A Book of the United States. VariousЧитать онлайн книгу.
The first, commencing at its sources, and terminating at Prairie du Chien, corresponds pretty accurately to the climate between Montreal and Boston; with this difference, that the amount of snow falling in the former is much less than in the latter region. The mean temperature of a year would be something higher on the Mississippi. The vegetables raised, the time of planting, and the modes of cultivating them, would, probably, be nearly the same. Vegetation will have nearly the same progress and periodical changes. The growing of gourd seed corn, which demands an increase of temperature to bring it to maturity, is not planted in this region. The Irish potatoe is raised in this climate in the utmost perfection. Wheat and cultivated grasses succeed well. The apple and the pear tree require fostering, and southern exposure, to bring fruit in perfection. The peach tree has still more the habits and the fragile delicacy of a southern stranger, and requires a sheltered declivity, with a southern exposure, to succeed at all. Five months in the year may be said to belong to the dominion of winter. For that length of time, the cattle require shelter in the severe weather, and the still waters remain frozen.
‘The next climate includes the opposite states of Missouri and Illinois, in their whole extent, or the country between forty-one and thirty-seven degrees. Cattle, though much benefited by sheltering, and often needing it, seldom receive it. It is not so favorable for cultivated grasses, as the preceding region. Gourd seed corn is the only kind extensively planted. The winter commences with January, and ends with the second week in February. The ice, in the still waters, after that time thaws. Wheat, the inhabitant of a variety of climates, is at home, as a native, in this. The persimon and the papaw are found in its whole extent. It is the favored region of the apple, the pear, and peach tree. Snows neither fall deep, nor lie long. The Irish potato succeeds to a certain extent, but not as well, as in the former climate; and this disadvantage is supplied by the sweet potato, which, though not at home in this climate, with a little care in the cultivation, flourishes. The grandeur of vegetation, and the temperature of March and April, indicate an approach towards a southern climate.
‘The next climate extends from thirty-seven to thirty-one degrees. Below thirty-five degrees, in the rich alluvial soils, the apple tree begins to fail in bringing its fruit to perfection. We have never tasted apples worth eating, raised much below New Madrid. Cotton, between this point and thirty-three degrees, is raised, in favorable positions, for home consumption; but is seldom to be depended upon for a crop. Below thirty-three degrees commences the proper climate for cotton, and it is the staple article of cultivation. Festoons of long moss hang from the trees, and darken the forests. The palmetto gives to the low alluvial grounds a grand and striking verdure. The muscadine grape, strongly designating climate, is first found here. Laurel trees become common in the forest, retaining their foliage and their verdure through the winter. Wheat is no longer seen, as an article of cultivation. The fig tree brings its fruit to full maturity.
‘Below this climate, to the gulf, is the region of the sugar-cane and the sweet orange tree. It would be, if it were cultivated, the region of the olive. Snow is no longer seen to fall, except a few flakes in the coldest storms. The streams are never frozen. Winter is only marked by nights of white frost, and days of north-west winds, which seldom last longer than three days in succession, and are followed by south winds and warm days. The trees are generally in leaf by the middle of February, and always by the first of March. Bats are hovering in the air during the night. Fireflies are seen in the middle of February. Early in March the forests are in blossom. The margins of the creeks and streams are perfumed with the meadow pink, or honeysuckle, yellow jessamine, and other fragrant flowers. During almost every night a thunder-storm occurs. Cotton and corn are planted from March to July. In these regions the summers are uniformly hot, although there are days when the mercury rises as high in New England, as in Louisiana. The heat, however, is more uniform and sustained, commences much earlier, and continues much later. From February to September thunder-storms are common, often accompanied with severe thunder, and sometimes with gales, or tornadoes, in which the trees of the forest are prostrated in every direction, and the tract of country, which is covered with the fallen trees, is called a ‘hurricane.’ The depressing influence of the summer heat results from its long continuance, and equable and unremitting tenor, rather than from the intensity of its ardor at any given time. It must however be admitted, that at all times the unclouded radiance of the vertical sun of this climate is extremely oppressive.—Such are the summers and autumns of the southern divisions of this valley.
