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TELESCOPIC - Two of the protective domed housings in the grounds of Herstmonceux Castle.





The Observatory and Science Centre is a discovery venue where people can experience Spectacular Science through the medium of interactive activities- every exhibit is designed to be played with to see what happens; investigate, learn and have fun!

They work in partnership with you and the education programme is constantly expanding offering options for both Day and Twilight experiences.

The Centre is unique among science centres because of its connection with astronomy: being located within buildings that were part of the former home of The Royal Greenwich Observatory.

The Centre opened in 1995, with the aim of increasing appreciation of science and technology through interactive hands-on exhibitions, educational events and activities, taking into account the site's historic links.The vision was to become a place where everyone could explore, discover and learn. The Centre has gone from strength to strength and offers Spectacular Science and discovery amongst the domes and telescopes of a world famous observatory.

The Observatory Science Centre is part of Science Projects Ltd., a company with charitable status dedicated to the promotion of science for everyone and designers of interactive exhibitions and hands-on exhibits since 1986. As a charitable organisation, profit from contract work is invested into the site to maintain the Grade II* Listed building and expand the exhibitions.

Registered in England No: 02186073 and a registered charity No: 298542. The registered office is 3 – 15 Stirling Road, Acton, London. W3 8DJ. UK.


After years of deteriorating conditions at Greenwich, the Observatory moved to Herstmonceux Castle in Sussex. The move began in 1948 and was completed in 1957. While at Herstmonceux, the Observatory was officially known as The Royal Greenwich Observatory, Herstmonceux, though in actuality, closer to Windmill Hill.

The Observatory remained at Herstmonceux until the end of the 1980s when it moved once again; this time to Cambridge. The site at Herstmonceux was sold in May 1989 and closed in 1990. It was subsequently acquired in 1993 by Queen's University, of Ontario, Canada. The equatorial group of telescopes is currently in the care of the Observatory Science Centre and can be visited by the public as can the Castle grounds and gardens.

During the nineteenth century, as London grew and became more industrialised, the observing conditions at Greenwich gradually deteriorated. Conditions were so bad in the early 1870s that Airy began noting in his journal the date of his first annual sighting of some of the central London landmarks. In 1873, he recorded that he had first seen the Victoria Tower at the south-west end of the Palace of Westminster (which was a mere five and a half miles away) on 2 June (RGO6/26/182). The following year, he recorded that St Paul’s Cathedral (which is less than five miles away and is today visible from the Observatory on most days of the year) became ‘fairly visible for the first time’ on 17 May (RGO6/26/201).

In 1881 Airy resigned as Astronomer Royal. William Christie his Chief Assistant, was appointed to replace him. It was under Christie, that the Observatory went through one of its greatest periods of expansion. In contrast to the changes that took place under Airy, the changes under Christie lacked focus being shaped instead by the unsolicited gifts of three large telescopes – the Lassell and the two Thompsons. Had a strategic plan been in place, it is not impossible that part of the Observatory at least, would have been located away from the smoke of Greenwich by the start of the twentieth century.

Even the unfortunate erection of the coal fired Greenwich Power Station on the line of the Meridian which commenced in 1902, and the furore that later followed, failed to motivate Christie and the Board of Visitors to consider a move. Quite the opposite in fact; for when in 1908, Melotte (a junior member of staff), discovered the eighth satellite of Jupiter, Christie claimed that this was testimony ‘to the suitability of the Greenwich climate for the observation of very difficult objects such as faint satellites and close double stars.’ One can only conclude that consciously or otherwise, Christie was more wedded to the convenience of his London location with its easy access to the learned societies, clubs and cultural opportunities, than he was to the need for securing improved observing conditions.

But the smoke pollution was not the only problem. By the time Christie retired, it was well established that a site like Greenwich, perched on the edge of a plateau, was less than ideal for making zenith observations due to the increased likelihood of refraction anomalies. What was required instead was a site where the terrain to the north and south was both level and open – a condition that could not be satisfied at Greenwich.

Spencer Jones went on to become His Majesty’s Astronomer at the Cape, before returning to Greenwich as Astronomer Royal in 1933. On arriving back, it was immediately obvious to him just how much further observing conditions had deteriorated. He immediately set about collecting the evidence he required in order to persuade the Board of Visitors and the Admiralty of the need for a move. Observations of the atmospheric concentration of particulates began on 1 July 1934 and of sulphur dioxide on 1 January 1935.


By 17 February 1944, the Admiralty had approved a move in principle (ADM190/6/264). Commenting to the press about the decision, Spencer Jones stated that there had been ‘only two alternatives, either to put up with the conditions at Greenwich and deteriorate into a second-rate institution, or to move away into conditions where useful work can be done’. By 1945, plans for relocating were advancing apace. Other things being equal, the Admiralty would have preferred a site some distance from the mainland of Europe, as this would have been easier to defend should there be future hostilities. But other things weren’t equal, and it was the view of the Astronomer Royal that owing to meteorological conditions and the presence of large industrial areas, a suitable site was not going to be found to the North or West of a line joining Kings Lynn, Reading and Bristol. This view was the one that prevailed as a suitable site was sought.

Over 70 possible sites were considered in the counties of Essex, Suffolk, Bedfordshire, Buckinghamshire, Hertfordshire, Kent, Surrey Sussex, Hampshire, Dorset and Wiltshire. From these a short list of five was compiled by the Astronomer Royal in consultation with the Department of the Civil Engineer-in-Chief, Admiralty, the Director of the Meteorological Office, and the Director of the geological Survey. All were substantial country estates in the south of England that had been requisitioned for the war effort. They were all visited in April by a subcommittee of the board along with the Astronomer Royal. Some had willing sellers and were on the market. Others, for example Hinton Ampner House in Hampshire, would have had to have been compulsorily purchased if selected.


Site A. Herstmonceux Castle, near Hailsham (the site selected)
Site B. Hinton Ampner House, near Winchester (now in the care of the National Trust)
Site C. Hackwood House, near Basingstoke
Site D. Amport House, near Andover
Site E. Kingston Maurward, near Dorchester (now in use as a college)

Three of the sites were then eliminated, leaving just Herstmonceux Castle and Amport House in the running. The final decision was made by the Admiralty in consultation with the Board. Royal approval was given for the move and in April 1946, it was announced that the Observatory would be moving to Herstmonceux. The Castle and its 368 acre estate was formally acquired from Sir Paul Latham on 18 February 1947 for £76,000, with an expectation (based on an analysis made in October 1945) that a further £225,000 would be required for modifications and further building works, which were initially scheduled to take place in three stages. The purchase price was over and above an independent valuation of £67,000 that would have been used had it been necessary to proceed by compulsory purchase, rather than an agreed sale. In 1948, the move finally began and the Observatory was renamed: The Royal Greenwich Observatory Herstmonceux. In practice, this title was seldom used, a contracted version – The Royal Greenwich Observatory – being used in preference.








The other unique building in Herstmonceux. The oldest surviving Generating Station in the world with load levelling via a battery store. This modest industrial building powered the whole village, until 1936, when the plant was officially decommissioned.




You can visit the monument records at TheKeep, in person or via their online search service. Or see HER, the Historic Environment Record of East Sussex County Council.














FREEDOM OF THOUGHT AND SPEECH - This website is protected by Articles 9 and 10 of the European Convention of Human Rights and Fundamental Freedoms, and Articles 18 and 19 of the Universal Declaration of Human Rights. Herstmonceux Walkers Association avers that the right to impart information is a right, no matter that the method of communication is unpalatable to the State.





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