Εικόνες σελίδας
Ηλεκτρ. έκδοση



Upon looking at the map of the Upper Mississippi, we have before us that very extensive net of streams and rivers which is bounded in the west, below the junction of the Ohio and Mississippi, by the Ozark Mountains, through which the Arkansas and Red Rivers have forced their passage; and in the east, by the projecting ridge of the Alleghany Mountains. High lands, elevated 2000 feet above the level of the sea, divide this district in the north from the Arctic river-district, together with which it was undoubtedly covered by a vast sheet of water, at an early period of the formation of the earth; the bills separating it from Lake Superior, which is situated 600 feet above the level of the sea, do not rise more than 1000 feet above it, and the boundary line dividing it from the river-district of the St. Lawrence, runs along the shores of the other great lakes. No chain of mountains, therefore, properly speaking, separates in the north this enormous territory, a small portion of which constitutes the State of Illinois, from the plateaux projecting to the north, which circumstance must necessarily exercise a decisive influence upon the climate of the State, situated as it is between the 430 and 37th degrees of north latitude, and separated by seven degrees from the Gulf of Mexico.

* Dr. Fred. Brendel, of Peoria, to whom we are indebted for many valuable contributions to this chapter, has for several years pursued with great zeal the study of the natural history of Illinois, and would be very happy, could he meet with fellow-laborers in this work; for which reason we take the liberty of calling the attention of those of our readers, who take an interest in Natural Sciences, to the following lines :

“A thorough examination of such an extensive State as Illinois, with respect to all the various branches of natural science, is a difficult undertaking for a single man, but might be easily accomplished by a number of scientific men, co-operating in the different parts of the country. Meteorological observations, catalogues of the plants, animals, and petrifactions found in the various districts, it would be advisable to publish in one annual collective report; specimens contributed from every district would form a State Museum; and naturalists, residing at distances from each other, would much more enhance and accelerate the advancement of knowledge by mutual correspondence, than by pursuing separate studies, each one for himself. Any person who is willing thus to promote the interests of science, will find me ready to assist him."

FREDERICK BRENDEL, M. D., Peoria, Illinois.


A sea open at all times of the year separates Europe from the North Pole; and the Mediterranean Sea washes between it and Africa; this will sufficiently account for her moderate climate. A frozen region sending during winter its icy blasts after the flying sun, bounds North America on the north, while her southern coast, penetrated in the sum. mer by the almost perpendicular rays of a burning sun, radiates its accumulated heat to the north. This will explain why a country situated within the same degrees of latitude with Spain and Italy, has cold winters and hot summers.

Illinois has an average temperature, which, if compared with that of Europe, equals that of Middle Germany; its winter is more severe than that at Copenhagen, and her summer as warm as those of Milan or Palermo. Compared with the other States of the Union, Northern Illinois

possesses a temperature similar to that of Northern Pennsylvania or Southern New York, while the temperature of Southern Illi. inois will not differ much from that of Kentucky or Virginia.

As far as we know, exact observations of the state of the weather have not yet been published in Illinois; we, therefore, confine ourselves to the observations of the celebrated Dr. Engelmann, at St. Louis, which at least serve for one part of Illinois. From his observations of 20 years we infer, that at a middle height of the barometer, of 29.477, (105' above the lowest height of water in the Mississippi), the greatest difference in

year (1852) amounted to 1" 5'', and that at a middle temperature of + 51° 8 F.(= + 13° 79 C. = + 10° 13 R.), very great fluctuations prevailed.

At the coldest day, (Feb. 8, 1835,) the thermometer stood · 25° F. (= -31° 6 C. - 25o 3 R.), while during the hottest days in July, 1833, '34, '38, and '41, and in August, 1834, the mercury indicated a little more than + 100° F., (= + 38° C. + 30° R.), making a difference of 125° F., (=69° 4 C. = 55° 5 R.) Very great and rapid changes often take place in the temperature; thus, the

temperature from the 16th to the 17th day of March, 1852, fell, within 17 hours, about 51° F., (=28° 3 C. 22° 5 R.) As for the rest, the thermometer very rarely falls below 0 F. (= - 17° 7 C. 14° 2 R.); on Jan. 19th, 1852,* the coldest day for 20 consecutive years, the mercury ranged - 12° F. (= -- 24° 4C. =-19° 5 R.) The lowest temperature is generally above 0 F., and on an average ranges highest in July; then follow June and August; January being the coldest month. The first frost generally appears on the 26th of October, the last on the 6th of April, 203 days thus intervening between the first frost in autumn and the last in spring. The earliest frost appeared on Oct. 4th, 1836, and the latest, May 2d, 1851.†

The prevailing winds are either western or south-eastern. Storms generally come from the west or north-west, in the summer sometimes from the south. The sererest storms are those coming from the west, as, on considering that they traverse the entire space between the. Rocky Mountains and the Mississippi, within 24 hours, and reach the Atlantic coast within the next 24 hours, will be placed beyond a doubt. A clear sky and dry air prevail while they sweep over the Mississippi Valley, and not before having reached the east, will they be accompa

* The winter of 1855–6 alone, which reigned with almost unexampled rigour throughout the United States, makes an exception; we here subjoin a report of the state of the thermometer on the coldest days of the winter, in the folowing places in Illinois :

