Derek Pratt (watchmaker)#Independent watchmaking

Pratt, born in Orpington, England, developed an early interest in watchmaking. He was known by the nickname 'Ticker' during his childhood. He attended Beckenham Technical School, and began formal training in watch and clock technology in 1955 at the National College of Horology in London. At the same time, he held a student apprenticeship at S Smith and Sons (now known as Smiths Group) in Cricklewood, north London.{{Cite journal |last=Treffry |first=Timothy |date=June 2008 |title=Derek Pratt at 70 - 'The Compleat Horologist' |url=https://bhi.devsoc.org/library/download/930/ |journal=Horological Journal |volume=150 |issue=6 |pages=17–19 |via=British Horological Institute}} The three-year training was intended to include the finishing and assembly of a pocket watch, but due to a slump in the British watch industry, the syllabus was abruptly changed, and the class was denied that experience. This change led to Pratt's early departure from the program.

The former director of Horology at the College and Pratt's tutor, Andrew Fell, hired him after he completed additional training in production engineering and tool design. Together, they worked on clocks inside black boxes used in aviation as well as micro-soldering devices for the then burgeoning field of microelectronics. It was this work that took Pratt to Switzerland, where he was to spend the rest of this life, and to embark on his career as a watchmaker.{{Cite journal |last=Treffry |first=Timothy |date=February 1990 |title=Derek Pratt, Watchmaker |url=https://bhi.devsoc.org/library/download/826/ |journal=Horological Journal |volume=132 |issue=8 |pages=60–66 |via=British Horological Institute}}

After his work at Andrew Fells's companies, A. & M. Fell Ltd. and Felmada, ended in the early 1960s, Pratt took jobs at small companies specializing in microelectronics. One of them was with Kulicke & Soffa, a semiconductor manufacturer. In 1972, Pratt established his own business, specializing in watch and clock restoration and development. His horological interests included Gothic iron clocks such as those by Erhard Liechti; he also repaired household clocks, and worked on intricate and singular pocket watches.File:Derek Pratt's Workshop in Bellach, Switzerland.jpgA commission to repair a watch for the Swiss entrepreneur and antique watch dealer Peter Baumberger led to friendship and a business partnership that spanned decades.{{Cite journal |last=Pratt, Baumberger |first=Derek, Peter |date=December 1990 |title=Urban Jürgensen & Sønner, Copenhagen |url=https://bhi.devsoc.org/library/download/5/ |journal=Horological Journal |volume=133 |issue=5 |pages=58–63 |via=British Horological Institute}}

Amidst the Quartz crisis in the Swiss watchmaking industry, Pratt saw an opportunity and pursued a different approach: he acquired those seemingly obsolete tools of the trade, expanding his workshop with lathes, milling and guilloché machines.{{Cite web |title=Derek Pratt: The Forgotten Watchmaker |url=https://www.acollectedman.com/blogs/journal/derek-pratt-the-forgotten-watchmaker |access-date=2025-02-14 |website=A COLLECTED MAN |language=en}} His focus was on hand making watches from the smallest screw to the case, and continuing restoration work on antique pieces. These machines were crucial for the work Pratt was to do under the historic brand Urban Jürgensen, which had been purchased and revived by Peter Baumberger in the late 1970s. Pratt also did a lot of work by hand, with a piercing saw or turns.File:Erhard Liechti 1580.jpgPratt possessed a strong understanding of mechanical principles{{Cite journal |last=Whyte |first=Philip |date=November 2009 |title=Obituary Derek Francis Pratt |url=https://bhi.devsoc.org/library/download/947/ |journal=Horological Journal |volume=151 |issue=11 |pages=7 |via=British Horological Institute}} and focused on the refinement of horological escapements. He developed noteworthy but little known solutions.{{Cite web |last=Chia |first=Cheryl |date=2021-05-31 |title=The Origins of Independent Watchmaking |url=https://revolutionwatch.com/origins-independent-watchmaking/ |access-date=2025-02-02 |website=Revolution Watch |language=en-US}}

He started crafting entirely handmade remontoire tourbillon pocket watches using hand tools and hand-operated machine tools. The remontoire, producing a constant force, was an equally constant theme in Pratt's work: he encountered it both in the aircraft clocks as well as John Harrison's famous H4 marine chronometer. Pratt achieved a configuration where the remontoire directly drove the escapement, even within a tourbillon.{{Cite journal |last=Pratt |first=Derek |date=March 2009 |title=In Breguets's Footsteps... Derek Pratt FBHI describes double wheel escapements. |url=https://bhi.devsoc.org/library/download/939/ |journal=Horological Journal |volume=151 |issue=3 |pages=10–14 |via=British Horological Institute}}

