"An Arab of the desert, lance in rest,
Mounted upon a dromedary."
The Arab rides forward to meet him; and the dreamer perceives, in the countenance of the rider, the agitation of fear, and that he often looks behind him in a troubled way, whilst in his hand he holds two books—one of which is "Euclid's Elements"; the other (which is a book and yet not a book) seeming, in fact, a shell as well as a book—seeming neither, and yet both at once. The Arab directs him to apply the shell to his ear; upon which,
"In an unknown tongue, which yet I understood,"
the dreamer says that he heard
"A wild prophetic blast of harmony,
An ode, as if in passion utter'd, that foretold
Destruction to the people of this earth
By deluge near at hand."
The Arab, with grave countenance, assures him that it is even so; that all was true which had been said; and that he himself was riding upon a divine mission, having it in charge
"To bury those two books;
The one that held acquaintance with the stars,
... undisturb'd by Space or Time;
The other, that was a god, yea, many gods,
Had voices more than all the winds, and was
A joy, a consolation, and a hope!"
That is, in effect, his mission is to secure the two great interests of poetry and mathematics from sharing in the watery ruin. As he talks, suddenly the dreamer perceives that the Arab's "countenance grew more disturbed," and that his eye was often reverted; upon which the dreaming poet also looks along the desert in the same direction; and in the far horizon he descries "a glittering light." What is it? he asks of the Arab rider. "It is," said the Arab, "the waters of the earth," that even then were travelling on their awful errand. Upon which, the poet sees this apostle of the desert riding
"Hurrying o'er the illimitable waste,
With the fleet waters of a drowning world
In chase of him: whereat I [meaning the poet] waked in terror,
And saw the sea before me, and the book
In which I had been reading at my side."[110]