Strange phenomenon of earthquakes.

—Natives of those countries who have experienced many hundred earthquakes, believe the difference to be less in the greater or less duration of the shocks, or the slowness or rapidity of the horizontal oscillation, than in the alternation of motion in opposite directions.

The circular (or gyratory) earthquakes are the most rare, and at the same time the most dangerous.

In the great earthquake of Riobamba, in the province of Quito, 14th February, 1797, and in that of Calabria (5th February and 28th March, 1783,) walls were changed in direction without being overthrown, straight or parallel rows of trees were inflected, and in fields having two sorts of cultivation, one crop even took the place before occupied by the other; the latter phenomenon showing either a movement of translation, or a mutual penetration of the different strata.

When making a plan of the ruined city of Riobamba, I was shown a place where the whole furniture of one house had been found under the remains of another; earth had evidently moved like a fluid in streams or currents, of which we must assume that the direction was first downward, then horizontal, and lastly, again upward.

Disputes concerning the ownership of objects which had been thus carried to distances of many hundred yards, were decided by the audiencia or court of justice.—Humboldt’s Cosmos.