anxious to make a rapid passage round Cape Horn, he searched in vain for information relating to the winds and currents. His attention was thus directed to this subject, and it was upon this voyage that he conceived the design of his celebrated Wind and Current Charts. He also began at this time to write papers for the American Journal of Science which attracted much attention, and on his return he published a Treatise on Navigation which was made a text-book for the pupils of the Naval Academy at Annapolis.
In 1842 Lieutenant Maury was placed in charge of the Depot of Charts and Instruments at Washington, which afterwards became the National Observatory and Hydrographic Office. Here he devoted his attention to collecting and converting into systematic tables the valuable data contained in the old log-books of the United States warships, which he found stowed away as so much rubbish, and which had narrowly escaped being sold for junk. At the same time he presented a paper to the National Institute, recommending that all merchant ships be provided with charts of sailing directions, "on which should be daily registered all observable facts relating to the winds, currents, and other phenomena of importance and interest, for the foundation of a true theory of the winds."
A general use of these charts would have constituted one of the greatest exploring expeditions ever devised, but for a time it met with much opposition. Lieutenant Maury's first convert was Captain Jackson of the Baltimore ship D. C. Wright, trading to Rio Janeiro, who made rapid voyages
