This 12th-century scientific manuscript originally formed a single
volume with Cotton MS Caligula A XV, ff. 120-53 (see Willetts, 'A
Reconstructed Astronomical Manuscript from Christ Church Library,
Canterbury' (1965), 22-30). It contains a large collection of
computistical, astronomical, and prognostic works that was written
a the . This includes extracts from the Compotus Constabularii
(1175): a work about the dating of Easter that was written by an
English author who had access to Arabic scientific materials. A
monk from the cathedral priory of Christ Church, Canterbury, refers
to him as ‘Magister Cunestabulus’. The cathedral priory’s
surviving library catalogue indicates that Christ Church once owned
three copies of this text (Moreton, ‘The Compotus’ (1999),
61-82; Nothaft, Dating the Passion (2012), pp. 146-54).
Contents:ff. 1v-8v: A gathering of 8 leaves probably compiled
entirely by Salomon, (fl. 1185), a monk of Christ Church cathedral
priory of Canterbury: his autograph and introductory note on f. 1v.
Miscellaneous mnemonic rules for the computus, mostly in verse form
(ff. 2r-6v); directions for calculating the Septuagesima moon (ff.
6r-6v); extracts from the computational treatise of 'magister
Cunestabulus' (ff. 6v-8r) marked by marginal guide letters by
Salomon; Salomon's table (f. 8v).ff. 9r-13v: Instructions and
mnemonic verses for determining Easter, and other moveable feasts
(Septuagesima, Quadragesima, Easter, Rogation, Pentecost). Tables
added for the years 1406-1433 and 1420-1447 to show the date of
Easter (f. 13r-v). ff. 14r-17r: Hermann of Reichenau (b. 1013, d.
1054), Computus (extract). ff. 17r-v: A treatise on the Calendar:
'Ratio Gaii Caesaris de ordine anni', followed by notes on the
discovery of the age of the Moon and a computational table of
moveable feasts. At the end, a short interrogatio on the cycle of
the Sun (f. 17v). f. 18r: A prognostic in verse referring to
Egyptian days. ff. 18v-30r: An astronomical calendar linked to the
Egyptian and Dogs days, with tables of moon and moveable feasts.
The names of the saints are entered only until the end of February.
Some notes added below the calendar are related to De natura rerum
(On the Nature of Things) of Bede the Venerable (b. c 673, d. 735),
and the Computus of Garland (fl. 1080); some of those concerning
the dating of Easter are copied by Salomon (ff. 20r-21r). ff.
30v-32r: Tables of Easter and other moveable feasts including a
table of lunar cycle (f. 31v). f. 34r: An extract from an anonymous
computational treatise often attributed to Bede, rubric: 'De locis
septem embolismorum' and notes on the computus based on Bede. Below
this extract is a 12th-century list of the Archbishops of
Canterbury from Augustine to Richard of Dover (consecrated 1174).
ff. 34v-37r: Computational notes mostly extracted from the
anonymous treatise De ratione computi (On the Reckoning of the
Computus)based on Bede's De temporum ratione (On the Reckoning of
Time)(imperfect). ff. 41r-44v: Astronomical and computational
extracts from Bede and similar sources. ff. 45r-72v: Several notes
on the computus, stars, winds and meteorology based on Bede,
Isidore of Seville (d. 636), and Hrabanus Maurus (d. 856)
(imperfect). An extract from the beginning of the anonymous
astronomical treatise, Liber Nimrod (Book of Nimrod) (f. 48v). A
series of astronomical verses (ff. 57v-61v). ff. 73r-75v:
Anonymous, De computus manualis (On the Manual Computus),
beginning: 'Quomodo inveniri possint concurrentes et data
cuiuslibet anni per manum' copied by Salomon. f. 78v: Verses on the
three Maries followed by an added astronomical table copied by
Salomon. The manuscript contains a number of later additions:f. 1r:
A title in a 13th-century hand probably written by the librarian of
Christ Church: 'Aedthelardus de compoto' preceded by an early
modern press-mark 'Gr' and '51'.f. 1r: Various later additions
including a note on a flood in Thanet and Sheppey in 1394. ff.
32v-33v: An added table of the dates of Easter 1269-1408 written in
a 15th-century hand. At the end is the note 'Quere residuum istius
operis in tabula Johannis Trendle'. John Trendle (d. 1433) was a
monk of Christ Church Canterbury; his tables are mentioned in
Oxford, Bodleian Library, MS Digby 92, f. 15r. ff. 37r-38v: A
general lunarium (prognostics according to the cycle of the Moon),
written in several late 14th- and early 15th-century hands. ff.
39r-40v: Ralph of Diceto (d. 1199/1200), description of Britain
(entitled 'Commendacio Britannie') from the Ymagines historiarum
(Images of History), beginning: 'Britannia sicut legitur in insulas
omne est vel prima vel maxima Quam natura benignior a deo reddidit
ad inhabitandum acceptam ut quicquid usus desiderat vel appetit
luxus ex ea proveniat aut aliunde transuehatur ad eam' (f. 39r),
written in a 15th-century hand. f. 78v: A (?) charm, '+ Karo.
karunce. Redibat. Insanum. Sabaoth. Emmanuel. Paraclitum. +', added
in a 12th-century script. f. 78v: Notes on the lunar calendar,
added in a (?) 14th-century script. [ff. 76r-78r are blank, with
the exception of a partially erased note on f. 76v].
Decoration:Diagram of a hand in brown and red (f. 6r). Diagrams of
hands in brown ink with numbers in red or green (ff. 73r, 73v, 74v,
75r). Pencil sketch of a hand (f. 75v). Tables in red, brown,
green, or blue (ff. 5, 8v). Large KL letters in red or green with
penwork decoration. Large and medium initials in blue, purple or
red, some with simple penwork decoration. Small initials in red,
green, blue, or brown, some with simple penwork decoration.
Highlighting of letters in green or red. Rubrics in red.
