British Library MS. Harley 3717. Parchment. 14th Century. Various manuscripts bound together. Imperfect in places. Alexandro Neckam, (de quo vid. ad num, 3737) olim perperam ascriptus. De 4 Elementis, et natura rerum, libri 19. Deest vicesimus, in auctoris prologo citatus, de motu siderum et planetarum.