Page:Great Neapolitan Earthquake of 1857.djvu/257

Rh at right angles to the former, or east and west, and extends about ten feet up and down, (commencing where the wall had been weakened by an aperture now built up) and vertical—width 0.15. It is higher up the tower by five feet, than the fissure $$\mathrm{C}$$ at its mid length. The inertia of the central core of masonry here is enormous in relation to its base; and to that, no doubt, is due these fissures, the only two formed in the whole building, which is solidly and well built of rubble and ashlar masonry.

The fissure $$\mathrm{C}$$ appears to have been produced by the spiral lapping of the staircase round the central column (through which the push of the latter was transmitted to the cylindrical shell) having prevented its vibration as a simple pendulum in the plane of the shock, or near it, and induced a movement of conical vibration. The movement indicated is one nearly from south to north by compass.

Several other buildings in and directly around Naples were fissured, but none were thrown down. Amongst those which I examined were Messrs. Turners' bank, in St. Lucia, the Tribunale, and several palazzi, amongst the latter the Palazzo Lieti, in the Toledo. In no case, however, could I find that the fissures had been originated by the shock of 17th December: they were all pre-existent, and due chiefly to settlements, but had all been slightly enlarged by the shock.

The derangement at the Palazzo Lieti was so considerable as to demand prompt measures to prevent the fall of one wall of the interior court, by building up solidly, a huge arched porte-cochère that had yawned beneath it, and was about twenty-four feet span, with a new wall and