Page 18 - Historic Churches 2013

18 BCD Special Report on Historic Churches 20th annual edition CATHEDRALC O M M U N I C A T I O N S
MEDIEVAL MASS
DIALS DECODED
Peter TJ Rumley
S ome 3,000 mass, tide
or scratch dials have
been recorded in the
UK. Typically located on
the south wall of a parish
church, this form of sundial
was used to mark the
‘variable’ time of liturgical
services in the medieval
world. This article will
consider the various types of
mass dial and their origins,
where they can be found,
and how they were used as
timekeeping instruments
in the organisation of
ecclesiastical and daily
agrarian medieval life.
Finally it will look at why
they went out of use.
MEDIEVAL TIME
RHYTHMS
The Roman Catholic
Church dominated and
regulated the daily lives of
the people of Britain in the
Middle Ages. The Great
Rood (a representation of
the Crucifixion), stained
glass windows and Doom
paintings depicting the Last
Judgement were potent
images that reminded
people of their fallibility on
earth and the perils of sin.
But the seasons were
also represented in church
iconography. At a time
when the majority of the
population could not read
or write, visual reminders of
the medieval calendar year
could be found in the cast
reliefs of lead fonts, such as
the celebrated 12th-century
Zodiac font at St Augustine’s
Church, Brookland, Kent. Here, in a series of
double arcades one above the other, farming
activities are represented below the Zodiac sign
for each month as the year unfolds. Life was
bound by water, the soil and the Julian calendar.
The cycle of labours and the celebration
of cardinal points in the year such as Easter,
Christmas and saints’ feast days were calculated
by illuminated calendars or medieval almanacs.
Such documents were for the exclusive use
of the elite. These, too, had richly decorated
images depicting seasonal activities such
as ploughing, sowing and harvesting.
Medieval society inherited the Julian
calendar system, in which dates
were reckoned by their relation
to three key dates in each month:
The Kalends, Nones and Ides,
but with variations which made
calculations slightly trickier.
The Kalends was the 1st day of
each month. The Ides was the
13th day of the month save for
March, July and October, when
it fell on the 15th. The Nones fell
on the 9th day before the Ides
(counting the Ides day in the
calculation). Every day of the
month was given a number and
calculated backwards from one
of the important key days. Thus,
in January the Kalends falls on
January 1st, the Ides on the 13th
and the Nones on January 5th.
While this system
determined the date it did
not establish the sequence
of the days of the week. By
manipulating other cryptic letter
codes within the calendar, the
days were established. Important
feast days such as Christmas
were highlighted in gold or red
(hence the phrase ‘red-letter
day’). The important saints’ days
had to be reckoned too. Added
to this was the problem of using
the 354-day lunar calendar to
set the Christian date of Easter,
which was celebrated on the first
Sunday following the first full
moon after the vernal equinox,
around 21 March, as it is today.
The vagaries of the system
meant that there were local
time variations across Britain.
But how was this religious
cycle measured in daily-time?
Perhaps the best known
illuminated medieval
manuscript of the period is
the Très Riches Heures, produced for John,
Duke of Berry, between 1412 and 1416 by
the Limbourg brothers, which gave the
prayers to be said at the daily canonical
hours (above left). But it was the Anglo-
Saxons who established the measuring
instrument for doing so – the mass sun dial.
‘March’ from Les Très Riches Heures du duc de Berry c1410 by the Limbourg brothers (Image:
RMN-Grand Palais (Domaine de Chantilly)/René-Gabriel Ojéda)