Roman numerals on clock dials

Roman
Numerals
on
Clock Dials

Compiled by Fred Kats

Subtractive notation of Roman numerals, like IV, IX, XIV, XIX, XL evolved over time from an ancient mostly additive system and became more popular after the invention of the printing press. Although its use was inconsistent in ancient times and during the Middle Ages.
While Romans initially preferred simpler additive forms like IIII for four, subtractive forms such as IV were also used, especially in inscriptions.

After the printing press's arrival, the more compact subtractive forms like IV and XL gained wider use in Europe, leading to the more standardized subtractive rules that are taught today. Although they were not universally applied even by the Romans themselves.

EARLY DIALS AS AN INTRODUCTION

All ancient additive numerals

1540

England ca.1370

All additive except for XIX.

All ancient except for IX and XIX.
Roman Numerals on Clock Dials.

Venice 1499.

The compact subtractive numerals

The shorter subtractive notation enabled better spacing on clock dials and facilitated the inclusion of half-hour markers, making it easier to read the time more accurately.

However, only the subtractive IX was universally applied on standard 12-hour dials, while the subtractive IV was not.

Like the earliest 24-hour public clock dials, early 12-hour dials employed the ancient additive system as well.

However, the lengthy VIIII usually gave way to the compact IX, thus avoiding crowding with VIII and some visual imbalance with the opposing III.

Other imbalances, such as
VII–V, IIII–II, VIII–X, proved unavoidable².

Roman Numerals on Clock Dials.

Custom images for comparison
Only the subtractive IX was universally applied on standard 12-hour dials, while the subtractive IV was

A rare instance of the ancient
additive numeral VIIII -rather unusual
on a 12 hour dial- appears on
the south-west face of a tower in
Udine, c.1527.

By contrast, the south-east
face bears a later dial, driven
by the same movement,
employing the compact
subtractive IX.

Torre dell’Orologio, La loggia di
San Giovanni, Piazza della Libertà,
Udine.

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.

Here is more on solar time

The ESTABLISHED ancient IIII

Heilbron c.1580

Subsidiary quarter chapters ¹

Prior to 1657, mechanical timekeeping technology was notoriously inaccurate, sometimes gaining or losing up to half an hour. In this context, single-handed clocks with quarter-hour divisions, and quarter-chapters¹ were considered entirely adequate.

c. 1700

c. 1600

Central quarter chapters¹.

Augsburg c.1710

South Germany c.1580

Bern c.1420

BBritish museum

Employment of the standard ancient numeral IIII became further entrenched through its practical application on quarter chapter-rings¹ of early public and domestic, often quarter-striking, clocks. On such chapters, the sequence I–II–III–IIII correctly reflects the strokes on the quarter-bell, whereas I–II–III–IV does not.

Click here for more about chapters¹.

From the 15th century onwards, public quarter-striking clocks became increasingly common and offered a
24-hour audible timekeeping service⁵ for both outdoor and indoor use.
The hours and quarter-hours were marked by distinct chimes, making them easy to distinguish.

4-hour prayer clock dials

Roman numerals on clock dials. Italian 4-hour dial.

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.

The subtractive IV was rarely USED

In comparison with the ancient additive 'IIII', the subtractive 'IV' was not widely used.
Athough, it does appear on quite a number of dials and its use increased somewhat
throughout the 20th century.

Subtractive IV on the dial
of a public clock in Tunbridge Wells, c.1760.

Subtractive roman numeral IV on the dial of a public clock in San Sebastián, c.1740.

Subtractive IV on the dial
of a public clock in San Sebastián, c.1740.

Paul Lewis

Clock dial with
subtractive IV, 20th c.
Palazzo del Sedile Matera.

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, 19th c.

Subtractive roman numeral IV on the dial of a public clock in Prague, 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.

Quittenbaum

A subtractive IV
employed in 1929.

Rijksmuseun

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

* 14th c. *15th c. * 16th c. * 17th c. * 18th c. * 19th c. * 20th c.

