I am trying to make a model of a Berossus type dial using a conical section
rather than a hemisphere. None of the references I have looked at (e.g
Cousins, "Sundials"; Rohr, "Sundials: Theory & Practice" etc)
specifically state the shape of the cone. My
intuition tells me that it should have an apical angle of 47 degrees (i.e.
2 x 23.5 degrees), and the drawings in the two references cited above
concur with this, but I cannot prove this to myself. Can anyone out there
CONFIRM that this is so ? I also take it that the axis of the cone , which
points to the Pole Star, must be at an angle with the horizontal equal to
the lattitude of the place it is for.
Peter Tandy
Department of Mineralogy, Natural History Museum,
Cromwell Road, London SW7 5BD
Tel: +44 (0)171-938-8778
INTERNET: [EMAIL PROTECTED]
