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.
In his _Gazette_ for December 15, 1737, there is an essay on the causes of earthquakes, summarizing the various explanations which had been given by learned men, and this essay is supposed to have been written by him. Six years afterwards he made what has been usually considered his first discovery,--namely, that the northeast storms of the Atlantic coast move against the wind; or, in other words, that instead of these storms coming from the northeast, whence the wind blows, they come from the southwest. He was led to this discovery by attempting to observe an eclipse of the moon which occurred on the evening of October 21, 1743; but he was prevented by a heavy northeaster which did great damage on the coast. He was surprised to find that it had not prevented the people of Boston from seeing the eclipse. The storm, though coming from the northeast, swept over Philadelphia before it reached Boston. For several years he carefully collected information about these storms, and found in every instance that they began to leeward and were often more violent there than farther to windward.
He seems to have been the first person to observe these facts, but he took no pains to make his observations public, except in conversation or in letters to prominent men like Jared Eliot, of Connecticut, and these letters were not published until long afterwards. This was his method in all his investigations. He never wrote a book on science; he merely reported his investigations and experiments by letter, usually to learned people in England or France. There were no scientific periodicals in those days. The men who were interested in such things kept in touch with one another by means of correspondence and an occasional pamphlet or book.