Note 1 — CANTO XXXIV.

This point is the centre of the universe; when Virgil had turned upon the haunch of Lucifer, the passage had been made from one hemisphere of the earth—the inhabited and known hemisphere— to the other where no living men dwell, and where the only land is the mountain of Purgatory. In changing one hemisphere for the other there is a change of time of twelve hours. A second Saturday morning begins for the poets, and they pass nearly as long a time as they have been in Hell, that is, twenty-four hours, in traversing the long and hard way that leads through the new hemisphere on which they have just entered.