The atmosphere of Boston was completely theological. There was no room, no opportunity, for science, and no inducement or even suggestion that would lead to it, still less to original research in it. We find Franklin in a state of rebellion against the prevailing tone of thought, writing against it in his brother’s newspaper at the risk of imprisonment, and in a manner more bitter and violent than anything he afterwards composed. If he had remained in Boston it is not likely that he would ever have taken seriously to science, for all his energies would have been absorbed in fighting those intolerant conditions which smothered all scientific inquiries. In Pennsylvania he found the conditions reversed. The Quakers and the German sects which made up the majority of the people of that province in colonial times had more advanced ideas of liberty and free thought than any of the other religious bodies in America, and in consequence science flourished in Pennsylvania long before it gained entrance into the other colonies. The first American medical college, the first hospital, and the first separate dispensary were established there. Several citizens of Philadelphia who were contemporaries of Franklin achieved sufficient reputation in science to make their names well known in Europe. David Rittenhouse invented the metallic thermometer, developed the construction of the compensation pendulum, and made valuable experiments on the compressibility of water. He became a famous astronomer, constructed an orrery to show the movements of the stars which was an improvement on all its predecessors, and conducted the observations of the transit of Venus in 1769. Pennsylvania was the only one of the colonies that took these observations, which in that year were taken by all the European governments in various parts of the world. The Legislature and public institutions, together with a large number of individuals, assisted in the undertaking, showing what very favorable conditions for science prevailed in the province.[18] These were the conditions which seem to have aroused Franklin. Without them his mind tended more naturally to literature, politics, and schemes of philanthropy and reform; but when his strong intellect was once directed towards science, he easily excelled in it. Some of the early questions discussed by the Junto, such as “Is sound an entity or body?” and “How may the phenomena of vapors be explained?” show an inclination towards scientific research; and it is very likely that he studied such subjects more or less during the ten years which followed his beginning business for himself.