Masters of Time: The Smith of Derby prayer clock

Jul 20,2011

The division of time into measurable units has been something of an obsession for mankind for at least the last 4,000 years. From the observation of shadows cast by stone stele, the movements of stars and planets and on through increasingly exotic mechanical, electrical and finally atomic regulated mechanisms, fine engineering and scientific minds have sought to measure the passage of time with increasing accuracy.

There is no single motive for this quest; they are many and various. If there is one underlying thread, a good candidate is the need to organize increasingly complex societies.


Two great movers in the development of accurate timekeeping have been military and religious. John Harrison’s H4 chronometer, first tested on a journey to Jamaica in 1762, allowed the accurate measurement of longitude and transformed the sciences of horology and cartography and gave Britain the edge in naval navigation for a century.


Since the dawn of Islam, the accuracy of the time of each of the five prayer calls each day has driven the development of horology. The early development of astronomical devices developed into more complex mechanical ones. Al Jazari’s 1206 water-clock and the geared astrolabic clock by Abu Rayhan Biruni in the 11th century and Muhammad ibn Abi Bakr in the 13th century are but two.

It seems then somehow very fitting that two of the great contributors to the measurement of time — British horology and the Islamic tradition — should come together to inspire a radical and unique clock both to measure time with tremendous accuracy and mark the precise moment for prayer anywhere on earth.

Smith of Derby, a fifth generation family business, was founded by John Smith in 1856 in premises owned by clockmaker John Whitehurst, to whom he had been apprenticed.  Whitehurst was a giant in the field of mechanical and clockwork devices and attracted a visit by Benjamin Franklin, himself an exceptional scientist, who became a friend. 

Since then, Smith of Derby clocks have spread across the globe, from Burma to Bolivia, Cape Town to Chicago and famously on the face of St. Paul’s Cathedral in the heart of London. If it is a pillar or tower clock, it is very likely to have been built by Smiths or at least maintained by the company, as they service 4,500 clocks in the UK alone.

A recent commission was to design and deliver the timepiece for the Harmony Tower in Ganzhou. It is the world’s largest pendulum regulated clock with dials two-and-a half times the size of Big Ben. They were also engaged to design and build another 15 pieces, which tell the story of timekeeping from its earliest inception.

The idea for the Smith prayer clock came after the company’s chief designer, Kevin Litchfield, visited Saudi Arabia. There, he noted the Islamic devotion to time and that almost exclusively, prayer clocks were digital. “We don’t do digital, but make clocks that are pleasing to the eye,” he said.

On the flight back from the Kingdom, he was doodling idly on a sketchpad when inspiration struck. “I just did a simple outline sketch and it developed from there. And, it fitted perfectly with our new smart-drive movements, which we had designed for another function.”

Litchfield explained that the Smart Drive, a new clock movement he had been designing for the company, is a movement that can operate within a segment of a circle and still tell time to the second. That concept he said fitted the prayer clock perfectly, as the 24 hours of the day are divided into five prayer segments. The design idea went to the graphics section and was developed into a 3-D rendition of the concept. “They interpreted the design in terms of what people of the faith saw as beautiful and luxurious. It was very much a cross-cultural exercise,” he said.

Litchfield took the designs to the Derby Mosque and the Central London Mosque to gauge where at an open evening some fifty leaders of the Islamic community were invited to comment on Litchfield’s conception. “They all loved it with no negative reactions at all, save perhaps the price,” he commented.

The price, thought Litchfield, was a major factor in the distribution of the prayer clock. Craftsmanship of the standard delivered by Smith of Derby’s incredibly skilled workforce is not cheap. “We wanted these very carefully designed timepieces to go to places of beauty; they were never intended to be mass produced,” he said.  Such is the standard of their work that the clock in St. Paul’s Cathedral recently had an overhaul after running for 100 years. “We changed one bearing,” said Litchfield adding modestly, “We do rather over-engineer them.”

The mechanics of the clock — a central face surrounded by five prayer segments — are controlled by a computer. “Each midnight, the on-board computer, linked to the Internet, calculates for that exact position on earth for prayer times for the following day and then adjusts the five sets of segmental hands accordingly.” Smith of Derby has world patents on the device, having spent most of a year developing the technology.

The prototype prayer clock has been making a tour of the GCC, including Saudi Arabia. Smith’s have orders in hand and are “in conversation” with other potential clients over bespoke versions. “We had tremendous and very serious interest in Jeddah,” said Litchfield, respectfully declining further detail.

The basic clock, a 700 mm diameter device, is just the starting point; it can be made in diameters of up to five meters. “Clients can choose whatever they wish in terms of finish. We have had serious inquiries about the use of diamonds, gold and so on to make it unique.”

The Smith prayer clock starts at SR195,000 and is limited only by your imagination.

(Roger Harrison/



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