In 2015, Guinness World Data offered an uncommon award on the Nationwide Maritime Museum in Greenwich (the “G” in “GMT”), England. After a 100-day testing whereas sealed in a transparent plastic field to stop tampering, Clock B by Martin Burgess and accomplished by Charles Frodsham and Co. was formally declared to be the world’s “most correct mechanical clock with a pendulum swinging in free air. ”
Mea culpa: within the title I described John Harrison as each “the inventor of the marine chronometer and winner of the British Admiralty’s Longitude Prize.” Whereas the primary of these statements is true, the second − although extensively believed to be so − isn’t.
2 hundred and fifty years in the past, the British Admiralty belatedly and begrudgingly paid Harrison for revolutionizing nautical navigation and saving 1000’s of lives misplaced at sea together with his H4 marine chronometer, which enabled a exact and dependable willpower of longitude (east-west place) at sea.
This invention heralded precision timekeeping as providing a lot superior navigation at sea in comparison with celestial observations. However the British Admiralty by no means truly awarded the Longitude Prize to Harrison or anyone else for that matter: it’s believed that was to keep away from paying out the complete prize cash.
Two-hundred fifty years is a very long time
Harrison was one of many world’s biggest horologists, however 250 years is a very long time and we now have superior to this point since then. Haven’t we?
Within the final 250 years we now have invented driverless vehicles, pilotless planes, widespread electrical energy, computer systems, web, area journey, and the smartphone.
And we’re regularly bettering in just about all areas thanks to higher supplies and our understanding of these supplies in addition to higher and extra exact machines. Enchancment can be largely due to a consistently expanded data base and centuries of enter from sensible and inventive minds.
2 hundred and fifty years may not be a very long time on a geological scale, however it’s a very long time for people; great-great-grandparent doesn’t even get midway.
However first there have been wall clocks
John Harrison (1693-1776) is famend for his H4 marine chronometer, however marine chronometers are removed from being pure timekeepers: the primary consideration for marine chronometers needs to be reliability and consistency within the extraordinarily hostile surroundings of a moist and salty environment on a extensively pitching and tossing ship subjected to a variety of continually various temperatures.
Precision is secondary to reliability for a marine chronometer. That isn’t the case nevertheless in a high-precision pendulum wall clock, and whereas it’s much less recognized, earlier than he began growing a marine chronometer to win the Longitude Prize, Harrison was already extraordinarily good at growing high-precision pendulum wall clocks that solely have temperature variations to deal with somewhat than the intense circumstances of months or years at sea.
Throughout Harrison’s early profession, George Graham (1673-1751), was extensively acknowledged because the most interesting horologist in England. Graham was making pendulum clocks referred to as regulators with an accuracy of 1 second per day. That’s the precision of a contemporary quartz watch, and it was very spectacular within the early eighteenth century.
However as spectacular as Graham’s regulators have been, Harrison, who had educated as a carpenter and made his clocks largely in wooden, began making timepieces that have been 30 occasions extra correct, dropping only one second per 30 days somewhat than Graham’s one second per day.
However that wasn’t sufficient for him. In his later life, Harrison wrote a small guide through which he criticized lots of his colleagues and claimed that he may make a wall clock with a then-unheard-of-precision of only one second over 100 days!
Even with the fame Harrison had, that stage of accuracy appeared like sheer lunacy on the time, the rantings of a madman. There have been feedback by distinguished horologists in discovered journals describing Harrison’s claims as “an incoherence and absurdity that was little in need of the signs of madness” and “. . . the ramblings of superannuated dotage.”
Harrison was by no means capable of show the naysayers incorrect as whereas he had designed his one-second-in-100-days clock, which might have a big pendulum arc, comparatively mild bob, and a recoil grasshopper escapement, he by no means obtained round to creating it.
And that was that. Till . . .
