Page:Great Neapolitan Earthquake of 1857 Vol 2.djvu/110

Rh examination of the drawing. Besides the great mass of fissures which run transverse to the axial line of the church, which is precisely east and west, and having a prevailing slope at the top towards the west, there are others parallel to the axial line, one, in particular, extending right along the soffit of the nave and chancel, and which has sent the whole length nearly, of the south side wall out of plumb, in its whole height 1½ inch to the south. There are also transverse roof fissures at various oblique angles through the arches, and a huge mass of the dome at the west side has parted off from the remainder, and the spherical triangle has gone westward, leaving fissures of 7 to 8 inches wide open to the sky. There are innumerable small fissures in the dome, and many small and short fissures in the walls and side arches, &c., produced by local structural causes, which are at angles having all possible directions. Some of these, particularly those at the crown of the first arch next the north transept to the westward in the nave, present evidence of having ground their surfaces together, by the oscillation of the elevated mass of the dome rocking the sub-structure.

The west end wall is fractured and split in its own thickness, and the east end of the chancel merely hangs together, a mass of dislocated fragments. The precisely cardinal position of this cathedral, and the nearly sub-normal path of the wave, all favoured the exact determination by fissures of its path. The result of my measurements produced a wave-path, (the mean of nine sets of fissures,) having a direction 92° 30' W. of north, and an emergence of 23° 7' from the west towards the east. The widest departure from the mean in these nine sets gave