Page:Great Neapolitan Earthquake of 1857.djvu/457

Rh keystone at each alternation, if already tolerably free above, by the fractures of the wall, produced at the first moment

of shock is thus moved up more or less, and finally remains at the height gained.

In this instance, the keyblock had been thus lifted up, $1 1⁄4$ inch above its former place. It is an excellent example, of one of the many cases, in which a misinterpretation of the phenomena, or misconception of the forces, &c., produces false notions as to the actual movement, of the shock productive of them. My attention was drawn to time arches, here and at Polla, by intelligent men (Syndici and Judici, &c.) as affording proof positive, of a sudden drop down, or jump up vertically, of the earth and the buildings upon it.