Quick ahead 250 years to English horologist Martin Burgess
In 1975, English artist and clockmaker Martin Burgess was commissioned to make a sculptural clock for Gurney’s Financial institution of Norwich. He took this as a chance to delve into John Harrison’s eighteenth-century precision clocks and made two clocks he referred to as A and B based on the ideas Harrison had specified by his writings.
Clock A was accomplished in 1987 (and is now on show at The Fortress Mall in Norwich), however Burgess by no means accomplished Clock B, and its components remained in his workshop for 30 years. Then in 2009 a collector purchased the components and commissioned it anew.
John Harrison vindicated after 250 years by the Martin Burgess Clock B
In the end the mission concerned a variety of horologists, who fashioned the Harrison Analysis Group to have a look at his theories afresh. Harrison had claimed that his earlier pendulum clocks have been correct to inside one second per 30 days and that his final, unfinished clock, “. . . shall carry out to a second in 100 days.”
Burgess’s two clocks have been primarily based on Harrison’s ideas, however utilizing trendy supplies the place this was thought-about applicable.
In 2009, a collector purchased Burgess’s components for Clock B and commissioned London clockmakers Charles Frodsham & Co. to finish the work. Frodsham started with intensive analysis into Harrison’s pondering, the teachings learnt by Burgess in making Clock A, and the needs of the consumer.
Clock B accomplished by Charles Frodsham & Co.
To finish Clock B, Charles Frodsham & Co. below the path of Philip Whyte and Richard Stenning consulted extensively with a workforce of distinguished horologists within the Harrison Analysis Group, which included William Andrewes, Andrew King, Donald Saff, Burgess, Mervyn Hobden, and others.
Frodsham watchmakers Roger Stevenson and Martin Dorsch in addition to different workforce members designed and produced the lacking parts for Clock B and examined it extensively in 2012.
It was determined to compete the clock based on Harrison’s design and ideas however utilizing trendy know-how the place applicable. As an example whereas the clock is pushed by a descending weight, the load is mechanically wound up by an electrical motor.
Clock B’s gear prepare wheels are fabricated from Duralumin, which run on oil-free bearings. The pinions are Harrison’s type of lantern pinions however use small ball races instead of Harrison’s lignum vitae wood rollers.
Harrison’s regulator clocks don’t require lubrication, and Burgess deliberate the identical for Clock A and Clock B. The previous has been retaining good time oil-free for close to 30 years with just about no upkeep.
Clock B is regulated by a low-friction, lubrication free Grasshopper escapement, which was invented by Harrison.
The escape wheel is pushed instantly by a remontoir, which is a coiled spring that rewinds each 30 seconds. This isolates the escapement from variations in torque from the gear prepare and ensures that the recoil of the escape wheel simply rewinds the remontoir spring somewhat than the entire gear prepare.
Constructing on classes learnt by Burgess, for Clock B Frodsham made a brand new pallet arbor resting on sapphire pads and used low friction PEEK for the pallets and composer bearings. The cycloidal suspension cheeks are an important a part of Harrison’s regulator concept, and these have been precision milled from giant brass blocks bolted to the large 90-kilogram metal again plate.
Far more work was required to finish the drive to the arms, the dials, and the hour, minute and second arms; the aesthetics have been rigorously agreed with the clock’s proprietor.
When completed, after preliminary changes and regulation, Clock B was discovered to be able to retaining a particularly good and steady charge. In actual fact, the precision of this 250-year-old design was so good that it was determined to have the clock independently examined by the Royal Observatory in Greenwich.
After being examined for 100 days in a tamper-proof case, Clock B had misplaced simply 0.625 seconds: that’s simply over half a second in additional than three months of various temperature, humidity, and air stress!
Not solely did Clock B vindicate Harrison’s theories, design, and genius, it set a brand new world-record stage of accuracy for pendulum clocks in free air and was formally declared by Guinness World Data to be the world’s “most correct mechanical clock with a pendulum swinging in free air.”
For extra data, please go to: burgessclockb.com/about-burgess-clock-b.
*This story was first posted on July 28, 2017 at Burgess Clock B, The World’s Most Exact Pendulum Clock.