With the aid of a replica clock this video shows the unusual features of the precision pendulum clocks built by John Harrison and his brother James between 1725 and 1730.
He was voted "only" 39th of most influential britons of all time. David Beckham made 33rd spot :-). More seriously, Harrison has throughout my life been number one. I've never seen one of his clocks in real life. It's about time I make the trip down to Greenwich to see No.4. Thank's for a great clip!
A REAL genius!!! An Autodidact who he had no specialist-prejudgements and mental independence. His clocks had the unbelievable accuracy of a few seconds in a half year!!!
Very nice presentations. For a great read on John Harrison and the search for Longitude read Dava Sobel's "Longitude", The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. I got it as a gift recently and was bowled over with this historical account.
Harrison did not follow contempory wisdom in the construction of his clocks because he wasn't trained as a clockmaker and could take liberties in his designs because he followed his head and not what was considered "correct" at the time. To think that he knew about friction, temperature and no need for lubrication by means of mechanical compensation and construction suggests he had an insight akin to Divine. A true genius and I am very proud to say an English one at that.
Waltham1892 not exactly. At the pocket watches the semi rings of brass and steel are riveted together and bend depending on temperature. Riveting the sheets together was also an invention of Harrison and it was used for temerature compensation of his H3 seaclock. But it was no yet a bimetal balance.
Did you get the original text-only version of 'Longitude' or the later illustrated version? If you got the former I advise you to also try and get hold of the latter - the illustrations add a great deal to the story. The book is 'The Illustrated Longitude' by Dava Sobel & William J. Andrewes. ISBN 1-85702-714-0