In 1979, Peter Baumberger bought the 18^th century Danish brand Urban Jürgensen und Sønner (now known as Urban Jürgensen or UJS) and brought Pratt on board as a consultant and technical director.{{Cite web |last=Doerr |first=Elizabeth |date=2016-12-28 |title=The Life And Times Of Legendary Independent Watchmaker Derek Pratt |url=https://quillandpad.com/2016/12/28/life-times-derek-pratt-legendary-watchmaker/ |access-date=2025-02-21 |website=Quill & Pad |language=en-US}} The vintage watch collector and expert Dr. Helmut Crott (and subsequent owner of the brand), noted in 2011 that perhaps "only his association with Derek gave Peter the confidence to finalize the deal. Derek was almost certainly the key factor in the acquisition of UJS; his extraordinary skills were needed for the 90 historic movements to be finished, cased and sold."{{Cite book |last=Crott |first=Helmut |title=Derek Pratt FBHI Watchmaker |date=September 2018 |publisher=British Horological Institute Ltd |isbn=978-0-9568003-2-9 |editor-last=Treffry |editor-first=Timothy |edition=2nd |location=Upton Hall, Upton, UK |pages=25 |language=english}} Pratt's involvement with Urban Jürgensen was pivotal to the brand's revival and success with collectors in the 1980s and 1990s.{{Cite web |last=Chia |first=Cheryl |date=2024-11-06 |title=A Closer Look: Derek Pratt Oval Pocket Watch |url=https://revolutionwatch.com/a-closer-look-derek-pratt-oval-pocket-watch/ |access-date=2025-04-29 |website=Revolution Watch |language=en-US}}

File:Remontoir carriage of a tourbillon pocket watch made by Derek Pratt.jpg

These decades were Pratt's most productive period: he made a series of pocket watches, mostly under the Urban Jürgensen name. He called these watches 'remontoire-tourbillons'. They are described in an article titled "A Tourbillon indicating full seconds with carriage-mounted remontoire, twin barrels and up & down indicator".{{Cite journal |last=Pratt |first=Derek |date=July 1991 |title=A Tourbillon indicating full seconds with carriage-mounted remontoire, twin barrels and up & down indicator |url=https://bhi.devsoc.org/library/download/356/ |journal=Horological Journal |volume=134 |issue=1 |pages=11–17 |via=British Horological Institute}} These watches marked the introduction of the Wankel-inspired Reuleux triangle to operate the remontoire.

In 1981, Pratt embarked on combining the two inventions, thus creating what is now known as his "First series remontoire-tourbillon watches".{{Cite book |last=Crisford |first=Andrew |title=Derek Pratt Watchmaker |date=September 18, 2011 |publisher=British Horological Institute Ltd |year=2011 |isbn=9780950962191 |editor-last=Treffry |editor-first=Timothy |edition=2nd |publication-date=September 2018 |pages=9–14 |language=English}} The three watches also feature Pratt's engine-turning (guilloché) skills. Guilloché dials often have different patterns in different regions with the hard-to-execute change hidden by a chapter ring. Pratt's precise execution enabled variations in the guilloché pattern without the need to hide the junction. In the nineteen nineties, Pratt made a further series of three watches, known as the "second series". Their mechanical principles are identical to those of the first series. These watches have a minimalist steel bridge replacing the back plate, which reveals the movement of the watch. Furthermore, in this series, the cam is made from synthetic ruby, rather than steel.

File:Derek-Pratt-Engine-Turning-Machine1.jpg

In addition to the pocket watches Pratt made under the Urban Jürgensen brand, he also completed a sizable number of unfinished pocket watches that had come with the sale of the brand. Pratt added complications, finished and cased them. He also produced many guilloché dials for USJ pocket watches and wristwatches.

While working for the Urban Jürgensen brand, Pratt was developing other ideas, and in regular exchange with his close friend George Daniels.{{Cite web |last=Betts |first=Jonathan |date=2017-11-03 |title=Remembering Derek Pratt, a Master of All Times |url=https://www.sothebys.com/en/articles/remembering-derek-pratt-a-master-of-all-times |access-date=2025-04-29 |website=Sothebys.com |language=en}}

