unidentified hands. A single hand has added rehearsal letters in all four parts of op. 44 no. 1. The two upper parts in all three quartets have been marked up in pencil with comprehensive fingering and bowing by a single person. The viola parts typically contain only a few fingerings, apparently in a different hand. The cello parts are bowed and fingered in another hand. Annotations suggest a 19th-century German origin for these markings.