PREFACE. xi
A further change has been made in the arrangement of the diagrams, which in Jebb’s edition were collected into two tables, and thus rendered inconvenient for comparison with the text, and which, morcover, in matiy cases are incorrectly drawn. “They have been carcfully re-copicd from a MS. in the British Muscum (Royal, 7 F. viit), which Sir E. Maunde Thompson, who was so kind as to examine this and several other Baconian MSS. in the British Muscum for me, pro- nounces to be of the latter part of the thirteenth century, i.e. contemporary, or very nearly so, with Bacon. Each diagram has been placed in its proper context,
It was found that in many cases the reasoning of the author had been entirely nullified by defective punctuation, This has been entirely revised, and the number of distinet sentenecs and paragraphs has been very largely increased. Students of the Ofus Afajus have found the work difficult to refer to, owing to the multiplicity and diversity of the subjects treated, and the want of such guidance as page-headings or marginal notes can supply. This defect has been remedied, an analysis of the work has been prefixed, and an improved index added,
A few remarks on the MSS. of the Opus Afazus. Jebb's edition was founded on a MS. in the library of Trinity College, Dublin, which at that time was the only MS. known to contain the complete work. Jt con- tains a note in Archbishop Usher’s handwriting to the effect that the MS. was presented to the College by Gordian Strowbridge, and that the diagrams were drawn by Sir Christopher Heyden. ‘This MS. is very clearly written in 249 folios of four columns. Sir Christopher Heyden, of Baconsthorpe, in Norfolk, was
