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imperial castle. These performances were also honored by the presence of the Empress Maria Theresa. The imperial couple were highly pleased with the experiments, and, to show their esteem for Divis, they presented him with two heavy golden medals with their busts engraved upon them.

In 1750 Divis demonstrated his superior knowledge of electricity in an amusing way. Father Francis, a learned Jesuit, was about to make some experiments with his electrical machine at the Vienna court. While he was making some preliminary remarks, the Bohemian scholar, who had concealed a number of small iron nails in his periwig, approached the machine and viewed it closely from all sides, as though he were going to make a critical examination of it. His true intention was, however, to take away all electricity stored on the metallic balls, in which hePSM V42 D374 Divis lightning rod.jpgFig. 1.—The Top of the Lightning-rod of Divissucceeded without touching the machine. Imagine the horror of Father Francis when he finally came to perform his experiment, and found that, although his accumulators were well insulated, all his electricity was gone!

In 1753 Prof. Richmann, of St. Petersburg, while observing a storm from a hut, was killed by lightning descending an insulated iron bar specially erected for the purposes of the study. Upon learning of the fate of that martyr of science, Divis drew up a memoir on that unhappy occurrence, in which he demonstrated that the iron bars, as used by Richmann, were both unsafe and dangerous, and clearly showed how, in case of a storm, the danger of a lightning-stroke could be averted by means of a conductor, the idea of which had already matured in his mind. This treatise he sent to the famous mathematician and naturalist, Euler, then President of the Berlin Academy of Sciences, asking for his judgment. But his application was in vain; the Academy failed to understand his reasoning. This is one of the numerous instances which go to show that it is always the individual workers to whom we have to look for any advance in science rather than learned societies. When Franklin's account of his discovery was read in the British Royal Society, it was laughed at by the connoisseurs.

Divis was not discouraged by the cold reception with which