g movement, which lasted four minutes. The same shock was
felt over a tract of 170 leagues from south to north, from Piura to
Popayan; and 140 from west to east, from the sea to the river Napo. In
the smaller district first mentioned, where the movement was more
intense, every town was levelled to the ground; and Riobamba, Quero, and
other places, were buried under masses detached from the mountains. At
the foot of Tunguragua the earth was rent open in several places; and
streams of water and fetid mud, called "moya," poured out, overflowing
and wasting every thing. In valleys 1000 feet broad, the water of these
floods reached to the height of 600 feet; and the mud deposit barred up
the course of the river, so as to form lakes, which in some places
continued for more than eighty days. Flames and suffocating vapors
escaped from the lake Quilotoa, and killed all the cattle on its shores.
The shocks continued all February and March; and on the 5th of April
they recurred with almost as much violence as at first. We are told that
the form of the surface in the district most shaken was entirely
altered, but no exact measurements are given whereby we may estimate the
degree of elevation or subsidence.[657] Indeed it would be difficult,
except in the immediate neighborhood of the sea, to obtain any certain
standard of comparison if the levels were really as much altered as the
narrations imply.

_Cumana_, 1797.--In the same year, on the 14th of December, the small
Antilles experienced subterranean movements, and four-fifths of the town
of Cumana was shaken down by a vertical shock. The form of the shoal of
Mornerouge, at the mouth of the river Bourdones, was changed by an
upheaving of the ground.[658]

_Canada--Quebec_, 1791.--We learn from Captain Bayfield's memoirs, that
earthquakes are very frequent on the shore of the estuary of the St.
Lawrence, of force sufficient at times to split walls and throw down
chimneys. Such were the effects experienced in December, 1721, in St.
Paul's Bay, about fifty miles N. E. from Quebec; and the inhabitants
say, that about every twenty-five years a violent earthquake returns,
which lasts forty days. In the History of Canada, it is stated that, in
1663, a tremendous convulsion lasted six months, extending from Quebec
to Tadeausac,--a distance of about 130 miles. The ice on the river was
broken up, and many landslips caused.[659]

_Caraccas_, 1790.--In the Caraccas, near where the Caura joi