of Arkansas and
Missouri. It seems to form a connecting link between the winds of
this zone and the south-easterly ones that we find south of it; and,
in some degree, to favor an idea that has been advanced, that there
is a vast eddy, extending from the western shore of the Gulf of
Mexico, to the eastern shore of the Atlantic; that the easterly
trade-winds of the Atlantic Ocean, when they strike the American
continent, veer northwardly, and then N. E., and thus recross the
Atlantic, and follow down the coast of Portugal and Africa, till they
complete the circuit."

This mean prevalence of the curving winds indicates the course of the
western portion of the concentrated counter-trade, of which we have so
fully spoken, and to which that portion owes its rains and fertility.
Doubtless the curve would have been traced somewhat further west, if
observations had been obtained from more westerly stations.

The idea of an eddy, to which Professor Coffin alludes, is of course
unsound; that of a counter-trade, most fully confirmed; the curve
corresponding with that of the regular rains and fertility as they are
known to exist.

Professor Coffin is a believer in the generally-received theory of
rarefaction, as the cause of all winds. His work is published by the
Smithsonian Institution, and the theory is, so far forth, nationalized.
But he found it very difficult to reconcile all the facts he obtained,
with the theory, and, possessing a truth-loving mind, he frankly admits
it. Alluding to the prevalence of N. E. winds off the coast of Africa in
the summer months, as shown by certain numbered wind-roses, he says:

"Nos. 81, 83, 86, and 91, have caused me much perplexity. The arrows
for the warmer months evidently indicate a point of rarefaction
situated to the _south_ or _south-west_, and yet all the observations
from which they were computed were taken within a few hundred miles
of the African coast and desert of Sahara; a region, the annual range
of whose temperature must be exceedingly great. The only way in which
I can account for a fact so astonishing, is, by supposing the
deflecting forces at these numbers to be secondary to the influence
which we see so strongly marked in Nos. 88, 89, and 90. Let us, then,
first devote our attention to these."

(We have not space for the map of Professor Coffin, nor is it necessary to
insert i