On Fri, 17 May 1996, Powers Patrick wrote: > > The hour markers on an analammatic dial are not lines from the centre of the > ellipse they are positions along the periphery of the ellipse and are > associated with the point of the shadow arising from the top of the vertical > gnomon. So I'm afraid you_will_need to specify the height of the person. > However, in my experience the observational accuracy of such dials is such > that you can have quite a wide variation in height before significant errors > are noticed!
In the case of an analemmatic sundial you cannot give lines for the time because the shadow casters position is not fixed through the year. But the time is given by the suns azimuth only and the shadow casts into the same direction not depending of the height of the shadow caster. So, you_will_not_need to specify the height of the person. Analemmatic sundials can be used by childrens as well as adults. As Fred mentioned you can use a standard horizontal sundial with markings for the persons height. - Daniel
