Dear Fer: Thanks for getting back to me. But I still have just a couple of clarifying questions on the subject.
>You use 7 lines for 12 dates. In that case I suggest to use the series >0, +/- 11* 29', +/- 20* 20', +/- 23* 27' for these lines. >I myself often use 0, 11.5, 20 and 23.44 degrees. >Thus calculte the lines as declination lines, not as lines of date. How were these specific declination values originally determined? Are they average values taken over many years or are they from a year half way between two leap years, and if so, which year was used? Would you consider the dial pictured opposite page 200 of Mayall to be correctly labeled for your suggested declinations? I needed a magnifying glass to read them, but they appear to be: Jan. 21, Mar. 21, Apr. 22, May 22, Jun. 21, Jul. 22, Aug. 22, Sep. 23, Oct. 21, Nov. 21, and Dec. 22. (The designer of this dial includes the declination line for Nov. 1, presumably to reduce the large spacial gap between the Oct. 22 and Nov. 21 lines.) Thanks again Fer, it's comforting to know that these answers are coming from the horse's mouth himself! John Carmichael http://www.azstarnet.com/~pappas