An astronomical public clock dial, 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.

A public astronomical
clock dial, Rouen c. 1389.

Rue du Gros Horloge

An English turret clock dial
c. 1390.

Wells Cathedral

15th c.

An Italian public clock dial, featuring radially applied numerals configured to accommodate the extended numeral XXIIII,
San Giacomo di Rialto,
Venice, c. 1410.

Another Italian public clock dial with counter wise rotating hour hand, Florence c. 1450

A roman numeral IIII on an Italian public clock dial with counter wise rotating hour hand, Florence c.1450

The Duomo

16th c.

An astronomical public
clock in Brescia c.1540.

A German table clock dial
c.1560.

Quarter striking public clock dial, frescoed directly onto the wall of the Uhrturm in Graz, c.1569.

A quarter chapter¹ on the subsidiary dial of
a late 16th c. German
astronomical table clock.

roman numerals on a table clock by Jost Burgi

The MET

The dial of an 'Italian 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?

Roman numerals on an 'Italian time' lantern clock c.1580,

La Misura del Tempo

A silvered subsidiary dial with quarter chapter on a French Renaissance table clock c. 1589.

British museum

17th c.

Another 'Italian time'³lantern 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 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.

The chapter ring1 of Christiaan Huygens' first pendulum clock, 1657.

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

The dial of an English
longcase clock c.1678, with calendrical, lunar, and tidal indications.

Roman numerals on the dial of an English longcase clock with Roman-striking c.1680,

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 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.

Roman numeral IIII on an English lantern clock dial.

Carter Marsh

18th c.

A 6-hour 'Italian time'³ lantern clock dial, with later 12-hour extension, early 18th c.

Roman numeral IIII on a 6-hour 'Italian time' lantern clock dial.

Sotheby's

A dial with 12 enamel cartouches (cadran á douze) early 18th c.

Roman numerals on a clock dial with 12 enamel cartouches (cadran á douze) early 18th c.

Mentink & Roest

A mid 18th c. Louis XV French mantel clock dial.

La Pendulerie

A mid-18th-century Italian lantern clock dial featuring a quarter chapter¹. Quarter chapters had become increasingly uncommon over the course of the 18th century.

Bonhams

The painted dial
of a Dutch wall clock,
c. 1760.

Gude Meis

A quarter striking Italian longcase clock with 'wandering' (rotating)
12 hour chapter¹, c. 1770.

La Misura del Tempo

The lavishly decorated dial of a French table regulator clock c.1780, featuring equation of time, annual calendar, and signs of the zodiac.

La Pendulerie.

An English 24 hour tidal longcase clock dial with both additive and subtractive
numerals 4, c.1780.

The Antique Clock co.

A late 18th-century French mantel clock with a dial of refined decoration, also marking the days of the month.

La Pendulerie

The horizontal rotating dial (cercle tournant) of a late 18th-century French vase clock.

Van Dreven Antique Clocks

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.

Les Heures Revolutionnaires

19th c.

A clean Empire wall clock dial, c.1810 .

Gude Meis

The silvered dial of a Vienna regulator wall clock, c.1830.

Mentink & Roest

The Gothic revival dial of the Westminster tower clock with subtractive IV, c.1859

A Neo Gothic English skeleton clock dial, c.1870

A US Ansonia
wall clock dial.
New York, c. 1895

20th c.

A German Jugendstil mantel clock dial with subtractive IV, c. 1903

Quittenbaum

An Art Deco desk
clock dial, c. 1920

Roman numeral IIII on a Cartier desk clock dial.

Marjan Sterk

An Art Deco mantel
clock dial, c. 1925

Christie's

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, 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.

Jeager le Coultre

* 14th c. *15th c. * 16th c. * 17th c. * 18th c. * 19th c. * 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 like '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 Italian 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.
By the late 18th and early 19th centuries, as standardization and modernization increased, the Italian six-hour system fell out of use in practical timekeeping.
* 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.

This article is subject to ongoing updates.