King's Observatory

The King's Observatory
General information
Location	Old Deer Park, Richmond, London, United Kingdom
Website
www.kingsobservatory.co.uk
Listed Building – Grade I
Official name	Kew Observatory
Designated	10 January 1950
Reference no.	1357729

The King's Observatory (until 1981 also known as Kew Observatory) is a Grade I listed building in Richmond, London that formerly housed an astronomical and terrestrial magnetic observatory founded by King George III. It was completed in 1769, in time for the king's observation of the transit of Venus that occurred on 3 June in that year. The architect was Sir William Chambers; his design of the King's Observatory influenced the architecture of two Irish observatories – Armagh Observatory and Dunsink Observatory near Dublin.

Location

The observatory is located within the Old Deer Park of the former Richmond Palace in Richmond, Surrey, now within Greater London. The former royal manor of Kew lies to the immediate north. The observatory grounds overlie to the south the site of the former Sheen Priory, the Carthusian monastery established by King Henry V in 1414.

People

Directors (superintendents) of the observatory included Stephen Demainbray, Francis Ronalds, John Welsh, Balfour Stewart, Francis John Welsh Whipple, Charles Chree, and George Clarke Simpson.

History

Observing the transit of Venus on 3 June 1769

A contemporary report by Stephen Demainbray, the superintendent of the observatory, says: "His Majesty the King who made his observation with a shorter reflecting telescope, magnifying Diameter 170 Times was the first to view the Penumbra of Venus touching the Edge of the Sun's Disk. The exact mean time (according to civil Reckoning) was attended to by Stephen Demainbray, appointed to take exact time by Shelton's Regulator, previously regulated by several astronomical observations."

Testing timepiece movements

In 1840, under the aegis of the British Association for the Advancement of Science, the facility performed a role in assessing and rating chronometers, watches, barometers, thermometers, sextants and other scientific instruments for accuracy until this duty was transferred to the National Physical Laboratory in 1910. An instrument which passed the tests was awarded a "Kew Certificate", a hallmark of excellence.

As marine navigation adopted the use of mechanical timepieces, their accuracy became more important. The need for precision resulted in the development of a testing regime involving various astronomical observatories. In Europe, the observatories at Neuchatel, Geneva, Besancon and Kew were examples of prominent observatories that tested timepiece movements for accuracy. The testing process lasted for many days, typically 45. Each movement was tested in five positions and two temperatures, in ten series of four or five days each. The tolerances for error were much finer than any other standard, including the modern COSC standard. Movements that passed the stringent tests were issued a certification from the observatory called a Bulletin de Marche, signed by the directeur of the observatory. The Bulletin de Marche stated the testing criteria and the actual performance of the movement. A movement with a Bulletin de Marche from an observatory became known as an Observatory Chronometer, and was issued a chronometer reference number by the observatory.

The role of the observatories in assessing the accuracy of mechanical timepieces was instrumental in driving the mechanical watchmaking industry toward higher and higher levels of accuracy. As a result, modern high quality mechanical watch movements have an extremely high degree of accuracy. However, no mechanical movement could ultimately compare to the accuracy of a quartz movement. Accordingly, such chronometer certification ceased in the late 1960s and early 1970s with the advent of the quartz watch movement.

In 1908 geomagnetic instruments were relocated from the King's Observatory to Eskdalemuir Observatory in Dumfries and Galloway, Scotland after the advent of electrification in London led to interference with their operations.

Later use

From 1910 to 1980, the observatory housed the Meteorological Office. In 1981 the facility was returned to the Crown Estate Commissioners and reverted to its original name, "King’s Observatory". In 1985 the observatory was refurbished and transformed into commercial offices; new brick buildings were added. Since 1989 the lease has been held by Kew Holdings Limited. From 1986 to 2011 it was used by Autoglass (now Belron) as their UK head office.

Current and future use

In 1999, landscape architect Kim Wilkie was commissioned to prepare a master plan linking the observatory's Grade I landscape to Kew Gardens, Syon Park and Richmond. These proposals were accepted by Kew Holdings Limited. In 2014 Richmond upon Thames London Borough Council granted planning permission for the observatory to be used as a private single family dwelling. All auxiliary buildings are being demolished. As of 2015 the current tenant is Mr R J F Brothers.

The Observatory in art

The Ashmolean Museum of Art and Archaeology in Oxford has a portrait, Peter Rigaud and Mary Anne Rigaud, by the 18th-century painter John Francis Rigaud. His portrait of his nephew and niece, exhibited at the Royal Academy in 1778, shows Stephen Peter Rigaud (1774–1839) (who became a mathematical historian and astronomer, and Savilian Chair of Geometry and Savilian Professor of Astronomy at the University of Oxford) and his elder sister. The picture, painted when they were aged four and seven, shows them in a park landscape with the observatory (where their father was observer) in the background. Although described here as Richmond Park, topographical considerations make it more likely that the park portrayed is Old Deer Park, where the observatory is situated.

See also

• Eskdalemuir Observatory

External links

• History of the Observatory and Old Deer Park; historical report by John Cloake
• The Observatory and Obelisks, Kew (Old Deer Park)
• Kew Observatory sunspot observations 1858–1897
• Google Books on the "Kew Observatory"
• Google Scholar on the "Kew Observatory"
• Richmond Local History Society
• The National Archives (UK): Records of the Kew Observatory
• Janus: Kew Observatory papers – at the Royal Greenwich Observatory Archives