Gregorian Tower

Gregory XIII and promulgated in 1582. It was then also known as the Tower of Winds.^[1][2]

Jesuit mathematician from the Roman College, was the expert on the committee who suggested the new system for the observations. The 73 metres (240 ft) tower was then built above the museum and library, flanked by the Belvedere and della Pigna courtyards. The instrumentation for the observation of the sun rays falling over it consisted of a meridian line designed by Ignazio Danti of Perugia. It was in the form of a circular marble plate in the centre, embellished with scientific designs. The tower still remains today, but has undergone improvements over the centuries.^[4]

Satellites of Jupiter and Mercury’s transit. As an addition, under the patronage of Pope Pius X, four rotary observatory domes were also added at strategic locations on the 1,300 feet (400 m) long fortification walls, more than a thousand years old.^[5]

polyglot with a knowledge of physics, biology, archeology and the Hebrew language, was in charge of the observatory from 1800 to 1821. He carried out continuous meteorological observations (twice a day at 6 AM and 2 PM) conforming to the programme of the Mannheim Meteorological Society. While the observation records for seven years were published, the balance data in a manuscript form was preserved in the Vatican Library.^[4][5] Subsequent to Gilii's death in 1821, the observatory on the tower was discontinued and the instruments were moved to the observatory at the Roman College. Established in 1787, it was considered more suitable for making observations than the Vatican.^[4]

Barnabite Francesco Denza with the approval of Pope Leo XIII.^[6] High quality instruments were procured, partly with generous donations from Hicks of London, and the automatic recording instruments were procured from Richard in Paris.^[7] A four-inch equatorial, a three-inch transit instrument, and four pendulum clocks with two chronometers, were also procured from the observatory at Modena. In 1888, the gift of a 16 inch long telescope to Pope Leo XIII, became a part of the observatory.^[4][5] Father Denza joined the observatory in 1889 after it was upgraded with more modern instruments. The same year, a second tower was built some 400 metres (1,300 ft) away from the main Gregorian Tower, overlooking the Vatican Gardens behind St. Peter's Basilica on the south-west border. It was built to a diameter of 17 metres (56 ft) with a lower wall thickness of 4.5 metres (15 ft), which could bear the load of a 13-inch photographic refractor, newly procured from Paris.^[4] Augustinian Father Rodriguez was the expert meteorologist who held the post of director from 1898 to 1905. In 1891, Pope Leo XIII, promulgating the motu proprio Ut mysticam, designated the second tower as the seat of the newly established Vatican Observatory, a decision which required altering the roof to provide a flat terrace for astronomical observations.^[8]

equatorial was installed on semicircular bastion. The east end of the bridge, above the barracks of the gendarmes, had a heliograph, with a camera attached, used to photograph the Sun (photoheliograph). A new 16-inch visual telescope, called Torre Pio X, was erected in the second tower.^[4] As a result of these modifications, the original library was moved to the Pontifical Academy Lincei, and the old meteorological and seismic instruments were shifted to the Valle di Pompei observatory. The new Astronomical Library was housed in two rooms of the building. The two new Repsold machines were used for recording on the astrographic plates. The recorded observations were published along with explanatory notes together with the last two series of the atlas of stars. Charts were printed on silver bromide paper.^[4]

Urban VIII had it enclosed and it was subsequently decorated with long sequences of frescoes painted between 1580 and 1582 by Simon Lagi and the two Flemish artists Paul and Matthijs Bril. Today the tower has paintings by Niccolò Circignani and Matteino da Siena.^[2][8]

cosmographer, in association with the Gregorian Calendar Reform. The sundial consisted of a straight line in white marble running across the floor in a north–south direction, intended to measure the height of the Sun at noon according to the seasons of the year.^[2][8]

Pantheons, religious themes, the buildings surrounding the area, and naval shipwrecks with Jesus calming the storm and so forth.^[8]