Leasing Tower of Pisa.

Waikato Times, Volume 107, Issue 17985, 2 April 1930, Page 14

Leasing Tower of Pisa.

Slowly But Steadily , Falling v

The leaning tower of Pisa is slowly hut continually falling. From 1919 to 1920 it has increased its inclination by ten millimetres, one millimetre each year, amounting to a little more than a third of an inch. This has been rigorously ascertained in the last weeks by the Commission nominated by the Italian Government to study, and possibly solve for ever, the agelong problem of the equilibrium of the beautiful tower, reports the New York “Times.”

The Pisan campanile, 180 feet high, deviates already about sixteen feet from the perpendicular. One foot more and the vertical line of its centre of gravity would fall outside its base, causing the walls to begin to crumble and fall. At the present rate of motion, this might be expeoted to happen in not less than 300 years. Unluckily, there are reasons to fear that the gradual falling of the tower will not increase in arithmetic but rather in geometrical progression. Steps, therefore, must be taken to prevent a disaster (or even the rising of any serious anxiety con. cerning it) which would deprive the world of one of its most admired buildings. The cause of this slow but steady progress in the leaning of the tower of Pisa is mainly- to be ascribed to the composition of the ground supporting it. Tha boring of this ground and other recent and more scientific electrical researches have revealed that the clay and sand layers go as far down as twelve yards, and that the water strata running through them are two. This explains why around the base of the tower there is always a little pool of greenish water, into which the incredibly numerous Pisan urchans delight in throwing all kinds of floating matter. The spot may be seen where, toward the end of the sixteenth century. Galileo Galilei took advantage of the thrusting forward of the tower to give a practical demonslration of his principle proclaiming the equality of the velocity of all falling bodies great and small. On the top floor of the campanile are the huge bells of the cathedral, seven in number, as are the musical notes they represent. Each one of them has a name, and the oldest, “La Pasquareccia,” bears engraved between the pictures of the Virgin and of the Angel Gabriel the words : “Locteringus of Pisa made me in A.D. 1262.” They are rung together only three times a year, because it is feared that their powerful vibrations may injure the stability of the tower. Among all the possible ways suggested by modern ingenuity to strengthen the falling tower, the best seems to be the cementing of the ground around and under it. Experiments made on another side of the same square with pillars laden whh iron weights, causing the same pressure on the ground as produced by the campanile, namely, ton kilograms per square centimetre, hove given very encouraging results. It is interesting to notice, just to realise the miracle of all that weight having been supported for centuries by the weak ground underneath, that new buildings raised in the neighbourhood never exceed the weight of one kilogramme per square centimetre. However precarious may become in the future the condition of the leaning tower of Pisa, visitors should ns yet feel no hesitation about entering it nnd. climbing its narrow slanting stairs. This is, on tlva contrary, to be still strongly recommended. Only from the top of it ran one fully perceive the degree of its deviation.