enormous bank of tufa through which the tunnel has been cut. I found their direction to be such, as indicated distinctly a wave-path and direction, of between N. 20° W. and N. 38° W. The last extreme appeared to me doubtful, and as only derived from one cleft. I am disposed to adopt the former azimuth only.
Upon the whole, the indications of wave-path at Naples are meagre, though not indistinct, nor discordant. They vary between the limits of N. 13° E. and N. 20° W., or, omitting Pausillipo wholly, vary between N. 6° E. and N. 13° E., and comparing all the indications, seem to give a resultant path of, N. 6° to 8° E. as the most trustworthy.
This appeared to point to a focus somewhere at sea, beneath the gulfs of Salerno, or Polycastre, a first impression that became not a little puzzling, when brought into contact with the facts, as they developed themselves in the interior provinces, and at first, for a day or two, almost caused me to despair of being able to trace out the true focus at all, the fresh evidence as collected appearing to be quite conflicting; and it was not until after I had found reiterated proofs of an inland focus, that could not connect itself directly with Naples, that the solution of the difficulty began to appear, in showing the shock at Naples city, to have been merely a reflected and refracted one.
