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was recorded in Part II. that the wave-paths, as traced by me at Naples and around the Bay, were at an early period found to be irreconcileable with those of the interior of the country, and appeared to come from no common origin. This apparent difficulty vanished, however, when I discovered, that the shock at and about Naples was but a secondary wave, and due to reflection and refraction, of which it affords the most striking and beautiful example: the phenomenon itself, although predicted by myself elsewhere upon à priori grounds as likely to be found, having never before (so far as I know) been observed as actually occurring, and doing so here, upon a very vast scale.

The impulse transmitted from the focal point (nearly beneath Caggiano) towards the N.W. and S.W., was obstructed, as has just been described, ''by meeting transversely the great ridges—four in, quam prox. parallel succession'', to the N.W., viz., that from Bella to Castelluccio, that from Laviano to Conturso, that from Calabrito to Eboli, and