ce in the courses of stone on
either side of the rent.

[Illustration: Fig. 77.

Shift or "fault" in the Round Tower of Terranuova in Calabria,
occasioned by the earthquake of 1783.]

Dolomieu saw a stone well in the convent of the Augustins at Terranuova,
which had the appearance of having been driven out of the earth. It
resembled a small tower eight or nine feet in height, and a little
inclined. This effect, he says, was produced by the consolidation and
consequent sinking of the sandy soil in which the well was dug.

In some walls which had been thrown down, or violently shaken, in
Monteleone, the separate stones were parted from the mortar, so as to
leave an exact mould where they had rested; whereas in other cases the
mortar was ground to dust between the stones.

It appears that the wave-like motions often produced effects of the most
capricious kind. Thus, in some streets of Monteleone, every house was
thrown down but one; in others, all but two; and the buildings which
were spared were often scarcely in the least degree injured. In many
cities of Calabria, all the most solid buildings were thrown down, while
those which were slightly built escaped; but at Rosarno, as also at
Messina in Sicily, it was precisely the reverse, the massive edifices
being the only ones that stood.

_Fissures._--It appears evident that a great part of the rending and
fissuring of the ground was the effect of a violent motion from below
upwards; and in a multitude of cases where the rents and chasms opened
and closed alternately, we must suppose that the earth was by turns
heaved up, and then let fall again.[670] We may conceive the same effect
to be produced on a small scale, if, by some mechanical force, a
pavement composed of large flags of stone should be raised up, and then
allowed to fall suddenly, so as to resume its original position. If any
small pebbles happened to be lying on the line of contact of two flags,
they would fall into the opening when the pavement rose, and be
swallowed up, so that no trace of them would appear after the subsidence
of the stones. In the same manner, when the earth was upheaved, large
houses, trees, cattle, and men were engulfed in an instant in chasms and
fissures; and when the ground sank down again, the earth closed upon
them, so that no vestige of them was discoverable on the surface. In
many instances, individuals were swallowed up by one shock, and then
thrown out again alive, togethe