Sacrobosco, "Sphera", "Algorismus" and other tracts Fourteenth-century composite manuscript volume containing tracts on mathematics, astronomy and astrology, including several by Johannes de Sacrobosco. This manuscript is a palimpsest with the erased texts in a 13th century Italian(?) hand still visible most clearly on folios 11r to 14v. and f.20. There are many diagrams and marginalia throughout. The manuscript consists of 33 leaves, in quires of 10, 8, 6, 4 and 6 leaves respectively. The last leaf of the 5th quire is missing. A piece of parchment has been torn from ff. 1 and 13, and there are holes in ff. 4 and 7. The last quire is of much finer and whiter parchment and may be of a later date than the other 4 sections. In her "Descriptive Catalogue of Manuscripts", Coveney suggests that the texts are written by at least 7 scribes in various minuscule hands of the 14th century. She identifies them as : (1) fols. 2r-10v ; (2) 11r-18r ; (3) 19r-24v ; (4) 25r-28v ; (5) 29r-31vb ; (6) 32ra ; (7) 33ry (corrected by later hands). The ink used is of various tints, that used by scribes 1, 3, 5 and 6 being much darker. Small black letters beside headings indicate that the manuscript was rubricated by a separate rubricator. Diagrams accompanying the text are in plain red or red and black. There is a list of titles in Latin on f.1, with an entry in another hand dated 1383. Below this also appear the date 1340 and another inscription possibly by a former owner, "A S Dawes", dated March 1782. The volume bears on the spine: 'Liber Astro/logic / M.S.'. A cutting from a sales catalogue describing the manuscript is pasted inside the front cover, with the Graves bookplate pasted on the first free endpaper opposite. The manuscript is structured as follows: f.1r List of contents (1) ff.2r-10v, Sacrobsco, "Tractatus d'spera" (note particularly the diagrams of eclipses on f.9v-10r and the further astronomical calculations in the marginalia) (2) ff.11r-16r, Sacrobosco, "Tractat[us] algorismi". (3) f.16r/v, De Lapidibus, de adamante. (4) f.16v, De Geometria (including Euclidean theory, followed by practical texts on measuring objects, e.g. a barrel, a vase) (5) ff.17r-18v, Explicit tractatus quadrantis (6) ff.19r-21v, Liber quadrantis, incipit: "Post compositionem chilindre nunc cuiusdam instrumenti morologici [horologici] videlicet quadrantis". Annotated in a later hand "Libro d'astologia". (7) ff.22-23v (begins imperfectly) (8) ff.23v-24v, De subita tristitia (what to do when suddenly overcome with sadness, depression) (9) ff.25-28v, Compotus lunaris per uersus (possibly a later hand not contemporary with the other texts?) (10) f.29r/v, Sermo de cruce (11) ff.29v-32r, De articulis fidei secundum fratrum Egidium (12) ff.32v-33v, Tabula temporum Solis et Lune 1349-1377 The first texts in the volume, including (1) Tractatus de Sphera (fols. 2r–10v), (2) Tractatus Algorismi (fols. 11r–16r), (3) De Lapidibus (fol. 16r), and (4) De Geometria (fol. 16v) are written continuously in a narrative style. Section (8) 23v-24r is in 3 cols., (11) 29r-32r is 2 cols., and (9) 25r-28v is written as verse. At least two of the texts above are palimpsest. Using multispectral imaging, the under-texts have been identified as: Folio 13 r/v [part of text (2), Sacrobosco 'Tractatus algorismi']: an abridged version of 'Breviarium Historiae Romanae', a history of the Roman Empire by Eutropius (fl. 363–387), specifically Book 9 ch. 13. Folio 20v [part of text (6) Liber quadrantis]: Julius Caesar’s 'Commentarii de Bello Gallico' (Commentaries on the Gallic War) book 7, section 15. Early 14th century