John Harrison - Subsequent History

Subsequent History

After World War I, Harrison's timepieces were rediscovered at the Royal Greenwich Observatory by retired naval officer Lieutenant Commander Rupert T. Gould. They were in a highly decrepit state, and Gould then spent many years documenting, repairing and restoring them without being compensated for his efforts. It was Gould, not Harrison, who gave them the designations H1 to H5, although initially he called them simply No.1 to No.5. Unfortunately Gould made some of his own modifications and repairs to these machines that would not pass today's standards of good museum conservation practice, although most Harrison scholars give Gould some credit for having ensured the survival of the historical artifacts as working mechanisms to the present time. Gould is the author of the book The Marine Chronometer, covering the history of chronometers from the Middle Ages through to the 1920s. It includes detailed descriptions of Harrison's work and the subsequent evolution of the chronometer. It remains the authoritative work on the marine chronometer.

Today the restored H1, H2, H3 and H4 can be seen on display in the National Maritime Museum at the Royal Observatory, Greenwich. H1, 2 and 3 are still running; H4 is kept in a stopped state because, unlike the first three, it requires oil for lubrication and will degrade as it runs. H5 is owned by the Worshipful Company of Clockmakers of London and is on display at the Clockmakers' Museum in the Guildhall, London, as part of the Company's collection.

In the final years of his life, John Harrison wrote about his research into musical tuning and manufacturing methods for bells. His tuning system, (a meantone system derived from pi), is described in his book Concerning Such Mechanism ........ (CSM). This system challenges the traditional view that "harmonics" occur at integer frequency ratios, and in consequence all music using this tuning produces low frequency beating. In 2002, Harrison's last manuscript, A true and short, but full Account of the Foundation of Musick, or, as principally therein, of the Existence of the Natural Notes of Melody was rediscovered in the US Library of Congress. His theories on the mathematics of bell manufacturing (using "Radical Numbers") are yet to be clearly understood.