levation of the ground above its primitive level,
or that of the surrounding plain, is no more than thirty-seven
feet; but towards the centre of the lifted district, the total
elevation is not less than five hundred feet.

"This phenomenon had been preceded by earthquakes that lasted
nearly two months; but when the catastrophe occurred, all
seemed tranquil; it was announced only by a horrible
subterranean noise, that took place at the moment when the
ground was lifted. Thousands of little cones, of from six to
ten feet in height, called by the natives ovens, arose in every
direction; finally six great projections were suddenly formed
along a great crevice lying in a north-east and south-west
direction, all of which were elevated from 1200 to 1600 feet
above the adjacent plains. The greatest of these small
mountains has become a true volcano, that of _Jorullo_, and
vomits forth lava.

"It will be seen that the most evident and well characterized
volcanic phenomena accompanied the catastrophe of Jorullo; that
they were perhaps its cause; but this did not prevent an
extensive plain, old and well consolidated, upon which the
sugar-cane and indigo were cultivated, from being, in our own
days, suddenly raised far above its primitive level. The escape
of inflamed matter, the formation of the ovens and of the
volcano of Jorullo, far from having contributed to produce this
effect, must on the contrary have lessened it; for all these
openings must have acted like safety valves, and permitted the
elevating cause to have dissipated itself, whether it were a
gas or a vapour. If the ground had opposed a greater
resistance; if it had not given way in so many points, the
plain of Jorullo, instead of becoming a simple hill five
hundred feet in height, might have acquired the relief of the
neighbouring summits of the Cordilleras.

"The circumstances that attended the formation of a new island
near Santorin, in the Greek Archipelago, seem to me also well
fitted to prove that subterranean fires not only contribute to
elevate mountains by the aid of ejections furnished by the
craters of volcanoes, but that they also sometimes lift the
already consolidated crust of the globe.

"On the 18th and 22d May 1707, there were slight shocks of an
earthq