,
instead of being modified and enlarged. Every stream might in that case
be compelled to begin its operations anew, and to shape out new
channels, instead of continuing to deepen and widen those already
excavated. But if the subterranean movements have been intermittent, and
if sufficient periods have always intervened between the severer shocks
to allow the drainage of the country to be nearly restored to its
original state, then are both the kind and degree of force supplied by
which running water may hollow out valleys of any depth or size
consistent with the elevation above the sea which the districts drained
by them may have attained.

When we read of the drying up and desertion of the channels of rivers,
the accounts most frequently refer to their deflection into some other
part of the same alluvial plain, perhaps several miles distant. Under
certain circumstances a change of level may undoubtedly force the water
to flow over into some distinct hydrographical basin; but even then it
will fall immediately into some other system of valleys already formed.

We learn from history that, ever since the first Greek colonists settled
in Calabria, that region has been subject to devastation by earthquakes;
and, for the last century and a half, ten years have seldom elapsed
without a shock; but the severer convulsions have not only been
separated by intervals of twenty, fifty, or one hundred years, but have
not affected precisely the same points when they recurred. Thus the
earthquake of 1783, although confined within the same geographical
limits as that of 1638, and not very inferior in violence, visited,
according to Grimaldi, very different districts. The points where the
local intensity of the force is developed being thus perpetually varied,
more time is allowed for the removal of separate mountain masses thrown
into river-channels by each shock.

_Number of persons who perished during the earthquake._--The number of
persons who perished during the earthquake in the two Calabrias and
Sicily, is estimated by Hamilton at about forty thousand; and about
twenty thousand more died by epidemics, which were caused by
insufficient nourishment, exposure to the atmosphere, and malaria,
arising from the new stagnant lakes and pools.

By far the greater number were buried under the ruins of their houses;
but many were burnt to death in the conflagrations which almost
invariably followed the shocks. These fires raged the more