Pelham Tompion Sundial This beautifully made and expertly calibrated, bronze horizontal sundial is a rare example of a sundial manufactured by Thomas Tompion, one of Britain’s most successful and innovative clock- and watchmakers.[1] It is one of only five known Tompion sundials to survive.[2] During the early modern period (1550 – 1760) many of London’s successful clockmakers also made and sold sundials to sell with their clocks and watches. During this time, the only reliable way to set a clock or watch correctly was still by reference to a sundial. Thus, these instruments were easily marketed and sold as fundamental optional extras. This dial, known as the Pelham Tompion Sundial, was made to specification for the latitude 50° 54’ N, which covers most of southern England. It also handily provides an Equation of Time table, as well as instructions for converting solar time to Greenwich Mean Time (GMT). It appears to have been made around 1710, specifically sometime between 1708 and 1712, and was probably commissioned by Sir Thomas Pelham, 4th Bt (later 1st Lord Pelham of Laughton, b. around 1653, d. 1712). Pelham then most likely installed it in the gardens of his country home, Halland House, which use to stand in the village of Laughton in East Sussex. Thus began this dial’s initial journey, in which it was quietly hidden away for years in the gardens of various historic homes. Fortunately, it appeared at auction in 2002, officially entering the historical record. Since then, much has been done to reveal its illustrious story and make better sense of its design. The optional extra that sold itself As mentioned above, when this sundial was made, the only reliable way to set a watch or clock to the correct time was by reference to such an instrument. This is because precision timekeepers capable of providing the correct time on demand are only a very recent development in human history. Indeed, sundials are the oldest known timekeeping instruments in the world and were probably the first human-made tools devised to track time during daylight. They first appeared in Egypt some 3500 years ago and were relied upon as the primary source for accurate timekeeping. You can read more about sundials and other types of early timekeeper in the Clocktime article The First Timekeepers. When the first mechanical clocks, known as turret, tower and Great clocks, began to appear in the medieval period, cathedrals and town halls used sundials to set the correct the time. Later, people in the countryside set their clocks locally using a sundial in their gardens. Even after the invention of the domestic pendulum clock by Christiaan Huygens in 1656, all clocks still had to be set locally by a sundial. Therefore, right on through to the 1700s, which encompassed Tompion’s period of production, it was essential that owners have a sundial by which to set their clocks and watches. In general, sundials from England’s early modern period (1550 – 1760) are rare survivals. Although many English clockmakers like Tompion provided sundials as a valuable optional extras to their customers who purchased a clock, most of these instruments became superfluous by the 19th century due to innovations in modern timekeeping. Many were then destroyed, while others quietly languished away in various gardens, because owners no longer had need of a sundial to help them set their watch or clock to the correct time. Pelham’s GMT sundial This square-plate bronze sundial was made specifically for use at latitude 50° 54’ N. As such, this coordinate has been handily engraved by Tompion at the top of the dialplate. This latitude covers much of southern England and the time zone for this area is Greenwich Mean Time (GMT). Tompion also provided instructions for the owner to set their watch and clock correctly to GMT. These are engraved within the dial’s chapter ring: Set the watch so much faster or slower Than the time by the Sun, according to the Table for the day of the month when set it; and if the watch go true , the difference of it from the Sun any day afterward will be the same with the Table To facilitate this calculation, Tompion also provided an engraved a version of an Equation of Time table just below these instructions. He did so to make it as easy as possible for the owner to convert the solar time indicated on the sundial to GMT. Why was all this necessary? It is because the reading of time on a sundial can be tricky. As mentioned above, the time indicated on the dial represents solar time, and an Equation of Time had to be used to calculate the difference between solar and local mean time. Solar time is determined by the location of the sun in the sky relative to where one is on the earth, whereas the Mean (average) time is determined by the twenty-four-hour day by which we run our clocks. Solar time can vary from mean time up to +/- 16 minutes depending upon the time of year, and the two correlate to one another on just four days per year (in April, June, September and December). There has never been a day on earth that is exactly 24 hours long! – Horologist and collector, Dr John C Taylor, OBE This variation is a by-product of the elliptical orbit of the earth round the sun, which ensures