circumstance Virgil alludes in his description of the sayings of the Cumaean Sibyl being written upon the leaves of the forest.  They were in the form of acrostic verses; the letters of the first verse of each oracle containing in regular sequence the initial letters of all the subsequent verses.  They were full of enigmas and mysterious analogies, founded upon the numerical value of the initial letters of certain names.  It is supposed that they contained not so much predictions of future events, as directions regarding the means by which the wrath of the gods, as revealed by prodigies and calamities, might be appeased.  They seemed to have been consulted in the same way as Eastern nations consult the Koran and Hafiz.  There was no attempt made to find a passage suitable to the occasion, but one of the palm leaves after being shuffled was selected at random.  To this custom of drawing fateful leaves from the Sibylline books—­called in consequence sortes sibyllinae—­there is frequent allusion by classic authors.  We know that the writings of Homer and Virgil were thus treated.  The elevation of Septimius Severus to the throne of the Roman Empire was supposed to have been foretold by the circumstance that he opened by chance the writings of Lampridius at the verse, “Remember, Roman, with imperial sway to rule the people.”  The Bible itself was used by the early Christians for such purposes of divination.  St. Augustine, though he condemned the practice as an abuse of the Divine Word, yet preferred that men should have recourse to the Gospels rather than to heathen works.  Heraclius is reported by Cedrenus to have asked counsel of the New Testament, and to have been thereby persuaded to winter in Albania.  Nicephorus Gregoras frequently opened his Psalter at random in order that there he might find support in the trial under which he laboured.  And even in these enlightened days, it is by no means rare to find superstitious men and women using the sacred Scriptures as the old Greeks and Romans used the Sibylline oracles—­dipping into them by chance for indications of the Divine Will.

The Cumaean Sibyl was not the only prophetess of the kind.  There were no less than ten females, endowed with the gift of prevision, and held in high repute, to whom the name of Sibyl was given.  We read of the Persian Sibyl, the Libyan, the Delphic, the Erythraean, the Hellespontine, the Phrygian, and the Tiburtine.  With the name of the last-mentioned Sibyl tourists make acquaintance at Tivoli.  Two ancient temples in tolerable preservation are still standing on the very edge of the deep rocky ravine through which the Anio pours its foaming flood.  The one is a small circular building, with ten pillars surrounding the broken-down cella, whose familiar appearance is often represented in plaster models and bronze and marble ornamental articles, taken home as souvenirs by travellers; and the other stands close by, and has been transformed into the present church of St. Giorgio.  This