The co-axial escapement was attributed solely to Daniels for many years. In the horological world, however, it is well known that Pratt played an important role in bringing this revolutionary invention to life.{{Cite web |last=Chia |first=Cheryl |date=May 31, 2021 |title=The Origins of Independent Watchmaking |url=https://revolutionwatch.com/origins-independent-watchmaking/ |website=Revolution}} Daniels and Pratt spoke on the phone every Sunday morning for years, discussing what they were working on in great detail, with sketches exchanged by fax.{{Cite web |title=The Greatest Unknown Watchmaker – Derek Pratt |url=https://watchesbysjx.com/2018/03/the-greatest-unknown-watchmaker-derek-pratt.html |access-date=2025-02-14 |website=SJX Watches}}

According to David Newman, former Chairman of the George Daniels Educational Trust, Pratt was Daniels' greatest horological friend, and a brilliant horologist.{{Cite web |title=Interview: David Newman, Chairman of The George Daniels Trust – Part I |url=https://watchesbysjx.com/2019/08/david-newman-george-daniels-trust.html |access-date=2025-01-17 |website=SJX Watches}} Daniels was among the contributors to "Remembering Derek", the Horological Journal's December 2009 issue containing Pratt's obituary. He wrote: "Derek's understanding of escapements was of great assistance to me. He immediately saw the benefit of the coaxial escapement and enthusiastically accompanied me in visiting factories to discuss its worth. He could speak French and Swiss German fluently, which was essential to our needs."

Pratt was a modest man. In the July 1999 issue of the Horological Journal, he happily gave Daniels full credit: "What a great time this is for British horology. All horologists should feel as proud and excited as I do about the launch of George Daniels' escapement in an Omega watch. The fact that Swatch Group have found the courage, not to mention the money, to put a new escapement into mid-market watches is wonderful news for mechanical horology. That this escapement is to succeed Mudge’s lever escapement (developed to its ultimate form by the Swiss) fills me with pride."{{Cite journal |last=Pratt |first=Derek |date=July 1999 |title=The Daniels Co-Axial Escapement |url=https://bhi.devsoc.org/library/download/663/ |journal=Horological Journal |volume=141 |issue=7 |pages=26–27 |via=British Horological Institute}}

In a Horological Journal article from July 1991, Pratt started out by stating "It is very difficult to produce anything new in mechanical horology. Something is lacking however in most contemporary horology and that is innovation." Whilst Pratt was talking about his remontoire-tourbillons in that piece, arguably, the co-axial escapement represents another one of these rare innovations that came out of modern times, and in part, his hands (he made the dual-purpose escape pinion – a necessary component of Daniels' co-axial escapement – using a spark erosion machine he had retained from his micro-engineering work){{Cite journal |last=Higginson |first=Derek |date=November 2009 |title=Obituary Derek Francis Pratt |url=https://bhi.devsoc.org/library/download/947/ |journal=Horological Journal |volume=151 |issue=11 |pages=6 |via=British Horological Institute}}. Today, the co-axial escapement is central to the mechanical identity of any Omega watch, used in most of the mechanical watch models currently produced by Omega SA.{{Cite web |last=Canter |first=Andrew |date=2024-11-26 |title=The Greatest Horological Inventions of All Time: Why George Daniels' Co-Axial Escapement Revolutionised Mechanical Watchmaking |url=https://wornandwound.com/the-greatest-horological-inventions-of-all-time-why-george-daniels-co-axial-escapement-revolutionised-mechanical-watchmaking/ |access-date=2025-04-29 |website=Worn & Wound}}

Daniels' tribute to Pratt ended with this note: "With Derek's passing we have all lost an important mechanical horologist of great experience and great knowledge, who was above all generous and congenial in his dealings with others. I have simply lost a brilliant horological friend and companion."{{Cite journal |last=Daniels |first=George |date=December 2009 |title=Remembering Derek |url=https://bhi.devsoc.org/library/download/948/ |journal=Horological Journal |volume=151 |issue=12 |pages=8 |via=British Horological Institute}}

Pratt loved solitude in the workshop, but cultivating friendships with fellow watch- and clockmakers was very important to him, too. In addition to the weekly calls with George Daniels, he had lively exchanges with peers in Switzerland, the UK and the US. He opened the doors to his workshop to countless students of horology and was interested in the next generation of watchmakers. He also frequently contributed articles for the Horological Journal and attended as many events hosted by the Worshipful Company of Clockmakers as possible. Pratt became a Freeman of the Worshipful Company of Clockmakers in 1979, and a Liveryman in 1982{{Cite web |title=Inside Derek Pratt's Oval Pocket Watch |url=https://www.phillips.com/article/149733060/derek-pratts-oval-pocket-watch-voutilainen-urban-jurgensen-phillips-reloaded |access-date=2025-02-19 |website=Phillips |language=en}} and received its rarely awarded Tompion Gold Medal in 2005.

