Exeter Cathedral is not rich in pre-Reformation glass and few complete or nearly complete medieval windows survive anywhere in Devon. The Great East Window at Exeter Cathedral, however, contains the largest assemblage of medieval glass still surviving in any church in the county. The panels are the earliest pieces of medieval glass in Britain for which it is possible to assign a known glazier. Even allowing for restoration, it seems remarkable that nine of the panels created and installed by Master Walter the Glazier over 700 years ago should still exist in the building for which they were made, especially when so much of the surrounding medieval city has been destroyed, including the original masonry of the window itself. Master Walter worked at the cathedral in 1311 when the fabric rolls record him fitting a window in the clerestory with the help of two young apprentices. Google with the Archive Organization has sponsored the digitisation of books from several libraries. The Internet Archive makes available, in its Community Texts Collection (originally known as Open Source Books), books that have been digitised by Google from a number of libraries. These are books on which copyright has expired, and are available free for educational and research use. This rare book was produced from a copy held by the Princeton University Library, and is available from the Internet Archive.