Roman numerals on clock dials



ROMAN NUMERALS On Clock Faces Compiled by Fred Kats

Anno 1389
The subtractive notation of Roman numerals -such as IV, IX, and XL- evolved from an ancient primarily additive system. While ancient Romans occasionally used subtractive forms in inscriptions, they initially preferred simpler additive forms like IIII for four. Throughout ancient times and the Middle Ages, the use of subtractive notation remained highly inconsistent. However, following the invention of the printing press around 1440, these compact forms gradually gained acceptance across Europe, leading to the standardized conventions we use today. These conventions, however, were not universally applied. At the time the earliest clocks were made, the subtractive IV was not used at all ⁶⁷, and it remained uncommon on clock faces for centuries afterward.


CONTENTS TABLE OF CONTENTS
The compact subtractive numerals The established ancient IIII The subtractive IV was rarely used Roman numerals on dials through the ages Notes & Acknowledgments

Early dials as an introduction


1580 No subtractive numerals. c.1500 All additive escept for XIX No subtractive numerals c.1540 All additive except for IX and XIX. England c.1370 No subtractive numerals.


THE COMPACT SUBTRACTIVE NUMERALS

The shorter subtractive notation enabled better spacing and inclusion of half-hour markers, making it easier to read the time more accurately. Astronomical clock Padua c.1344 Chapter version 19 th c. Yet, only the subtractive IX was universally applied, while the subtractive IV was not used at the time of the oldest clocks ⁶⁷. Like the earliest 24-hour public clock dials, early 12-hour dials used the ancient additive numerals as well, though the lengthy VIIII usually gave way to the compact subtractive IX, also avoiding crowding with VIII. A rare instance of the ancient additive numeral VIIII on a 12 hour dial appears on the south-west face of a tower in Udine, c.1527. Torre dell’Orologio, La loggia di San Giovanni, Piazza della Libertà, Udine. By contrast, the south-east face bears a later dial, driven by the same movement, employing the compact subtractive IX. Here is more on solar time The same building - La Loggia di San Giovanni - also featured a meridian noon sundial used to set the tower clock to 12:00 local time.

The ESTABLISHED ancient IIII

Before 1657, mechanical timekeeping technology was notoriously inaccurate, with timepieces sometimes gaining or losing as much as twenty minutes. Hence, minute graduations were of little practical value. Clocks equipped with a single hand and quarter-hour graduations, or with quarter-chapters¹, were already regarded as sufficiently precise for everyday purposes. Heilbron c.1580 The hours were divided in quarters, not in minutes. In the course of the 16th century, the subtractive numeral IV appeared more in documents and inscriptions. However, clock faces retained the traditional IIII, which proved especially practical on quarter chapters of early public and domestic clocks, many of which struck the quarters. Here the sequence I-II-III-IIII correctly represents the number of strokes on the quarter bells. I-II-III-IV does not. Since they provided a much valued audible time telling service⁵, quarter-striking public clocks became increasingly common from the 15th century onwards. They marked the hours and quarter-hours by different chimes, making them easy to distinguish. Subsidiary quarter chapters ¹ Central quarter chapters¹. It was only with the advent of precision pendulum clocks in 1657 that central minute hands, pointing to Arabic minute divisions on the chapter-ring¹, acquired real significance. 24 hour prayer timer dials Divided in 4 six hour sections

