1. Cotton MS Vitellius A I, ff 1–20 Reference (shelfmark): Cotton MS Vitellius A I, ff 1–20 Title: John Somer, Kalendarium (1r–20r), including a working model of an astrolabe (17v) and On the Twelve Signs (18v: Boffey 688) Collection Area: Western Manuscripts Languages: English, Middle and Latin Date Range: Mid 15th century Extent: 1 item