Pratt had wanted to make a wristwatch featuring the Reuleux triangle remontoire mechanism for a long time. In 2008, already in quite poor health, Pratt shared this idea with Stewart Lesemann and Ron DeCorte, two American watchmakers. DeCorte was the driving force behind the project. Together, they envisioned a wristwatch with a movement that would house twin suspended barrels and a one-second remontoire. Small wristwatch movements make the application of a remontoire quite challenging. This challenge aligned with Pratt's interest in resolving complex mechanical problems.

As Lesemann was working on the first and second prototype of the Derek Pratt Remontoire d'Égalité, Luca Soprana expressed interest in the work. Pratt and Soprana first met some years earlier, when Soprana, an Italian watchmaker, had visited Pratt’s workshop as a WOSTEP student. Lesemann continued work on the watch after Pratt's passing, and in 2011, presented the third prototype at the Derek Pratt Memorial Seminar, hosted by the British Horological Institute.{{Cite book |last=Lesemann |first=Stewart |title=Derek Pratt Watchmaker |date=July 2012 |publisher=British Horological Institute |isbn=978-0-9568003-2-9 |editor-last=Treffry |editor-first=Timothy |edition=2nd |publication-date=July 2012 |pages=31–33 |language=English}}

In 2014, DeCorte brought in Tom Bales, an American entrepreneur and watch collector. Bales invested into the completion of the watch, which Soprana took on. Since then, a handful of Derek Pratt Remontoir d'Égalité watches have been produced under the Derek Pratt trademark. With these watches, Derek Pratt's legacy is carried forth by Luca Soprana.{{Cite web |title=A Look at Luca Soprana's Revival of a Master Watchmaker |url=https://www.phillips.com/article/149870440/luca-soprana-derek-pratt-about-history |access-date=2025-02-03 |website=Phillips |language=en}}{{Cite web |title=An Afternoon with Luca Soprana |url=https://www.acollectedman.com/blogs/journal/an-afternoon-with-luca-soprana |access-date=2025-02-26 |website=A COLLECTED MAN |language=en}}

File:Derek-Pratt-Oval-Pocket-Watch.jpg

In 1982, Pratt embarked on a new project, a pocket watch known as The Oval. It has been described as Pratt’s magnum opus.{{cite web |last=Su |first=JX |date=2024-11-06 |title=Hands On: Urban Jürgensen and Derek Pratt Oval Pocket Watch |url=https://watchesbysjx.com/2024/11/urban-jurgensen-derek-pratt-oval-pocket-watch.html |access-date=2025-02-09 |website=watchesbysjx.com}} In 1985, financial constraints led him to sell the watch in its raw state to Peter Baumberger. This explains why the Urban Jürgensen name is on the dial. Baumberger engaged Pratt to continue his work on the Oval. Pratt wrote in April 1993 for the trade publication Horological Journal, "...on seeing the oval Breguet No. 1682 / 4761, [...] I felt positively inspired and resolved to make an oval watch myself."{{Cite journal |last=Pratt |first=Derek |date=April 1993 |title=Oval Watches |url=https://bhi.devsoc.org/library/download/149/ |journal=Horological Journal |volume=135 |issue=9 |pages=54–55 |via=British Horological Institute}} In the same year, the watch was shown as a working version at Baselworld. Pratt worked on the Oval on and off for the next 22 years. 

Pratt constructed this watch, along with the Double-wheel Remontoire Tourbillon described below, entirely by hand, including the case, dials, and the movement. Even the convex oval glass was made by Pratt, because none of the craftsmen he usually went to for glass were willing to take on the challenge. It required purchasing a small furnace and lots of practice. He described his process of experimentation with the glass in the same April 1993 Horological Journal article.

The Oval watch incorporates a remontoire within a flying tourbillon (a combination which he invented){{Cite web |last=Crott |first=Helmut |title=In-Depth: The Unique and Magical Oval Tourbillon Watch by Derek Pratt |url=https://watchesbysjx.com/2021/09/derek-pratt-oval-pocket-watch-tourbillon.html |access-date=2025-02-23 |website=SJX Watches}}, detent escapement, moon phase, power reserve and thermometer. It is considered one of the greatest achievements in modern watchmaking by many.

In articles about the watch, the authors call out the guilloché work, noting that Pratt's "engine-turned dials are as legendary as his mechanical work". The large silver dial is engine-turned in different styles, ranging from a basketweave motif to circular and straight-line barley corn patterns. Edges are outlined by a fluted border referred to as a filet sauté.

