Sidereal Tompion Regulator This highly complex clock, made in 1708 by the great Thomas Tompion and his then protégé and partner Edward Banger, is thought to be the first sidereal regulator.[1] Sidereal time, or ‘star time’, is so called because it is based on the position of a particular star. This feature is exceptional because, typically, clocks used for daily living show only mean solar time, which is based on the position of the sun. Although the Sidereal Tompion Regulator allows you to read the time of day (mean solar time) as you do on any other regular clock, it was not made for general use. It was a highly specialised, cutting-edge astronomical instrument, made to be used by astronomers to locate the position of celestial objects and to determine where they might appear in the night sky. What is more, this regulator is doubly unique within Tompion’s vast output.[2] Firstly, it is the most complicated geared clock known among Tompion’s timekeepers. Secondly, it is the only known Tompion clock to show geared mean solar and sidereal time. Since the rediscovery of the regulator when it appeared at auction in 1982, there has been much speculation about its original intended use, specifically whether it was originally designed to be a sidereal regulator or a mean solar time regulator.[3] This matter is discussed below. The regulator was almost certainly created as part of a special order, probably one part of a collection of high-end commissions known as the Denmark group, reflecting the fact that they were probably commissioned by Tompion’s royal patron, Prince George of Denmark and Norway and Duke of Cumberland.[4] Prince George of Denmark was husband and consort to Queen Anne from 1702 until his death in 1708. During this 6-year period, he ordered many groundbreaking horological innovations from Tompion. It is likely that Prince George of Denmark died just before this regulator was completed. This brought the commissioning of the Denmark group to an end and also left Tompion with unpaid expenses due to the tremendous financial output required to produce such a technically advanced timekeeper. Then, immediately following the regulator’s completion but still within the same year, the partnership between Tompion and Banger abruptly dissolved. Thus, the year 1708 marks a dramatic shift, effectively the end of an era, in Tompion’s workshop. The Sidereal Tompion Regulator also provides tangible evidence of Tompion’s fury at Banger over their split, because he covered the regulator’s original Tompion–Banger signature with a silver Tompion signature plaque. This rebranding was a deliberate erasure from Tompion’s output of the evidence of Banger’s contributions. What follows is the story of this groundbreaking, royally commissioned horological masterpiece. The stars and the sun With its two concentric silvered chapter rings, a seconds ring and three hands, the dial of the Sidereal Tompion Regulator is both intriguing and confusing. Upon inspection, how to go about reading it is not immediately obvious. Solar time: the inner chapter ring The inner conventional chapter ring on the dial is like any other chapter ring on traditional clocks. It is a fixed ring that is engraved in the usual manner with Roman numerals I–XII and is based on the traditional 24-hour solar day. It allows you to read the time of day as you do on any other regular clock and indicates mean solar time (or ‘clock time’). The Sidereal Tompion Regulator’s inner chapter ring would have been set to mean solar time by reference to a sundial. To do this, the owner first read solar time on a sundial. Solar time is a reckoning of the passage of time based on the sun’s position in the sky as seen from Earth. Once read, an Equation of Time was then used to calculate the difference between solar and mean solar time. This calculation must be performed, because the elliptical orbit of the earth round the sun is not exactly 24 hours long. Generally everything you learn about time in school is wrong. Never in the history of the universe has there been any day where the solar revolution has been exactly 24 hours. Dr John C. Taylor, OBE FREng, horologist, inventor and creator of Clocktime This is because the earth makes one perfect rotation on its axis in 23 hours, 56 minutes and 4.09 seconds as it revolves around the sun. Therefore, each day that the earth rotates on its axis in space, it requires a bit of extra turn to come back and face the sun on the next day. Additionally, the time needed to execute that extra bit of turn differs slightly from day to day, because the earth travels at different speeds in its elliptical orbit around the sun. To simplify matters, we use an average of 24 hours as the fundamental unit of the solar day, and we organise our daily living around this evenly timed 24-hour day.