At the beginning of his work at the Depot of Charts and Instruments, he uncovered in the old log books facts relating to the Gulf Stream, which led him to certain interesting conclusions concerning this great ocean current that had not been previously recognized. In July, 1843 he gave an address before the President, the Corps Diplomatique, and important government officials on “The Gulf Stream and Its Causes”, which was reread with certain variations before several different learned societies during the following year. He continued to write such scientific papers on topics bearing on oceanography, while he was engaged in astronomical work and the preparation of his wind and current charts, and these papers, after being delivered before scientific societies, were published by him in the astronomical and meteorological publications of his office. Of particular note were those which appeared in the different editions of his “Sailing Directions” under such titles as “The Influence of the Gulf Stream on the Trade of Charleston”, “The Currents of the Sea”, “On the Saltness of the Sea”, “On the General Circulation of the Atmosphere”, “Red Fogs and Sea Dust”, “On the Probable Relation between Magnetism and the Circulation of the Atmosphere”, “Of Clouds and Equatorial Cloud Rings”, “On the Geological Agency of the Winds”, and “Deep Sea Soundings”. [Illustration: _Copy of engraving furnished by Captain E. T. Pollock, U. S. N. Superintendent Naval Observatory._ COPY OF AN ENGRAVING OF MAURY WHICH HANGS IN THE SUPERINTENDENT’S OFFICE AT THE UNITED STATES NAVAL OBSERVATORY] The last-mentioned paper was made possible by the coöperation afforded by the government in authorizing in 1849 the Secretary of the Navy to detail three suitable vessels to assist in Maury’s wind and current investigations and to order all ships of the navy to coöperate in so far as it was compatible with the public interest. Maury had long had a desire to explore the bottom of the ocean, and he now saw to it that these ships especially detailed to help him were equipped and thoroughly instructed for making soundings. The first attempts were made by the schooner _Taney_, under the command of Lieutenant J. C. Walsh, in the autumn of 1849. But her work was of negligible value, as she succeeded only in losing some 5700 fathoms of line as well as her deep-sea sounding apparatus, and then proved so unseaworthy that she had to be condemned and sent back home under escort. Later, however, the results secured particularly by Captain Charles T. Platt in the sloop of war _Albany_ and by Lieutenants S. P. Lee and O. H. Berryman in the brig _Dolphin_ were of great importance. So extensive was the data regarding soundings at Maury’s command by the close of the year 1853 that he was able to publish in the sixth edition of his “Sailing Directions” (1854) ninety pages of matter under the heading of “Physical Geography of the Sea”.