Earth screw

The globe of the PIETRA globe sundial is aligned like the real earth, the highest point on the globe is always the location of the sundial. The Sun moves around the globe (apparently, in reality the earth rotates) and always illuminates it like our blue planet. You can always see in real time where it is day and where it is night. The sunrise and sunset terminators are also visible. The sun's cone of light moving up and down between the tropics leads to the seasons and the constantly changing lengths of day in the northern and southern hemispheres.

The stainless steel noon bracket can be rotated around the polar axis and is swivelled to display the time until it points towards the sun and the shadow disappears to the right and left of the bracket. The time can then be read off precisely from the time ring. The time ring is rotatable and can be set to read off Central European Time (CET/CEST) or any other standard time to the nearest minute, taking into account the equation of time (difference between true and mean solar time).

At the same time, it is midday (true noon) on the longitude below the noon bracket, i.e. the Sun reaches its highest point of the day there in the world. At this time, the day is divided into two halves of equal length. This midday is therefore "the middle of the day" in the true sense of the word.

The globe has a supporting bolt that is embedded exactly in the point on the earth opposite its own location (antipode).  The supporting bolt in turn sits in a levellable base, so that after alignment your own location is at the highest point on the globe. There you will find a marker. If desired, the name of the place (for short names) or the car registration number (for long names) can also be inscribed.

The globe has a diameter of 300 mm and is made of fine natural sand using the 3D printing process. This achieves an unrivalled level of detail and precision that is superior to conventional stonemasonry. The sandstone surface is consolidated with epoxy resin and finally coated with a protective PU varnish. The surface can be cleaned with water and a gentle detergent.

To match the globe, we offer a post made of the same art sandstone. This has a levelling base made of stainless steel, which can be fixed to a solid surface (stone, concrete foundation) with the dowels and screws included in the delivery. We also offer an earth screw for mounting in the ground. The total height with the post is 1400 mm.

If you do not wish to use a fixed mounting, a stainless steel base plate (5kg, diameter 370mm) with rubber feet is available.

Larger diameters (600mm and 900mm) of the globe are available on request.