[5] This means that solar (sun) time and mean solar time are never exactly the same. Thus, the Equation of Time calculates the difference on each day of the year between the time indicated by the shadow of the sun on a sundial and the time shown on a clock. Once the Equation of Time was applied, the regulator’s chapter ring was probably set to Greenwich Mean Time (GMT – the mean solar time at the Royal Observatory in Greenwich, London), as it was probably intended for use in Britain. Notably, the Sidereal Tompion Regulator can show mean solar time through a geared mechanism. Sidereal time: the outer ring Sidereal (star) time is based on the position of a particular star relative to Earth. It is indicated in the regulator’s outer ring, which surrounds the chapter ring on the dial. Unlike the fixed chapter ring, the outer sidereal ring rotates to indicate star time. This is one of the earliest regulators to include this feature, and it is the only Tompion production to show sidereal time through a geared mechanism. This feature was such a technical feat that it would not be replicated until almost 20 years later.[6] While the length of a solar day varies by a few minutes from day to day, sidereal time is constant. A sidereal day on Earth is approximately 23 hours, 56 minutes and 4.09 seconds long every single day of the year. This is roughly four minutes shorter than a solar day on earth, which is an average of 24 hours (as explained above). The outer sidereal ring revolves twice a year, making two full revolutions in 366.25 days. On it, sidereal time can be read to the minute, from the end of the extended blued-steel hour hand. There is also a sidereal seconds ring just below the XII, and every tick of the seconds dial is 0.99727 of a second. This is slightly quicker than a normal swinging pendulum, allowing for precision sidereal readings in hours, minutes or seconds, or even in degrees. The massive construction of the movement’s backplate makes the above possible, as it holds the large gears in place to achieve the outer sidereal dial’s twice-yearly rotation. Sun vs. stars There has been debate over whether the Sidereal Tompion Regulator was originally designed to be a mean solar time regulator or a sidereal regulator. This is because it can be adjusted to fulfil either function. When the pendulum is regulated to beat solar seconds, the inner chapter ring will indicate mean solar time, as it does for any normal clock, while the outer sidereal ring will rotate clockwise to indicate sidereal time. However, some calculation is required to actually read sidereal time when the regulator is in this mode. To do so, you must first read mean solar time on the inner chapter ring, then count the engraved divisions between XII on the outer sidereal ring and XII on the inner chapter ring, going in an anticlockwise direction. Finally, you must subtract the result from the mean solar time to reveal the sidereal time of day. In this way, the inner ring acts as a vernier scale (a visual aid to take an accurate measurement reading between two markings). While not difficult, this process is complicated and time-consuming. It is also impractical for an astronomer (or anyone else for that matter), when you consider how much more straightforward it is to read sidereal time when the pendulum is regulated to sidereal seconds. In this mode, the outer sidereal ring will rotate clockwise, and the extended hour hand will in turn indicate sidereal time on the outer sidereal ring, while also indicating mean solar time to the nearest minute on the inner chapter ring. This makes for much easier reading, because no calculation is required. In a letter published in 1977 in Antiquarian Horology, William Todd demonstrated not only the ease with which sidereal time is read when the regulator is regulated to beat sidereal seconds, but also how the outer sidereal ring automatically accounts for the difference between the sidereal and solar day when in this mode.