On January 4th, 1856, at Aurora, Kane Co., 22 degrees below zero; at Sterling, Whiteside Co., 26°; at Dixon, Lee Co., 23°; at Sycamore, De Kalb Co., 24°; at Waukegan, Lake Co., 21°; at Moline, Rock Island Co., 18o. On January 5th, at Elgin, Kane Co., 26°; at Moline, 14°; January 6th, at Moline, 30°; January 8th, at Sterling, 21°; at Springfield, Sangamon Co., 20°; at Rock Island, 22° ; -et. Bloomington, McLean Co., 18°; at Belvidere, Boone Co., 22°; at Macomb, McDonough Co., 17°; at Elgin, 18°; at Moline, 20°; at Oquawka, Henderson Co., 250; at Peoria, 14°. January 9th, at Springfield, 24°; at Chicago, 24°; Alton, Madison Co., 22°; at Aurora, 30°; at Geneseo, Henry Co., 29°; at Jerseyville, Jersey Co., 20°; at Macomb, 20°; at Mendota, La Salle Co., 28°; at Monmouth, Warren Co., 28°; at Morris, Grundy Co., 20°; at Paris, Edgar Co., 30°; at Peoria, 20°; and at Sterling, 21°.

† In the summer of 1850, while the temperature of St. Louis ranged very high, that of St. Clair Co. was continually lower, by about 2o R., than the former, which difference was probably in consequence of the calcareous soil of

the city.

nied with heavy showers of rain; which latter fact we may account for by the condensation of the vapours abstracted by them from the Mississippi Valley, coming in contact with the Alleghany Mountains.

Rainy days there were in 1838 but 78; in 1836, however, 115; there are, on an average, 89 in every year, with a quantity of rain amounting to 42 inches, the smallest portion of which (2") falls in Japuary; the quantity of rain falling increasing with every succeeding month, until in June it reaches the height of 6". More than 4 inches of rain fell within 24 hours, June 23, 1852.

The first fall of snow generally takes place in November, often, however, not before December; the last, in March, it occurring but very rarely in April. The greatest quantity of snow which fell in a single month, (December, 1839, and December, 1846,) amounted to scarcely 1” 5. Thunderstorms there were on an average 49; beautiful days, 137 ; changeable days, 180; days without sunshine, 45.

Upon comparing these results with the observations made in 1852, in Wisconsin, at eight different places, the observation made at one of which, to wit, at Beloit, near the Illinoisian frontier, half way

between the Mississippi and Lake Michigan, may be considered as valid for the northern part of Illinois also; we find the thermometer ranging between 29.597 and 28.665, being a difference of 0.932, while in the south the same amounted to 1.584; an average temperature reigns there of + 47° 421 F.(= +8° 10.= +6° 5 R.), being 7° 1 F. (= 4° C. = 3° 1 R.) less than in the south. On the coldest day the mer. cury indicated — 18° F. (= -27° 7 C. - 22° 1 R.), and therefore 6° F., (= 3o 3 C. 2° 6 R.) less than at the south; and on the hottest day + 93° F. (= + 34° C. = + 27°R.) and therefore only 2° F. (= 1° 10. 0° 9 R.) less than in the south. Here we must remark that the winter at that place was unusually cold. It rained 40 inches, 2 inches less than at the south, which difference, as already observed, was created by a single day's rain. The prevailing winds were north-west by north, and south-west.

From the direction of its hills and rivers, which generally run from north-east to south-west, a plain forms, gently sloping to the southwest; in this plain the rivers have worn channels from 60 to 200 feet deep; being dammed up at one side by a terrace-like, rising bank, they inundate the opposite plain to a considerable depth, overflowing it from winter to summer, and producing a luxuriant growth of grass; causing also the intermittent fever, the principal sickness of the country, which, however, only seizes the incautious settler, at places near the river; and never, except in very rainy years, visits the settlers on the ocean-like, undulating prairies.*

That the channels have gradually sunken we may distinctly see, on the shores of the Upper Mississippi, walls of rock rising perpendicularly, upon the sloping banks of which extend from Lake Pepin to below the junction of the Wisconsin with the Mississippi, as if they were walls built of equal height by the hand of men. Wherever the river describes a curve, walls may be found on the convex side of the latter. Here, the force of the river, ere it had yet excavated its channel, was broken, and the river, tired of being resisted, turned against the other side; not, however, without causing some damage to the rock which it washed; just as at the present day the river may

be seen undermining its steep, rocky bank, above and below St. Paul, in Minnesota.

The upper coal formation occupies three-fifths of the State; commencing at 41° 12' north latitude, where, as also along the Mississippi, whose banks it touches between the places of junction of the Illinois and Missouri Rivers, it is enclosed by a narrow layer of calcareous coal. This immense coal-field extends south-easterly beyond the Wabash and Ohio Rivers, far into the States of Kentucky and Ohio. The shores of Lake Michigan, and that narrow strip of land, which, commencing near them, runs along the northern bank of the Illinois, towards its south-western bend, until it meets Rock River, at its junction with the Mississippi, belongs to the Devonian system; the residue of the northern territory consists of Silurian strata, which, containing the rich lead mines of Galena, in the north-western corner of the State, rise at intervals in conical hills, thus giving the landscape a character different from that of the middle or southern portion of the State.

Over these various geological formations, underlaid at intervals by beds of sand, a process of putrefaction, which, for thousands of years

* The attention of those readers wishing more minute information regarding the state of health in Illinois, is called to the chapter treating of that subject in particular.

« ΠροηγούμενηΣυνέχεια »