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Pavilion Tea House, Royal Greenwich Observatory, Meridian Line, Shepherd
Gate Clock, Standard Measurements
14. Opposite the South Building is the
octagonal Pavilion Tea House, dating from 1906 and designed by Sir Henry
Tanner. On its roof is a dovecot, and above that a weather vane showing
Admiral Lord Nelson surveying the scene through his telescope. The
ground floor part was built as an open veranda but in 1967 it was
enclosed and more recently the interior has been opened up to improve
the use of space. It is surrounded by a hedged garden where visitors can
enjoy their refreshments at tables under large parasols, providing a
safe area for those with children, as well as some peace and space away
from the crowds of tourists in and around the Observatory buildings. The
tea house is open all year round and toilet facilities are available
nearby behind the South Building, accessible from The Avenue.
(139 words)
15. In 1675 King Charles II commissioned the building of the Royal
Observatory
on the promontory in Greenwich Park known as Castle Hill. John
Flamsteed was appointed the first Astronomer Royal, whose
duties
were to "apply
himself with the most exact care and diligence to the rectifying of
the tables of the motions of the heavens, and the places of the
fixed stars, so as to find out the so much desired longitude of
places for the perfecting of the art of navigation." The octagonal
building is named Flamsteed House and was built on the foundations
of the previous structure, Greenwich Castle, and so is not exactly
aligned with the meridian.
The
scientific work of the Royal Greenwich Observatory moved to
Herstmonceux Castle in Sussex over the period 1947 to 1957 due to
light pollution in London, where it remained until 1990. The
buildings at Greenwich are now administered by the National Maritime
Museum. The entry charge covers the Meridian Building, Flamsteed
House and the Meridian Courtyard.
(167 words)
16. In the rear of the Meridian Building there is an extensive
collection of portable chronometers on display, with the
conservation laboratory in full view behind, which will warm the
heart of anyone with this special interest, and is free to enter.
The measurement of longitude was essential for accurate navigation
and this seemingly impossible problem was eventually solved by the
ingenuity of John Harrison, a Yorkshire carpenter and clock-maker.
He spent 50 years inventing and working on a succession of accurate
and reliable portable chronometers that could be taken on sea
voyages. This enabled the ship's captain to compare local time with
the chronometer which would remain set at a standard time, such as
that at Greenwich. In this way he could compute the distance
travelled and, in conjunction with his other measurements, find the
exact position of his ship.
John Harrison eventually received a total of £23,000 (more than two
million pounds in today's values) for his contributions to solving the
longitude problem, although the actual prize money itself was never paid
out. Other smaller amounts were granted to other inventors for their
contributions. Four of Harrison's timepieces are on display in the main
museum, three of them in full working order, along with other historical
astronomical and scientific equipment. To see these you will have to
enter the chargeable part of the museum, but you can see, at no cost, a
replica of Harrison's first timekeeper, made by Leonard Salzer of Biggin
Hill between 1970 and
1976,
on display in the National Maritime Museum building at the bottom of the
hill. (263 words)
17. Some time in the 1980's Sir Isaac Newton appeared at the Observatory
in the form of this snowman built in the Meridian Courtyard of Flamsteed
House. Unfortunately he seems to have his back to the view of the Thames
and London, but he is in just the right place to welcome visitors. On
the same day the grassy slope beyond was
transformed
into a magnificent icy downhill ride, full of parents and children
rolling and sliding down on anything they could find to sit on,
including one person trying out his skis. This was all rather
reminiscent of the historical accounts of the game of tumbling which was
a popular entertainment for visitors to Greenwich Fair in past
centuries, and may account for Snowman Newton's amused grin! His name
appears amongst the other scientists on the South Building, over the
terracotta figure of Astronomia. (144 words)
18. The time ball on top of Flamsteed House was installed by the
Astronomer Royal John Pond. The
explanatory plaque on the gate reads: "The red Time Ball on top of
Flamsteed House is one of the world's first visual time signals. It
was installed in 1833 (though the present one dates to 1919) to
enable navigators on ships in the Thames to check their marine
chronometers. The Time Ball drops daily at 1300 hours (GMT in
winter, BST in summer). It is raised halfway up the mast at 1255
hours as a preparatory signal and to the top 2 minutes before it
drops." The time is counted when the ball starts its descent, not
when it reaches the bottom. The ball's descent is actually a stately
lowering rather than a rapid drop. It would also have been of
service to everyone within sight of it who owned a timepiece, and
especially clock and watch makers, who could then provide the
correct time to their customers.