that there has never been a day that is exactly 24 hours long. In fact, the Earth makes one perfect rotation on its axis in relation to the stars in 23hrs 56min and 4.09secs. Also, each day the Earth moves in space around its orbit, it requires a bit of extra turn to come back facing the sun on the next day. As the Earth travels at different speeds in its elliptical orbit, the time undertaken to execute that extra bit of turn differs slightly from day to day. Horologist Brian Loomes explains that before the invention of the pendulum in 1656, the solar-mean time variance was of less importance to clock owners, because pre-pendulum balance wheel clocks almost always run within a 15-minute margin of error either way. Therefore, they are not able to keep time accurately or consistently enough to require an Equation of Time.[3] But with the new pendulum clocks, which were reasonably accurate over a period of several days, it was possible for the clock owner to attain greater precision by using a sundial with an Equation of Time. Since the invention of the domestic pendulum clock, clocks have been set for an average day of 24 hours: hence the mean in Greenwich Mean Time. Within a short time of the establishment of the Greenwich Observatory, the first Astronomer Royal, John Flamsteed, published Equation of Time tables for the correction of sundial (solar) time to mean clock time. Apparently, even Huygens saw fit to publish an Equation of Time in table form around the time that his pendulum clocks began being produced. In response, makers like Tompion produced sundials like this one by which the time could be set as precisely as possible on the new pendulum clocks.[4] As such, sundials made during this period typically feature engraved traditional clockfaces on their dialplates, as does the Pelham Tompion Sundial. However, there are some notable differences. The Pelham Tompion Sundial’s chapter ring features engraved Roman numerals IIII-XII-VIII and delicate fleur-de-lys half-hour markers. Thoughtfully, the numerals have been transposed to be read from the outside of the dialplate, rather than from the inside as is usually seen on a traditional clock face. Tompion also split the hours into one-minutes units. These can be seen in the sundial’s outer ring, which is engraved with one-minute markers and Arabic numerals every ten minutes. There are also engraved internal rings divided for half-quarters and quarters. Thus, he created a sundial by which the time can be set to the minute and, therefore, as precisely as possible on a pendulum clock. This sundial was also finished off with tasteful decorations. There are finely engraved floral spandrels, and the gnomon is constructed with elegantly forged scrollwork. Finally, the signature Tho Tompion London is engraved at the top of the dial, just above the chapter ring. Most sundials were kept outdoors, and the worn surface of this sundial certainly bears witness to the ravages of 300 years of British weather. Tompion’s sundials As mentioned above, the Pelham Tompion Sundial is one of only five known Tompion sundials to survive. These all appear to have been made in the latter part of Tompion’s career, roughly between 1690 and 1713, the year that Tompion died.[5] In addition to the Pelham Tompion Sundial, there is a circular pair of Tompion sundials from Hampton Court Palace in London and now part of the Royal Collection (RCIN Numbers 11959 and 95190). They were probably made in the late 1690s. There is also the Wrest Park Sundial, also known as the Duke of Kent Sundial, made around 1710 and coming soon to Clocktime. It was commissioned by the 12th Earl and (later) 1st Duke of Kent, Henry Grey (b. 1671, d. 1740), who was a British politician and courtier.[6] Although circular in shape, it is similar to the Pelham Tompion Sundial in several respects: it is engraved around its edge with an hour scale IIII-XII-VIII with one-minute units, and, within its chapter ring, and Tompion also provided engraved bespoke instructions above an Equation of Time table. This sundial is also made to specification for use in not one, but two specific locations: 52°, 8’ north for use in Wrest Park and 50°, 26’ north for use in Cornwall. Finally, there is Tompion’s Pump Room Sundial, which is located above the Roman Baths in Bath, UK. It was made in 1709 for the coordinates N 51° 22' 51", W 02° 21' 49" for use in Bath. Less complicated than the Pelham Tompion sundial, its chapter ring engravings are oriented inwards, and it features engraved quarter hours. It also includes an 8-point compass rose labelled to the Northeast.[7] It is possible that the above dials made after 1700, namely the Pelham Tompion Sundial, the Wrest Park Sundial and the Pump Room Sundial, were all designed by the instrument maker John Rowley. Just after 1700, Tompion sub-contracted Rowley to produce instruments. At the time, Rowley was one of the foremost English mechanicians working in London. He is best known for creating ornate and innovative ring dials (a highly technical variation of the sundial form) and is also credited with the invention of the orrery. Additionally, he was appointed Master of Mechanics to King George I and enjoyed the patronage of Prince George of Denmark and Norway, who was also one of Tompion’s major patrons.