In my recent visit to Florence, I was amazed with this Armillary sphere which is the largest in the world ever constructed.
An armillary sphere is a model that represents the objects in the sky which consist on a spherical device based on rings where the Earth or the Sun are at the center in most of the cases. The model adresses the representation of those lines that govern the celestial longitude and latitude among other astronomical important measurements such as those related to eclipses. It was invented in ancient Greece and China, but then was used in the medieval age in Europe.
The Santucci´s Armillary with the Earth as the center is well known as a “Ptolemaic” arrangement which differ from the “Copernican” which is with the sun arranged at the center of the model.
An armillary sphere painting made by Italian artist Sandro Botticelli, circa 1480.
The Santucci´s model represents the “universal machinery” that govern the world according to the concepts developed by Aristotle and perfected by Ptolemy, that is why this specific model was coined as a “Ptolemiac” one. The terrestrial globe is placed at the center, displaying those territories and “continents” that were still relatively little known in the era.
This amazing device was restored in the 19th century, including those paintings and gold leaf coverings that it has in their surface, including the four mermaids that are holding the entire model.