Longitude is one of my favorite DVDs. It is based upon Dava Sobel's fantastic book - you guessed it - Longitude. The book is the story of John Harrison's quest to solve the until then unsolvable riddle of longitude. What is important to bear in mind is that until that point, navigation at sea was not even remotely an exact science. Or as one member of the Admiralty put it, was "bobbing around at sea like a blind man in a brothel". 'Nuff said!
There were several competing theories for how to calculate the longitude and after several abortive theories put forward by "Longitude Lunatics", two ideas came to the fore - "Celestial Navigation" - that being navigation by the night sky, and the concept of time to determine the longitude. This would require a clock of such precision that it could only afford a second's deviation to avoid calamaty.
John Harrison was a carpenter who had managed to complete a clock at his farm made of wood. What was compelling about this clock was that it was perhaps the most accurate time keeper in the world at that time - but owing to his profession, he was an unlikely candidate for horological immortality.
During the reign of Queen Ann, the Longitude Act of 1714 brought Harrison to London to work on assembling a time keeper that would be accurate at sea. He was introduced to George Graham - also known by many as "Honest George", and with his assistance began work on his series of Marine Clocks (very large clocks that had to be hoisted onto the ship), which culminated in the creation of what is refered to as H3 - resembling a very large pocket-watch. Finally, here was a time keeper that was both "practical and useful" for calculating the Longitude at sea.
And in the spirit of John Harrison's achievement, Girard Perregaux is releasing a new version of their WW.TC -
And in their own words -
With its long history of continuous research into precision, the Girard-Perregaux Manufacture pays tribute to this remarkable 18th-century watchmaker by adding an exclusive creation to its ww.tc (world wide time control) collection
The dial of this exceptional timepiece depicts the journey undertaken by John Harrison's son William from Portsmouth, England, to Port Royal, Jamaica, against a map of the Atlantic Ocean. The trip lasted from November 1761 to March 1762 and was intended to test the reliability of the H-4 timepiece, which was much smaller than the first prototypes developed to calculate longitude. The H-1, for example, weighed 32.5 kg.
The dial of the ww.tc John Harrison offers a superb example of delicate champlevé enamel, produced in the enamelling workshop of the Girard-Perregaux Manufacture. The contours of the map are engraved on an unprocessed plate of white gold, while the compass rose, showing the eight directions of the wind and measuring no more than 3 mm, is hand-sculpted by a craftsman-engraver. The liquid green and blue enamel is laid into the cavities using a brush. Next comes the firing, timed to the minute in a furnace at 800°C, to create the magic of vitrification. After cooling, the excess enamel is removed by vigorous sanding using a hard stone and water. The dial is then manually polished with a diamond file, before a last firing called "Dorure" or gilding adds shine and reveals the enamel’s full splendour. William Harrison's journey is delicately indicated by a trace of silvered powder stretching from Europe to America.
Echoing the dial, Portsmouth and Port Royal are highlighted in royal blue on the cities ring, which is activated by the white-gold crown and delicately engraved with the GP logo at 9 o'clock. Universal time, as distinct from local time, can be instantly read off from the blue/white hours ring using the rhodium-plated leaf-shaped minutes hand.
The hands are also subtly skeletonised, adding exquisite elegance and discretion to their ballet around the enamelled dial. The alternation of satin-brushed and polished finishes on the white-gold case adds a sense of distinguished finesse to its beautifully balanced proportions.
The transparent case-back reveals the Girard-Perregaux 033G0 automatic calibre, which is widely recognised for the excellence and reliability of its construction. It is fitted with an ingenious coupling mechanism that activates the bicoloured ring indicating the time in 24 time zones. As an ultimate tribute to this fabulous journey in watchmaking history, the pink gold oscillating weight is engraved with a parchment bearing the dates on which the H-4 started and finished its Atlantic crossing.
The ww.tc John Harrison is available in a limited series of 50 individually numbered timepieces.
www.girard-perregaux.com
There were several competing theories for how to calculate the longitude and after several abortive theories put forward by "Longitude Lunatics", two ideas came to the fore - "Celestial Navigation" - that being navigation by the night sky, and the concept of time to determine the longitude. This would require a clock of such precision that it could only afford a second's deviation to avoid calamaty.
During the reign of Queen Ann, the Longitude Act of 1714 brought Harrison to London to work on assembling a time keeper that would be accurate at sea. He was introduced to George Graham - also known by many as "Honest George", and with his assistance began work on his series of Marine Clocks (very large clocks that had to be hoisted onto the ship), which culminated in the creation of what is refered to as H3 - resembling a very large pocket-watch. Finally, here was a time keeper that was both "practical and useful" for calculating the Longitude at sea.
And in the spirit of John Harrison's achievement, Girard Perregaux is releasing a new version of their WW.TC -
 |
| Courtesy of Griard-Perregaux |
With its long history of continuous research into precision, the Girard-Perregaux Manufacture pays tribute to this remarkable 18th-century watchmaker by adding an exclusive creation to its ww.tc (world wide time control) collection
 |
| Courtesy of Girard-Perregaux |
 |
| Courtesy of Girard-Perregaux |
 |
| Courtesy of Girard-Perregaux |
The hands are also subtly skeletonised, adding exquisite elegance and discretion to their ballet around the enamelled dial. The alternation of satin-brushed and polished finishes on the white-gold case adds a sense of distinguished finesse to its beautifully balanced proportions.
 |
| Courtesy of Girard-Perregaux |
The ww.tc John Harrison is available in a limited series of 50 individually numbered timepieces.
www.girard-perregaux.com
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