[7] He did so by setting the hour and minute hand to XII on the inner chapter ring and then rotating the outer sidereal ring to XII, so that the two rings and the hands all line up. He then let the regulator run for 24 hours. Over the course of the day, the regulator correctly accounted for the 4-minute difference between sidereal and solar time. Also conveniently, at the end of the 24 hours, the outer sidereal ring lined up with and converged on the XII along with the hour and minute hands. Clock experts at Christie’s, who re-evaluated and serviced the regulator before it came up for auction in 2003, also believe the regulator was designed to be a sidereal regulator. They argue that it would have been illogical to design the outer sidereal dial to rotate clockwise (as it does) when the pendulum is regulated to beat solar seconds, because ... it would have been a simple matter for Tompion to have designed the outer ring to rotate anticlockwise, thus enabling true sidereal time to be read directly against the inner fixed ring.[8] Additionally, Tompion (and Banger) went to a lot of trouble to design the regulator’s massive and highly complex sidereal gear system. Why would they have done so if primary use as a sidereal regulator was not intended? All the above strongly suggests that the Sidereal Tompion Regulator was primarily intended as a sidereal regulator with noteworthy but nonetheless secondary capabilities as a mean solar time regulator. Finally, there is the matter of the opulent gilt recording hand. Horologist Meyrick Neilson has suggested that it might be a manually operated equation hand.[9] Alternatively, the team at Christie’s have suggested that ‘it may have been intended to indicate sidereal time for a given longitude east or west of the clock’s location’ on the British mainland.[10] Finally, horologist Dr John C Taylor believes it is a later edition. Currently, there is no consensus on the hand’s purpose or status. Graham’s hand: perfecting the dead-beat escapement Another feature of the Sidereal Tompion Regulator is its innovative dead-beat escapement. Although the mathematician and astronomer Richard Towneley is credited with inventing this type of escapement around 1675, his initial design appears to have been largely theoretical and not quite fit for purpose. While Tompion was probably the first to implement Towneley’s design for practical use, it was George Graham who definitively perfected it in 1715, 7 years after the Sidereal Tompion Regulator was completed. Graham’s refined dead-beat escapement heralded a marked improvement upon Towneley’s design as well as earlier types of escapements, such as the verge and anchor escapements. Earlier types of escapements were limited largely because of their recoil action. Recoil can be observed on clocks as the seconds hand moves forward with each ‘tick’ and then moves slightly backward before proceeding to the next ‘tick’. This jerky action affects the consistency of the pendulum swing and is why early clocks fell behind as the day went on. The dead-beat escapement eliminates recoil altogether, because its pallets bring the going train to a dead stop, hence its name. By eliminating recoil, the pendulum swing is comparatively more consistent than it is with other types of escapements. It is widely assumed among horologists, such as Taylor, Jeremy Evans, Jonathan Carter and Ben Wright, that the Sidereal Tompion Regulator’s dead-beat escapement is not original; that it is a later addition. Many suggest that it was probably made by Graham around 1715.[11] Analyses of the Sidereal Tompion Regulator’s movement and that of another movement made by Graham in 1722 (detailed below), support but do not confirm this premise. At the very least, they strongly suggest that Graham had a hand in the making of this regulator’s refined dead-beat escapement. Exactly when he did so is unclear. In 1983, an analysis of the Sidereal Tompion Regulator’s dead-beat escapement was carried out by archaeologists Mark Pollard and Carl Heron at the Research Laboratory for Archaeology at the Department for History of Art at Oxford University.[12] Pollard and Heron subjected the regulator’s movement as well as the movement from a Graham regulator, dated to 1722, to x-ray fluorescence, a type of metallurgical test. They then analysed and compared the two movements’ content levels of the elements nickel, zinc, arsenic, lead, silver, tin, copper and antimony (a lustrous grey metal or metalloid). Results indicate that the metallurgical content of each movement was remarkably similar to those of other British movements of the period. However, it was difficult to compare like-for-like composition between the levels of the Sidereal Tompion Regulator movement and the Graham movement. Although 15 components from the Graham movement were analysed, these were comparatively less homogeneous than those analysed from the Sidereal Tompion Regulator’s movement. Also, 9 of the 15 components in the Graham movement are similar to the Sidereal