Immediately after becoming superintendent, Maury moved the depot to a building between 24th and 25th Streets, N. W., known formerly as 2222–24 Pennsylvania Avenue, and to the rather limited accommodations here he brought his family. Meanwhile a new building was being constructed on a reservation at 23d and E Streets, N. W., where the Naval Medical School is now located,—a site covering about seventeen acres which had been reserved by General Washington for a great university. This new building was to be of brick, in the form of a square about 50 feet by 50, surmounted by a dome 23 feet in diameter, with wings to the south, east, and west. Later, in 1847, the superintendent’s residence was constructed and connected with the main building by an extension of the east wing. [Illustration: AN ENGRAVING OF THE UNITED STATES NAVAL OBSERVATORY BUILDINGS AS THEY APPEARED WHEN MAURY WAS SUPERINTENDENT ABOUT 1845 From an engraving in the title page of “Astronomical and Meteorological Observations Made during the Year 1875, at the U. S. Naval Observatory,” 1878.] The name of the institution varied. As the Depot of Charts and Instruments it was officially known from 1830 to 1844; but for the next ten years the names Naval Observatory and National Observatory were used indiscriminately, sometimes even in the same publication. In December, 1854, the Secretary of the Navy instructed that it should henceforth be called the United States Naval Observatory and Hydrographical Office, and as such it was known until the establishment of the Hydrographic Office as a separate division in 1866. Since that date the official name of the institution has been the United States Naval Observatory. Near the close of September, 1844, the Observatory was reported to be completed, and on October 1 Maury was ordered to take charge with a staff of line officers and professors of mathematics of the navy, and civilian professors. Lieutenant James M. Gilliss, Maury’s predecessor, had been greatly interested in astronomy, especially that field of the science having to do with navigation, and it was largely through his exertions that the necessary legislation had been passed making possible a building, adapted not merely to the housing of charts and instruments but suitable as well for astronomical observations. He had been sent to Europe to consult about the purchasing of instruments for the new Observatory, and there were those who thought that he should have been made its first superintendent.