[8] Stylistically, the Pelham Tompion Sundial appears to have been made by Rowley based on its transposed Roman numerals on the chapter ring and the design of its engraved floral spandrels. Similar floral spandrels are engraved on Rowley’s Horizontal Garden Dial made around 1700 in the Museum of the History of Science in Oxford (Inventory Number 41686). As alluded to above, there are also similarities between the Pelham Tompion Sundial and the Wrest Park Sundial, such as the engraved hour scale IIII-XII-VIII. What is more, the Pump Room Sundial appears to be a simpler version of the Pelham Tompion Sundial.[9] The consistency of design across the post-1700 sundials that is described above strongly suggests that these sundials were made by Rowley. Perhaps the sub-contracted Rowley was responsible for Tompion’s entire sundial output during the last decade of Tompion’s life. A sundial’s origin story When the Pelham Tompion Sundial first appeared at Sotheby’s in 2002, very little was known about it beyond its design features and the following. It is a signed Tompion dial (a rare and exciting find in of itself). It is constructed for use at latitude 50° 54’ N, which covers southern England. The owner inherited it by descent.[10] There was also the added clue that the owner recalled it ‘resting on a plinth in the gardens of their 200-year-old family cottage in Sussex since the 19th century’.[11] Fortunately, Tompion is an extremely well-documented maker, whose timeline is well known, so these details proved to be a great starting point for investigation. By considering the evidence for other Tompion commissions and who Tompion was working with and when, as well as the geographical perimeter of Sussex, horologists were able to trace a through-line between a notable family and historic homes in Sussex. By doing so, they were also able to identify a probable original owner and home in upon a very narrow window of time in which the dial was probably commissioned and made. Horologist and antiquarian Jonathan Carter most recently got to grips with the above evidence and argues compellingly that the dial was probably commissioned by Sir Thomas Pelham, 4th Bt (later 1st Lord Pelham of Laughton) and made around 1710.[12] What follows is summary of the case that he made as well as observations. Tompion’s timeline and the dial Tompion was professionally active as a maker from the early 1670s until his death in 1713. His surviving sundials appear to have been made during the last two decades of his life, from the 1690s. We also know that Tompion sub-contracted Rowley just after 1700 and that is likely that the Pelham Tompion sundial was made by Rowley. Additionally, by 1701, Tompion had taken Edward Banger into partnership. During this so-called Banger phase from 1701, joint Tompion-Bangor signatures appeared on all Tompion productions. However, this practice abruptly ceased in 1708, when, for reasons unknown, the Tompion-Bangor partnership unceremoniously dissolved. What is more, the dissolution of the partnership was so final that Tompion rebranded his existing stock: he deliberately covered the Tompion-Banger signature on all remaining stock with silvered plaques engraved with the singular Tompion signature.[13] The Pelham Tompion sundial is signed Tho Tompion London, and there is no evidence of a Banger signature on it. This combined with the likelihood that it was made by Rowley strongly suggests that it was made after Banger’s departure in 1708, thus providing a window for making from 1708 to 1713. Yet, this window can be further narrowed when we unpack the sundial’s links to the Pelham family. Links to a large house in Sussex Based on the engraving of latitude 50° 54’ N, the Pelham Tompion sundial was expressly made for the garden of a stately home in southern England. As stated above, when this dial appeared at Sotheby’s for auction in 2002, it had come directly from the garden of 200-year-old family cottage in the village of Falmer in Sussex and, according to the owner, it had been there since the 19th century.[14] Still, it was unclear how a high-end, expensive sundial such as this wound up in a humble family cottage in Sussex. Carter argues that the sundial must have been gifted to a local working family from a stately home in the area, which is Sussex.[15] This is supported by two points: (i) before the late 19th century, the working class rarely travelled far from where they lived and tended to stay put in one area; and (ii) Sussex is covered by the engraved latitude 50° 54’ N. Around 1700, only three large houses were established in Sussex within the limits of this latitude. Also, all three families were known Tompion customers: (i) John Ashburnham, 1st Lord Ashburnham (b. 1656, d. 1710); (ii) Charles Lennox, 1st Duke of Richmond (b. 1672, d. 1723); and (iii) Sir Thomas I. Pelham, 4th Bt, later 1st Lord Pelham of Laughton (b. 1653, d. 1712). During the time in which the sundial was probably made, Lord Ashburnham was focused on improving his other estate, Ampthill – a location which is outside the range of the Pelham Tompion Sundial’s latitude, thus disqualifying this large house as the original owner. While there is documentation for other Tompion commissions from the Duke of Richmond, none of these transactions include the provision of a sundial. Also, there is no evidence of a sundial ever having been installed in the gardens of Goodwin House, his stately home. There is, however, much circumstantial evidence to support a strong case for Sir Pelham being the original owner. He was the first son of Sir John Pelham Sr (b. 1623, d. 1703) and educated at Christ Church Oxford. As a member of the Whig party, he went on to serve as a Member of Parliament at various points for the constituencies of East Grinstead, Lewes and Sussex from 1678 to 1705.