In the _Prenostica Pitagorice_ we are assured that we may rest easy as to the integrity of the Catholic Faith being observed, “for that does not happen of necessity which human caution forewarned, can avoid.” It answers any one of a list of thirty-six questions by means of a number obtained by chance between one and twelve. The inquirer is referred to one of 36 birds whose pictures are drawn in the margins with twelve lines of answers opposite each bird. Other schemes of divination found with the _Experimentarius_ in some manuscripts differ from the foregoing only in the number of questions concerning which inquiry can be made, the number of Judges and the names given them, the number of lines under each Judge, and the number of intermediate directory tables that have to be consulted before the final Judge is reached. As Judges we meet the twelve sons of Jacob, the thirty-six decans or thirds of the twelve signs, and another astrological group of twenty made up of the twelve signs, seven planets, and the dragon.[314] [Sidenote: Experimental character of geomancy.] In one manuscript[315] the directions for consulting this last group of Judges are given under the heading, _Documentum experimenti retrogradi_, which like Bernard’s _Experimentarius_ suggests the experimental character of the art of geomancy or the arts of divination in general. Later we shall hear Albertus Magnus in the _Speculum astronomiae_ call treatises of aerimancy,[316] pyromancy, and hydromancy, as well as of geomancy “experimental books.” [Sidenote: Various other geomancies.]