The MS is a very small quarto on vellum, and is No. 17, A1. in the Bibl. Reg., British Museum. It is described in David Casley’s Catalogue of the MSS. of the Old Royal Library, as 'A Poem of Moral Duties: here entitled, Constitutiones Artis Gemetrie secundem Euclidem. - 'Whoso wol bothe wel rede and loke.' The age of the MS. has been variously estimated. Mr. Halliwell and the late Rev. A.F.A. Woodford supposed it to have been written about 1390, or earlier. The MS. is admitted to be the oldest genuine record of the Craft of Masonry known. Mr. Halliwell pointed out that the writer of the poem was evidently a priest , from the words, 'And when the gospel me rede schal,' on line 629. He also drew attention to line 143, which intimates a still older MS. must have existed when the poem was written.