Reading Sundials

Before the days of clocks Florentines used sundials to tell time. Several examples of these instruments have survived around the city. Each one tells time in a different way.

Two are in piazza Santa Maria Novella, on the façade of the church. They were built by the Dominican friar Ignazio Danti who was the cosmographer, or mapmaker, at the court of Cosimo de’ Medici.

On the sundial to the right, the needle casts a shadow on the marble surface to indicate the time of day. The hours are marked on the stone.

South sundial at Santa Maria Novella (Credit: Flickr / Creative Commons: Groume)

The one on the left is very different. It is a bronze sphere which represents the sphere of the heavens. It shows the movement of the stars around the earth or the sun. It was used to determine when the solstice or equinox would be.

Sphere sundial at Santa Maria Novella (Credit: Flickr / Creative Commons: berendbotje54)

On top of one of the gold shops on the Ponte Vecchio is a very old and damaged sundial. Instead of telling time, it was used to indicate the five prayer times throughout the day. Each stone ridge represented a prayer time.

Ponte Vecchio sundial (Sphere sundial at Santa Maria Novella (Credit: Flickr / Creative Commons: Groume)

A modern version of the sundial can be found outside the Galileo Museum. It was built just four years ago, in 2008, when the museum opened. Here, the whole structure serves as the needle, casting a shadow on the ground.

The brass lines are used to tell the time, whereas the stone lines indicate the date.

Galileo Museum sundial (Credit: Flickr / Creative Commons: GordyBrown)

Next time you’re passing one of these sundials see if you can work out what time it is showing – it can be a bit of a challenge! I, for one, am very glad I can just glance at my watch!

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