Winthrop, of Harvard College, some of which he was enabled to attend under trying conditions. Having received special official consideration by appointment to office under one of the colonial governors, he was accused at the breaking out of the Revolutionary War of a leaning towards Toryism, and was thus prevented from making his career among his own people. At the age of twenty-two years he fled to England, returning to America only for a brief period in command of a British regiment. In England he soon became eminent as an experimental philosopher, and in 1778 became a Fellow of the Royal Society. He afterwards entered the service of the Elector of Bavaria, by whom he was made a Count of the Holy Roman Empire. In 1799 he returned to London and founded the “Royal Institution,” which was destined during the next hundred years to surpass all other foundations in the richness and importance of its contributions to physical science. It was while at Munich that Rumford made his famous experiments on the nature of heat, to which he had been led by observing the great amount of heat generated in the boring of cannon. Finding that he was able to make a considerable quantity of water actually boil by the heat generated by a blunt boring tool, he concluded that the supply of heat from such a source was practically inexhaustible and that it could be generated continuously if only the motion of the tool under friction was kept up. He declared that anything which could thus be produced without limitation by an insulated body or system of bodies could not possibly be a material substance, and that under the circumstances of the experiment, the only thing that was or could be thus continuously communicated was _motion_.