The Oval watch was sold at auction in November 2024, for 3,690,000 Swiss francs (then about $4,200,000).{{cite web |url=https://www.phillips.com/detail/derek-pratt-for-urban-jurgensen/CH080524/40 |title=Derek Pratt for Urban Jürgensen |website=phillips.com |date=2024-11-08 |access-date=2025-02-09 }}

File:Derek-Pratt-Double-Wheel-Remontoir-Tourbillon.jpg

File:Derek Pratt in his workshop.jpg

In 1997, Pratt created a pocket watch known as the Derek Pratt Double-wheel Remontoire Tourbillon. It was his submission for the Prix Abraham-Louis Breguet, a tourbillon contest held by the Breguet foundation to commemorate the 250th anniversary of Abraham-Louis Breguet's birth. The competition was to celebrate innovative mechanical ideas in horology. Pratt chose to make a Double-wheel Remontoire Tourbillon pocket watch, knowing that this produced far better timekeeping. It also perfected and enhanced two of Breguet's inventions. Pratt's realization that a fixed wheel with both inward and outward facing teeth would drive the twin escape wheels in opposite directions provided the only tenable solution for an échappement naturel in a tourbillon watch.

His pocket watch submission features a hand-cut and guilloché dial divided into different patterns, with two fan-shaped displays on the top half of the dial. The sector on the left indicates the power reserve, and the one on the right indicates the temperature in Breguet style. The skeletonized steel train bridge reads 'Invenit et fecit, Derek Pratt, 1997'. Pratt did not win the competition, the award went to Carole Forestier for her concept that eventually became the Ulysse Nardin Freak.

The watch is on display in The Science Museum in London.{{Cite web |date=2020-10-28 |title=A Visit to the Clockmakers' Museum, London |url=https://www.watchaffinity.co.uk/blog/a-visit-to-the-clockmakers-museum/ |access-date=2025-04-29 |website=Watch Affinity |language=en-GB}}

File:Derek Pratt's H4 replica of John Harrison's H4, frontal view.webpFile:H4 Diamond Pallet with matchstick for scale.jpg

Pratt held John Harrison, the 18^th century carpenter and horologist whose work led to the developed marine chronometer, in high regard. In the 1990s, Pratt decided to re-create Harrison's H4.{{Cite web |title=H4 {{!}} Royal Museums Greenwich |url=https://www.rmg.co.uk/collections/objects/rmgc-object-79142 |access-date=2025-02-14 |website=www.rmg.co.uk}} The original timekeeper was completed by Harrison in 1759, and won him the Longitude reward (colloquially known as the Longitude Prize). Unlike Harrison's H1, H2 and H3 timekeepers, which are quite large clocks, H4 could be described as an oversized pocket watch. It is equipped with tiny diamond pallets in the escapement measuring a mere 1mm x 2mm – a very challenging part of the watch, and how the original pallets were made is a mystery.{{Cite journal |last=Murray |first=Carl |date=March 2015 |title=Completing Derek Pratt's H4 Part 2 Making the Diamond Pallets |url=https://bhi.devsoc.org/library/download/1011/ |journal=Horological Journal |volume=157 |issue=3 |pages=10–12 |via=British Horological Institute}}

Pratt started work on "his H4" in 1997. He worked on it for the next 12 years, researching, planning and making the various parts. Harrison's masterpiece H4 is located at the National Maritime Museum in Greenwich, London, and was at the time under the auspices of the MoD (Ministry of Defence) Art Collection. Thanks to Jonathan Betts, the museum's Senior Horology Conservator at the time, it was possible for Pratt to gather information needed for this ambitious undertaking. Pratt's exhaustive research filled over a dozen ring binders.{{Cite journal |last=Stevenson |first=Roger |date=February 2015 |title=Completing Derek Pratt's H4 Part 1 – Charles Frodsham & Co on the Power Train and Jewelling |url=https://bhi.devsoc.org/library/download/1010/ |journal=Horological Journal |volume=157 |issue=2 |pages=10–14 |via=British Horological Institute}} (Ownership of the Ministry of Defence Art Collection was transferred to museums and public bodies in 2017.{{Cite web |date=2017-04-27 |title=[Withdrawn] Ministry of Defence art collection |url=https://www.gov.uk/guidance/ministry-of-defence-art-collection |access-date=2025-02-14 |website=GOV.UK |language=en}})

