Jack, I think your drawing has captured it all, exactly. The green circles could also be described as the camera location at 4 different points of the year (following the 24hour path), while trying to record a yearly circle, and if you look at it that way, you'll see why no annual circle can be recorded....you've moved around the same axis as the nightly.... therfeore you'll have only recorded the nightly. The red lines show where you would like for your camera to be, in order to record an annual circle (because the path is perpendicular to the axis), except that those points only exist along a 23hour 56minute path, and as shown in a drawing that Allen did, there is no rotation of the camera on those paths, so no annual circle can be recorded there either. This is why I have dropped out from those supporting this proof. Since the mechanics involved make it impossible to record anything other than a nightly trail, the lack of a yearly trail in recordings is not proof of anything. JA... Jack Lewis <jack.lewis@xxxxxxxxxxxx> wrote: Dear All, This is my attempt to explain more graphically Neville's last drawing showing the two axes of rotation. 1 The green circles are a fixed spot on the world shown in four different positions traversing the ecliptic path. The NEP is perpendicular to the grey ecliptic plane. This illustrates the world's 24 hour rotation. I have tried to take great care to get the geometry correct within the limitations of my drawing software. 2 The green circles also represent the world traversing its annual orbit about the NCP. These are shown as red ellipses. The NEP, according to my drawing geometry, also traverses the NCP. Since there are two rotations happening simultaneously but at very different velocities the illustration can only show an NCP rotation (red ellipses) extrapolated for a whole year. I value comments by all as to whether I have understood the problem or not. I do have a series of 12 illustrations, similar to the one below, showing the position of the ecliptic plane every 30 degrees about the NCP. Jack Lewis www.classiccarartist.co.uk --------------------------------- Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now.