Harley MS 80, ff 1r-57r, ff 34r-54r

Richard of Wallingford, Tractatus Albionis.

This treatise by Richard of Wallingford (c. 1292-1336), abbot of St Albans and astronomer, relates to an equatorium, an astronomical instrument for the calculation of planetary positions. It was probably composed around 1326, at much the same period as the Tractatus rectanguli that follows. Its title, Albion, is an English pun for 'all by one'.

Title (upper margin) '3 quaternum astronomie? cum tabulis', incipit: 'Albyon est geometricum instrumentum. Almanach', explicit (f. 46r) 'et hec est forma / tabule continens tantummodo centrum equatum Saturni', followed by tables (ff. 46v-54r).

The work is divided into 4 parts, each beginning respectivelly on ff. 34r, 38r, 42r, 46r, and subdivided into propositions (conclusiones), chapters (capitula), uses (utilitates), and tables (tabulae), with marginal diagrams.

Lacking text from mid III, 34 to end of III, 42. With minor editorial amendments. Another copy in Harley MS 625. For the text see also L. Thorndike and P. Kibre, Catalogue of Incipits of Medieval Scientific Writings in Latin, rev. edn (London, 1963; The Mediaeval Academy of America Publication, 29; with supplements in 1965 and 1968), p. 74h; its electronic version on CD-ROM ed. (Ann Arbor, MI, 2000=eTK), no. 74h.

Decoration:

Chapter initials (3 lines) in blue, with pen-flourished decoration in red extending into the margin. Geometrical diagrams in the margins (ff. 34r-36v, 37v-42r) mostly in red. Astronomical tables (ff. 46v-54r) in red and dark brown ink. Occasional paragraph marks in red and occasional sentence initials touched in red. Headings in red.