Jim and John, Indeed the "épure" is the result of projecting a 3-D figure onto one or many planes according to the rules of a branch of geometry we call in french "géométrie descriptive". It is still used in technical drawing and the method was very popular in gnomonics before the PCs and the hand-held computers. It is a bit obsolete now, except for drawing the hours lines of the most simple sundials for teaching purposes. Good luck
Jean-Paul Cornec 22300 LANNION FRANCE ---------- > De : Jim Morrison <[EMAIL PROTECTED]> > A : sundial <sundial@rrz.uni-koeln.de> > Objet : Fw: epure > Date : vendredi 4 juin 1999 17:13 > > John, > > My French is not what it once was, but I think an épure is just a working > drawing. > > Jim > > James E. Morrison > Astrolabe web pages at: http://myhouse.com/mc/planet/astrodir/astrolab.htm > ----- Original Message ----- > From: John Carmichael <[EMAIL PROTECTED]> > To: <sundial@rrz.uni-koeln.de> > Sent: Friday, June 04, 1999 10:05 AM > Subject: epure > > > > Hi Dialists: > > > > I'm halfway through reading Rohr's sundial book for the first time. In > > laying out hour lines for many types of sundials, Rohr uses a devise > called > > an "epure" (w/ an accent mark over the last e.). He assumes that the > reader > > knows what this is. From the context I think it must be some sort of > > drawing tool or something like a trigon, but I'm not sure. Does anybody > > know? Is it still used by any of you? Supposedly it aids in laying out > > hour lines using graphic methods, but many of Rohr's drawings are so > > complicated, that they are very difficult to understand. > > > > I'm so glad that my first sundial book was the easy to read Mayalls' book. > > I think that if I had started with Rohr I would have given up! > > > > Thanks, > > > > John Carmichael > > http://www.azstarnet.com/~pappas > > > > >
