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Royal Observatory, Greenwich

The Royal Observatory at Greenwich is crucial to the history of the British Empire, the Industrial Revolution, the development of science and by extension to the development of the modern world.

The Observatory was founded in 1675 by Charles the Second, with John Flamsteen appointed as the first Astronomer Royal. The aim of the observatory was to study the stars, as a means of improving navigation at sea. The challenge was to calculate longitude, positions east and west, while at sea and out of sight of land. The observatory's work was to track the moon and the stars, and to eventually publish a record of where the moon would be in relation to the stars on any given day. The moon moved at a fixed rate across the stars. The position of the moon at set times, in relation to set stars, could then be used to calculate the time on a ship relative to the time at the ship's home port. Every hour's time difference is equivalent to fifteen degrees of longitude, so knowing the time difference between two places allows longitude to be calculated.

With a huge amount of work, and lots of complex calculations, this method of working out longitude did eventually work. But it was not easy, and at times when the sky was obscured, impossible. Meanwhile a clock maker named John Harrison was trying to solve the problem of longitude by creating a clock that would tell the time accurately at sea. This represented a huge technical challenge, due to the constant movement of a ship, and the wide range of temperature a clock would have to endure. In 1730 Harrison submitted plans for a sea clock to the Board of Longitude, which was offering a £60000 prize for an idea that would allow accurate calculation of longitude. Work started on the first sea clock, Harrison Number 1, or H1, and continued for seven years. Harrison ran into opposition from astronomers working at the Royal Observatory, who looked down on his "mechanics" status. But with grants from the Board of Longitude, the design for the sea clock was slowly refined, until 1760 when Harrison produced his revolutionary H4, much smaller and neater than the three models which had preceded it.

The Royal Observatory from Greenwich Park

Eventually it was the successors of Harrison's clocks that became standard pieces of equipment at sea allowing calculation of longitude. The question than arose as to where longitude should be calculated from. Where was the imaginary "home port" for all the world's ships, from which longitude lines could be plotted on standardised charts? Nature sets the first meridian of latitude at the equator, where the sun travels through the sky directly over head. Points north and south can then be plotted by observing the position of the sun each side of the central line. But longitude is a man made construct. Anywhere in the world could be chosen as the Prime Meridian from which all other lines of longitude east or west are calculated. Since work on moon and star charts had been done at Greenwich, charts plotted positions east and west of this point. These charts continued to be used even after the widespread adoption of sea clocks, for lunar observations used in occasional correction of clocks. In this way Greenwich provided an unofficial prime meridian. In 1884 the International Meridian Conference held in Washington DC made this common practice official. The Greenwich meridian became the Prime Meridian of the world. Days begin at Greenwich. GMT even extends into outer space, where it is called Universal Time,and is used by astronomers to time their observations.

The Harrison clocks were taken from their creator and stored at the Observatory for "testing" by Harrison's arch enemy, the fifth astronomer royal Nevil Maskelyne. These incredible clocks were rescued from a sad state of decay by Lieutenant Commander Robert T. Gould of the Royal Navy. Starting his unpaid work in 1920, and with no previous training, he worked quietly on the clocks for many years, restoring them, and in the process restoring himself from a breakdown suffered at the beginning of the First World War. H1, H2, H3, and H4 can now be seen on display at the Royal Observatory. H1, 2 and 3 are all working, their huge and intricate mechanisms open for visitors to view. H4, to avoid wear, is never wound up. (Read more about the story of Harrison's clocks in Dava Sopel's lovely book Longitude.)

"Time Ball" on the observatory roof

A "time ball" which dropped down a short pole daily at 1pm on the Royal Observatory roof, still works today. The original purpose was to provide a time signal to ships on the Thames. Today it serves more as a time signal to tourists, showing how times have changed in a world where ships position themselves by satellite.

Accurate navigation at sea allowed the sea bourne travel on which Britain's Empire depended. Accurate time keeping was also an important feature of the Industrial Revolution. Mechanical processes required the precise ordering of time. The days had passed when people followed the sun and the seasons through an agricultural year. Days were now divided up into organised time to suit an industrial world. This dependence on accurate time keeping has only increased in the computer age, since computers require precise time keeping to work effectively.

The observatory itself was designed by Christopher Wren. The Octagon Room housing the telescopes is the only surviving Wren interior.

The Royal Observatory is a fascinating place to visit; there's the Wren designed building, the displays on the history of time keeping, the nearby Planetarium giving daily displays on the stars and planets. Greenwich Park in which the observatory stands is itself an historic environment. Also within walking distance is the National Martime Museum, the Wren designed buildings of the Old Royal Naval College, and the old tea clipper Cutty Sark. But for me the greatest thrill of the observatory is the feeling that you are standing at some kind of rare crossing point. This was the place where the old world crossed into the modern world; this is the place where east meets west. You stand up on the observatory looking out over London, seeing the Prime Meridian running right through the former Millennium Dome where the new millennium began.

 

 

 

 

 

 

 

 

 

By some strange coincidence, the area of Greenwich has a very long history as a border between east and west. In the ninth century Britain was divided in two between a Saxon west and a Danish east. The border between the two reached a crucial junction at the confluence of the rivers Thames and Lea. This point lies directly opposite the position occupied by the Millennium Dome today. It seems that the Royal Observatory Greenwich lies on a line which has run through this part of the world for a long time. It is sometimes claimed that Stonehenge represents an ancient observatory, and that this location lies on some kind of line of force in the landscape. The coincidences seem intriguing.

Opening Times: The observatory is open 10am to 5pm every day, last admission 4.30pm. The observatory tends to be busiest between 1pm and 4pm at weekends and quiet before 11.30am. It is closed 24th - 26th December and closes early 31st December, opening late on 1st January.

Directions: The observatory is in Greenwich Park. Car parking is difficult, so it is best to use public transport if possible. The Docklands Railway runs to Island Gardens, where there is a foot tunnel which takes you to Greenwich. Alternatively there are regular river boat sailings from central London. This is a great way to get to Greenwich. Go to www.tfl.gov.uk for details of sailings. Click on "River". Click here for an interactive map centred on the Royal Observatory.

Access: the Royal Observatory is at the top of a steep hill. A road train runs up this hill regularly from the National Maritime Museum. Running times for the road train vary. Ring +44 (0) 20 88584422 for details. Access into the observatory courtyard, the gift shop and the Meridian Line display is level, but the building itself is difficult for those with mobility problems. For those with sight problems there are braille guides, large print guides and tactile plans.

Contact:

telephone: +44 (0) 20 8858 4422

web site: www.rog.nmm.ac.uk

 

It is possible to stay in the Greenwich World Heritage Site. Davenport House offers historic, and high quality accommodation.