‘The winters, in the whole extent of the country, are variable, passing rapidly from warm to cold, and the reverse. Near the Mississippi, and where there is little to vary the general direction of the winds, they ordinarily blow three or four days from the north. In the northern and middle regions, the consequence is cold weather, frost more or less severe, and perhaps storm, with snow and sleet. During these days the rivers are covered with ice. The opposite breeze alternates. There is immediately a bland and relaxing feeling in the atmosphere. It becomes warm; and the red-birds sing in these days, in January and February, as far north as Prairie du Chien. These abrupt and frequent transitions can hardly fail to have an unfavorable influence upon health. From forty to thirty-six degrees the rivers almost invariably freeze, for a longer or shorter period, through the winter. At St. Louis on the Mississippi, and at Cincinnati on the Ohio, in nearly the same parallels, between thirty-eight and thirty-nine degrees, the two rivers are sometimes capable of being crossed on the ice for eight weeks together.
‘Although the summers over all this valley must be admitted to be hot, yet the exemption of the country from mountains and impediments to the free course of the winds, and the circumstance, that the greater proportion of the country has a surface bare of forests, and, probably, other unexplained atmospheric agents, concur to create, during the sultry months, almost a constant breeze. It thence happens, that the air on these wide prairies is rendered fresh, and the heats are tempered, in the same manner, as is felt on the ocean.’
The annual and mean quantity of rain that falls in the United States is much greater than in most countries of Europe, certain mountainous regions and heads of gulfs excepted. This has been ascertained by numerous and accurate observations made on different parts of the Atlantic coast. It is said, on the authority of tabular views, that, on a medium, one third less rain falls in Europe than in the United States; yet Dr. Holyoke mentions, in his memoir on the climate of the United States, twenty cities in Europe, which, at a mean of twenty years, have had one hundred and twenty days of rain; while Cambridge has had but eighty-eight days, Salem ninety-five days of rain, and Philadelphia seventy-six days, at a medium of twenty years. The mean annual quantity of rain at Philadelphia is very little more than the mean annual quantity at Glasgow for a term of thirty years preceding 1790. The above greater quantity of rain, in fewer days, in America, indicates the rain to be much heavier there than in Europe. On the other hand, it is equally well ascertained, that the evaporation of these rains proceeds much quicker in America than in Europe; and that, consequently, the air is habitually drier, and less calm, unless Charleston be taken as an exception. It has been found, that the mean annual quantity of evaporation at Cambridge, near Boston, was fifty-six inches, for a term of seven years; while in seven German and Italian cities, on a mean of twenty years, the annual evaporation was forty-nine inches, or seven of difference; although the Italian cities are in a much more favorable situation for evaporation than the vicinity of Boston, adjacent to the Atlantic ocean. The same fact of greater evaporation was also observed to take place in Upper Louisiana, and along the higher Missouri, as far as the Rocky Mountains, by Captain Lewis.
The habitual dryness of the American climate increases, as we advance west and north-west from the Missouri, where there frequently is not a drop of rain for six months. This is owing to the great distance from any sea, the superior elevation, and the comparative want of timber, combined with the greater intensity and longer duration of the north-west wind, which sweeps with unobstructed force over the naked plains. It appears, then, that more rain falls in fewer days, in America, than in Europe; and that there are fewer cloudy days, more fair days, and quicker evaporation. It is to this last circumstance we must ascribe those immense dews, unknown in European climates, which occur in America, and which are so copious in summer, as to resemble heavy showers of rain. But it must also be observed, that dews are comparatively unknown in the tract watered by the Upper Missouri; and which, in all probability, is owing to the want of timber, wood being limited to the banks of the rivers, which are commonly bordered with trees.