Roderick Wall wrote: > > Hi all again, > > Some more comments with regard to my last email on the unusual sundial. > > And a pointer is fixed to the added hour disk (the hour disk as shown in my > last email) and the pointer then indicates local noon on the longitude > scale of the longitude disk? > > I would have thought that the globe would have been locked into a position > so that it would be in the same position as real earth (so that local > longitude would be at the top). > > Roderick Wall. > > The following is a copy of my 1st email: > > >Hi all, > > > >My comments on the unusual sundial: > > > >Could there be another disk (Hour Disk) that is above the disk that is shown > >in the photo. And this hour disk is rotated by the HOUR ANGLE ARC (the HOUR > >ANGLE ARC as shown in Fer j. de vries's email and image Image1.gif). With the > >pointer at the top indicating the hour when: > > > >2. Move Hour angle until a circular sunspot is formed on the globe. > > > >Question: > >Is the top rod a pointer and has a sharp point or has the rod been broken? > > > >Roderick Wall. > > > > (o o) Roderick Wall > --ooO-(_)-Ooo--------------------------- > [EMAIL PROTECTED] > Melbourne Victoria Australia. > .oooO > ( ) Oooo. Would you like to build a small electric motor? > \ ( ( ) Yes, then have a look at: > \_) ) / http://www.Hotkey.net.au/~roderick > (_/
Hello all, I think there is no second disk above the one in the photo. I ( think to ) see some inscriptions on the disk. A double scale in degrees 0 - 180, step 15 degrees At 0 : Greenwich At 180 : International Date Line At one side : Eastern Longitude At the other side : Western Longitude. Also a scale 1HR, 2HR and so on. All 15 degrees apart. Could this mean 1 hour and so on? If this is all right there already is an hourscale. If the disk is set with 0 at top the hourscale can be used to read the local suntime. If the disk is set with 0 at the Greenwich meridian on the globe the universal time can be read as well on what longitude the time is noon. In this case I assume a globe with local meridian in top. Is this an instrument to show the relations between longitude and time? These just are speculations, nothing will be for sure as long as there is no orignal description of the dial. I am curious about what Bob has discovered so far. Fer.
