Page:Great Neapolitan Earthquake of 1857 Vol 2.djvu/318

Rh thus —·—·—·—·. This is the meizoseismal area, within which the greater portion of the cities and towns were perfectly prostrated; they are marked by black dots thus.

The first isoseismal outside the last is marked thus ..........and defines the boundary of the space within which, large portions of the cities and towns were thrown down, and persons killed and wounded by their fall, as in the preceding. All such towns are marked thus .....

The second isoseismal, the last marked upon the Maps A and B, is defined thus ......, and marks the boundary of the space within which, the effort was chiefly limited to the production of fissures, and slight dislodgments in the buildings, and in which no loss of life occurred. The towns within this area are distinguished thus ....

Lastly, upon the Map C (as the large scale of A and B did not admit of it) I have marked the third isoseismal thus ......., being the boundary of the area at which the shock was perceived at all by the unassisted senses, and all the towns, &c., at which it was observed are marked thus ..... so far as such are shown on Maps A and B. Beyond this, a portion of a fourth isoseismal is marked in Map C by a dotted line thus —......., being the probable boundary at which the wave was sensible, even to the instrumental delicacy as a seismometer, of Padre Secchi's floating barometer at Rome. Within the meizoseismal, and first isoseismal, a few towns will be observed marked thus .... in place of thus ...., and between the first and second isoseismals a few will be found marked thus ....; to these I shall refer again, when remarking on the eflfects of physical configuration, &c. In the Map B the principal mountain ranges, with the river courses, constituting the chief