The wanderers climb along the hairy sides of Lucifer and finally reach a cavity which corresponds to the lowest part of hell, and up into which are thrust the legs of the monster. They have thus passed the center of earth and are now in the other or southern hemisphere. Making their way upward along the course of a stream they finally come out into the open air, where the mount of purgatory rises sheer up from the surface of the great southern sea. The first cantos of Purgatory are of wonderful beauty, and their loveliness is heightened by contrast, coming as it does after the darkness, filth, and horrors of hell. Issuing from the subterranean passage just before sunrise, the poets see before them a vast expanse of sea, lighted up by the soft rays of Venus, the morning star, and gradually becoming brighter as the dawn advances: "Sweet hue of eastern sapphire, that was spread O'er the serene aspect of the pure air, High up as the first circle, to mine eyes Unwonted joy renew'd, soon as I 'scaped Forth from the atmosphere of deadly gloom, That had mine eyes and bosom fill'd with grief. The radiant planet, that to love invites, Made all the Orient laugh, and veiled beneath The Pisces' light, that in his escort came. "To the right hand I turned, and fixed my mind On the other pole attentive, where I saw Four stars ne'er seen before save by the ken Of our first parents. Heaven of their rays Seemed joyous. O thou northern site! bereft Indeed, and widowed, since of these deprived." As they stand watching this scene, a venerable old man (Cato, the guardian of the island) approaches and tells them to go to the seashore and wipe off the stains of hell with the reeds that grow there: "The dawn had chased the matin hour of prime, Which fled before it, so that from afar I spied the trembling of the ocean stream. "We traversed the deserted plain, as one Who, wandered from his track, thinks every step Trodden in vain till he regain the path. "When we had come where yet the tender dew Strove with the sun, and in a place where fresh The wind breathed o'er it, while it slowly dried; Both hands extended on the watery grass My master placed, in graceful act and kind. Whence I of his intent before apprized, Stretched out to him my cheeks suffused with tears. There to my visage he anew restored That hue which the dun shades of hell concealed. "Then on the solitary shore arrived, That never sailing on its waters saw Man that could after measure back his course, He girt me in such manner as had pleased Him who instructed; and O strange to tell! As he selected every humble plant, Wherever one was plucked another there Resembling, straightway in its place arose."