nison, for at this time three
considerable waves rolled in upon the town. But clearly these waves
must not be compared with those which in other instances had made
their appearance within half an hour of the earth-throes. There is
little reason to doubt that if the separate oscillations had
re-enforced each other earlier, Callao would have been completely
destroyed. As it was, a considerable amount of mischief was effected;
but the motion of the sea presently became irregular again, and so
continued until the morning of August 14th, when it began to ebb with
some regularity. But during the 14th there were occasional renewals of
the irregular motion, and several days elapsed before the regular ebb
and flow of the sea were resumed.

Such were among the phenomena presented in the region where the
earthquake itself was felt. It will be seen at once that within this
region, or rather along that portion of the sea-coast which falls
within the central region of disturbance, the true character of the
sea-wave generated by the earthquake could not be recognized. If a
rock fall from a lofty cliff into a comparatively shallow sea, the
water around the place where the rock has fallen is disturbed in an
irregular manner. The sea seems at one place to leap up and down;
elsewhere one wave seems to beat against another, and the sharpest eye
can detect no law in the motion of the seething waters. But presently,
outside the scene of disturbance, a circular wave is seen to form, and
if the motion of this wave be watched it is seen to present the most
striking contrast with the turmoil and confusion at its centre. It
sweeps onward and outward in a regular undulation. Gradually it loses
its circular figure (unless the sea-bottom happens to be unusually
level), showing that although its motion is everywhere regular, it is
not everywhere equally swift. A wave of this sort, though incomparably
vaster, swept swiftly away on every side from the scene of the great
earthquake near the Peruvian Andes. It has been calculated that the
width of this wave varied from one million to five million feet, or,
roughly, from two hundred to one thousand miles, while, when in
mid-Pacific, the length of the wave, measured along its summit in a
widely-curved path from one side to another of the great ocean,
cannot have been less than eight thousand miles.

[Illustration: OVER A LARGE PORTION OF ITS COURSE ITS PASSAGE WAS
UNNOTED.]

We cannot tell how deep-sea