1:1 model of the dial
Realization
1:10 model of the dial and several models of the semitransparent indicator.
1:1 model of the dial
From the many possibilities of polar map projections, the polar stereographic projection was used, which is the only polar projection without local distortions. Therefore, despite the distortions in area, the continents have the familiar shape which we know from the globe.
The materials used are brass, steel and granite. The advantage of these materials is the fact that the exposure to rain, wind and sun gives the material their best appearance. The basis of the dial is a disc from black granite with a diameter of 1m.
The hour lines are not placed on the granite disc, they are placed on a separate brass ring. This is necessary in order to preserve the universality of the dial. Since the standard time is divided into time zones, the world map must be rotated in case one moves the dial to another longitude. The scale however should not be rotated. Therefore, the world map and the scale have to be decoupled.
The scale has marks for the minute, where 1 minute is represented by 2.18mm on the edge of the disc. Therefore the time can be read to the minute. The scale is fixed to the disc in the position of the hour numbers. These numbers are on small discs which are screwed to the scale and therefore hide the big screws. This also allows to change the dial to 'daylight saving' time.
The indicators of the dial are made from brass. For reading the calendar, horizontal lines are carved into the surface. The calendar is then plced along the diagonals. For every days of the year the is a 1mm hole. The first of the month is indicated by a 2mm hole. Therefore the date can be read with an accuracy of ±1 day.
The base of the dial is made from solid granite. It is fixed to a steel plate which is connected to the ground via three threaded rods. This allows all the degrees of freedom that are necessary to correctly position the dial.
After accurate positioning of the disc with respect to the granite block, the metal support rods were glued into the dial. Consequently, for accurate alignment of the dial in it's final place, the whole structure simply had to be moved until it showed the correct date and time.
