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1707-2007 : 300th Anniversary



On the 22nd October 1707 the Isles of Scilly bore witness to the second worst disaster in the history of the Royal Navy.

The British naval fleet, under the command of Sir Clowdisley Shovell, was returning from Gibraltar to Portsmouth during October 1707. Due to a combination of bad weather and the inability of mariners to accurately calculate their longitudinal position, the fleet lost its way approaching the Isles of Scilly. Subsequently four men-o'-war, together with the flagship HMS Association, were wrecked on the Western Rocks. 1450 men lost their lives, including Sir Clowdisley Shovell whose body was later washed ashore at Porth Hellick on St Mary's.

The tragic events of this day shocked the nation and led to an Act of Parliament - The Longitude Act of 1714. A prize of £20,000 was offered (an enormous sum at the time) for a solution to the navigational riddle that plagued maritime nations across the world.

The finding of HMS Association in 1967, by a Royal Naval Diving expedition and the discovery of hoards of silver coins led to more government legislation, notably the 1973 Protection of Wrecks Act - an attempt to preserve British historic wreck sites as part of our maritime heritage.

The Council of the Isles of Scilly in partnership with the AONB, English Heritage, the Isles of Scilly Museum and Natural England are commemorating the 300th Anniversary of the disaster and its consequences.

A number of events are being organised throughout the summer and autumn of 2007 to raise public awareness and understanding of the legacy of this significant maritime disaster.


July 14th/15th - Saturday/Sunday 10.00 am-4.00 pm

Geophysical Survey on St Agnes - Archaeologists will be demonstrating the use of geophysics to find buried archaeology as part of National Archaeology Week. St Agnes Playing Field.

Archaeologists will be looking for the graves of sailors from the wreck of HMS Association, who were reputedly buried on the St Agnes playing field.

There may be an opportunity for those interested in participating in some archaeological recording and activities. Open to people of all ages.

Contact the Tourist Information Centre (TIC), telephone 01720 422536 for more details.

Aug 2nd-Sept 6th 10.00 am-8.00 pm

Free Exhibition - Old Wesleyan Chapel A collection of photographs from the 1967 diving expedition and a display of artefacts and treasure found on the 1707 wrecks. Contact the TIC (01720 422536) for details.

Sept 17th & 18th and Oct 17th & 18th 8.00 pm

Town Hall

Dead Reckoning. A theatre production, produced by the Isles of Scilly Theatre Club and the Hall for Cornwall, Truro. Tickets will be available on the door. Contact the TIC (01720 422536) for details.

Oct 19th-Friday 8.15pm

Talk by Richard Larn, Maritime Historian, in the Old Wesleyan Chapel. Admission free.

Oct 20th - Saturday 8.15pm

Talk by Sir Arnold Wolfendale, 14th Astronomer Royal. (Retd). Old Wesleyan Chapel. Admission free.

Oct 21st - Sunday 3.00 pm

Commemoration Church Service, Old Town - conducted by the Chaplain to the Isles, Father Guy Scott.

Oct 21st - Sunday 8.15 pm

Talk by Dava Sobel, award-winning author of the book 'Longitude', Old Wesleyan Chapel. Admission free.

Oct 22nd - Monday

HMS Mersey arrives at 1 pm and anchors in St Mary's Roads. Official wreath-laying ceremony by the Chaplain of the Fleet and guests. By invitation only.

Oct 23rd - Tuesday 8.15 pm

HMS Mersey open to the public (weather permitting). Contact TIC (01720 422536) for details.

Talk by Simon Harris, biographer of !#8220;Sir Cloudesley Shovell, Stuart Admiral!#8221;. Admission free.

Oct 24th - Wednesday

HMS Mersey departs.

Oct 19th-26th 10.00 am-8.00 pm

Free Exhibition - Old Wesleyan Chapel A collection of photographs from the 1967 diving expedition and a display of artefacts and treasure found on the 1707 wrecks. Contact the TIC (01720 422536) for details.

Isles of Scilly Museum Events

Permanent HMS Association Exhibition and Children's Summer Quiz. Contact the Museum for opening times (422337).

Children's Events

August 1st-31st

Painting and Poetry Competition. Application forms available from the TIC. Fantastic prizes to be won.

* Please note our preferred spelling is 'Clowdisley' although other publications often use 'Cloudesley'.

The Longitude Problem and Harrison's Chronometer

How could a ship's master know how far west or east his ship had sailed from its home port? That was perhaps the most vexing question of the 18th Century.

Longitude is the angular distance east or west from a standard meridian, such as Greenwich, to the meridian of any place. On global maps, longitude lines loop from the North Pole to the South Pole in great circles that converge at the ends of the Earth.

When trying to navigate across an open ocean, the ability to calculate longitude is vital. An ignorance of longitude killed many sailors, who could rely only on instinct to find their destinations.

Early sailors were well aware of the principle of calculating longitude. They knew that for every 15 degrees travelled eastward, the local time moves forward one hour. Similarly, it was understood that time moves back one hour for every 15 degrees travelled west.

Sailors could measure time by observing the sun!#8217;s position but in order to obtain a precise bearing they needed to know the time at a fixed point, such as Greenwich. Unfortunately, ships carried pendulum clocks which were rendered hopelessly inaccurate by the motion of the sea.

The spectacular loss of life caused by the wrecking of the Association, Romney, Firebrand and the Eagle in 1707 on the Isles of Scilly, galvanised Parliament into offering what amounted to a King!#8217;s ransom for a final and accurate solution for calculating longitude and led to the Longitude Act of 1714.

Mariners had long been able to work out their latitude by studying the stars and plotting the position of the sun and moon; it was not surprising, therefore, that many believed that the solution to longitude could also be determined through astronomy. The answer had been sought for centuries by the likes of Ptolemy and Galileo. In 1714 the best brains in the land, including Isaac Newton and Edmund Halley, attempted to solve the problem.

The offer of such a large reward resulted in hundreds of competitors from throughout Europe, producing some weird and wonderful ideas.

A carpenter turned 'amateur' clock-maker from Barton-on-Humber, John Harrison, finally claimed the £20,000 prize in 1772 with his mechanical solution - a chronometer.

From 1727 Harrison devoted his life to perfecting the measurement of time at sea. He made four timepieces, the first from wood - all of which can still be seen at the National Maritime Museum in Greenwich. His final prize-winning piece H-4, a timekeeper that resembled a. large pocket watch, was completed in 1759. Over a period of six weeks this chronometer was out by just five seconds; an accuracy three times better than that required to win the £20,000 prize.


A booklet, 'Poor England has lost so many men', published by the Council of the Isles of Scilly and edited by Richard Larn with contributions from local authors, as well as Dava Sobel and English Heritage, is available from local shops and the Tourist Information Centre.

Price: £3.99 plus p&p


The text of this webpage is extracted from the leaflet produced by The Council of the Isles of Scilly Association Commemoration Group 2007, funded and supported by the AONB and Natural England.