At summer solstice the ball on the upper tropic ring casts its shadow exactly onto the opposite ring below. The upper tropical ring is the tropic of Cancer and lower ring is Capricorn.
The armillary sphere dates back to ancient times when astronomers created their own vision of the earth and the heavens. The idea still works today and our own design creates a sundial with a special feature of two balls that mark the passage of the seasons by their shadows. One of the balls reads summer solstice. This is the high point of the year when the sun is highest in the sky.
The balls are carefully positioned at the meridian point on two tropical rings, the upper one on the Tropic of Cancer and the lower one on the Tropic of Capricorn. When the sun is at noon, the highest point of the day, the ball on the Tropic of Cancer casts its shadow right across the sundial to the opposite tropical ring, exactly at summer solstice. This year the actual time of the solstice is 9.13am GMT (10.13am BST) on 21st June 2022. You will find a full explanation of summer solstice at the Royal Museums Greenwich.
The shadow of the ball on the sundial follows the sun all year round. The sun is low in the sky in winter, and it reaches its lowest point at the Winter Solstice on 21st December. This photo is one month later on 20th January. The sun is already higher in the sky, and the ball’s shadow has moved down.
Sundials catch a shadow from the sun. It is such a simple idea. The shadow on the sundial shows the sun’s position in the sky and the sundial reads it out as time, usually the time of day and often the time of year as well. Our armillary sundial is a special one with two balls that give the time of the year measured by the height of their shadow at noon. One ball casts a shadow in the winter months and the other one in summer. Continue reading
The sundial is in our client’s garden in North London. The sundial faces due south. We set it up at Noon on 28 November, using accurate corrections for the Equation of Time and local Longitude. The photo shows Solar Time at 12.30pm.
The world of solar time has fascinating ideas to explore. Our accurate sundial is almost a compendium of what a sundial can do. The client’s wish was something special for their newly created garden, and our design of a vertical sundial display appealed to them. Continue reading
Silver Dihelion dual sundial sculpture able to read solstice and equinox, summer, winter, spring and autumn seasons, and the daytime hours.
Summer Solstice 2020 in Edinburgh was a day of beautiful sunshine. What could be a better time to show off our Dihelion dual sundial, which can read the solstice and the equinox seasons and the daytime hours. Shifting patterns of sunlight and shadow and petals of the sunflower show through so clearly. There is a lovely Continue reading
Thank you Alastair. It looks superb. Am looking forward to installing it. Kent, EnglandMore testimonials