Tompion Regulator’s movement components. However, two elements from the Graham movement, present in its escapement and pendulum, had a much higher zinc content of 32. This is not consistent with British clocks made during the early 1700s, and indicates that the Graham movement is likely to be a later one, an alteration dating from after 1722. This finding complicates matters, and it is still unclear whether the Sidereal Tompion Regulator’s dead-beat escapement is indeed a later alteration. The construction of the Sidereal Tompion Regulator and Graham movements was also analysed and compared. Results indicate that the escape wheel from Graham’s movement is very similar to that of the Sidereal Tompion Regulator’s movement. Additionally, in the Sidereal Tompion Regulator’s movement, there is no evidence of tampering or redrilling of the bearing holes of the escape wheel arbor.[13] Thus, by way of contrast to the elemental analysis, the movement analysis suggests a strong likelihood that the escape wheel from the Sidereal Tompion Regulator is contemporary to the rest of the movement and therefore not a later alteration. These results do nothing to pinpoint exactly when the Sidereal Tompion Regulator’s dead-beat escapement was made. They also do not rule out the possibility that Tompion could have made the dead-beat escapement. He certainly had access to this technology. As early as 1675, he apparently worked with Towneley to fit an early iteration of the dead-beat escapement to the two clocks that he made for the (then) new Greenwich Observatory.[14] The timeline of Graham’s involvement with Tompion and possible access to the regulator brings no further clarity. Graham joined Tompion’s business as early as 1695, the year he finished his apprenticeship to Henry Aske. By 1704, Graham had become Tompion’s protégé and joined the Tompion family by marrying Tompion’s niece, Elizabeth Tompion, on 25 September that same year. By 1712, Tompion had taken Graham into partnership, 4 years after his split with Banger. When Tompion died in 1713, Graham then inherited Tompion’s business and went on to enjoy a long career as a highly respected maker in his own right. We also know that the Sidereal Tompion Regulator probably remained in Tompion’s store for some time after it was completed or was returned to the workshop for service between Bangor’s departure in 1708 and before Tompion’s death in 1713, because Tompion covered the regulator’s original Tompion–Banger signature with a Tompion signature plaque. This was a practice that he implemented after the split with Banger in 1708. Tompion then amended this practice when he took Graham into partnership by 1712, by covering Banger-Tompion signatures with Tompion–Graham plaques. Based on the presence of the Tompion signature plaque on the Sidereal Tompion Regulator, logic dictates that Graham did not work on this regulator between 1712 and 1713. If he had, a Tompion–Graham signature plaque, rather than the Tompion signature plaque, would have been used in its place. All this allows for a wide range of possibilities for when and by whom the Sidereal Tompion Regulator’s dead-beat escapement was made. It is possible that Tompion very well could have worked on the regulator’s dead-beat escapement at any point between when it was commissioned to the time of his death in 1713. Also, Graham could have had a hand in the making of the regulator or worked on the dead-beat escapement anytime between its completion from 1708 to at least 1722, excepting the years of 1712–1713. A Type 3 case with a thrifty veneer Being a royal commission and part of the Denmark group, the Sidereal Tompion Regulator was outfitted with a Type 3 case, the standard case format that Tompion used for his top-of-the-line productions made from this time. Tompion’s standard case formats can be identified by: (i) the construction of the hood, (ii) the case finish, (iii) identical scratch-mould tooling marks on the hood and case, and (iv) the use of the same castings that were produced for Tompion’s longcases.