Page:Great Neapolitan Earthquake of 1857.djvu/301

Rh mean = 74° 30' W. of N. Those at the former end are pretty evenly and uniformly sloped, and at an angle with the vertical = 24°, giving that for the angle of emergence of the wave-path. Some of the fissures, however, gave an angle of emergence as steep as 32° or 33°.

This indication puzzled me much. The N. and S. direction of wave-path at Naples, and on the south side of the bay, led me to expect that I should find the focus of the shock had been somewhere at sea, under the Gulf of Salerno, or that of Polycastro; and this was supported by continuing to find that the wave-path from Salerno and southwards was W. and E. more or less. I was not shaken from this hypothesis, by finding that no traces of the incoming of a roller or great sea wave had been observed anywhere along the coast from Salerno downwards; but the finding these fissures at Duchessa, leaning off towards the south and east, seemed irreconcileable with any possible position of focus that could account for the observed wave-path at Naples, inasmuch as it could alone be the result of a focus to the eastward of Duchessa, and therefore far away from intersecting any line drawn nearly north and south through Naples. I summoned my faith in induction to my aid, however, and trusted to the witness of further facts to solve the mystery.

The postmaster here, had heard a sound along with the shock: he thought it came rather before the actual oscillation, which was undulatory also. He was standing up, in the room in which he slept, and described the sound at or preceding the first shock, "Not loud but a quick sort of deep hoarse buzz"—"Roco ronzio profondo vivace, ma piccolo." He could not tell whether there was any sound with the second shock or not—"he thought there