- Mayall , R.N. and Mayall , M.L. 1962 . Sundials: How to Know, Use and Make Them Boston
- Although what appears to be a remarkable hybrid dial, originally incorporating a polar gnomon but graduated to read in seasonal hours, was excavated in Afghanistan in 1975 and associated with Alexander's campaign of 329 B.C. See Rohr R.R.-J. A Unique Greek Sundial Bulletin of the British Sundial Society 1990 3 14 17
- Ward , F.A.B. 1976 . The Earliest String-Gnomon Sundials . Antiquarian Horology , 9 : 800 – 801 .
- Rohr , R.R.-J. 1965 . Les Cadrans Solaires Paris English edition as Sundials: History, Theory and Practice (Toronto, 1970), plate 7.
- Mills , A.A. 1990 . Seasonal-Hour Sundials . Antiquarian Horology , 19 : 147 – 170 . Some errors were corrected in the next issue of this journal; 19 (1990), 315.
- Gibbs , S.L. 1976 . Greek and Roman Sundials New Haven
- Brown , G.B. 1921 . The Arts in Early England Vol. 6 , 171 – 175 . London V
- Eden , H.F.K. and Lloyd , E. 1900 . The Book of Sundials London
- For a bibliography of literature on scratch dials see the paper referred to in footnote 7; to these should be added ‘Sundial Literature Published by T. W. Cole’, collated by Aked C.K. Bulletin of the British Sundial Society 1991 3 5 12
- For a discussion of the so-called ‘octaval’ or ‘tidal’ system of time measurement attributed to the Vikings, see Turner A.J. Anglo-Saxon Sundials and the “Tidal” or “Octaval” System of Time Measurement Antiquarian Horology 1984 15 76 77
- Fortunately, the British Sundial Society is now recording details of scratch dials in Britain. The Secretary is Young D.A. Brook Cottage, 112 Whitehall Road, Chingford, London E4 6DW
- See, for example, Archinard M. The Diagram of Unequal Hours Annals of Science 1990 47 173 190 and references cited therein.
- An extensive list is given in the paper referenced in Mills A.A. Seasonal-Hour Sundials Antiquarian Horology 1990 19 147 170
- Mills , A.A. 1990 . Seasonal-hour Sundials for the British Isles . Bulletin of the British Sundial Society , : 15 – 21 .
- Therefore, the easiest way to determine whether a vertical plane dial is intended to delineate seasonal or equal hours is to see whether the vertical midday line is marked ‘6’ or ‘12’ respectively. This criterion is particularly useful when examining folding diptych dials with multiple pin-gnomons. Cases are known where the dial pattern is an incorrect hybrid of the two systems: see, for example Mills A.A. Isaac Newton's Sundials Antiquarian Horology 1992 20 126 139
- Buchner , E. 1982 . Die Sonnenuhr des Augustus Mainz
Annals of Science
Volume 50, 1993 - Issue 1