[16] In 1706, Sir Pelham received a peerage as 1st Lord Pelham of Laughton in Sussex and retired to Halland House, a stately home in the Laughton area of Sussex. Once there, he set to work on making improvements to the Elizabethan house and gardens. Around this time, he also ordered a longcase from Tompion.[17] This is probably when he commissioned the Pelham Tompion Sundial for his gardens. Sir Pelham died in 1712, thus slightly reducing the possible window for the commissioning and making of the Pelham Tompion Sundial from 1708 to 1712. Thus, Carter’s dating of the dial to c1710 is indeed sound. As for how the sundial ended up in the garden of the cottage in Falmer, Carter argues that it probably came there by way of Stanmer estate. Stanmer was owned by Sir Pelham’s younger brother, Baron Pelham of Stanmer (b. around 1661, d. 1721).[18] When his descendent, the 2nd Lord Pelham of Stanmer inherited Stanmer House, he moved some of the contents of Halland House to Stanmer, including two Tompion clocks. Perhaps the sundial was also re-located to Stanmer gardens at this time. The workers’ cottage in Falmer, where the dial was found in 2002, was just a short walk from Stanmer. Additionally, in 1776, a later Thomas Pelham bought the adjoining manor in Falmer, and, in 1801, renamed the combined estates The Chichester Estates. Although details of exactly how the sundial then came to the cottage garden in Falmer cannot be known, its journey there, via Stanmer, from Halland House, is a plausible one. Dr Kristin Leith, Curator of Clocktime March 2026 End notes [1] British Sundial Society Bulletin 2010; Carter 2021, 144 – 151, Catalogue No. 29; Evans et al. 2013, 634; Evans 2006, 108; Taylor et al. 2019, 27, Exhibition No.4:4. [2] For a detailed list of surviving Tompion sundials see Carter 2021, 150. [3] Loomes 2006 and 2014. [4] Loomes 2013. Sundials were also created by specialist instrument makers, such as Hilkiah Bedford (see his bronze sundial with octagonal base made around 1663 and coming soon to Clocktime). [5] There is documentary evidence of a sixth possible Tompion sundial at Melbourne in Derbyshire. In a bill dated to 1707, there is a description of a large, brass horizontal dial that was bought by Rt. Hon. James Coke. Carter 2021, 150 (see table); Evans et al. 203, 236. [6] Carter 2021, 144 and 2022, 188–197, Catalogue No. 28; Evans et al. 2013, 558–559; Garnier and Hollis 2018, 370–371, Catalogue No. 114. [7] The Pump Room Tompion Sundial, made in 1709, was lost until 1971. You can read more about it on the British Sundial Society’s website. [8] Appleby 1996; Brown 1979. [9] Carter 2021, 146; Evans et al. 2013, 119 and 537–539. [10] Sotheby’s ‘Masterpieces from the Time Museum: Olympia, London’ Sale, 30 October 2002, Lot No. 93. [11] Carter 2021, 147; Sotheby’s 2002. [12] For Carter’s full argument for the Pelham provenance of the sundial, see Carter 2021, 146–151. [13] Evans et al. 2013, 113 and 153. [14] Supra no. 10. [15] Carter 2021, 147–149. [16] For Sir Pelham’s detailed political biography (with sources) see the History of Parliament website. [17] Evans et al. 2013, 245. [18] Baron Pelham also had connections to Tompion. He commissioned two Tompion clocks. References September 2010. British Sundial Society Bulletin, vol. 22 (ii). Appleby, J. H. 1996. ‘A new perspective on John Rowley, virtuoso master of mechanics and hydraulic engineer’ in Annals of Science 53: 1–27. Brown, J. 1979. Mathematical Instrument-makers in the Grocers’ Company, 1688–1800. London: Science Museum.Anonymous. September 2010. British Sundial Society Bulletin, vol. 22 (ii). 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. Evans, J., J. Carter and B. Wright. 2013. Thomas Tompion – 300 Years: A celebration of the life and work of Thomas Tompion. Stroud, Gloucestershire: Walter Lane Publishing. Evans, J. L. 2006. Thomas Tompion at the Dial and Three Crowns. Ticehurst: Antiquarian Horological Society. Garnier, R. and L. Hollis. 2018. Innovation & Collaboration: The early development of the pendulum clock in London. Isle of Man: Fromanteel Ltd. Loomes, B. 2006. Watchmakers and Clockmakers of the World. London: N.A.G. Press. Loomes, B. 2013. Hilkiah Bedford and a Charles II sundial. Loomes, B. 2014. Clockmakers of Britain: 1286–1700. Mayfield, Ashbourne: Mayfield Books. Symonds, R. W. 1951. Thomas Tompion: His life and Work 1639 – 1713. London: B.T. Battsford Ltd. Taylor, J. C. and K. Leith (with contributions by T. Phillipson). 2019. The Luxury of Time: Clocks from 1550–1750. Isle of Man: Fromanteel Ltd.
