f the higher portion of the trade-wind was marked by
the eruption of Tuxtla, latitude 18 deg. 30', longitude 95 deg., which
covered the houses in Vera Cruz with ashes, at the distance of 80
miles north, 55 deg. west, and also at Perote, 160 miles north, 60 deg. west.
The ashes from the volcano, at St. Vincent, which fell at Barbadoes,
and east of that island, in 1812, mark the course of a current from
the westward, which appears there at times, in the region of clouds,
and may, perhaps, be connected with the permanent winds on the
Pacific coast of Mexico."

As to one of the instances cited in the foregoing paragraph, that of
Tuxtla, it may be laid out of the case--the direction conforming
substantially to the assumed course of the counter-trade at that point.
St. Vincent lies W. N. W., or nearly so, of Barbadoes, and a N. W. or
westerly surface-wind, prior to, and during storms, is common in the West
Indies as the N. E. is here--both alike, blowing in opposition to the
progressive course of the storm. There is nothing strange or peculiar,
therefore, respecting that instance, or the existence of variable and
especially S. W. currents, between the trades, with occasional partial
condensation.

The falling of the ashes from Cosiguina, upon Jamaica, has long and often
been cited, as proof that in the West Indies the prevailing upper currents
run from the S. W. But it has been ascertained that, _during the same
eruption, ashes fell 700 miles to the westward, on the deck of the
Conway_, a vessel then upon the Pacific Ocean. That case, therefore, does
not prove the absence of the S. E. counter-trade at the time, but only the
presence of another, and a different current above or below it--and it may
have been either, and transient.

So of the Jorullo instance. Investigation would probably have shown that
ashes fell to the N. W., and that they were carried N. E. by a transient
S. W. wind produced by the existence of a storm to the eastward, or one of
those states of partial condensation of the counter-trade which often
produce currents at greater distances without a storm. Not one of these
cases disproves the existence of a S. E. counter-trade, and the invariable
N. W. progression of the storms of those latitudes demonstrates it.

Occasional anomalous currents, depending upon storm action at considerable
distance, are found in our atmosphere, and doubtless are there also. Thus,
although