1822), from two to seven feet above its former level, leaving the beach
below the old low-water mark high and dry. One of the Andean peaks
upheaved on this occasion was the colossal mass of Aconcagua, which
overlooks Valparaiso, and measures nearly 24,000 feet in height. On the
same occasion, at least 10,000 square miles of country were estimated as
having been upheaved; and the upheaval was not confined to the land, but
extended far away to sea,--which was proved by the soundings off
Valparaiso and along the coast having been found considerably shallower
than they were before the shock.

In the year 1819, in an earthquake in India, in the district of Cutch,
bordering on the Indus, a tract of country more than fifty miles long
and sixteen miles broad was suddenly raised _ten feet_ above its former
level. The raised portion still stands up above the unraised, like a
long perpendicular rampart, known by the name of Ullah Bund, or God's
Wall.

* * * * *

With a similar fertility of illustration, Herschel sets before us the
phenomena of volcanic eruptions and their extraordinary effects.

In a district of Mexico, between the two streams of the Cintimba and the
San Pedro, on the 28th of September 1789, a whole tract of ground, from
three to four miles in extent, surged up like a foam-bubble, or the
swell of a wave, to a height of upwards of 500 feet. Flames, lurid and
crackling, broke forth over a surface of more than half a square league;
and the earth, as if softened by heat, was seen to rise and sink like
the rolling tide. Vast chasms opened in the earth, into which the two
rivers poured their waters headlong; reappearing afterwards at no great