I’m working from Albert Waugh’s book “Sun dials, Their Theory and Construction”. On page 45 he presents a method for computing hour lines. I lack significant math skills, but I know how to work Excel. I don’t understand how he is calculating these values.
He says, for example, that “log tan t” of 7°30’ is 9.11943. In my simple-minded way I asked Excel to show me log(tan(7)) and got a very different value. I tried converting 7°30’ to radians and that didn’t get any closer. How can I calculate "log tan t" or "log sin latitude” with Excel to get the values he shows? I anticipate further problems with the last two columns, but you have to start somewhere…. - Bryan --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