[15] Further, the style of these characteristics correlates with their date of manufacture. For example, Carter argues that the use of a ‘regal’ flat front-and-back bell upstand is an almost ubiquitous feature of Tompion’s special cases produced during the turn of the century, during the late 1690s and early 1700s. It was around 1697 that Tompion introduced his fully developed Type 3 longcases. These are characterised by forward-sliding hoods, a hood door and large caddy tops. They also have concave mouldings. The use of concave mouldings, rather than the traditional convex mouldings seen on earlier clock cases, was deliberate. By way of contrast, concave mouldings create a smooth visual line in which the trunk blends seamlessly into the hood and the base. This smooth line differentiated Tompion’s case form from that of Ahasuerus Fromanteel, one of his main competitors, as well as from his own case forms that had come before. Tompion’s concave mouldings made his longcases look modern; thus, the maker was advancing decorative fashions and designs. The presence of the above characteristics are why we can confidently categorise the Sidereal Tompion Regulator’s case as a Type 3 case. It has a caddy top, concave throat mouldings, and a strikingly tall height of 2267mm. As is typical of Type 3 cases, its caddy top hood is decorated with three brass ball finials and also features brass-capped Doric columns. Additionally, it is adorned with chased spandrels framing the dial and a bellflower escutcheon on the rectangular trunk door. Unusually, it has a plain ebonised veneer. The use of such a comparatively inexpensive veneer on what was otherwise a spectacular production, is in stark contrast to the sumptuous burr-walnut veneer used on the special Type 3 case of the Millbourn Tompion month-going longcase clock No. 333, which was made around 1699 and is exhibited on Clocktime. Carter points out that the use of the ebony veneer was a ‘thrifty’ choice, no doubt made by Tompion to cover the considerable costs of producing the regulator and to offset the loss of income due to the death of his royal patron, Prince George of Denmark, who died in 1708 before he could pay the bill for his commission.[16] 1708, a year of completions The Sidereal Tompion Regulator was completed in 1708. This was a year of completions, because, to all intents and purposes, it marks the end of an era in the Tompion business and household. Poor old Banger Poor old Banger has been written out of history again. Dr John C. Taylor, OBE FREng, horologist, inventor and creator of Clocktime The year 1708 marks the dramatic and abrupt end to the partnership between Tompion and Banger. Completed this same year, the Sidereal Tompion Regulator appears to be one of the final productions to bear the Tompion–Banger signature. As such, the regulator is testament to Tompion’s rancour over the split. Affixed to its dial, just above the VI, is a silvered oval plaque signed Tho Tompion London. Hidden from view beneath this plaque, in a reserve, is the original engraved signature, Tho Tompion Edw Banger London. With this deliberate act of rebranding, Tompion did his level best to take all the credit for this horological masterpiece and erase Banger from its story. In fact, the dissolution of the Tompion–Banger partnership was so bitter and irrevocable that Tompion deliberately covered Tompion–Banger signatures on all remaining stock with his silver Tompion signature plaques.[17] Although no details of the reason(s) behind the split survive, Tompion and Banger’s abrupt parting of ways must have been personally and professionally cataclysmic for all concerned, especially considering the long history and nature of their relationship. Banger had originally joined the Tompion household as an apprentice around 1687. Upon completion of his indenture, he remained with Tompion, working as a journeyman. Banger then cemented his connection to Tompion’s dynasty by marrying Tompion’s niece, Margaret Kent, on 18 December 1694, and he and his wife lived in Tompion’s house until the split of 1708. Tompion took Banger into partnership by 1701.[18] From this date, Banger assumed more and more responsibility, and clocks produced between 1701 and 1708 are signed Tompion and Banger.[19] These include 8 of the 14 clocks in the Denmark group. Apparently, Tompion’s anger at Banger did not mellow with time. As mentioned above, when he took Graham into partnership by 1712, he continued his rebranding of the Banger. This practice appears to have continued until Graham took over the business following Tompion’s death in 1713. The last of the Denmark group The year 1708 is also important in Tompion’s story because it was the final year of the commissions comprising the Denmark group, the collection to which the Sidereal Tompion Regulator belongs. In 1683, Prince George of Denmark married Anne, second daughter of James VII and II. When Anne became Queen of England, Scotland and Ireland on 8 March 1702, her husband became the royal consort.[20] It was in this role that he patronised many of the leading scientists, mechanicians and architects of his day. He also became one of Tompion’s regular and ‘most ambitious’ royal patrons, as described by the antiquarian and horologist Richard Garnier.