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 scratch dials.
   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. 9, 1967.
   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, 1988.
   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 Chilindri.
   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 midday.
   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, Sept 2005.
   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