The author of the following pages does not write because he is a learned man; he is conscious of the reverse; and that his merits give him no claim to that appellation; neither does he make this attempt because he is well acquainted with either the new, or the old theories of the earth; but, from having observed that the Theory of Concentric Spheres has been before the world for six or seven years, without attracting the attention of the scientific, except in a very few instances;――few besides the author himself having come forward to advocate its correctness. The newspaper scribblers, who have noticed the theory at all, have almost uniformly appeared to consider it as a fit subject on which to indulge their wit, the sallies of which, clothed in all the humour and satire their fancies could suggest, have in some degree had a tendency to throw around it an air of levity very unfavourable to serious investigation. But to deal in sarcasm is not always reasoning; and the truth is not to be ascertained by indulging in ridicule. Considerations of this nature, first induced the author to devote a short time to the task of investigating a subject, to which he had paid but little attention, and to give the several papers, published by Captain Symmes, a cursory examination; in the course of which, he noted such of Symmes's principles and proofs as attracted his attention, as they occurred; and has since presumed to arrange them in such order as his own fancy suggested; supposing that, as they had struck forcibly on his mind, they might perhaps attract the attention of some other person, whose habits of thinking may be similar to his own. He has in a few instances inserted, in addition to those which he has seen advanced by Captain Symmes, such reasons and proofs in support of the theory as occurred to him at the time. However, he has no claim to originality; as he has made a liberal use of the publications of Captain Symmes, as well as the remarks made on them by others, which came in his way. The reader will not look for a complete analysis of the theory in this short treatise; it is not intended as such by the author, his object being merely to attract the attention of the learned, who are in the habit of indulging in more abstruse researches into the operation and effect of natural causes; and should it be found to merit the attention of such, it is hoped their enquiries may be so directed as to accelerate the march of scientific improvement, enlarge the field of philosophic speculation, and open to the world new objects of ambition and enterprise.