Robert Hooke and his Interest in Clocks

Author:  Mike Blandford


Robert’s lifelong interest in anything mechanical naturally attracted him to the working of clocks. As a child; growing up in the West Wight, the only time he would have seen a clock, I suspect, is on visits to see Sir John Oglander at Nunwell House with his father.


Robert's first experience of clocks would have been of a type known as a Lantern Clock. They were basic brass framed clocks with a balance wheel escapement. These clocks had a duration of only about 8 hours and an accuracy of about 15 minutes a day. Time is of no matter if you are the only person in the neighbourhood with a clock. They should be regarded as rich men’s playthings.


Robert built a copy in wood which according to his words “ worked well enough”. Whilst it’s easy to dismiss this it must be remembered that John Harrison, [ who discovered the timepiece answer to the longitude problem ] seventy years later, also chose to make his first clocks out of wood. He considered certain woods had lubricating properties superior to metal because of the poor quality oil available then. One of these clocks is still running today at Brocklesby Park in Lincolnshire.


Christiaan Huygens, working with the clockmaker Salomon Coster in the Hague, invented a clock with a verge escapement in 1657. This, together with better gear cutting improved the duration first to about 30 hours and then eight days. This improved the accuracy to about 1 minute a day. Robert later would be involved with the development of improved gear cutting engines.


During his time at Westminster School, visiting workshops, Robert would have seen clocks with a verge escapement. He obviously studied the design and noted the accuracy problems of this escapement, with its short pendulum and wide arc of swing, because as soon as he arrived at Christ Church he modified the Dean’s clock to improve the accuracy for lunar observations.


We tend to think of the Longitude problem as an 18th century issue. The Royal Society was involved with the design of two ships' clocks in 1663. One was sent to the African coast with Robert Holmes. We know this because it is mentioned in the Diary of Samuel Pepys. He was afraid of Holmes and sent another in his place to interview him. As Curator of Experiments Robert would have been involved with the design of these clocks. One was built by the King’s clockmaker, Edward East and the other by John Hillderson.  


Robert quickly realised the problems at sea associated with the use of a pendulum and in 1660, working with Thomas Thompion, designed a watch that used a fine coil spring, no thicker than a hair to regulate the balance wheel. This led to a dispute with Christiaan Huygens that continued for the rest of his life. He received little support from the Royal Society and particularly the Secretary; Henry Oldenburg, who had a financial interest in Huygens receiving a patent, over Robert’s claim.


We have no definite proof, but Robert is the obvious designer of the anchor escapement introduced as a more accurate method of regulating clocks. We tend to know these clocks as either long case or grandfather clocks. They have a just over three foot pendulum and ‘tick’ every second. The first was made in 1672. This method of regulating clocks of all sizes continued in use for three hundred years until quartz clocks appeared in the 1970s. It is called an anchor escapement because if you turn it upside down it looks like a ship’s anchor.


In later life Robert became good friends with Thomas Thompion, who is rightly known as the father of English clockmaking. Robert and Thomas dined together most weeks and if you take the time to look up photos of Thomas Thompion clocks you will be amazed at the complexity of his clock movements. We know Robert made suggestions on designs and also asked Thomas to make instruments for him. Robert, impatient as ever, refers to Thomas in his diary as “a dog” when kept waiting for an instrument.


I cannot find any record of Robert having a personal pocket watch. His friend, Samuel Pepys owned a Thomas Thompion pocket watch. It is mentioned in the record of his passing. I would love to know if Robert owned one and who made it.