With some leisure at his command, Maury determined to become an author, under the encouragement of the recent appearance in the _American Journal of Science and Arts_ of his first scientific article, “On the Navigation of Cape Horn”. This, the first fruit of his sea experience, described forcefully the dangers of the passage of Cape Horn, and gave specific information concerning the winds and the peculiar rising and falling of the barometer in those latitudes. In the same number of this journal there appeared another article describing Maury’s “Plan of an Instrument for Finding the True Lunar Distance”, the instrument in question having been invented by him. With these beginnings, he ambitiously set to work to finish a book on navigation, which he had commenced during the last part of his recent tour of sea duty. He did not expect to receive much direct profit from such a nautical book, but hoped that it might be of a collateral advantage to him in making his name known to the Navy Department and to his brother officers. As it was the first nautical work of science ever to come from the pen of an American naval officer, he expected to base a claim for promotion on the merits of the book, and had hopes of being made a lieutenant of ten years’ rank with the accompanying back pay amounting to $4,000 or $5,000. [Illustration: _Courtesy of “The Journal of American History,” Vol. IV, Number 3 (1910)._ LIEUT. M. F. MAURY From a daguerreotype of about the year 1855] These plans of Maury’s did not fully materialize. President Jackson was of the opinion that the young author deserved promotion for his scientific work and reimbursement for the money which he had expended in its publication, but the Secretary of the Navy, Mahlon Dickerson, did not carry out the President’s wishes. The book itself, however, was a great success on its appearance early in the year 1836, under the title of “A New Theoretical and Practical Treatise on Navigation”. The publishers, E. C. and J. Biddle of Philadelphia, soon had the pleasure of printing a long list of favorable opinions of the work from professors and distinguished officers in the navy, among which the commendation of Nathaniel Bowditch gave Maury the greatest satisfaction. His book very quickly took the place of Bowditch’s “Practical Navigator” as a textbook for junior officers in the navy, and when the Naval Academy was established at Annapolis it was used for several years as the basis of the instruction given to midshipmen in navigation. In the title page appeared the significant words, “Cur Non?” (Why not?), the motto adopted by Lafayette when he espoused the cause of the American colonies; this was in effect Maury’s answer to any query that might be made as to why a young naval officer should attempt the writing of a book.