The science of meteorology, to which the following pages are devoted, is, and always has been, a confessedly complex subject; and on this account, any suggestions and facts which observation gleans,--no matter how humble the source may be, should not be denied a hearing by those professedly engaged in the pursuit of truth. Step by step, the author became more and more confirmed in his doubts of the soundness of many modern theories; and in 1838 he had attained a position which enabled him to allege in the public prints of the day, that there did exist certain erroneous dogmas in the schools, which stood in the way of a fuller development of the causes of many meteorological phenomena. This annunciation was made in general terms, and no notice was taken of it. Subsequently, he forwarded to the British Association of Science, then convened at Birmingham, a communication of similar tenor; and at a later date still, a more particular statement of the advantages of his discoveries to the navigator and agriculturist, was sent to the British admiralty. The first of these communications was treated with silent contempt; the last elicited some unimportant reply. In 1844 a memorial was presented to Congress, accompanied with a certified copy of _predictions_ of the weather, written several weeks before the event, and attested in due form by two impartial witnesses; but neither did this result in any inquiry as to its truth. During the time since elapsed, he has been engaged in pursuits which prevented him from pressing the subject elsewhere, until the spring of 1853, he brought his theory under the notice of the Smithsonian Institution. This led to a correspondence between himself and the gentlemanly Secretary of the Institution, whose doubts of the truth of his allegations were expressed with kindness, and whose courtesy was in strange contrast with the conduct of others. In the communications which he forwarded to that Institution, he gave a detailed statement of the difficulties he had met with, and expressed the hope that an Institution, created for the purpose of increasing and diffusing knowledge, would feel justified in lending the influence of its name to facilitate the completion of a theory which was yet undeniably imperfect. In view of this, a test was proposed.[1] "Give us, for example, a prediction of the weather for one month in each season of the year 1854, for the City of Washington." This test the author refused, for the reason that he did not consider it necessary to wait so long; but he informed the Secretary of the Institution, that he would prepare an outline of his theory, which would enable him to decide upon the merits of the discoveries claimed. This outline is contained in the following pages. During the summer of 1853 he called upon Professor Henry, then at Chicago, with his manuscript; but a sudden indisposition prevented that gentleman from having it read.