David, I calculated a week ago a sundial of 7 m x 4 m on a cilindric part of the façade of a new building in Brussels at a heigth of 15 m. One has to stand at the other side of the avenue to see the shadow of a ball indicating the hour on the façade.
Your 'simple' solution is here not suitable. Willy Leenders Flanders, Belgium [EMAIL PROTECTED] wrote: > My feeling is that the simpler you make the dial, the more likely it is to be > used/understood. So.....make a dial with only one scale of hours, arranged to > show local time i.e. noon line vertical, and noon (preferably) or 1pm marked > on that vertical line. then in the equation of time correction curve, allow > for longitude in the scale of minutes correction (the curve is 'lifted' on > the minutes axis by 4minutes for everey degree west of the time zone standard > meridian, and lowered correspondinglyfor every degree east. Then put a short > instruction clearly on the area of the correction curve that says (if in UK, > for example, for a dial that has 12 marked on the local noon line) GMT: apply > minutes. BST: + 1 hr. > David Brown, Somerton, Somerset, UK > - -