Timeline of English carpenter and clockmaker John Harrison, who invented the marine chronometer to solve the longitude problem, from his birth in 1693 to his death in 1776.
John Harrison is born in Foulby, West Yorkshire, England, the eldest of five children. His father, Henry Harrison, works as a carpenter. #history #invention
Harrison's family moves to Barrow upon Humber, Lincolnshire, where he grows up and learns carpentry and clockmaking from his father. #history
At age 20, Harrison builds his first longcase clock entirely from wood, demonstrating his innovative use of materials and design. #clockmaking #horology
Harrison completes another wooden longcase clock, now in the Science Museum, London. It features a unique grasshopper escapement. #horology #innovation
Harrison marries Elizabeth Barret; they have one son, John Harrison Jr., who later becomes an assistant. #personal
Harrison invents the grasshopper escapement, a low-friction mechanism that would be crucial for his future chronometers. #invention #horology
Harrison builds a precision turret clock for Brocklesby Park, regulating it with a grasshopper escapement and a gridiron pendulum. #clockmaking
Harrison develops the gridiron pendulum, using alternating brass and steel rods to compensate for temperature expansion. #invention #physics
Harrison travels to London to present his ideas for a marine timekeeper to the Board of Longitude, gaining initial support. #longitude #history
Harrison finishes H1, his first marine timekeeper, a large and heavy device with springs and balances but no pendulum. #chronometer #invention
H1 is tested on a voyage to Lisbon and back on HMS Centurion and HMS Orford. The clock performs well, allowing Harrison to apply for further funding. #navigation #history
After the successful test, the Board of Longitude grants Harrison £500 to build a second, improved timekeeper, H2. #longitude #innovation
Harrison completes H2, which incorporates a more advanced design with a remontoire and a pair of balances to counter ship motion. #chronometer
Harrison starts building H3, intended to be his most accurate timekeeper. It takes 19 years to complete and includes a bimetallic compensation curb. #invention
Elizabeth Barret dies; Harrison remarries later in life. #personal
The Royal Society awards Harrison the Copley Medal for his contribution to horology, especially the gridiron pendulum and temperature compensation. #award #science
After years of labor, Harrison finishes H3, a massive and complex timekeeper weighing 75 pounds. It introduces the bimetallic strip and caged anti-friction bearings. #chronometer #innovation
Harrison, realizing the shortcomings of large clocks, starts designing a much smaller precision watch, H4, intended as the ultimate solution. #horology
Harrison completes H4, a large pocket watch of unprecedented accuracy. It uses a high-frequency balance and a remontoire, and later proves successful at sea. #breakthrough #navigation
H4 is tested on a voyage from Portsmouth to Jamaica aboard HMS Deptford. Harrison's son William accompanies the watch. #trial #navigation
After 81 days at sea, H4 is only 5 seconds slow, equivalent to a longitude error of 1.25 minutes, well within the prize requirements. #success
The Board of Longitude, skeptical of Harrison's method, demands a second test and refuses to award the full prize immediately. #controversy
H4 undergoes a second trial on a voyage to Barbados. William Harrison again accompanies the watch. #trial
H4 is found to be only 39.2 seconds off after 47 days, corresponding to a longitude error of less than 10 miles. #success #navigation
The Board of Longitude awards Harrison £10,000 (half the grand prize) but demands he fully reveal the design of H4 and hand over his timekeepers. #prize
Harrison provides complete descriptions and drawings of H4 to the Board, which then has copies made by watchmakers. #documentation
Watchmaker Larcum Kendall creates a faithful copy of H4, designated K1, with Harrison's approval. This chronometer later accompanies Captain Cook. #horology
Harrison petitions the Board for the remaining £10,000, but they refuse, demanding further tests and that he build replicas. #dispute
Captain James Cook takes Kendall's K1 on his first voyage to the Pacific. The chronometer proves invaluable for mapping. #exploration #navigation
Harrison appeals to King George III, who tests H5 (a precision watch) at his private observatory and supports Harrison's case. #royalty #history
Harrison constructs H5, an even more refined watch, to demonstrate his capability and to show the board that his methods are reliable. #invention
Parliament passes a special act awarding Harrison a final payment of £8,750, bringing his total compensation to £23,065. #victory
Harrison publishes a detailed account of his timekeeper's principles and construction, solidifying his legacy. #publication
John Harrison's health deteriorates in his final years; he continues to work on clocks. #life
John Harrison dies in London at age 83. He is buried in St. John's Church, Hampstead, and his contributions to navigation are widely recognized posthumously. #legacy #history
After John's death, his son William continues to promote his father's work and eventually donates the timekeepers to the nation. #legacy
Harrison's original marine timekeepers H1 through H4 are deposited at the Royal Observatory, Greenwich, now part of the National Maritime Museum. #preservation
K1 survives Cook's third voyage and is returned, proving the reliability of Harrison's design. #exploration
By the early 19th century, Harrison's design principles are adopted by makers like Thomas Earnshaw and John Arnold, revolutionizing navigation. #legacy #navigation
The Board of Longitude is dissolved, having fulfilled its purpose; Harrison's chronometer is credited with solving the longitude problem. #history
The Clockmakers' Company restores Harrison's tomb in St. John's, Hampstead, marking renewed recognition of his contribution. #commemoration
The original Harrison timekeepers are moved to the National Maritime Museum in Greenwich, where they remain on display. #preservation
Dava Sobel's book 'Longitude' brings Harrison's story to a wide audience, sparking renewed interest in his life and work. #literature #history )
A bronze statue of John Harrison is unveiled in his childhood village to honor his achievements. #commemoration
The Science Museum in London features H1 in a major exhibition, highlighting its significance. #exhibition