In the first of these catastrophes, the life of a peasant was preserved in a wonderful manner. An immense block came toppling down close to his châlet and covered it like a shield, so as to preserve it from being crushed by the following débris, though piled up two hundred feet above it. Thus, immured as it were in a living tomb, the unfortunate man spent miserable weeks and months, subsisting on the stores of cheese hoarded in his hut, without light and air, and in constant fear that the rocks above his head might give way and bury him under their ruins. With all the energy of despair, he endeavoured to find his way out of the mighty mound of rubbish, and at length, after incredible toil, emerged into the open daylight. More like a spectre than a human being, pale and emaciated, with torn clothes, and covered with bruises, he knocked at the door of his house[12] in the lower valley, where his wife and children, who had already long reckoned him among the dead, were at first terrified at his ghost-like appearance, and called in the village pastor to convince them of his identity, before they ventured to rejoice at his return. Footnote 12: It is almost superfluous to mention that in the Alps many of the peasants lead a migratory existence. During the summer they ascend, with their herds, into the higher valleys, where they remain, separated from their families, until the first night-frosts force them to return to their homes on a lower level. On the road from Sallenches to Servoz, in the Valley of the Arve, well known to all the visitors of Mont Blanc, may be seen the ruins of a high mountain which collapsed in the year 1751, causing so dreadful a crash and raising such clouds of dust that the whole neighbourhood thought the world was at an end. The black dust was taken for smoke; flames had been seen darting about in the murky clouds, and the report spread to Turin that a new Vesuvius had suddenly opened its subterranean furnaces among the highest of the Alpine mountains. The king, alarmed or interested at the news, immediately sent the famous geologist Vitaliano Donati to gather accurate information on the spot. Donati, travelling night and day, with all the eagerness of a zealous naturalist, arrived while the appalling phenomenon was still in full activity.