PISA’S LEANING TOWER

Sun (Auckland), Volume IV, Issue 1054, 19 August 1930, Page 14

PISA’S LEANING TOWER

SLANT TO BE ARRESTED COMMISSION'S REPORT Pisa’s beautiful Leaning Tower i 3 to be consolidated at last. There is every reason to believe that the dangerous slant will be arrested. As far back as December, 1927, Signor Mussolini appointed a commission to examine its condition. It has now presented its report. First, it has discovered that the increase in the tilt of the tower, which was 10 millimetres between 1918 and 1929, has brought the total tilt up to 4.265 metres. But they hasten to add that the deviation would probably have to increase by another 30 centimetres before there is danger of collapse. This opinion, of course, does not take earthquake shocks or landslides into account, and the commission, while saying there is no immediate danger of a catastrophe, strongly recommends that steps be taken as soon as possible to cement the subsoil by injecting a preparation of cement. The Francois system, an English patent, will probably be used, but certain changes will be made owing to the nature of the ground, which is chiefly made up of clay and sand. The commission experimented, choosing two areas about 150 feet away from the tower. They injected solutions of sulphate of aluminium and silicate of sodium in one area, placing pillars weighted with iron bars on both areas. The injected soil gave way for three millimetres under each pillar, while the area which was not. treated gave way 52 centimetres a pillar. The commission has exploded the tradition that Bonanno Pisano and William of Innsbruck, who started the tower, meant it to be crooked because William was a hunchback. Its examtion, it says, proves that the building was planned to be straight, and started as planned. But the soil was watery, and the pumping which had to be resorted to from the first made holes in the gravel and marl strata. The foundations were sunk only nine feet, and failed to reach firm soil. The tower began to tilt when the second storey was up, and so frightened were the builders that they left it for many years.