The original National Observatory was authorized by President Tyler in 1842 and completed in 1844 according to plans prepared by Lieutenant James Melville Gilliss. The observatory was the site of notable advances in astronomy and mathematics, and is associated with its first superintendent, Matthew Fontaine Maury, who supervised the publication of numerous volumes of oceanographical charts, and was the author of the first oceanographical textbook. The observatory installed a new transit circle instrument by the end of the Civil War. The domed south wing housed the 26-inch Great Equatorial telescope, the largest of its day, installed in 1873. In 1877, astronomer Asaph Hall discovered the moons of Mars with this instrument.
From its inception, the observatory was authorized to calculate and keep official time, which was indicated by the dropping of a time ball from the flagstaff each day at noon. By 1878, poor atmospheric conditions in Foggy Bottom led Congress to authorize relocation to a new site, and in 1893, the observatory moved to its new home on Massachusetts Avenue. After its relocation, the property was transferred to the Navy’s Bureau of Medicine and Surgery to serve as a Museum of Hygiene, and later the Naval Medical School.
DC Inventory: November 8, 1964 (Joint Committee on Landmarks)
National Register: October 15, 1966
National Historic Landmark: January 12, 1965
]]>The United States Gundelo Philadelphia is the only surviving gunboat built and manned by American forces during the Revolutionary War. Further, the vessel is one of the 15 small craft with which Benedict Arnold fought 29 British vessels in the battle of Valcour Island, Lake Champlain, on October 11, 1776. The year of grace won by the building of Arnold's "fleet" and the battle off Valcour Island paved the way for the decisive American victory at Saratoga in the fall of the following year.
Little more than a rowboat compared with modern vessels, the Philadelphia was one of the hastily-built fleet constructed in early summer of 1776 at the present Whitehall, New York. On September 23, 1776, the fleet took position in the small bay west of Valcour Island, about seven miles south of what is now Plattsburg, New York. The sound between the Island and the mainland was about three quarters of a mile wide, divided by a high bluff projecting from the west side of the Island. Arnold's fleet formed its line south of the bluff and in this position fought the heavier British fleet to a standstill on October 11. The American force was badly damaged in the action, and only with considerable luck was Arnold able to elude the enemy and escape southward during the night.
In 1935, the Philadelphia, remarkably well preserved by the cold water, was identified and salvaged from the sandy lake bottom near the mid-channel of Valcour Bay. In addition to her guns, hundreds of other relics were found on the vessel, including utensils, tools, buttons, buckles, and human bones.
Since 1964, the Philadelphia has been a part of the collection of the National Museum of American History.
DC Inventory: March 3, 1979
National Register: October 15, 1966
National Historic Landmark: January 20, 1961
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