There was, as I have said, a great burning at Alexandria in 47 B.C., when Caesar set the fleet in the harbour on fire to prevent its falling into the hands of the Egyptians. The flames spread, and the great library stood but 400 yards from the quayside, with warehouses full of books yet closer. The last great burning was perpetrated in A.D. 642. Gibbon quotes the famous sentence of Omar, the great Mohammedan who gave the order: 'If these writings of the Greeks agree with the book of God, they are useless and need not be preserved; if they disagree, they are pernicious and ought to be destroyed,' and goes on: The sentence was executed with blind obedience; the volumes of paper or parchment were distributed to the four thousand baths of the city; and such was their incredible multitude that six months were barely sufficient for the consumption of this precious fuel.... The tale has been repeatedly transcribed; and every scholar, with pious indignation, has deplored the irreparable shipwreck of the learning, the arts, and the genius, of antiquity. For my own part, I am strongly tempted to deny both the fact and the consequences. Of the consequence he writes: Perhaps the church and seat of the patriarchs might be enriched with a repository of books: but, if the ponderous mass of Arian and Monophysite controversy were indeed consumed in the public baths, a philosopher may allow, with a smile, that it was ultimately devoted to the benefit of mankind. I sincerely regret the more valuable libraries, which have been involved in the ruin of the Roman empire; but, when I seriously compute the lapse of ages, the waste of ignorance, and the calamities of war, our treasures, rather than our losses, are the object of my surprise. Many curious and interesting facts are buried in oblivion: the three great historians of Rome have been transmitted to our hands in a mutilated state, and we are deprived of many pleasing compositions of the lyric, iambic, and dramatic poetry of the Greeks. Yet we should gratefully remember that the mischances of time and accident have spared the classic works to which the suffrage of antiquity had adjudged the first place of genius and glory; the teachers of ancient knowledge, who are still extant, had perused and compared the writings of their predecessors; nor can it fairly be presumed that any important truth, any useful discovery in art or nature, has been snatched away from the curiosity of modern ages.