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51°, giving a difference of 14°. * According to the meteorological observations of Mr Dunbar, in the summer of 1800, the thermometer, in north latitude, 31° 28', and longitude 91° 33' west of Greenwich, four miles east of the river Mississippi, rose often to 96 and 97°, and under the shade of trees to 91°. This gentleman has furnished a table of the greatest and least degree of heat, for every month of different years. t We copy that of 1802. January, 79° greatest, 27° least temperature. February, 78°-24°. March, 82°-35°. April, 88-52°. May, 92° 47°. June, 93°-62°. July, 93°-62°. August, 92°-61°. September, 98°-45°. October, 90°-32°. November, 80°—28°. December, 70°-26°. In July there are heavy rains and thunder, and the heat is then at its maximum; but it continues without much diminution till the close of September, the thermometer ranging between 80° and 87°, and sometimes rising above 90°. The most unhealthy months are August and September, when the miasma exhaled from decaying animal and vegetable matters are most abundant, and most injurious to the human frame. At this season bilious disorders prevail, especially in new settlements. Amore familiar idea of the climate of this country may be derived from the

See Ellicot's Journal. According to Mr Darby, the mean temperature of spring water is 52°. See his Geographical Description, &c. p. 233.

+ See No. 30 of the 6th volume of the Philosophical Transactions of Philadelphia.

About the

developement of its vegetable productions. 1st of February peach and plum trees, peas, and strawberries, are in blossom. About the 1st of March, the trees generally are in leaf, or in blossom. Peas are ripe towards the middle of June, and the earlier fruit before the close of July. Spring regularly commences with southern breezes, the warmth of which is so favourable to vegetation, that it is here more advanced in April than in May, in the northern states. Hurricanes were experienced in 1780 and 1794, in the month of August. The wind blew with violence during twelve hours, and so retarded the current of the Mississippi, that it overflowed its banks, and inundated the country from two to ten feet, as high as the English turn. These storms were accompa nied with thunder, and with hailstones of uncommon size. * In 1802 the engineer who directed the works of Fort Plaquemines, situated at the distance of twelve or thirteen leagues from the sea, was drowned in his cabin, by a sudden rising of the waters. The workmen and garrison found refuge in the most elevated part of the fort, where there was from two to three feet water.

Rivers of Louisiana :

* Dupratz states, that some which fell in 1737 were as large as a hen's egg.

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This plan, which exhibits the course of the Mississippi, from the junction of Red river to the sea, will illustrate the position of the various outlets and streams connected with it; which, in the lower part of its course, are so numerous, and so interlocked with each other, as not to be easily understood. It is necessary to explain, that the Mississippi, below Red river, and most of the other streams in the Delta, flow on the top of ridges, their waters being higher than the country immediately beyond their banks. It will be observed, accordingly, that very few of them receive any tributary streams in the space which the plan includes. On the contrary, they generally send off part of their waters by lateral courses, some of which (though rarely) return again into the parent stream lower down, while others find their way to the sea, sending off other lateral branches as they advance, and forming lakes where they meet with considerable hollows. All the streams between Teche river, on the south-west, and the lakes Maurepas and Ponchartrain, on the north-east, derive their waters from the Mississippi, either directly, by openings in its banks, or indirectly, from the moisture it diffuses

through the subjacent soil; and all the country in cluded between these limits, and extending in a transverse direction to the north-west and south-east angles of the plan, is subject to inundation, from the annual swell of the river, except where it is protected by artificial embankments, or, in a few places, by the natural elevation of the soil. This alluvial tract forms the proper Delta of the Mississippi. Its length, in a north-east and south-west direction, is above 200 miles, its breadth about 100. Its surface is almost an unvaried level; and eastward of the Lafourche it is generally a morass, of the same height as the tidewater, except on the banks of the river. Of the outlets of the Mississippi, included in this space, the Atchafalaya, the Lafourche, and the Ibberville, are the most considerable. Others are channels which are filled during the overflow, and during the season of low water are dry; while a considerable number serve as drains to carry off the surcharge of moisture from the soil, deeply impregnated with water. It will be observed also, that there are numerous cross courses and interlocking channels between these streams, which run into one another like net-work, and divide the surface of the country into numerous islands. In many of these channels, near the sea, there is no visible current, during the dry season; and at this period the tide reaches up the Atchafalaya river and the Bayou Plaquemines, within five miles of the Mississippi on the one side, and up Ibberville, within nine miles of it on the other. The Red river, and the upper parts of the channel of the Mississippi, as far as the Ohio, have also an annual

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