The Calculation of Longitude at Sea

The Harrison Chronometer

Amazing how one can go through life in total ignorance of matters right under our nose? Something that occurred to me of late, when I came across the saga surrounding the business of calculating Longitude at Sea and the chronometer invented by John Harrison.

  His original idea was prompted by a competition created by the 1714 Navigation Act which offered £20,000 to the person who could find a simple and practical method for the precise determination of a ship's longitude.The Act was passed by Parliament in July of 1714. But it was to be 10 years or so around 1724/5 when Harrison came to London seeking assistance. He approached Edmond Halley the 2^nd Astronomer Royal who felt he knew little of clock making and sent him to George Graham a clock-maker to help develop the appropriate timepiece

  My interest in this subject came about when I picked up on a suggestion from France that the East/West Greenwich Timeline should be moved to run through Paris. I soon realised I needed to look into this suggestion more closely and figure out what the devious ‘Frogs’ were up to, as I researched the reason behind this move.

  I soon figured what it was all about, as I was aware that for decades, both Paris and Frankfurt had frothed at the mouth over the City of London’s dominance of Financial Markets. It occurred to me when I came across a fascinating book ‘This England’ by John Burke with a forward by Sir Arthur Bryant.

 The forward explained London’s significance to international trade by the fact that it sits athwart The European/Atlantic trade-routes with exceptional geographical potential for commercial and strategic opportunity.  Almost entirely due to the fact that Greenwich is the point where East meets West and the 'Burghers' of Paris were attempting to use EU dogma to take advantage of this fact of life for themselves.

  Scurrilous I reckoned and decided they should not be allowed to Slip it past us on the Blindside, when attention is diverted by the on-running saga of Brin - Brout or Brexit. To be finally determined by referendum via the British Parliamentary System. Before the end of 2017 something we are now pretty sure will take place in the summer of 2016.

  The business of moving the East /West timeline to Paris however will not be resolved by Brexit nor will it go away. The French Republic will raise it again and again. In much the same way Argentina uses Falkland Islands Sovereignty as a Political Football to shore-up national pride in the South Atlantic, whenever Nationalist sentiment needs a boost       

  Our Longitude Act  is an Act of Parliament by the United Kingdom passed in July 1714 at the end of the reign of Queen Anne. It established the Board of Longitude and offered  a monetary reward  to anyone who could find a simple and practical methods for the precise determination of a ship's longitude. The Act of 1714 was followed by a series of other Longitude Acts, which revised or replaced the original.

  But it was to be 1765 before the matter of awarding the prize was settled and even then the Board of Longitude was playing jerk-off with John Harrison to make him reveal the secret of his timepiece - so it could be copied universally.  It awarded only half of the prize money with the other half dependent on revealing his methodology. Insofar far as I can determine, his secret rested on modification of the balance movement, calculated to speed up the ticking of the timepiece at the heart of the Harrison chronometer - to a rate that matched the angular rotation of Planet Earth.

  In this way he managed to cross the Atlantic to Barbados to an accuracy hither too unknown which confirmed Harrison’s Chronometer had kept time within the most stringent limits of the 1714 Act. The margin of error being just 39.2 seconds or 9.8 miles (15.8 km) at the latitude of Barbados. 

Researched courtesy of Wikipedia. 

Watch this space, I'll be Back 

 

Yours truly,

Daz.