The volume on the sundial in the Cathedral of Milan, very complete and with a lot of technical and historical news, described by Giovanni Barbi and published in 1976, is now out of print.
A small volume, with a short description of the sundial, has been published in 2001 and is in sale in the cathedral. The cost is 5 euro (around 5 US $) Probably it can be asked also at the address [EMAIL PROTECTED] Publisher " VENERANDA FABBRICA DEL DUOMO" - 2001 Carlo Ferrari dal Passano - Carlo Monti - Luigi Mussio La meridiana solare del Duomo di Milano - 25 pag. - 10 photos Some data on the sundial. Since the Milan cathedral has the direction East-West (entry in the West side), the meridian line crosses the naves of the church and it is traced at few meters from the principal entry. Design and construction: Giovanni Angelo De Cesaris (astronomer of the Observatory of Brera) -1786 Height of the Hole 23.82 m Diameter of the hole 25.2 mm (1/945 of the height) Since the meridian line is longer than the width of the cathedral it is developed on the floor for 53.85m and then it "climbs" on the North wall for around 2.90 m The dimensions of the image of the Sun change from around 0.26 x 0.26m on summer Solstice to around 1.27 x 0.55m on November 20. The speed of the movement of the image on the floor is between 4 mm/sec (winter) and 1.7 mm (summer) The sundial has been verified and restored in 1827, in 1921 and in 1976, Originally, plates of marble with the zodiacal signs were present but they have been removed in the 1827 restauration: only the plate of the Capricorn sign remains. Some sundials in other Italian churches (as. that in the church of S. Petronio in Bologna - see Heilbron volume) were built mainly as astronomical instruments to determine the ecliptic inclination, the dates of the equinoxes, etc. On the contrary, the sundial in Milan was built as "official clock" to determine the instant of the noon with which to regulate the city clocks. On October 23rd 1786 the authority emanated a decree in which it was established that from December 1st 1786 in Lombardy (the italian region in which Milan is) the ancient system of the "italic hours" had to have abandoned and replaced from the system of the "French hours" (the modern hours with the beginning of the day at midnight) In 1786, Lombardy belonged, from 1713, to the Austrian Empire. Gianni Ferrari 44° 39' N 10° 55' E Mailto : [EMAIL PROTECTED] -
