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 that the coming famine must be laid upon the shoulders of its owner and inventor. This absurd idea took such forcible possession of the minds of the populace of Liége, that great mobs collected together, uttering all kinds of maledictions against the mirror and its inventor, and at last became so violent that they attacked Villette's house with the intention of smashing his great work, and administering to the unfortunate philosopher the chastisement they supposed he deserved. Happily, however, for M. Villette and his mirror, Liége was governed in those days by the Prince Bishop of Cologne, who was a man of great enlightenment. He put the crowds round M. Villette's to flight by armed force, but he found that the conviction that all the coming mischief would result from the unlucky mirror was so strong, that he was obliged to issue a pastoral peremptorily declaring that the idea had originated with a number of malicious people, who spared no pains to propagate it for their own bad purposes, and that it was a mischievous and dangerous error to ascribe to a mirror a power which only belonged to the Almighty.

In 1747, Buffon performed many extraordinary experiments with burning mirrors, which were more surprising than any that had hitherto been described. They were mostly performed at the Jardin des Plantes, at Paris, of which institution Buffon was director; and many of them are worth describing.

On the 3rd of April, at about two o'clock in the afternoon, the great mirror was mounted on its stand, and was found to be capable of setting a plank of wood on fire at a distance of 138 feet, when 128 glasses were used, although the light was weak at the time, and the sun was covered with mist. In pursuing these experiments great care had to be taken to prevent the by-standers placing themselves within range of its terrible power, for several were nearly blinded by looking