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Old Naval Observatory

Old Naval Observatory is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Old Naval Observatory rather than just read about it. In short: The Old Naval Observatory is a historic site at 23rd and E Street in Northwest, Washington, D.C. It is where the United States Naval Observatory was located from 1844 to 1893, when it moved to its present grounds.

Old Naval Observatory — main illustration
Old Naval Observatory — illustration

Key takeaways

  • Old Naval Observatory belongs to engineering; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Old Naval Observatory to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Old Naval Observatory from memory before moving on to harder problems.

Reference excerpt

The Old Naval Observatory is a historic site at 23rd and E Street in Northwest, Washington, D.C. It is where the United States Naval Observatory was located from 1844 to 1893, when it moved to its present grounds. The original observatory building, built 1839–40, still stands, and is a designated National Historic Landmark as of 1965. The Washington meridian of 1850 passes through the Observatory. The campus around the old observatory is split into two parts: the Potomac Annex to the east (where the observatory stands) and the E Street Complex, also known as Navy Hill, to the west. These two parts are separated geographically as the Potomac Annex is at the top of the hill, while the E Street Complex is farther down. The E Street Complex is also designated as a National Historical Landmark as of December 14, 2016. The campus for many years housed the Navy's Bureau of Medicine and Surgery, which moved out in 2012. The property has been taken over by the State Department.

History

Observatory The observatory was built in order to compete with European observatories. The observatory operated from 1844 to 1893. Matthew Fontaine Maury was the first superintendent of the observatory, despite his interests lying more in oceanography and wind currents (The Naval Observatory was at that time still called The Depot of Charts and Instruments). Under Maury, the observatory drafted charts on wind and ocean currents along with numerous volumes of sailing instructions. As a Virginian, Maury resigned in 1861 to join the Confederacy. He was replaced with James M. Gilliss, who had been in charge of the construction of the observatory. In 1863, Abraham Lincoln visited the observatory at night to ask an astrological question to the astronomer on duty, Asaph Hall. Gilliss died suddenly in February of 1865 and Admiral Charles Davis appointed himself superintendent in Gilliss' stead. In 1870, Congress passed a special appropriation to allow Davis to purchase a new refracting telescope as their old telescope, a 9.6in refractor, had been outdated since its purchase. The new telescope was purchased from a shop in Cambridgeport, Massachusetts and was delivered a full two years ahead of schedule. The telescope had a 26in refractor lens and was 32ft long, weighed 1 and 1/4th tons, and dubbed the "Great Equatorial." It was the largest refracting telescope in the world at that time, and brought prestige to both the observatory and the United States. It was with this telescope that the Moons of Mars were discovered by Asaph Hall in 1877. This telescope is still in operation today in the new U.S. Naval Observatory. In 1845, a time ball was added to the top of the observatory's dome which dropped every day at noon to signal the time. With Davis at the head, the observatory's exact time-keeping was used to standardize the time not only across Washington, D.C. but also around the country. Telegraph lines were laid by 1869 to the Navy Department, the Washington fire bells, and, thanks to the Western Union Telegraph Company, nearly all railroads operating in the southern states. The observatory also had a line to the Mutual Life Insurance Company in New York City that, when signaled by the observatory, would drop their own time ball. The observatory was closed in 1893 in favor of a new U.S. Naval Observatory facility on Massachusetts Avenue due to persistent malaria outbreaks. The building and grounds were retained by the U.S. Navy, which first used it to house the Naval Museum of Hygiene from 1894 to 1902.

Naval Medical Hospital and National Institute of Health

The Museum of Hygiene was made into a Navy medical school in 1902. Beginning in 1903, the Naval Medical Hospital was constructed behind the old observatory, and it remained in use until 1942, when both the medical school and hospital operations were transferred to the National Naval Medical Center in Bethesda, Maryland. While the Potomac Annex was used as a hospital, a nurse's building and doctor's quarters were also built to the east and west of the hospital. The U.S. Public Health Service Hygienic Laboratory, later the National Institutes of Health, moved into the other side of the campus in 1904 from the Marine Hospital in Stapleton, Staten Island. The Potomac Annex was largely undeveloped and unused until this time. Five buildings would be built in the E Street Complex: the North Building in 1904, an animal house in 1915, the Central Building in 1919, and the Administration and South Buildings in 1934. The animal house was used for animal testing, and is today called the East Building. In 1938, NIH moved to a new campus in Bethesda.

Office of Strategic Services and Central Intelligence Agency

The headquarters of the Office of Strategic Services was located in the E Street Complex until its dissolution in 1945. The superseding Central Intelligence Agency kept their headquarters in the E Street Complex until 1961. While the CIA moved their headquarters off of Navy Hill in 1961, they retained offices on the campus until 1987. In 1963, multiple buildings were demolished to construct the E Street Expressway.

Navy Bureau of Medicine and Surgery The campus housed the Navy's Bureau of Medicine and Surgery from 1942 until 2012.

Department of State The grounds and observatory are closed to the public. The entire Navy Hill has been transferred to the United States Department of State due to Base Realignment and Closure, although the Navy retains ownership of some structures on the campus. In 2014, the Department of State began expanding onto Navy Hill. A joint venture consisting of the architectural firms of Goody, Clancy and the Louis Berger Group won a $2.5 million contract in January 2014 to begin planning the renovation of the buildings on the 11.8-acre (4.8 ha) Navy Hill campus.

See also List of astronomical observatories

References

Historic American Buildings Survey (HABS) No. DC-341, "Old Naval Observatory, Twenty-Third & E Streets Northwest, Washington, District of Columbia, DC", 2 photos, 2 data pages, 1 photo caption page

Illustrations

Old Naval Observatory illustration
Old Naval Observatory: The campus in 1936, looking east. The NIH buildings are along the bottom, the Naval Hospital is at center, and the old observatory is at top left.
The campus in 1936, looking east. The NIH buildings are along the bottom, the Naval Hospital is at center, and the old observatory is at top left.

Worked examples

Example 1 — a first encounter with Old Naval Observatory

Start with the simplest possible case. Write down what Old Naval Observatory claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Old Naval Observatory before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Old Naval Observatory ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Old Naval Observatory

In research
Old Naval Observatory appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Old Naval Observatory in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Old Naval Observatory is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1843 establishments in Washington, D.C., Astronomical observatories in Washington, D.C., Buildings and structures completed in 1843, so understanding it makes those chapters shorter.
In everyday life
Look for Old Naval Observatory outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Old Naval Observatory in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Old Naval Observatory means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Old Naval Observatory out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Old Naval Observatory in simple terms?

The Old Naval Observatory is a historic site at 23rd and E Street in Northwest, Washington, D.C. It is where the United States Naval Observatory was located from 1844 to 1893, when it moved to its present grounds.

Why does Old Naval Observatory matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Old Naval Observatory?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Old Naval Observatory.

Tags

  • 1843 establishments in Washington, D.C.
  • Astronomical observatories in Washington, D.C.
  • Buildings and structures completed in 1843
  • Buildings and structures in Foggy Bottom
  • Buildings of the United States Navy
  • Buildings of the United States government in Washington, D.C.
  • Former installations of the United States Navy
  • Historic American Buildings Survey in Washington, D.C.
  • Military installations closed in 2012
  • Military installations established in 1844
  • National Historic Landmarks in Washington, D.C.

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