Here let us break the chain of rhymes that are unbroken in the text, to notice the extraordinary skill with which the rhythm has been woven in one paragraph, suggesting by recurrences of sound the passing of a multitude, which is presented at the same time to the eye of fancy by accumulated images.  The next eleven triplets introduce the presiding genius of the pageant.  Students of Petrarch’s “Trionfi” will not fail to note what Shelley owes to that poet, and how he has transmuted the definite imagery of mediaeval symbolism into something metaphysical and mystic.

    And as I gazed, methought that in the way
    The throng grew wilder, as the woods of June
    When the south wind shakes the extinguished day;

    And a cold glare, intenser than the noon
    But icy cold, obscured with blinding light
    The sun, as he the stars.  Like the young moon—­

    When on the sunlit limits of the night
    Her white shell trembles amid crimson air,
    And whilst the sleeping tempest gathers might,—­

    Doth, as the herald of its coming, bear
    The ghost of its dead mother, whose dim form
    Bends in dark ether from her infant’s chair;

    So came a chariot on the silent storm
    Of its own rushing splendour, and a Shape
    So sate within, as one whom years deform,

    Beneath a dusky hood and double cape,
    Crouching within the shadow of a tomb. 
    And o’er what seemed the head a cloud-like crape

    Was bent, a dun and faint ethereal gloom
    Tempering the light.  Upon the chariot beam
    A Janus-visaged Shadow did assume

    The guidance of that wonder-winged team;
    The shapes which drew it in thick lightnings
    Were lost:—­I heard alone on the air’s soft stream

    The music of their ever-moving wings. 
    All the four faces of that charioteer
    Had their eyes banded; little profit brings

    Speed in the van and blindness in the rear,
    Nor then avail the beams that quench the sun,
    Or that with banded eyes could pierce the sphere

    Of all that is, has been, or will be done. 
    So ill was the car guided—­but it past
    With solemn speed majestically on.

The intense stirring of his imagination implied by this supreme poetic effort, the solitude of the Villa Magni, and the elemental fervour of Italian heat to which he recklessly exposed himself, contributed to make Shelley more than usually nervous.  His somnambulism returned, and he saw visions.  On one occasion he thought that the dead Allegra rose from the sea, and clapped her hands, and laughed, and beckoned to him.  On another he roused the whole house at night by his screams, and remained terror-frozen in the trance produced by an appalling vision.  This mood he communicated, in some measure, to his friends.  One of them saw what she afterwards believed to have been his phantom, and another dreamed that he was dead.  They talked much of death, and it is noticeable that the last words written to him by Jane were these:—­“Are you going to join your friend Plato?”