This poem has always been greatly admired by students of Latin literature for its epigrammatic neatness and conciseness, and has been thought too good to be the work of a medieval writer, and has been even attributed to Petronius. Another version, by the medieval poet, Peter Riga, entitled _De ortu et morte pueri monstruosi_, is longer and far less elegant. Hauréau, however, regarded _the Hermaphrodite_ as a medieval composition, since there are no manuscripts of it earlier than the twelfth century; but he was in doubt whether to ascribe it to Hildebert or to Matthew of Vendôme, who in listing his own poems mentions _hic et haec hermaphroditus homo_.[295] [Sidenote: The art of geomancy.] We turn to the association of the name of Bernard Silvester with the superstitious art of geomancy. It may be briefly defined as a method of divination in which, by marking down a number of points at random and then connecting or cancelling them by lines, a number or figure is obtained which is used as a key to sets of tables or to astrological constellations. The only reason for calling this geomancy, that is, divination by means of the element earth, would seem to be that at first the marks were made and figures drawn in the sand or dust, like those of Archimedes during the siege of Syracuse. But by the middle ages, at least, any kind of writing material would do as well. Although a somewhat more abstruse form of superstition than the ouija board, it seems to have been nearly as popular in the medieval period as the ouija board is now. [Sidenote: Prologue of the _Experimentarius_.]