[21] From 1702 the prince ordered many groundbreaking horological innovations from Tompion. These commissions are often referred to as the Denmark group. Garnier suggests that it was competition with King William III and II (Queen Anne’s predecessor) that drove George to commission (or recommission) ‘a large number of Tompion’s most ambitious and highly complicated productions’. Apparently, George had a contentious relationship with William, who had an interest in horology and had also been a patron of Tompion’s. Undoubtedly, George’s fascination with horology and wider scientific innovation was also a driver behind the commissions. On 28 October 1708, George died, bringing an end to the 6-year run of the Denmark group commissions. Carter has provided the most up-to-date list of the 14 timekeepers that are known and likely to be part of this group.[22] It includes several Tompion–Banger productions and one Tompion–Graham production (most likely commissioned by Prince George of Denmark but completed for Queen Anne in 1710, after her husband’s death). It is widely accepted among horologists, Garnier and Carter among them, that the Sidereal Tompion Regulator is one of the Denmark group commissions. This is because it is a special commission, a technically innovative and accomplished production, and (as explained above) the only Tompion production to show a geared mechanism for mean solar and sidereal time. This alone indicates that the patron not only had deep pockets but was also interested in pushing the limits of scientific instrument development. George fits this profile perfectly. The Sidereal Tompion Regulator was probably completed just before George died of chronic lung disease in 1708. This strongly suggests that the regulator may be the last of the Denmark group. Therefore, it is highly unlikely that Tompion was paid for the commission, as Queen Anne did not appear to share her husband’s interest in horology. In support of this view, Garnier helpfully cites Treasury papers dated 19 May 1703 that report The Queen reads the petition of Thomas Tompion praying payment of 564l. 15s. 0d. due to him for clocks, watches &c. presented by the late King [William III] to the Duke of Florence. The Queen’s reply is her Majesty has no occasion for his clocks and watches.[23] Whatever the case, it appears that the patron (or parties responsible) for the regulator’s commission never paid for or claimed it. This certainly goes towards explaining why Tompion chose to cut costs by selecting a comparatively inexpensive ebony veneer for the regulator’s Type 3 case (as discussed above). Evidence also suggests that the regulator remained or was resold in Tompion’s (or later Graham’s) shop. Thence by descent To the manor Prince George of Denmark’s death, documentation suggesting Queen Anne’s reluctance to pay for horological commissions and Tompion’s rebranding all suggest that the Sidereal Tompion Regulator was resold after its completion. Recouping the cost of such an expensive production certainly would have necessitated this. Exactly when the regulator was resold is unclear. Based on the Tompion signature plaque (applied by Tompion himself), Garnier suggests that Tompion probably managed to sell the regulator sometime between 1708 and 1713, before he died.[24] According to the regulator’s provenance, its first known owner was Henry Compton (b. 1694, d. 1724) of Minstead Manor, Hampshire. Garnier argues that the regulator could have made its way to Compton’s estate before Tompion died but seems to favour a scenario in which the regulator was resold to Compton after it was returned to the workshop, most likely after Graham inherited Tompion’s business following his death. Garnier muses that perhaps Compton visited Graham’s shop upon the completion of Minstead Manor house in 1719, keen to decorate his new home. This timing would also allow for a scenario in which Graham added the refined dead-beat escapement, having perfected the design of this type of mechanism in 1715. However, this cannot be confirmed because, as discussed in detail above, the results of the 1996 analysis by Drs Pollard and Heron were inconclusive as to when the dead-beat escapement was altered (if at all). What is more, the archaeologists also allow for the possibility that the escapement could have been worked on during Tompion’s lifetime.[25] Although we do not know exactly when the regulator was installed at Minstead Manor, Garnier and Carter confirm that the Sidereal Tompion Regulator remained in the possession of the Compton family until it was eventually sold at auction at Christie’s on 16 December 1982.