March 25, 2024

Time Keeping 

How do you tell the time? Do you look at a watch or a clock or perhaps a mobile phone? In past times, you might have had a sundial in your garden or just have estimated the time of day from the sun and its shadows. Once upon a time you might even have been conscious of the months of year from contemplating the great “time pieces” of the earth such as Stonehenge.

Highclere has both longcase clocks and clocks on mantelshelves and tables. Clocks from Germany and France and of course England. One of the most remarkable pendulum long case clocks sits in the corner of the Dining Room. I am quite sure you might have noticed it in the background whether on a tour or on tv in Downton Abbey or enjoyed the detail of it in Friends of Highclere. It was made by John Shelton about 280 years ago and is both truly beautiful and rare but also a practical work of art.

Over the centuries, measuring time has absorbed some of humanity’s finest minds. One of the first designs for a clock that worked using a pendulum was made by the Italian Galileo Galilei (1564-1642). Before the pendulum, clocks had used turning wheels but the mechanism was unreliable and tended to lose time. The Dutchman  Chritiaan Huygens (1629-1695) made the first working pendulum clock in 1657. It only lost a maximum of 15 seconds per day and thus immensely increased the accuracy of timekeeping.

Often referred to as the “time of tremendous enlightenment” these decades would lead to advances in the measurement of time which would eventually allow Isaac Newton to time his experiments with gravity.

However, pendulum clocks do not work at sea and the problem of knowing where ships and their crews were was considered so important that, in 1714, the British government passed the Longitude Act offering a financial reward of up to £20,000 (perhaps £10 million today) to solve the problem. John Harrison was a carpenter by trade who taught himself clock making. He built his first longcase clock in 1713 at the age of 20 where the mechanism was made entirely of wood. During the mid-1720s he designed a series of remarkable precision longcase clocks which achieved an accuracy of one second in a month, far better than any other clocks of the time.

In order to solve the problem of longitude, Harrison aimed to devise a portable clock which kept time to within three seconds a day which would make it far more accurate than even the best watches of the time. In May 1736, Harrison and H1 were taken aboard HM ship Centurion, which was about to set sail for Lisbon. It had good results and led to H2, H3 and H4, Harrison’s masterpiece – an instrument of beauty, resembling an oversize pocket watch from the period. It is engraved with Harrison’s signature, marked Number 1 and dated AD 1759.

It was confirmed that John Harrison’s timekeeper had kept time within the most stringent limits of the 1714 Act. The Board however recommended that parliament awarded Harrison only £10,000 until it was shown that other makers could produce similar timekeepers. They needed to ensure Harrison’s clock wasn’t a one-off wonder before paying out. Very upset, Harrison took his clock to King George III. He tested the watch No.2 (H5) himself at the palace and after ten weeks of daily observations between May and July in 1772, found it to be accurate to within one third of one second per day. King George then advised Harrison to petition Parliament for the full prize after threatening to appear in person to dress them down.

John Shelton was some 5 years younger than Harrison but again a joiner who turned to crafting timepieces. He made his first long clock at the age of 18 and, like John Harrison, he worked for George Graham, a businessman who underwrote entrepreneurs.

For his part, John Shelton became a famous London clockmaker and went on to make five astronomical regulators for the Royal Society in order to time the transits of Venus in 1761 and 1769. Regulators were accurate clocks used specifically for timing transit observations to the exact second. They were used for gravitational experiments as well but also by doctors so they could accurately determine a patient’s pulse rate and they made it possible to measure velocity and changes in velocity in different conditions such as at altitude, in a vacuum and in variations of air pressure.

The 20th century saw the beautiful workings of old clocks taken over by modern technology, no doubt lovely to some but not the works of art these old timepieces were. Despite the fact that they intrinsically have the same purpose and that time always seems to march on far too swiftly, there is still something reassuring about the steady movement of an old-fashioned pendulum.