The extensive ruins in Melfi, the evident signs of strong pulsatory shocks, the fissures and rents in the ground, and the subterraneous noise which always accompanied the shocks (sometimes preceding them, sometimes simultaneously with them) prove that this city, as we have already affirmed, was the centre of the terrible phenomenon; and all who at the moment of the earthquake chanced to be in the open country agree in stating that they observed the country houses fall one after the other, according to their distance from Melfi. But if Melfi must be considered the physical centre of the earthquake, it does not equally represent the geometrical centre of the afiected region, on which subject we have some important observations to bring forward. In the first place, the earthquake was felt with more intensity on the volcanic formations. Consequently Ginestra and Ripacandida suffered incomparably less injury than Barieli and Rionero; and yet the last town is in a direct line, furtlier from Melfi than Ginestra. Secondly. The impetus of the earthquake decreased rapidly when it came in contact with the Apennine limestone, and extended more on the hills of sub-Apennine rock and Macigno formation, on which the towns of Venosa and Lavello on one side, Monteverde and Carbonara on the other, are built, than over the plains of Puglia. As you approach the summit of the Apennines, looking for the villages and towns that are built on the compact limestone formation, you soon perceive, from the houses, that some power must reside in these mountains to weaken the earthquake, or resist its influence. Lastly, Ruvo and St. Fele are distant from Melfi in a direct line, the same as, or even less, than Ascoli, and yet this place suffered much, while the former towns show no trace of the earthquake, except the terror of their inhabitants. And to look at St. Fele, perched on a rock or steep ascent, you are inclined to judge that at the slightest motion it must be precipitated into the ravine below. Thus, too, Calitri, Bisaccia, Maschito, Fiorenza, Avigliano, and Muro, built on the inclination of precipices, were untouched, or nearly so, in comparison with Ascoli, Candela, and Canosa, which were greatly injured. But without multiplying instances of this kind, we shall enable the reader to judge for himself, by showing how the towns may be classed with regard to the intensity of the earthquake, so
