eruptions and continental elevations. In that paper I notice a very
remarkable coincidence in volcanic eruptions in S. America at very distant
places. I have also drawn up some short tables showing, as it appears to
me, that there are periods of unusually great volcanic activity affecting
large portions of S. America. I have no record of any coincidences between
shocks there and in Europe. Humboldt, by his table in the "Pers.
Narrative" (Volume IV., page 36, English Translation), seems to consider
the elevation of Sabrina off the Azores as connected with S. American
subterranean activity: this connection appears to be exceedingly vague. I
have during the past year seen it stated that a severe shock in the
northern parts of S. America coincided with one in Kamstchatka. Believing,
then, that such coincidences are purely accidental, I neglected to take a
note of the reference; but I believe the statement was somewhere in
"L'Institut" for 1839. (479/2. "L'Institut, Journal General des Societes
et Travaux Scientifiques de la France et de l'Etranger," Tome VIII. page
412, Paris, 1840. In a note on some earthquakes in the province Maurienne
it is stated that they occurred during a change in the weather, and at
times when a south wind followed a north wind, etc.) I was myself anxious
to see the list of the 1200 shocks alluded to by you, but I have not been
able to find out that the list has been published. With respect to any
coincidences you may discover between shocks in S. America and Europe, let
me venture to suggest to you that it is probably a quite accurate statement
that scarcely one hour in the year elapses in S. America without an
accompanying shock in some part of that large continent. There are many
regions in which earthquakes take place every three and four days; and
after the severer shocks the ground trembles almost half-hourly for months.
If, therefore, you had a list of the earthquakes of two or three of these
districts, it is almost certain that some of them would coincide with those
in Scotland, without any other connection than mere chance.