4 T.W. Cole, Origin
and Use of Church Scratch-Dials, 1935.
5 The British Sundial Society was
founded in 1988 and has a mass dial group dedicated to recording
6 See for example Horne, 1929, op.
cit.; R.J.R Rohr, Les Cadrans Solaires Anciens d’Alsace,
1971; E. Zinner, Alte Sonnenuhren an Europäischen Gebauden,
1964; T. Przypkowski, ‘The Art of Sundials in Poland from the
13th to the 19th Centuries’, Vistas in Astronomy, Vol.
7 R. Ovens and S. Sleath, Time
in Rutland. A History and Gazetteer of the Bells, Scratch Dials,
Sundials and Clocks of Rutland, 2002.
8 R. and C. Botzum, Scratch
Dials, Sundials and Unusual Marks on Herefordshire Churches,
9 A system of time subdivision
that can be traced back to at least Babylonian times.
10 A fact well known to astronomer
mathematicians of the time who could not use the prevailing
conventional approach (with its ‘flexible’ hours) for the
scientific study of astronomical phenomena.
11 This provided a practical
stimulus for the measurement of passing/successive hours in
addition to sundials – both for cloudy weather and the
determination of night time devotional offices. Monasteries
initially used water clocks for this purpose and went on in the
late thirteenth century to develop the mechanical clock. See
C.F.C. Beeson, English Church Clocks 1280-1850, 1977; and
L.A.A. Romeyn, Torenuurwerken. Tijd voor ledereen, 2005.
12 As no original scratch dial
gnomon survives this was once a matter of hot debate. Most
authorities firmly believed the rod gnomon was horizontal, but
Green, op. cit., postulated a bent rod – with severe
implications for the interpretation of scratch dial markings.
Documentary evidence has since been found confirming the
horizontal rod gnomon – John Hovedon (d.1275) Practica
13 For a detailed technical
discussion of this and related issues see A.A. Mills ‘Seasonal-Hour
Sundials’, Antiquarian Horology, Vol. XIX, Winter 1990.
In brief allowing for latitude results in the hour lines:
- converging on a point vertically above the
horizontal rod gnomon.
- no longer being equiangular but bunching around
14 Such texts outlined the
scientific and practical basis for the angled gnomon, the
bunching of hour lines around noon, and the relationship between
traditional seasonal hours and equal (equinoctial) hours – the
latter, of course, becoming the modern time system. This paper
refers to such dials as scientific sundials.
15 The first categorically
rigorous statement was J.R. Findlay, ‘The Construction and Use
of Wheel Dials’, Antiquarian Journal, Vol. 7, 1927. See
also Cole, op. cit.
16 The first clocks were in
monasteries and would have kept seasonal time as did their water
clock predecessors; see C.B. Drover ‘A Medieval Monastic
Water-Clock’ Antiquarian Horology, Vol. 1, Dec. 1954.
There is evidence of equal hour clocks as early as the
fourteenth and fifteenth century in Europe. But these were
confined to major cities where civic and commercial needs
rivalled those of the church. Documentary evidence suggests the
two time systems ran in parallel. See E.L. Edwards, Weight-driven
Chamber Clocks of the Middle Ages and Renaissance, 1965.
17 Additional evidence is provided
by the dial makers of Nuremberg and Augsburg who exported widely
in Europe. Their sixteenth and seventeenth century portable
compass sundials include dials marked to show both equal and
seasonal hours. See M. Lennox-Boyd, Sundials; History, Art,
People, Science, 2005 and M. Cowham, ‘Portable Sundial
Making in Nuremberg’ Antiquarian Horology, Vol. 29,
18 There were of course dials
before this but, reflecting the fate of the structures on which
they were mounted, very few have survived. Surviving Anglo-Saxon
dials are of very high