Dial folk, Those who rely on the sundial formulae in the second edition (1998) of Jean Meeus's book _Astronomical Algorithms_ should be aware of the following erratum: On page 406, in the chapter titled "Calculation of a Planar Sundial", by R. Sagot and D. Savoie, in subsection (3) on vertical sundials, the third equation, the one for "y", should have a "tan delta" in the numerator, not a "tan phi" as is shown.
This error does *not* occur in the first edition (1991). I've already brought this issue to Jean Meeus's attention. He replied today with the following e-mail, which lists two other typographical errors in the second edition. Owners of this later edition should make the necessary corrections to their copies. > Date: Mon, 27 Nov 2000 10:01:05 -0500 > From: Jean Meeus > Subject: Erratum in Astronomical Algorithms, 2nd Ed. > To: Mark Gingrich <[EMAIL PROTECTED]> > > Thank you for mentioning that typographical error. It is my own fault : > the error didn't appear in the first edition of the book. > > Here are two other typographical errors in the book : > > (1) Page 63 : If Z is equal to or larger than 2299161 (same constant as > on the previous line), not 2291161. > > (2) Page 144, fifth line from the bottom : the double negative sign should > be a single one. > > Thanks and best regards. > > Jean Meeus ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Mark Gingrich [EMAIL PROTECTED] San Leandro, California