The subtractive IV was rarely USED

In comparison with the ancient additive 'IIII', the subtractive 'IV' was not widely used⁶. Although, it does appear on quite a number of later dials and its use increased somewhat throughout the 20th century, often on renovated tower clock faces. A survey* of 211 Italian clocks with six-hour dials³ revealed that 14.2% featured a subtractive IV, some of which on restored chapters. Padua 1665 Amsterdam 1659. In contrast to actual clock faces, these mid-17th-century prints reveal that the subtractive ‘IV’ was indeed used in pictorial representations. The prints also suggest that the illustrators did not necessarily model their depictions on actual clocks. Arezzo c.1552. Archival records document several major interventions over the clock's history. Its present dial, with a frescoed 12-hour chapter, features a subtractive IV. The Hague, Sept. 1658. Subtractive IV on a drawing within the draft sheet of Christiaan Huygens' letter to John Wallis. Codices Hugeniani, Hug 45. Ben Hordijk, Rob Memel. Subtractive IV on the dial of a public clock in Tunbridge Wells, c.1760. Subtractive IV on the dial of a public clock in San Sebastián, c.1740. Clock dial with subtractive IV, 20th c. Palazzo del Sedile Matera. Antide Janvier, c. 1805. Perhaps the only time the subtractive IV was used by this esteemed French horologist. La Pendulerie Sundial with subtractive IV, a.d. 1509 Sundials divided daylight in two roughly 6 hour sections at either side of the 'noon centerline' A subtractive IV on the dial of a public clock in Prague, late 19th c. Despite the dial’s narrow numeral cartouches, the compact subtractive IV proves an excellent fit, while the additive VIII had to be reduced in size. A subtractive IV employed in 1929. Rijksmuseum Carter Marsh The IV was also found on exclusive, late 17th c, clocks with a month going movement and Roman striking, an energy efficient system in which the number of chimes corresponded to the Roman numeral itself. ‘I’ = one stroke on a high bell, ‘V’ = one stroke on a low bell, ‘X’ = two strokes on a low bell. At twelve o’clock the train strikes four times (V-V-I-I = XII); at four o’clock, twice (I-V). The system requires only 60 strokes in 24 hours, against 156 on a conventional striking train. A considerable saving of energy, particularly for spring driven long-duration clocks.