File:Derek Pratt working on his H4 replica.jpg

File:H4 replica (movement) created by Derek Pratt.webp

For some work, Pratt commissioned specialists. The case was made by the late Martin Matthews,{{Cite web |title=Martin Matthews Watchcase Maker |url=https://martinmatthewswatchcasemaker.com |access-date=2025-01-04 |website=Martin Matthews Watchcase Maker |language=en-GB}} a fourth generation watchcase maker. The dial was made by Jos Houbraken, an enameler in the Netherlands. Charles Scarr did the engraving.{{Cite book |last=Treffry |first=Timothy |title=BHI 150: A Seminar Programme Celebrating the 150th Anniversary of the British Horological Institute, June 7-9, 2008 |date=2010 |publisher=British Horological Institute |isbn=9780950962184 |publication-date=2010}}

By 2009, much of the work on the movement was done. But with Pratt's health in decline, he consulted very closely with expert watchmakers Roger Stevenson and Philip Whyte of Charles Frodsham & Co. He maintained a long-standing friendship with the Frodsham team, and frequently spent time in their workshop, discussing detent escapements for wristwatches and other horological topics.

At the Derek Pratt Memorial Seminar at Upton Hall on September 18th, 2011, Whyte and Stevenson each described in detail their recollections from how Pratt approached the making of the project, and how Pratt "had always said that he didn't set out to make a copy or a replica, he decided, quite simply, 'to make another one'." (Whyte).{{Cite book |last=Whyte |first=Philip |title=Derek Pratt Watchmaker |publisher=British Horological Institute Ltd. |isbn=978-0-9568003-2-9 |editor-last=Treffry |editor-first=Timothy |edition=2nd |publication-date=September 2018 |pages=43–58}} They described Pratt's 'Work in Progress' and the many steps: the making of the silver pair cases, the enamel dial, the piercing and engraving of various parts of the movement, as well as all the research that went into it. Stevenson noted how Pratt's generous spirit paid off in that he could now lean on the generosity of others: his friend, the horologist Anthony Randall, freely shared information as well as special tools from Randall's own work on another Harrison piece.{{Cite book |last=Stevenson |first=Roger |title=Derek Pratt's 'Work in Progress' – Continuing the Project |publisher=British Horological Institute Ltd |isbn=9780950962191 |editor-last=Treffry |editor-first=Timothy |edition=2nd |publication-date=September 2018 |pages=49–58}}

File:Derek Pratt's working cardboard and rubberband model of the double wheel remontoir escapement.jpg

For the completion of the project, the Frodsham team introduced SolidWorks CAD – a tool Pratt never worked with, but was still around to witness (he often joked about his system, CARD, derived from models built out of cardboard).{{Cite journal |last=Treffry |first=Timothy |date=November 2009 |title=Obituary Derek Francis Pratt |url=https://bhi.devsoc.org/library/download/947/ |journal=Horological Journal |volume=151 |issue=11 |pages=7 |via=British Horological Institute}} Pratt had completed much of the work on the movement himself, but there was still work to be done. The Frodsham team completed the watch in 2014.{{Cite web |title=Harrison H4 Charles Frodsham and Co Ltd. |url=https://frodsham.com/commissions/h4/ |access-date=2025-02-14 |website=frodsham.com}}

The Pratt-Frodsham H4 replica was exhibited as a loan alongside John Harrison's original H4 in the exhibition Ships, Clocks & Stars: The Quest for Longitude {{Cite journal |last=Falk |first=Seb |date=Autumn 2014 |title=Review: Ships, Clocks & Stars: The Quest for Longitude |url=https://journal.sciencemuseum.ac.uk/article/the-quest-for-longitude/#main-body |journal=Science Museum Group Journal |language=en-GB |volume=Autumn 2014}}, celebrating the 300th anniversary of the Longitude Act. It was first shown at the National Maritime Museum in Greenwich, England, in 2014,{{Cite web |last=Dunn & Higgitt |first=Richard & Rebekah |date=2014 |title=Past exhibitions Royal Museums Greenwich |url=https://www.rmg.co.uk/collections/library/search/ships%20clocks%20stars |archive-url= |access-date=2025-01-04 |website=www.rmg.co.uk |publisher=Collins |language=en}} and subsequently, at the Folger Shakespeare Library in Washington, DC, The Museum of America and the Sea, in Mystic Seaport, CT, and The Australian National Maritime Museum, in Sydney, Australia.{{Cite web |title=Ships, Clocks and Stars: The Quest for Longitude - Folgerpedia |url=https://folgerpedia.folger.edu/Ships,_Clocks_and_Stars:_The_Quest_for_Longitude |access-date=2025-04-29 |website=folgerpedia.folger.edu}}{{Cite web |last=Museum |first=Mystic Seaport |date=2015-08-20 |title="Ships, Clocks & Stars: The Quest for Longitude" Exhibition Opens September 19 |url=https://mysticseaport.org/press-release/ships-clocks-stars-the-quest-for-longitude-exhibition-opens-september-19/ |access-date=2025-04-29 |website=Mystic Seaport Museum |language=en-US}}

