It may seem difficult to fathom for people living in the world today, but there was once an age during which man had not yet mastered the idea of timezones and accurate calculations of longitude at sea.  Ocean-going tragedies related to botched longitudinal calculations, such as the 1707 grounding of an entire English squadron of warships upon the Scilly Isles, which resulted in 2,000 deaths, heightened the desire of the British government to solve the problem of inaccurate calculations of longitude at sea.  In order to entice the greatest scientific minds of the day to apply their smarts to this particularly relevant problem during the age of English exploration (After all, one cannot expand the empire if one's ships are routinely running aground!), Britain's Parliament passed the Longitude Act in 1714.  The Longitude Act offered a reward of 20,000 pounds (The modern equivalent of several million dollars!) to anyone who could find a method of calculating a ship’s longitude to within half a degree (approximately 18.64 mi/30 km).

The longitude problem was studied carefully by many intellectuals of the era, including a watchmaker named John Harrison.  Harrison's simple approach showed great promise.  His idea was to use a clock to measure the time difference between the journey’s starting point and the ship’s current position.  Because the Earth completes one full revolution in approximately 24 hours, each hour thus represents 15 degrees of rotation, or 15 degrees’ difference in longitude.  By measuring the difference between the exact local time at the ship’s position (determined using a sextant) and the exact reference time (at the point of departure, indicated by the clock) the longitude of the ship can be calculated (No more math!  My head hurts!).

The main challenge inherent to Harrison's idea was that the reference clock had to maintain its accuracy despite the pitching and rolling of the world's rough seas.  Making this timepiece became John Harrison’s lifelong quest.  The self-taught watchmaker, who was born March 24, 1693, was trained as a carpenter, but ultimately devoted his life to developing reliable and accurate timepieces.  In the pursuit of this goal, he built novel mechanisms based on the work that Christian Huygens and Robert Hooke had carried out on the spiral spring, and used brass and steel alloys to reduce the effect of expansion and contraction.  In 1773, after many successes and failures, the amazing performance of his H-4 watch was recognized and earned him part of the reward promised in the Longitude Act.  Due to the intense rivalries engendered by the cash prize, as well as the ambiguous conditions imposed to obtain it, the total sum was never awarded in full.

Not unlike John Harrison, Girard-Perregaux has long researched issues of precision.  As a tribute to Harrison, who shared their goal of timekeeping accuracy, the Manufacture is issuing a special version of the WW.TC that commemorates the 250th anniversary of his historic trip from Portsmouth, England to Jamaica.




On that trip, Harrison tested his H-4 pocketwatch, which embodied all his best efforts toward creating a highly precise timepiece.  The trip was a success, as Harrison and crew navigated safely to Jamaica and back.  For this accomplishment, and Harrison's contribution to the fields of watchmaking and navigation, he has earned the moniker "father of the marine chronometer."





The limited edition of 50 pieces honoring John Harrison's historic voyage with his son William and crew depicts the journey undertaken from Portsmouth, England, to Port Royal, Jamaica, against a map of the Atlantic Ocean.  The trip spanned the time period from November 1761 to March 1762 and was intended to test the reliability of the H-4 timepiece. 

The dial of the ww.tc John Harrison is crafted in delicate champlevé enamel, produced in the enameling workshop of the Girard-Perregaux Manufacture. 




Chisels are used to create the engravings on the rotor and dial of the watch.



Raw enamel is mixed with metal oxides to create various shades.  The traditional process of enameling is equal parts art and science.  A master enameler develops a feel for the enamel over time after years of practice.  They learn how different enamels react to different firing temperatures and conditions.  The complexities of the chemical reactions inherent in the traditional enameling process ensure that each dial is truly a piece unique.



Preparing the enamel the old-fashioned way involves some elbow grease!









Tinting enamel is challenging, but several colors can be created -- some in eye-popping shades.

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 splendor. 




The Harrisons' journey is delicately indicated on the dial by a trace of silvered powder stretching from England to Jamaica, and back again.  Echoing the dial's color scheme, Portsmouth and Port Royal are highlighted in royal blue on the cities ring, which is activated by the white-gold crown and engraved with the GP logo at 9 o’clock.  Universal time, as distinct from local time, can be instantly read from the blue/white hours ring using the rhodium-plated leaf-shaped minutes hand.  The hands are also subtly skeletonized. The alternation of satin-brushed and polished finishes on the white-gold case adds a sense of finesse, beauty, and proportion. 




The transparent case-back reveals the Girard-Perregaux 033G0 automatic caliber, which is widely recognized for the excellence and reliability of its construction.  It is fitted with a coupling mechanism that activates the bi-colored ring indicating the time in 24 time zones.  As a 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.




Technical specifications for World Wide Time Control John Harrison limited edition (ww.tc John Harrison):

Case in white gold
Diameter: 41 mm
Height: 11 mm
Crystal: antireflective sapphire
Case-back: sapphire crystal, secured with six screws
Water resistance: 50 metres
Dial in champlevé enamel
Girard-Perregaux GP033G0 movement
Mechanical with automatic winding
Calibre: 11 ½ ’’’
Frequency: 28,800 vibrations/hour (4 Hz)
Jewels: 26
Power reserve: minimum 46 hours
Functions: hours, minutes, display of world times with day/night indicator
Black alligator strap
Folding clasp in white gold

Thank you to our friends at GP for providing the lovely making-of photos detailing the creation of the hauntingly beautiful champlevé enamel dial on this piece.  I'm actually not a world timer fan, but this dial is STUNNING!  If I was in the market for a world timer for my collection, this would definitely be it.

Hope you enjoyed this glimpse into the life of John Harrison and the new watch that bears his name.

Cheers,
Daos


This message has been edited by dxboon on 2011-06-08 10:23:30