Did no foreign causes intervene, the sea breezes would be a little southwardly of the east, that direction being perpendicular to our coast.  But within the tropics, there are winds which blow continually and strongly from the east.  This current affects the course of the air, even without the tropics.  The same cause, too, which produces a strong motion of the air, from east to west, between the tropics, to wit, the sun, exercises its influence without those limits, but more feebly, in proportion as the surface of the globe is there more obliquely presented to its rays.  This effect, though not great, is not to be neglected when the sun is in or near our summer solstice, which is the season of these easterly breezes.  The northern air, too, flowing towards the equatorial parts, to supply the vacuum made there by the ascent of their heated air, has only the small rotary motion of the polar latitudes from which it comes.  Nor does it suddenly acquire the swifter rotation of the parts into which it enters.  This gives it the effect of a motion opposed to that of the earth, that is to say, of an easterly one.  And all these causes together are known to produce currents of air in the Atlantic, varying from east to northeast, as far as the fortieth degree of latitude.  It is this current which presses our sea breeze out of its natural southeasterly direction, to an easterly, and sometimes almost a northeasterly one.

We are led naturally to ask, where the progress of our sea breezes will ultimately be stopped?  No confidence can be placed in any answer to this question.  If they should ever pass the mountainous country which separates the waters of the ocean from those of the Mississippi, there may be circumstances which might aid their further progress, as far as the Mississippi.  That mountainous country commences about two hundred miles from the sea coast, and consists of successive ranges passing from northeast to southwest, and rising the one above the other to the Allegany Ridge, which is the highest of all.  From that, lower and lower ridges succeed one another again, till having covered, in the whole, a breadth of two hundred miles from southeast to northwest, they subside into a plain, fertile country, extending four hundred miles to the Mississippi, and probably much further on the other side, towards the heads of the western waters.  When this country shall become cultivated, it will, for the reasons before explained, draw to it winds from the east and west.  In this case, should the sea breezes pass the intermediate mountains, they will rather be aided than opposed in their further progress to the Mississippi.  There are circumstances, however, which render it possible that they may not be able to pass those intermediate mountains. 1.  These mountains constitute the highest lands within the United States.  The air on them must consequently be very cold and heavy, and have a tendency to flow 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.