Danti Sundials at Santa Maria Novella, Florence Italy
Posted by: arby101ca
N 43° 46.445 E 011° 14.963
32T E 681027 N 4849240
Danti set three sundial systems at Santa Maria Novella church in Florence in 1574 to determine the length of the year and the obiquity of the ecliptic. Two are on the facade. The pictures show the armillary.
Waymark Code: WM9EGY
Location: Toscana, Italy
Date Posted: 08/09/2010
Views: 24
In the 16th century, the key scientific concern was the reform of the calendar. Solar instruments were very important in this scientific quest. Ignatio Danti built three solar instruments at Santa Maria Novella to help in this investigation. These include:
1. An armillary sphere on the facade to determine the time of the vernal equinox by the sun's shadow on the equatorial ring.
2. A complex astronomical quadrant on the facade to observe not just the time of day but the equinoxes and solstices, to determine the length of the year, and the obliquity of the ecliptic.
3. A "meridiana" based on a shaft of light through a hole in the circular window 21.3 m high onto a meridian line drawn on the pavement inside the church. This was was built soon after the armillary and quadrant. His intention was to count the days between the reappearances of the sun at the same equinox in order to determine the exact length of the tropical year. This meridian was later enlargered by Cassini.
When I visited on a damp overcast day in 2004, the only useful photo opportunities were the facade and the armillary. The quadrant was only represented by the support bracket with east and west facing sundials. The lighting did not allow useful photos of the these or the corresponding sundial lines on the facade.
Since then the quadrant has be properly restored to it former glory. This is described in the BSS Journal March 2010 in the article "The Restoration of Egnazio Danti’s Astronomical Quadrant on the Santa Maria Novella Basilica in Florence" by Simone Bartolini & Marco Pierozzi. Here are links to pictures available through Google Earth.
For the east face see (
visit link)
For the west face see (
visit link)
These pictures show the large number of complex sundials on the faces of the quadrant. The pictures also show the sundial lines on the facade. This location is now well worth visiting on a sunny day.