File:Derek Pratt's Waterclock in Luterbach, Switzerland.jpg

Pratt also had a significant interest in water clocks. He knew of the Earl of Meath's explorations from the early 20th century.{{Cite news |title=Make some time for Killruddery's water clock |url=https://www.irishtimes.com/news/science/make-some-time-for-killruddery-s-water-clock-1.1859486 |access-date=2025-01-19 |newspaper=The Irish Times}} In 1995, upon seeing his childhood friend Derek Goldsmith's unfinished indoor swimming pool, he was inspired to propose a site-specific water clock. He subsequently created two more outdoor water clocks for Luterbach and Langendorf, villages near his workshop. The Luterbach clock celebrated the municipality's 950th anniversary. The Langendorf one was for the 700-year-anniversary. He detailed his process in articles in the Horological Journal.{{Cite journal |last=Pratt |first=Derek |date=December 2002 |title=Tempus Fluit – Time Flows |url=https://bhi.devsoc.org/library/download/863/ |journal=Horological Journal |volume=144 |issue=12 |pages=19–22 |via=British Horological Institute}}{{Cite journal |last=Pratt |first=Derek |date=December 2005 |title=A Water Clock for Langendorf |url=https://bhi.devsoc.org/library/download/900/ |journal=Horological Journal |volume=147 |issue=12 |pages=14–17 |via=British Horological Institute}} The first Pratt water clock, as a proof of concept piece, was made and installed in his workshops. It was subsequently removed and gifted by is wife to the British Horological Institute at Upton Hall, where it remains on public display.{{Cite book |title=Derek Pratt FBHI Watchmaker |date=September 2018 |publisher=British Horological Institute Ltd. |isbn=978-0-9568003-2-9 |edition=2nd |pages=41–42}}

Derek Pratt was married to the Swiss Franziska Hess whom he'd met in a pub in the UK a few months before work took him to Switzerland, from 1965 to 1985. They had two daughters. In 1988, Pratt married a fellow expat, Jenny Haller. At the time of his death she survived him, along with his daughters, his sister and a grandson.{{Cite journal |last=Randall |first=Anthony |date=November 2009 |title=Obituary Derek Francis Pratt |url=https://bhi.devsoc.org/library/download/947/ |journal=Horological Journal |volume=151 |issue=11 |pages=6 |via=British Horological Institute}}

{{multiple image

|image1=Derek Mazda RX-7.tif

|caption1=Pratt with his Wankel-engined Mazda RX-7 in Balm bei Günsberg, Switzerland

|image2=Derek Dursley Pedersen.tif

|caption2=Pratt riding his Dursley Pedersen bicycle

}}

In addition to horological heroes, Pratt also admired outliers in mechanical inventions: Franz Reuleaux, the inventor after whom the curved triangle is named. He drove a first-generation Mazda RX-7, a sportscar with a Wankel engine based on the Reuleaux triangle. The Reuleaux triangle made appearances in his watches time and again.

Pratt was an avid cyclist – he considered the bicycle mankind's most important invention – and collected bicycles. His favorite was a Dursley Pedersen, a late 19th century bicycle known for its hammock-style saddle, but he also owned three ordinary bicycles (commonly known as Penny-farthings), a Swiss Army bike, and many others. Some of his other interests encompassed aviation, pop-pop boats, nature and making music.

File:Wankel Rotary Engine Mazda RX-7.jpg

Derek Pratt died on 16 September 2009, at the age of 71.

• The British Horological Institute: Silver Medal (1992), for the "Restoration and construction of precision and complicated mechanical watches"{{Cite web |title=The BHI Barrett Silver Medal : British Horological Institute |url=https://bhi.co.uk/about-us/barrettsilvermedal/ |access-date=2025-01-04 |website=bhi.co.uk}}
• Musée international d'horlogerie: Prix Gaïa (1999), "for his specialization in the repair of iron clocks and complicated watches as well as in the design of complicated pieces."{{Cite web |last=Watchonista |date=1999-09-02 |title=Prix Gaïa 1999 – Derek Pratt. Craftsmanship-Creation category |url=https://www.watchonista.com/articles/history/prix-gaia-1999-derek-pratt-craftsmanship-creation-category |access-date=2025-01-04 |website=Watchonista |language=en}}
• The Worshipful Company of Clockmakers: Tompion Medal (2005), for "outstanding contributions to horology; a top class watch and clock maker; his ingenuity, technical ability and curiosity have helped to solve a variety of prototype and production problems; a supreme artist-craftsman"https://s3.eu-west-2.amazonaws.com/clockmakers/HNBGCNfqTPmQyLr4gY4b-tompion-medal-pdf

