Even Virgil is somewhat abashed on account of his participation in the delay (Canto iii.); but soon recovers his equanimity, and resumes his usual dignified pace. Dante for the first time observes that his companion casts no shadow on the ground, and Virgil explaining that the spiritual form, while capable of feeling pain, has not the property of intercepting light, takes occasion to point out that there are mysteries for which the human reason is unable to account, and that this very inability forms the chief unhappiness of the great thinkers whom they saw among the virtuous heathen on the border of Hell. With this they reach the foot of the mountain of Purgatory. As is explained elsewhere, this occupies a position exactly opposite to the conical pit of Hell; being indeed formed of that portion of the earth which fled at the approach of Satan when he fell from Heaven. Some of its features are no doubt borrowed from the legendary accounts which Pliny and others have preserved of a great mountain seen by navigators to the west of the Straits of Gibraltar; these accounts being probably based on imperfect descriptions of Atlas or Teneriffe, or both confused together. Its summit is exactly at the Antipodes of Jerusalem, a point which must be carefully borne in mind if the various astronomical indications of time given in the course of the journey are to be rightly understood. The mountain-side, which Dante compares to the steepest and most rugged parts of the Genoese Riviera, appears at first, quite inaccessible; but before long they meet a company of spirits, who, after recovering from their first astonishment at seeing from Dante’s shadow that he is not one of themselves, indicate to them the point at which the cliff may be attacked. Before they proceed further, one of the shades addressing Dante makes himself known as Manfred, son to the Emperor Frederick II., and gives an account of his end, explaining that excommunication--for he had died under the ban of the Church--is powerless to do more than protract the interval between the soul’s admission to Purgatory. After this (Canto iv.) they enter a steep and narrow cleft in the rock, from which they emerge upon a ledge on the mountain face, and a further climb up this lands them about noon on a broader terrace. Hitherto they have been mounting from the eastward, and on looking back in that direction, Dante is surprised to find the sun on his left hand. Virgil explains the topography; and is saying, in order to encourage Dante, that the labour of climbing will diminish as they get higher, when a bantering voice interrupts with the assurance that he will need plenty of sitting yet. The poet recognises in the speaker a Florentine friend. Another playful sarcasm on his thirst for information makes Dante address the shade and inquire as to his state. He, like Manfred, is debarred from entering Purgatory, but on the ground that he had led an easy life, and taken no