Beginning with navigational instruments
On 6 December 1830, the Secretary of the Navy ordered the establishment of a Depot of Charts and Instruments under the Board of Navy Commissioners. Ocean navigation required reliable charts and timekeeping tools, so the Navy brought dispersed materials and instruments under central management. Louis Goldsborough collected chronometers, sextants, theodolites and charts from New York and elsewhere; in 1831, naval yards were also instructed to transfer navigational books and charts.
The institution initially stored, issued, repaired and tested equipment. Checking marine chronometers required reliable astronomical time, prompting the depot gradually to add observing facilities. Between 1831 and 1833, staff used a transit instrument made by the New York craftsman Patten to compare the times at which stars crossed a fixed direction with clock readings. Observation grew from the practical requirements of routine instrument management.
Sites near the White House and Capitol Hill
In February 1831, the depot occupied a brick house northwest of the White House, near Seventeenth and G Streets. Charles Wilkes took charge in 1833 and found that damp ground affected the instruments, prompting him to seek another site. In May 1834, the institution moved to higher ground north of the Capitol, where conditions were more suitable for observation.
Wilkes constructed a small observing building and borrowed a Troughton transit instrument from Ferdinand Hassler, head of the Coast Survey. The Navy thus used equipment belonging to another surveying institution. The timekeeping facilities initially served everyday instrument management, then gradually became part of a sustained astronomical programme.
The order for coordinated observations in 1838
After James Melville Gilliss took over the depot, its observations became linked with the United States Exploring Expedition. On 13 August 1838, Navy Secretary Paulding ordered him to make astronomical observations in Washington and cooperate with William Cranch Bond in Boston, providing shore-based reference observations for Wilkes’s expedition.
Lunar transits, occultations and solar and lunar eclipses allowed observers at different locations to compare timings and help establish longitude. The order specified both the observing targets and records of instruments, magnification, sidereal-clock corrections and weather. The series begun in September 1838 continued until 1842, with Gilliss carrying out much of the work. The records were subsequently published so that other observers could examine and compare them.
References: [1]
Weather records and comparable instruments
Alongside astronomy, Gilliss promoted meteorological and geomagnetic records and sought additional instruments and assistants. Early weather observations were taken four times daily, at 3 a.m., 9 a.m., 3 p.m. and 9 p.m., recording pressure, temperature, humidity, wind direction and strength, and weather. Regular observations at fixed times extended the station’s work beyond occasional celestial events.
Consistency also required recording changes to equipment. When the existing barometer was damaged and sent for repair in 1841, a French-made instrument temporarily replaced it; readings from the two were compared after the original was repaired. Grice’s station history preserves this detail. Recording instruments, repairs and replacements alongside measurements makes differences in a continuous series easier to interpret.
References: [2]
Permanent facilities in 1844 and later responsibilities
Limited space and inadequate older instruments led Gilliss to pursue permanent facilities. Legislation approved on 31 August 1842 authorized the Navy to build a suitable Depot of Charts and Instruments. By late September 1844, the new building and instruments were ready. On 1 October, Matthew Fontaine Maury was assigned to take charge, moving staff, charts and instruments into the Foggy Bottom site. On high ground along the Potomac’s north bank, it housed a refracting telescope, transit instrument, mural measuring instrument, and meteorological and geomagnetic equipment.
The new institution exchanged books with European scholarly societies and observatories, gradually combining navigational service with professional astronomy. In 1854 the Navy Department formally adopted the name United States Naval Observatory and Hydrographical Office; hydrographic work became a separate institution in 1866. The move to Massachusetts Avenue in 1893 belonged to a later phase. The administrative beginning in 1830, permanent observatory in 1844 and subsequent relocation each marked different institutional and physical changes.