[26] New discoveries In 1982, the Sidereal Tompion Regulator become part of the private collection of Professor Edward T ‘Teddy’ Hall CBE, Hon FBA, FSA (b. 10 May 1924, d. 11 August 2001). In this new home, the regulator began a new chapter. It was Professor Hall who funded and facilitated Pollard and Heron’s metallurgical analysis and study.[27] Professor Hall’s investment is exceptional, because scientific analysis of early clocks is the exception rather than the rule. Analyses such as these are expensive, because they must be carried out by highly qualified specialists and performed in a laboratory environment with specialist equipment. They also take time. Hall was uniquely placed and qualified to make this happen. He was an inventor and scientist who also happened to be a leading expert in the development of archaeometry. Archaeometry encompasses scientific techniques and methods, such as chemical and metallurgical analysis, for the dating and study of archaeological artefacts, materials, sites and remains. Born in London, Hall went to Eton and served in the Second World War as a seaman in the Royal Navy. After the war, he studied chemistry and later physics at New College, Oxford, earning a DPhil in 1953. Later, he became an MP for Brecon and Radnor. However, he is best known for exposing the Piltdown Man as a fraud. In 1912, an amateur archaeologist by the name of Charles Dawson ‘discovered’ bone fragments in Pleistocene gravel beds near Piltdown village in Sussex, England. On 18 December 1912, Dawson fraudulently presented these fragments as the 500,000-year-old fossilised remains of a heretofore unidentified early human species. In the decades following his ‘find’, scientists could not make sense of the fragments, and most considered them to be an aberration, because they were inconsistent within any other known evidence of early human evolution. In the 1950s, Hall devised a technique for detecting microscopic traces of contamination of important artefacts, based on x-ray fluorescence techniques. This technique was used on the Piltdown Man remains, and in November 1953, Time magazine published the irrefutable evidence that Piltdown Man was a forgery. Results confirmed that Piltdown Man was actually a composite of three distinct species: a medieval human skull, a 500-year-old mandible (lower jaw) from an orangutan, and fossilised teeth from a chimpanzee. The identity of the forger remains unconfirmed, but Dawson is suspected of deliberately participating in the fraud to some extent. On the heels of this revelation, Hall was in 1955 given permission to establish the Research Laboratory for Archaeology and the History of Art at the University of Oxford. He served as its first Director and assembled and led an internationally renowned team. In 1988, Hall and his colleagues also famously analysed a fragment of the Shroud of Turin. They dated the fragment between 1260 and 1390 AD, which proved that the imprint on the shroud was not old enough to be connected to Jesus, thus causing an outcry in certain religious circles. That same year, Hall was awarded the rank of CBE (Commander of the Order of the British Empire). It was during the 1990s that Hall facilitated and funded the research on the Sidereal Tompion Regulator at his world-leading archaeometry laboratory. He died on 11 August 2001, at the age of 77. Soon after, another new chapter began for regulator. In 2003, it became part of the John C. Taylor Collection, where it resides today, under the care of yet another trailblazing inventor. Under Dr Taylor’s care, the Sidereal Tompion Regulator is presented in all its complex glory on Clocktime, and research continues. Watch this space for new discoveries and revelations. Dr Kristin Leith, Senior Curator of Clocktime February 2025 End Notes [1] Carter 2022, 212–221, Catalogue No. 31; Ende et al. 2004, 260–261; Evans et al. 2013, 534–535; Garnier and Carter 2015, 34–35; Neilson 1977, 214–216; Roberts 1998, 110–112; Roberts 2003, 178–179. [2] Over his lifetime, the formidable Tompion produced some 5000 watches and 650 clocks using subcontracted parts. Dawson et al 1994 [1982]; Symonds 1951. [3] The Sidereal Tompion Regulator was probably originally acquired by Henry Compton (b. 1694, d. 1724) of Minstead Manor (which used to stand on the site of what is now Minstead Manor Farm & Estate in Lyndhurst in the New Forest, England). It possibly stayed in his family by descent until it appeared at auction in 1982 (Christie’s, London, Lot No. 185, 16 December 1982). [4] Garnier and Carter 2015, 34–35; Carter 2022, 212. [5] Since the invention of the domestic pendulum clock in 1656, clocks have been set for the mean solar time using the adjusted 24-hour day. [6] The next clockmaker to accomplish this feat was George Graham. Around 1725, Graham produced the month-going mean solar time and sidereal regulator, No. 634, which successfully combined mean and sidereal time with perpetual calendar. It was sold at auction by Sotheby’s, Lot 172, on 19 June 2002. Although Graham certainly had access to this technology long before 1725 and was working in Tompion’s workshop when the Sidereal Tompion Regulator was made, there is no way of knowing whether he worked on Tompion’s regulator. [7] Todd 1977, 366. Todd’s ‘letter’ was published in response to Neilson 1977. [8] See Christie’s Lot No. 156, July 2003, https://www.christies.com/en/lot/lot-4128210. [9] Neilson 1977. [10] Supra no. 8. [11] Evans et al. 2013, 535. For Dr John C Taylor, see this exhibit’s accompanying explanatory video. [12] Pollard and Heron 1996, 220–238. This analysis was commissioned by Professor E. T. ‘Teddy’ Hall. At the time, the Sidereal Tompion Regulator was part of Hall’s private collection. [13] Ibid. There is one small hole evident on the inside of the frontplate. This does not extend through to the front, and it cannot have been used as a pivot hole. [14] Tompion made and fitted two clocks with 13-foot pendulums into the Octagon Room at Greenwich Observatory. The room was designed with the clock dials framed in the panelling at eye level. A third Tompion clock was added later. Tompion was part of the team brought together by the first Astronomer Royal John Flamsteed to construct the new Greenwich Observatory. The other members of the building team were the Royal Surveyor of Works Christopher Wren and the polymath Robert Hooke. The Observatory was completed by July 1676. For a history of the Royal Observatory at Greenwich, visit https://www.rmg.co.uk/royal-observatory/history. Also see Carter 2021, 102–103. [15] The use of standard case formats saved time and money. It also enabled customers to order a standard case type and embellish it with added extras as they saw fit. Carter 2022, 202 and 203. [16] Carter 2022, 212. [17] Evans et al. 2013, 113 and 153. It is also likely that all stock watch dial centres with joint signatures were scrapped. [18] Evans et al. 2013, 152. [19] Evans et al. 2013, 152–153. [20] In 1703, the newly crowned Queen Anne famously refused payment of debts accumulated by her predecessor, the late King William III. See Garnier and Carter 2015, 34–35; Carter 2022, 212 and 216. [21] Garnier and Carter 2015, 34–35. [22] Carter 2022, 220. [23] Supra no. 20. [24] Ibid. [25] Supra no. 12. [26] Garnier and Carter 2015, 34–35. Also, Supra no. 8. [27] Supra no. 12. For Professor E. T. Hall’s obituary see https://www.theguardian.com/news/2001/aug/20/guardianobituaries.physicalsciences References Carter, J. 2021. The John C Taylor Collection: Part I (Selling Exhibition Catalogue, Carter Marsh & Co). Winchester: Carter Marsh & Co. Carter, J. 2022. The John C Taylor Collection: Part III (Selling Exhibition Catalogue, Carter Marsh & Co). Winchester: Carter Marsh & Co. Dawson, P. G., C. B. Drover and D. W. Parkes. 1994 [1982]. Early English Clocks: A discussion of domestic clocks up to the beginning of the eighteenth century. Woodbridge: The Antique Collectors’ Club. Ende, H. van der, J. C. Taylor and F. Van Kersen.2004. Huygens’ Legacy: The golden age of the pendulum clock (Exhibition Catalogue). Isle of Man: Fromanteel Limited. Evans, J., J. Carter and B. Wright. 2013. Thomas Tompion – 300 Years: A celebration of the life and work of Thomas Tompion. Stroud: Walter Lane Publishing. Garnier, R. and J. Carter. 2015. The Golden Age of English Horology: Masterpieces from the Tom Scott Collection. Winchester: The Square Press. Neilson, M. 1977. ‘Important sidereal regulator by Tompion & Banger’ in Antiquarian Horology, 214–216. Pollard, M. and C. Heron. 1996. ‘The chemical study of metals’ in Archaeological Chemistry (M. Pollard and C. Heron, editors). RSC Paperback Series, London: Royal Society of Chemistry, pp. 220–238. Roberts, D. 1998. British Longcase Clocks. Atglen, PA: Schiffer Publishing, Ltd. Roberts, D. 2003. Precision Pendulum Clocks: The question for accurate timekeeping in England. West Chester, PA, USA: Schiffer Publishing. Symonds, R. W. 1951. Thomas Tompion: His life and work 1639–1713. London: B. T. Battsford. Todd, W. 1977. ‘Letter’ in Antiquarian Horology 10:2, 366.
