The year later, he was made deputy postmaster, and soon became especially helpful in city affairs. He obtained better watch or police regulations, organized the first fire-company, and invented the Franklin stove, which was used far and wide. At thirty-seven, so interested was he in education that he set on foot a subscription for an academy, which resulted in the noble University of Pennsylvania, of which Franklin was a trustee for over forty years. The following year his only daughter, Sarah, was born, who helped to fill the vacant chair of the lovely boy. The father, Josiah, now died at eighty-seven, already proud of his son Benjamin, for whom in his poverty he had done the best he could. About this time, the Leyden jar was discovered in Europe by Musschenbroeck, and became the talk of the scientific world. Franklin, always eager for knowledge, began to study electricity, with all the books at his command. Dr. Spence, a gentleman from Great Britain, having come to America to lecture on the subject, Franklin bought all his instruments. So much did he desire to give his entire time to this fascinating subject that he sold his printing-house, paper, and almanac, for ninety thousand dollars, and retired from business. This at forty-two; and at fifteen selling ballads about the streets! Industry, temperance, and economy had paid good wages. He used to say that these virtues, with "sincerity and justice," had won for him "the confidence of his country." And yet Franklin, with all his saving, was generous. The great preacher Whitefield came to Philadelphia to obtain money for an orphan-house in Georgia. Franklin thought the scheme unwise, and silently resolved not to give when the collection should be taken. Then, as his heart warmed under the preaching, he concluded to give the copper coins in his pocket; then all the silver, several dollars; and finally all his five gold pistoles, so that he emptied his pocket into the collector's plate. Franklin now constructed electrical batteries, introduced the terms "positive" and "negative" electricity, and published articles on the subject, which his friend in London, Peter Collinson, laid before the Royal Society. When he declared his belief that lightning and electricity were identical, and gave his reasons, and that points would draw off electricity, and therefore lightning-rods be of benefit, learned people ridiculed the ideas. Still, his pamphlets were eagerly read, and Count de Buffon had them translated into French. They soon appeared in German, Latin, and Italian. Louis XV. was so deeply interested that he ordered all Franklin's experiments to be performed in his presence, and caused a letter to be written to the Royal Society of London, expressing his admiration of Franklin's learning and skill. Strange indeed that such a scientist should arise in the new world, be a man self-taught, and one so busy in public life.