(165 words)
19. The red line above the door on the Meridian Building in the
courtyard marks the Prime Meridian. The line is also marked in a double
steel strip in the granite surface on the right of the photo, which was
taken from the east side at the gates. The meridian line designates zero
degrees longitude and marks the boundary between the east and west
hemispheres of the earth. The International Meridian Conference held in
Washington DC in the United States of America in 1884 chose Greenwich as
the location of the Prime Meridian. Greenwich won the vote because it
was already being used as such by two-thirds of shipping and it was felt
that a change from the established usage would not be beneficial. (123
words)
20. The steel line continues across the courtyard, with this sculpture
placed on it as a visual description of the line. This photo of the
sculpture was taken on the west side, within the courtyard.
When the place is thronging with visitors,
it can be difficult to get a clear photo of the buildings as a whole.
Cold or dull weather would seem to be the most likely option to avoid
the crowds, as hopefully the tourists would be warming themselves in the
museums and coffee shops. Early in the morning might also prove fruitful
for your photographic endeavours. At peak visitor times consideration
for others taking photos can result in a halting and zigzag progress
from one point to another!
(120 words)
21. Standing astride the Meridian
Line seems to be the favourite place for tourists to have their
photos taken. An orderly queue is formed and everyone takes their
turn to stand on the line with a friend taking the picture. Most of
them seem to prefer to have the sculpture and scenery in the
background. There is a charge to enter the courtyard and museums, but reasonable pictures can be taken from outside or
through the railings.
If the courtyard is too crowded or
too expensive for your liking, there are two free places nearby
where you can have your photo taken astride a marked Meridian Line.
Firstly, just below the courtyard through the gate on the path that
leads down behind the buildings, where the line is marked in brass
on the wall and ground. Secondly on The Avenue, immediately behind
the South Building, just a little way past the public toilets, where
the line is marked by a row of granite setts in both pathways and in
the road.
At night the meridian line laser is
beamed northwards from the Meridian Building and is visible for many
miles. The park closes at dusk so the easiest way to see it during
the day is via the illustration on the park notice boards.
(213 words)
www.panoramio.com/photo/49359728 Panoramio user's excellent view of
this laser in the snow at dusk
www.nmm.ac.uk/visit/scenic-attractions/meridian-line/standing-on-the-meridian-line-360-panorama
A controllable 360 degree still panorama
of the Meridian Courtyard
www.waymarking.com/cat/details.aspx?f=1&guid=a088c7d0-af6d-425d-a673-9b6cc93d4640
More Meridian Line
markers throughout the UK
www.thegreenwichmeridian.org
22. The Shepherd Gate Clock outside the courtyard was originally an
electric slave clock, reproducing the time from the master clock
within the building. The system was designed and built by Charles
Shepherd Junior, who was commissioned by Astronomer Royal George
Airy in 1852 to provide a master
clock
and three subsidiary clocks for the Observatory. The master clock
also controlled the dropping of the time ball, and sent time signals
to the London Bridge Terminus of the South Eastern Railway, for
onward transmission to receivers throughout the country. Now the
clock is quartz-controlled, and the other clocks are displayed in
the museum. The face shows 24 hours, with midnight marked at the top
zero. (114 words)
-
sent:
short form, written above the line, to distinguish it from "send".
-
midnight: "mid" and "night" are halved when written separately
23. The standard measurements beneath the clock are one British yard,
two feet, one foot, six inches and three inches. The two pins near the
ends of each measurement are to hold the measuring rod being tested. The
measurements are accurate at an ambient temperature of 60 degrees
Fahrenheit or 16 degrees Celsius. The explanatory plaque reads: "These
British Imperial standards were first mounted outside the Observatory
main gates some time before 1866, to enable the public to check measures
of length. The stated length is the distance between the inner faces of
the two D-shaped studs."
Brass yardsticks and brass ells were
commonly kept as standard measurements. Elizabeth I had a brass yard
made and copies were distributed to the principal market towns. A less
common measurement was the ell, the length of a man's outstretched arms, and was used
to measure out cloth. The English Ell was approximately 45 inches.
Standard weights and measures were stipulated in Clause 35 of Magna
Carta in 1215: "There shall be standard measures of wine, ale, and corn
(the London quarter), throughout the kingdom. There shall also be a
standard width of dyed cloth ... weights are to be standardised
similarly."
(199 words)
24. The second plaque shows the
height above sea level as 154.7 feet, compared with the benchmark
which is measured and maintained by the National Tidal and Sea Level
Facility at their tidal observatory in Newlyn, Cornwall. This
organisation is responsible for monitoring sea levels in the UK to
assist with flood warnings, navigation and climatology. As
coincidence would have it, this is a little more than the height of
the main mast of the Cutty Sark ship above her deck, at 146 feet,
giving pause for thought as you look down the hill and imagine that
the tiny figures on the grass below are walking about on the ship's
deck, with you perched aloft!
(114 words)
-
benchmark: stroke Em intersected for "mark"
-
UK: The
shorthand shows this spoken as the letters of the alphabet "yoo-kay". For the
full words, see placename list at end of
Contractions Optional page
Greenwich:
Part 1
- Part 2 -
Part 3
- Part 4
- Part 5
- Part 6
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