But a few years sometimes change the whole face of a country. Sir Woodbine Parish informed Darwin that during the three years' drought in Buenos Ayres, beginning in 1827, the ground being so long dry, such quantities of dust were blown about that in the open country the landmarks became obliterated, and people could not tell the limits of their estates. But what shall we say of the instability of human greatness? The career and end of Pompey furnish a striking example. "He who a few days before commanded kings and consuls, and all the noblest of Rome, was sentenced to die by a council of slaves; murdered by a base deserter; cast out naked and headless on the Egyptian strand; and when the whole earth, as Velleius says, had scarce been sufficient for his victories, could not find a spot upon it at last for a grave. His body was burnt on the shore by one of his freedmen, with the planks of an old fishing-boat; and his ashes, being conveyed to Rome, were deposited privately by his wife Cornelia in a vault of his Alban villa." Aristotle, that prince of all true thinkers, loaded with immortal glory, was compelled to flee suddenly and by stealth to Chalcis, in order to save his life, and spare, as he said, the Athenians a new crime against philosophy. There, it is believed, the great man, in his old age, wearied with persecutions, poisoned himself. The venerable Hildebrand, the greatest of all the popes, after the herculean labors of his self-devoted and mighty career, crushed by an accumulation of hardships, said, "I have loved justice and hated iniquity; therefore I die in exile." "The ceremony of Galileo's abjuration," says Sir David Brewster, in his biography of that great man, "was one of exciting interest and of awful formality. Clothed in the sackcloth of a repentant criminal, the venerable sage fell upon his knees before the assembled cardinals; and, laying his hands upon the Holy Evangelists, he invoked the divine aid in abjuring and detesting, and vowing never again to teach, the doctrine of the earth's motion and of the sun's stability. He pledged himself that he would never again, either in words or in writing, propagate such heresies; and he swore that he would fulfill and observe the penances which had been inflicted upon him. At the conclusion of this ceremony, in which he recited his abjuration word for word, and then signed it, he was conveyed, in conformity with his sentence, to the prison of the Inquisition." All because it had been said that the "sun runneth about from one end of heaven to the other," and that "the foundations of the earth are so firmly fixed that they cannot be moved."