both to the east and west. 2.
Ranging across the current of the sea breezes, they are in themselves,
so many successive barriers opposed to their progress. 3. The country
they occupy is covered with trees, which assist to weaken and spend
the force of the breezes. 4. It will remain so covered; a very small
proportion of it being capable of culture. 5. The temperature of its
air, then, will never be softened by culture.

Whether in the plain country between the Mississippi and Allegany
mountains, easterly or westerly winds prevail at present, I am not
informed. I conjecture, however, that they must be westerly: and I
think with you, Sir, that if those mountains were to subside into
plain country, as their opposition to the westerly winds would then be
removed, they would repress more powerfully those from the east, and of
course would remove the line of equilibrium nearer to the sea coast for
the present.

Having had occasion to mention the course of the tropical winds from
east to west, I will add some observations connected with them. They are
known to occasion a strong current in the ocean, in the same direction.
This current breaks on that wedge of land of which Saint Roque is the
point; the southern column of it probably turning off and washing the
coast of Brazil. I say probably, because I have never heard the fact,
and conjecture it from reason only. The northern column, having its
western motion diverted towards the north, and reinforced by the
currents of the great rivers Orinoko, Amazons, and Tocantin, has
probably been the agent which formed the Gulf of Mexico, cutting the
American continent nearly in two, in that part. It re-issues into the
ocean at the northern end of the Gulf, and passes by the name of the
Gulf Stream, all along the coast of the United States, to its northern
extremity. There it turns off eastwardly, having formed by its eddy, at
this turn, the Banks of Newfoundland. Through the whole of its course,
from the Gulf to the Banks, it retains a very sensible warmth. The
Spaniards are, at this time, desirous of trading to their Philippine
Islands, by the way of the Cape of Good Hope: but opposed in it by the
Dutch, under authority of the treaty of Munster, they are examining the
practicability of a common passage through the Straits of Magellan, or
round Cape Horn. Were they to make an opening through the Isthmus of
Panama, a work much less difficult than some even of the inferior canals
of Fr