roman numerals on dials through the ages

bm14 14th century. 14th. 15th. 16th. 17th. 18th. 19th. 20th. c. An Italian astronomical public clock dial with the hours counting from sunset ³. No subtractive numerals. Padua c.1344 (1437). 24-hour dials highlight that, unlike sundials, mechanical clocks are capable of keeping time around the clock, both day and night. An astronomical public clock dial, Lyon c.1383 A public astronomical clock dial, Rouen c. 1389. Wells Cathedral exterior. Wells Cathedral interior. The exterior and interior faces of the Wells Cathedral turret clock, c. 1390. bm15 15th century. 14th. 15th. 16th. 17th. 18th. 19th. 20th. c. The dial of an Italian public clock, with the hours counting from sunset ³. The radially applied numerals accommodate the lengthy XVIIII and XXIIII. No subtractive numerals. San Giacomo di Rialto, Venice, c. 1410. Another Italian public clock dial with a counter-rotating hour hand, like the nodus shadow on mural sundials. No subtractive numerals. The Duomo Florence, dial painted by Paolo Uccello in 1443. Another Italian public astronomical clock dial, with the hours counting from sunset³. Mantova c. 1473 A French public clock dial in Auxerre c.1490. bm16 16th century. 14th. 15th. 16th. 17th. 18th. 19th. 20th. c. An astronomical public clock in Chartres c.1525. An astronomical public clock, with the hours counting from sunset ³. No subtractve numerals. Brescia c.1540. An Italian circular public mural sundial. San Rocco church, Spilimbergo 1536. Padre Garcia. A German table clock dial c.1560. A quarter striking public clock, the dial frescoed directly onto the wall of the Uhrturm in Graz, c.1569. South Germany, with quarter chapter c.1580. A quarter chapter¹ on the subsidiary dial of a late 16th c. German astronomical table clock. The MET The dial of an 'Italic time'³ lantern clock c.1580, striking four 6-hour cycles per day. Its vertical center line accentuates the two 6-hour halves of the chapter¹. The radial applied numerals allow space for the full additive VIIII. Who cares about visual imbalances? La Misura del Tempo Colmar 1582. A silvered subsidiary dial with quarter chapter on a French Renaissance table clock c. 1589. British museum bm17 17th century. 14th. 15th. 16th. 17th. 18th. 19th. 20th. c. Another 'Italic time'³ lantern clock dial c. 1600. Displaying 'sunset hours' within the first quarter of the chapter¹. J.Venema An English lantern clock dial c.1623. Bonhams The dial of a Dutch captain's watch witn moon-age and tidal information The Hague c.1630. Rijksmuseum The chapter ring¹ of Christiaan Huygens' first pendulum clock, 1657, marking not just minutes, but a turning point in horological history. The dawn of precise timekeeping. Museum Boerhaave It’s a quarter to eight on this backlit Italian night clock dial from the late 17th century, with 'wandering hours' moving across an ajour arc-shaped quarter chapter¹. Easy live Auction It’s 20 to five on the dial of a late 17th c. English pocket watch with one finger pointing to a 'wandering hours' arc-shaped aperture and another finger pointing to a date aperture. The MET The dial of an English longcase clock c.1678, with calendrical, lunar, and tidal indications. The MET The dial of an English longcase clock with Roman-striking c.1680, hence the silvered chapter ring¹ with subtractive IV. Carter Marsh An English clock watch dial c. 1690, featuring a single hand pointing to quarter and five minutes divisions on the outer chapter¹. Pieces of Time An English lantern clock dial c. 1690, Featuring a small alarm time setting disk, the single hand pointing to quarter divisions on the chapter ring¹. The making of single-handed domestic clocks persisted until the early 19th century. Carter Marsh An English pocket watch c.1700. The dial with 6-hour 'Italic time' ³ chapter¹, Stephen Bogoff bm18 18th century. 14th. 15th. 16th. 17th. 18th. 19th. 20th. c. Augsburg c. 1710. Shows the ongoing use of quarter marks. Groningen c.1720. Watch dial with 'Wandering hours' moving across semi circle minute and quarter chapters. Weltenburg Abbey c.1730. A 6-hour 'Italic time'³ lantern clock dial, with 12 o'clock extension, early 18th c. Szczecin 1736 A dial with 12 enamel cartouches (cadran á douze) early 18th c. A mid 18th c. Louis XV French mantel clock dial. A mid-18th-century Italic time³ lantern clock dial featuring a quarter chapter¹. Quarter chapters had become increasingly uncommon over the course of the 18th century. The painted dial of a Dutch wall clock, c. 1760. Circular public mural sundial. Italy 1767. San Matteo Apostolo church. Borgo Velino. Padre Garcia A quarter striking Italian longcase clock with 'wandering' (rotating) 12 hour chapter¹, c. 1770. The lavishly decorated dial of a French table regulator clock c.1780, featuring equation of time, annual calendar, and signs of the zodiac. An English 24 hour tidal longcase clock dial with both additive and subtractive numerals four, c.1780. A late 18th-century French mantel clock with a dial of refined decoration, also marking the days of the month. The horizontal rotating dial (cercle tournant) of a late 18th-century French vase clock. A French mantel clock dial c.1795, displaying the newly introduced revolutionary Decimal Time⁴ on the inner chapter while the outer chapter retains conventional Gregorian hours. bm19 19th century. 