Page:Great Neapolitan Earthquake of 1857 Vol 2.djvu/349

284 The other wave-paths observed at La Cava and Salerno, in directions due east and west, were obviously the residual impulse, of the direct wave; obstracted by the north and south transverse ranges, north of Eboli, and at last transmitted in part, from the last of these, that between Montella, and a point two or three geographical miles west of Eboli.

We have now accounted for all the directions, of these secondary wave-paths; and it only remains to make a few remarks upon the peculiar forms of the isoseismals of reflection and of refraction to the north and south of the range. The local centre of effort in this separate system, was necessarily, at a point in the axis of the range, mid-way between Nocera and Minori, for this was about the place at which the full and unobstructed effort of the direct wave, arriving obliquely at the range, impinged upon it; hence, we should find the longest wave-paths diverging from this point to the northward, and the isoseismal where broadest opposite this: it is so in fact.

The greatest amount of destruction happened in the towns of the Terra di Lavoro, in and about Nola, and the line north of it. But the most striking and confirmatory fact, as to these complex wave phenomena, here, is to be found in Capri Island having escaped, (Part II.) without even having been conscious of any shock. Looking at the maps, and observing the wave-paths, and the forms of the isoseismals to the north and south of the range, it is obvious that Capri stands in a position where the energy of such of the waves as could reach it at all, would be the least possible; and where it is extremely probable, that by mutual interference, they destroyed each other totally. The local wave