Pratt's replica of John Harrison’s H4 timepiece was shown alongside the original at the 2014 exhibition Ships, Clocks & Stars: The Quest for Longitude , at the National Maritime Museum in Greenwich, England, presenting an account of why longitude was so important some 300 years ago. The exhibition subsequently travelled to the Folger Shakespeare Library in Washington, DC; The Museum of America and the Sea, in Mystic Seaport, CT; and The Australian National Maritime Museum, in Sydney, Australia.

Between the early 1990s until 2008, Pratt published many articles in the British Horological Institute's monthly publication, the Horological Journal.{{Cite journal |last=Pratt |first=Derek |date=August 1991 |title=The Art of George Daniels: a 65th Birthday Tribute by Derek Pratt |url=https://bhi.devsoc.org/library/download/356/ |journal=Horological Journal |volume=134 |issue=2 |pages=56–62 |via=British Horological Institute}}{{Cite journal |last=Pratt |first=Derek |date=September 1993 |title=The first replica of John Harrison's Sea Clock H1 |url=https://bhi.devsoc.org/library/download/301/ |journal=Horological Journal |volume=136 |issue=3 |pages=18–21 |via=British Horological Institute}}

Pratt also translated several books on horology, along with his wife, Jenny Haller Pratt, for example the MIH: Catalogue d'œuvres choisies, by Catherine Cardinal and Jean-Michel Piguet ISBN 978-2-940088-07-2.{{Cite book |last1=Cardinal |first1=Catherine |title=Catalogue d'oeuvres choisies |last2=Piquet |first2=Jean-Michel |date=1999 |publisher=Institut l'homme et le temps |others=Musée international d'horlogerie |isbn=978-2-940088-07-2 |location=La Chaux-de-Fonds, Switz}}

The book Derek Pratt Watchmaker was edited by Timothy Treffry and first published in July 2012 by the British Horological Institute. It was reprinted in November 2012, August 2014, and in September 2018 in a 2nd edition. It was first published in conjunction with a Memorial Seminar held by the BHI at Upton Hall in September 2011 and contains transcripts of presentations given that day by Andrew Crisford, Jonathan Betts, Roger Stevenson, Philip Whyte, Anthony Randall, Helmut Crott and others. It also includes wide-ranging articles re-published from the Horological Journal by various authors, including Pratt.{{Cite web |last= |first= |title=Derek Pratt – Watchmaker : British Horological Institute |url=https://bhi.co.uk/about-us/derekpratt/ |access-date=2025-02-23 |website=bhi.co.uk}}

The two-part documentary A detailed study of H4, directed and produced by Barbara Darby, gives insight into Pratt’s journey in the reconstruction of John Harrison's Longitude timekeeper H4, including his collaboration and commissioning other craftsmen for parts such as the case (Martin Matthews) and the dial (Jos Houbraken), and subsequently, Charles Frodsham & Co.'s completion of the watch.{{Cite web |title=Harrison H4 Charles Frodsham and Co Ltd. |url=https://frodsham.com/commissions/h4/ |access-date=2025-04-29 |website=frodsham.com}}

The Derek Pratt Prize, a £20,000 award, recognizes individuals or organizations worldwide that demonstrate innovation, ingenuity, elegance, and the highest standards of workmanship and precision in the craft and science of timekeeping. It is intended to inspire future generations in this field and is awarded no more often than every three years.https://s3.eu-west-2.amazonaws.com/clockmakers/HNBGCNfqTPmQyLr4gY4b-tompion-medal-pdf

{{Reflist}}

• [https://watchesbysjx.com/2018/03/the-greatest-unknown-watchmaker-derek-pratt.html The Greatest Unknown Watchmaker – Derek Pratt / SJX Watches]
• [https://www.acollectedman.com/blogs/journal/derek-pratt-the-forgotten-watchmaker Derek Pratt – The forgotten watchmaker / A Collected Man]
• [https://ovr.thehourglass.com/pages/derek-pratt The Great Unknown Derek Pratt / The Hourglass]
• [https://frodsham.com/commissions/h4/ Derek Pratt / Charles Frodsham & Co. Harrison H4 Replica]

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Category:1938 births

Category:2009 deaths

Category:Watchmakers (people)

Category:Watchmaking

Category:English watchmakers (people)