Little-known facts about time, astronomy and the ROG
Feuding astronomers
The Astronomer Royal was supposed to make his findings known to the scientific community. He was often reluctant to do so and information was sometimes forcibly taken from him. This led to conflicts between such luminaries as Newton and Flamsteed.
George Airy and the story of electrical time
George Airy, 7th Astronomer Royal, pioneered an electrical system, spreading time from Greenwich throughout Britain via railway stations and telegraph lines.
Sir Christopher Wren's observatory
Wren was a keen professional astronomer as well as an architect. In 1675, King Charles II commissioned Wren to design his new Royal Observatory at Greenwich. Find out more about Sir Christopher Wren in our fact file.
The history of the Observatory site
The Observatory was built on the site of Greenwich Castle, which originally belonged to Humphrey, Duke of Gloucester (brother of Henry V) and was often used as a guest house and hunting lodge by Henry VIII.
The Astronomer Royal in the Tower of London
While the Observatory was being constructed, John Flamsteed took up residence in the Tower of London. His astronomical duties were often disrupted by the ravens at the Tower who would perch on and foul his telescopes. The King was on the point of giving orders for the ravens to be disposed of when he was told of the tradition that said when the ravens left the Tower, the Tower would fall, and probably the throne also. Charles modified his orders and spared some birds.
John Flamsteed moves to the Queen's House
John Flamsteed, first Astronomer Royal, moved all his equipment to the Queen's House, the 17th century Palladian Palace now in the National Maritime Museum grounds, to oversee the continuing building work on the Observatory.
Flamsteed House in the wrong place
The positioning of Flamsteed House meant that the original purpose of the Observatory could not be fulfilled from the famous Octagon Room. With big windows, the Room was perfect for watching the sky, but not ideal for positional observations, because none of the walls were aligned with a meridian. Most important positional observations were actually made in a small 'shed' in the Observatory gardens. The King remained blissfully unaware.
After the death of Flamsteed
When John Flamsteed died in 1719, his widow removed all the telescopes and clocks from the Observatory, claiming they had been his personal property. Despite a threatened lawsuit by the Office of Ordnance, Mrs Flamsteed stuck by her claim with the result that none of Flamsteed's astronomical instruments can be traced after 1721.
Included among the items that were removed was a pair of clocks originally built into the panelling of the Octagon Room in the Observatory. Made by Thomas Tompion, they had 13-foot (almost 4 m) pendulums suspended above them. The clocks were removed by Flamsteed's widow, sold and converted to domestic longcase clocks.
Fortunately they were tracked down. One is preserved at the British Museum and the other was returned to Greenwich in 1994. The picture (right) shows a detail of the movement. The primary achievement of the clocks was to prove to Flamsteed's satisfaction that the earth spins on its axis at a uniform rate. We now know that there is some slight variation, but there were no instruments that could detect this until the 20th century.
Fixing the Meridian
At an international conference in 1884, 25 countries met to fix a standard world meridian. When it was put to the vote, Greenwich won the prize of Longitude 0°. Only San Domingo voted against, with abstentions from France and Brazil. Algeria, a French dependent, made a point by insisting that GMT be expressed as 'Paris Mean Time diminished by 9 mins 21 secs' which amounts to GMT but avoids use of the word Greenwich.
Big Ben and the story of the pips
GMT entered British homes by way of the BBC which broadcast the chimes of Big Ben to greet New Year 1924. The 'pips' were the brain-child of Frank Dyson, who discussed the idea with Frank Hope-Jones, who favoured a '5 pip' signal. In February 1924, Dyson broadcast to the nation, inaugurating the service. Later he presided over a dinner when Hope-Jones was guest of honour. A guest remembered Hope-Jones' link with time signals and handed him 6 orange pips on a plate. Hope-Jones then made a flamboyant presentation of the sixth pip to Dyson.
The history of the Speaking Clock
In 1905, Paris established time over the phone, available on demand. With a microphone transmitting the sound of ticking, a member of the Observatory staff counted the minutes and seconds verbally on the same line. This system was extremely popular but time consuming. In 1933, Paris Observatory introduced an automatic speaking clock. Britain's current system was introduced in 1936.
The moving Meridian Line
Most people think of the Meridian Line as a fixed point defined by Nature. However, in reality it is simply a north/south line defined by the position of an astronomer's meridian telescope. The Ordnance Survey used Bradley's Meridian for its charts, although it is Airy's line which was chosen by the 1884 conference. As the earth's crust is moving slightly all the time the exact position of the Meridian shifts slightly too. But the original reference for the Prime Meridian of the world remains the Airy Transit Circle in the Royal Observatory.
The struggle for Harrison's reward
Yorkshireman John Harrison, inventor of the revolutionary marine chronometer was involved in a struggle with Parliament over rewards due to him from the Board of Longitude for solving the problem of finding longitude at sea. After many long trials, Harrison, at the age of 80, was finally granted a sum of money slightly larger than the mentioned reward.
Plot to blow-up the Observatory
The plot of Joseph Conrad's novel The Secret Agent was based on the real-life bomb explosion at the foot of the Observatory in 1896.
Missing Neptune
Astronomer Royal George Airy was accused of missing out on the discovery of Neptune in September 1846. Airy did not consider looking for new planets to be within the remit of the Royal Observatory and suggested that the Observatory in Cambridge should take the lead. It was officially observed by three independent astronomers in England, France and Germany, although it was first spotted by Galileo in 1612, but he did not recognise it as a planet.
Greenwich – mecca of discovery
It may seem hard to believe today, but the Observatory was the birthplace of modern technology and mecca of discovery. All technical innovations depended upon the Observatory and the work going on there. Even Peter the Great came to the Observatory in an attempt to pull Russia out of the dark ages. The Observatory was founded at Greenwich because, at the time, the majority of London's wealth was based in this part of the city.
Why the Observatory moved from Greenwich
The working Observatory eventually moved from Greenwich for several reasons, principal among them being the effects of light pollution. The London lights would badly disrupt the work of the astronomer who needed a clear view of the skies. Work was also affected by the London railway system which caused magnetic variations to show up in the new equipment set up to measure the Earth's magnetic field.
28-inch refracting telescope
This the largest refractor in the UK (i.e. it uses lenses to collect the light as opposed to mirrors) and the eighth largest in the world. It was built in 1893, and the first observations were taken the following year. It is 28 feet long and weighs 1.4 tons. The objective lens (at the top) is 28 inches (70 centimeters) in diameter – hence the name of the telescope. It weighs 102 kg.
It has an English equatorial mounting so that, by the aid of a small motor, it can be kept pointing at a fixed point in space, such as a star, as the Earth rotates on its axis. For this reason it is also known as the Great Equatorial Telescope.
The dome surrounding the telescope was originally made of papier maché. This was destroyed by a near miss from a VI flying bomb during World War II. A new replica dome was constructed in 1974 of fibreglass.