14th. 15th. 16th. 17th. 18th. 19th. 20th. c. A clean Empire wall clock dial, c.1810. The silvered dial of a Vienna regulator wall clock, c.1830. The Gothic revival dial of the Westminster tower clock with subtractive IV, c.1859 Elizabeth tower A Neo Gothic English skeleton clock dial, c.1870 A US Ansonia wall clock dial. New York, c. 1895 bm20 20th century. 14th. 15th. 16th. 17th. 18th. 19th. 20th. c. A German Jugendstil mantel clock dial with subtractive IV, c. 1903 Quittenbaum An Art Deco desk clock dial, c. 1920 Marjan Sterk An Art Deco mantel clock dial, c. 1925 A Cartier carriage clock face, 'Cadran Breveté' c. 1928 Bonhams An Art Deco desk clock dial, c. 1929 Christie's An Art Nouveau mantel clock dial with subtractive IV, G. H. Lantman c.1929. Rijksmuseum An Art Deco desk clock dial, c. 1929 Ms Rau An Art Deco mantel clock dial, c. 1930 A J. L. Reutter Art Deco Atmos clock dial, c. 1935 Gude Meis Arabic numerals and non-numerical indices became commonplace over the course of the 20th century, gradually replacing Roman numerals, though not entirely. 14th. 15th. 1 6th. 1 7th. 1 8th. 1 9th. 20th c. NOTES 1 Chapters. In a horological context, a chapter is the scale of divisions and markings -such as numbers or signs- used to read the time and related indications on a dial. These markings may be engraved, painted, printed or otherwise applied, either directly onto the dial or on attached elements such as 'cartouches' or a 'chapter ring'. 2 Imbalances. Correcting the IIII–II imbalance would in turn create a new, albeit relatively minor, IV–VIII imbalance. 3 Italic 6-hour time. The temporal system emerged in the Middle Ages in the Papal States, rooted in monastic timekeeping and canonical hours. The day began at the advent of the evening, about half an hour after sunset, and was divided into four six-hour* segments. Consequently, such clocks need to be regularly synchronised with sunset. By the late 18th and early 19th centuries, as standardization and modernization increased, the Italic six-hour system fell out of use in practical timekeeping. (many more 6 hour dials) * Sundials already measured the sun’s course in two roughly six-hour spans -one before and one after the noon reference line (mid-day). 4 French Revolutionary Decimal Time. A short-lived system introduced during the French Revolution (1793–1805) as part of a broader attempt to decimalize all aspects of daily life (calendar, measurements, currency, etc.). Each day was divided in 10 hours of 100 minutes. Here is more on decimal time. 5 It can reasonably be assumed that the earliest late 13th c. monastic mechanical clocks indicated time by striking chimes rather than visually by means of dials. 6 Bernard Roobaert. ....So the conclusion is simple: the dial of the oldest clocks and watches has a Roman “IIII” because “IV” was not used at the time. More on this subject https://en.wikipedia.org/wiki/Roman_numerals 8 Paul Lewis: ....."Clearly there is much less power here in the symmetrical balance argument, the dial is not symmetrical anyway. The Arabic numerals do not balance and the two or three stars in each sector of the clock-face are certainly not arranged to match those in the sector opposite"...... http://www.web40571.clarahost.co.uk/roman/clockface.htm 7 Bernard Roobaert: Peutinger Table (late 4th century) .... uses additive notation: IIII, VIIII, XIIII, XXIIII, XXVIIII Subtractive notation: IX, XIX, XXIX, XL, XLII No mention of "IV" https://www.researchgate.net/publication/369661683 Bernard Roobaert. ....So the conclusion is simple: the dial of the oldest clocks and watches has a Roman “IIII” because “IV” was not used at the time. https://www.researchgate.net/publication/369661600 Acknowledgments Illustrations: Bonhams. British museum. Carter Marsh. Gude Meis. Guiseppe Brusa, La misura del tempo. Joachim Köhler. Koller auctioneers. La Pendulerie. Bonhams. British museum. Carter Marsh. Gude Meis. Guiseppe Brusa, La misura del tempo. Joachim Köhler. Koller auctioneers. La Pendulerie. Yves Droz et Joseph Flores, Les Heures Revolutionnaires. Marjan Sterk. Mentink & Roest. The MET. Museum Boerhaave. Quittenbaum Kunstauktionen. Rijksmuseum. San Domenico Bologna. Sotheby's. Van Dreven. Wells Cathedral. The Horological Foundation gratefully acknowledges Jo Dickenson-Schepp for her highly esteemed contributions. Links Bernard Roobaert Bonhams British museum Carter Marsh van Dreven GudeMeis Koller auctioneers Guiseppe Brusa La misura del tempo La Pendulerie Mentink & Roest Museum Boerhaave Quittenbaum Kunstauktionen Rijksmuseum The MET

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