Other Altitude sundial that became very popular during the fifteenth, sixteenth and seventeenth centuries, is this ring, which its reduced size allowed to carry easily into any pocket.
This time the gnomon is replaced by a small hole made in the ring surface. This hole could move around to place it on the date on which would make the measurement.
Its operation is very simple, as you just have to suspend freely and orient it to the sun, so we get a ray of light to penetrate through the hole, providing the local solar time on the opposite wall, on the scale is engraved inside the ring.
Our ring is a reproduction ot the one made by German astronomer HS Thorn circa 1700.
Manufactured in brass plated metal comes in a nice case for a perfect gift. It is also accompanied by a small booklet with instructions to make it work.
We serve with three modes:
- As clip (See photographs modalities)
Diameter: 3 cm