The Asinelli Tower in lockdown

It is still not possible to say with certainty when and by whom the Asinelli tower was built. It is assumed that the tower owes its name to Gherardo Asinelli, the noble knight of the Ghibelline faction to whom the construction is attributed, which began according to a consolidated tradition on 11 October 1109 and finished ten years later, in 1119. [2] A possibility of dating to the second half of the 11th century is instead offered by a thermoluminescence campaign conducted on the bricks at the base of the building: [3] in this way the tower would have been erected in a period of contrasts between the Papacy and the Empire, with exponents of both factions that perched in the towers. The hypothesis that the Asinelli family simply took legal possession of the tower with the subsiding of political hostilities between Guelphs and Ghibellines thus appears equally plausible. [4] Jakob Alt, Die Türme Asinelli und Garisenda in Bologna (around 1836); watercolor, 51.6 x 41.1 cm, Albertina, Vienna. The Asinelli tower is the one on the left; on the right the Garisenda is visible Taking this hypothesis as true, the Asinelli family - being part of the aristocratic coterie that arose between the dissolution of the feudal world and the affirmation of the Municipality - would have proceeded to raise the tower for about thirty meters, so as to equip it for observation at distance from Bologna and the surrounding countryside. With the decline of the Asinellis, and the progressive purchase of parts of the tower, the entire structure at the end of the fourteenth century was purchased by the municipality of Bologna to be used as a prison and fortress. In the same years a wooden frame was built around the tower, placed thirty meters from the ground and joined with an aerial walkway to the Garisenda, then destroyed by a fire in 1398. It is said that the construction was commissioned by Giovanni Visconti, Duke of Milan , to keep a better eye on the turbulent Mercato di Mezzo (today via Rizzoli and neighboring streets) and to be able to quell any riots in time. The history of the Asinelli tower is full of curious events, meticulously reported in the Bologna chronicles of the time. In 1513, in fact, the Asinelli tower was hit by an eight-pound cannonball fired from Porta Maggiore on the occasion of some celebrations, which, however, failed to affect its stability; the tower was also targeted by numerous fires, which were mostly harmless, causing only the destruction of the wooden stairs. Contrary to what one might suppose, in fact, the greatest offenses to the Asinelli tower were caused by lightning, which raged on the structure for over seven centuries, until a lightning rod was installed in 1824: previously, the protection from discharges atmosphere was entrusted to an ineffective wooden cage designed by Gianandrea Taruffi in September 1706 and a bas-relief of St. Michael the Archangel, the work of Giovan Battista Gnudi. [2] The Asinelli tower was also the place where the iron cage was placed, a particular instrument of death reserved for religious who had committed crimes. From the thirteenth century up to the sixteenth century, members of the clergy convicted of serious crimes were locked up in these suspended cages until their death. Initially this form of execution took place at the Palazzo del Podestà, subsequently the cages were placed on the side of the Asinelli tower overlooking Strada Maggiore, at a height of 20 meters. [5] A glimpse of Piazza Maggiore seen from the top of the tower Finally, the scientific role played by the Asinelli tower is also remarkable. To recognize the effects caused by the earth's rotation, in fact, at the beginning of July 1790 the scientist Giovanni Battista Guglielmini carried out an experiment which consisted in letting lead spheres fall from the top of the tower and measuring their deviation: despite the difficulties (the wind coming from the holes of the structure in fact caused several tests to fail), Guglielmini managed to collect the results of the experiment in a work called De diurno Terrae motu, which aroused much consensus in the Italian scientific world. [6] In 1888 the engineer Alessandro Ferretti proposed to mount an elevator inside the tower to make the climb easier. The Municipality examined the project but rejected it for fear of structural damage to the building. In February 1902, a project was again presented to replace the dilapidated stairs with an elevator, but once again the Municipality diets failed. A third installation proposal arrived in 1932, but the Podestà refused as the stairs had been restored a few years earlier. A final attempt was made in 1991, but this too was rejected.