before one of these mirrors, in order to observe the effect, was surprised to find himself face to face with an armed hand apparently directed against him. When he advanced, the hand seemed to spring forward to meet him. The king could not conceal his surprise and fright, and afterwards felt so ashamed at being terrified with a mere shadow that he ordered the mirror to be taken away, and could never be prevailed upon to look into it again.” The _Journal des Savants_ then goes on quaintly to remark on the various startling effects produced by these mirrors, winding up by stating that its powers of reflection were so great, that at night the light of a torch or flambeau was reflected so perfectly that an observer placed at four hundred feet distant could read the smallest print. It also mentions a curious piece of superstition on the authority of a scientific writer of the name of Robertson, who states that it happened at Liége. In reading the accounts of these experiments we can see how easily the minds of individuals were affected in those days by the wonderful. It happened while one of Villette’s mirrors was at Liége, that the latter end of the summer was somewhat rainy, and great fears were entertained that a bad harvest and dear bread would be the result. Certain evil-minded people, who had taken a fancy to the mirror and wished to possess it by unfair means, spread the report that the continual rain was entirely caused by its action on the clouds and sun, and 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. [Illustration: FIG. 25.—Burning Mirror. ]