Hi Anselmo & all, In my webpage www.fransmaes.nl/sundials/ - "Analemmatic" - "extra info" - "The human scale", I calculated the shadow paths for a 2 meter gnomon (human with hands above head) in dials of 6 and 10 meter major axis, for latitudes of 35, 45 and 55 deg.
I find it no problem to extend the symmetry line through my shadow accurately by half my height (the summer case). In fact, I find it more difficult to make an accurate reading when my body's shadow (in winter) is falling on the ellipse. >From my graphs and these considerations, I would say that 7 meter is about the maximum. When you set the date scale on a 30 cm step, you could add 15%, making 8 m (25 ft) the maximum. Best regards, Frans Maes ----- Original Message ----- From: "anselmo" <[EMAIL PROTECTED]> To: <sundial@rrz.uni-koeln.de> Sent: Friday, April 08, 2005 8:23 AM Subject: On the greatest size of an analemmatic > Dear all, > > I need your opinions and advice on which could be the greatest > *effective* size of an analemmatic sundial for average latitudes. > > As you all know, for latitudes about 40 deg, the least longitude > of the style equals more or less the major semiaxis of the ellipse > so that the shadow can reach the ellipse on the worst case, this is, > at summer solstice noon. However, in practice it could be too > conservative to suppose so (who, except us, stands on an analemmatic > in the worst of summer?), and perhaps there are some practical rules > you know... Any hint? > > I am considering that the date scale can be on a 30 cm high step > where the user gets up to and that the user can rise his/her hand > so that the effective height of the style could be around 220 cm or so. > > Best regards, > > Anselmo > > > - > -
