CHAPTER XVIII.
SECONDARY EFFECTS PRODUCED BY THE PASSAGE OF THE SHOCK.
These, as observed in the present earthquake, have been of three classes—1. Landslips and earth fissures; 2. Rock fissures and shattering falls of rock; 3. Alterations of water courses, which are only a consequence, of one or both of the two former.
Fissures were found formed in the earth, at Auletta, at Brienza, (where a fissure crossed the market-place at the top of the town,) at Carlotta D'Isca, near Bella, at Campostrina Road, at Vietri di Potenza, at Atena, and near Polla. In all these cases, the widths of the lips of the fissure at the surface was small, not exceeding a few inches, (unless when accompanied, as at Carlotta D'Isca, with active landslip,) and the depth was not traceable even when just after the fissure had been opened, beyond a very few feet. The directions of the lengths (which were often considerable) of the fissures, was always more or less transverse to the wave-path, but also always had reference to the slope of the rock, subjacent to the fissured earth; the tendency being for the fissure to run along, more or less parallel to the strike, of the subjacent rock surface. So that, in general, the lengthway of the earth fissure, runs in a direc-
