In preparing a sundial, that would eventually be cast in bronze, or some such material, one pauses to question the sanity of using a dialface with correction for one's longitude. Assuming such a sundial costs in excess of $100, it would seem appropriate to ensure that it can be moved, if necessary, should the owner's residence change.
I should explain that ever since I learned that a dial could read standard time, I thought it a capital idea to make it include the longitudinal correction. I'm curious here as to how to proceed. With a sundial that reads local apparent time, only the gnomon angle or horizontal plane need be changed, should the new site's latitude change. But all of the hourlines would need moving if the longitude were to change. The benefit of a dial that reads standard time (as opposed to local) is obvious, since the regular long. correction need not be applied every time the dial is read. However, is there something more aesthetically pleasing about a local dial (more historically true, etc.) that might lead me to forego the "accuracy" of the standard dial (which only needs equation of time adjustment)? Afterall, even a dial that reads standard time needs some calculation nearly 99% of the time for the equation of time. One might argue that if you're going to calculate at all, might as well throw in the long. correction. So... How about a vote? All in favor that I pursue a local time dial, WITHOUT correction built in for longitude, please reply as such. Those who think I should forget about ever moving the dial and go with a standard time dial, I invite your reply as well. Feel free to mail me directly at [EMAIL PROTECTED] so as to keep the sundial mail group somewhat less cluttered... I might add, that I am in the process of planning a horizontal dial that includes a date line for the birthday of my firstborn, 6/25/96... thanks! john.
