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bonate of lime, previously existing there; in which cases the gypsum is of course not an original deposit as the great one at Fort Dodge is supposed to be.

The existence of these comparatively minute quantities of gypsum in the shales of the coal measures and the subcarboniferous limestone which are exposed within the region of and occupy a stratigraphical position beneath the great gypsum deposits, suggests the possibility that the former may have originated as a precipitate from percolating waters, holding gypsum in solution which they had derived from that deposit in passing over or through it. Since, however, the same substance is found in similar small quantities and under similar conditions in regions where they could have had no possible connection with that deposit, it is believed that none of those mentioned have necessarily originated from it, not even those that are found in close proximity to it.

The gypsum found in the lead caves is usually in the form of efflorescent fibers, and is always in small quantity. In the lower coal-measure shale near Fort Dodge, a small mass was found in the form of an intercalated layer, which had a distinct fibrous structure, the fibers being perpendicular to the plane of the layer. The same mass had also distinct, horizontal planes of cleavage at right angles with the perpendicular fibers. Thus, being more or less transparent, the mass combined the characters of both fibrous gypsum and selenite. No anhydrous sulphate of lime (anhydrite) has been found in connection with the great gypsum deposit, nor elsewhere in Iowa, so far as yet known.

SULPHATE OF STRONTIA.

(Celestine.)

The only locality at which this interesting mineral has yet been found in Iowa, or, so far as is known, in the great valley of the Mississippi, is at Fort Dodge. It occurs there in very small quantity in both the shales of the lower coal measures and in the clays that overlie the gypsum deposit, and which are regarded as of the same age with it. The first is just below the city, near Rees' coal bank, and occurs as a layer intercalated among the coal measure shales, amounting in quantity to only a few hundred pounds' weight. The mineral is fibrous and crystalline, the fibers being perpendicular to the plane of the layer. Breaking also with more or less distinct horizontal planes of cleavage, it resembles, in physical character, the layer of fibro-crystalline gypsum before mentioned. Its color is light blue, is transparent and shows crystaline facets upon both the upper and under surfaces of the layer; those of the upper surface being smallest and most numerous. It breaks up readily into small masses along the lines of the perpendicular fibers or columns. The layer is probably not more than a rod in extent in any direction and about three inches in maximum thickness. Apparent lines of stratification occur in it, corresponding with those of the shales which imbed it.

The other deposit was still smaller in amount, and occurred as a mass of crystals imbedded in the clays that overlie the gypsum at Cummins' quarry in

the valley of Soldier Creek, upon the north side of the town. The mineral is in this case nearly colorless, and but for the form of the separate crystals would closely resemble masses of impure salt. The crystals are so closely aggregated that they enclose but little impurity in the mass, but in almost all cases their fundamental forms are obscured. This mineral has almost no real practical value, and its occurrence, as described, is interesting only as a mineralogical fact.

SULPHATE OF BARYTA.

(Barytes, Heavy Spar.)

This mineral has been found only in minute quantities in Iowa. It has been detected in the coal-measure shales of Decatur, Madison and Marion Counties, the Devonian limestone of Johnson and Bremer Counties and in the lead caves of Dubuque. In all these cases, it is in the form of crystals or small crystalline masses.

SULPHATE OF MAGNESIA.

(Epsomite.)

Epsomite, or native epsom salts, having been discovered near Burlington, we have thus recognized in Iowa all the sulphates of the alkaline earths of natural origin; all of them, except the sulphate of lime, being in very small quantity. Even if the sulphate of magnesia were produced in nature, in large quantities, it is so very soluble that it can accumulate only in such positions as afford it complete shelter from the rains or running water. The epsomite mentioned was found beneath the overhanging cliff of Burlington limestone, near Starr's mill, which are represented in the sketch upon another page, illustrating the subcarboniferous rocks. It occurs in the form of efflorescent encrustations upon the surface of stones and in similar small fragile masses among the fine debris that has fallen down beneath the overhanging cliff. The projection of the cliff over the perpendicular face of the strata beneath amounts to near twenty feet at the point where epsomite was found. Consequently the rains never reach far beneath it from any quarter. The rock upon which the epsomite accumulates is an impure limestone, containing also some carbonate of magnesia, together with a small proportion of iron pyrites in a finely divided condition. It is doubtless by double decomposition of these that the epsomite results. By experiments with this native salt in the office of the Survey, a fine article of epsom salts was produced, but the quantity that might be annually obtained there would amount to only a few pounds, and of course is of no practical value whatever, on account of its cheapness in the market.

CLIMATOLOGY.

No extended record of the climatology of Iowa has been made, yet much of great value may be learned from observations made at a single point. Prof. T. S. Parvin, of the State University, has recorded observations made from 1839 to the present time. Previous to 1860, these observations were made at Mus-.

catine. Since that date, they were made in Iowa City. The result is that the atmospheric conditions of the climate of Iowa are in the highest degree favorable to health.

The highest temperature here occurs in August, while July is the hottest month in the year by two degrees, and January the coldest by three degrees.

The mean temperature of April and October most nearly corresponds to the mean temperature of the year, as well as their seasons of Spring and Fall, while that of Summer and Winter is best represented in that of August and December.

The period of greatest heat ranges from June 22d to August 31st; the next mean time being July 27th. The lowest temperature extends from December 16th to February 15th, the average being January 20th-the range in each case being two full months.

The climate of Iowa embraces the range of that of New York, Pennsylvania, Ohio, Indiana and Illinois. The seasons are not characterized by the frequent and sudden changes so common in the latitudes further south. The temperature of the Winters is somewhat lower than States eastward, but of other seasons it is higher. The atmosphere is dry and invigorating. The surface of the State being free at all seasons of the year from stagnant water, with good breezes at nearly all seasons, the miasmatic and pulmonary diseases are unknown. Mortuary statistics show this to be one of the most healthful States in the Union, being one death to every ninety-four persons. The Spring, Summer and Fall months are delightful; indeed, the glory of Iowa is her Autumn, and nothing can transcend the splendor of her Indian Summer, which lasts for weeks, and finally blends, almost imperceptibly, into Winter.

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HISTORY OF THE STATE OF IOWA.

DISCOVERY AND OCCUPATION.

Iowa, in the symbolical and expressive language of the aboriginal inhabitants, is said to signify "The Beautiful Land," and was applied to this magnificent and fruitful region by its ancient owners, to express their appreciation of its superiority of climate, soil and location. Prior to 1803, the Mississippi River was the extreme western boundary of the United States. All the great empire lying west of the "Father of Waters," from the Gulf of Mexico on the south to British America on the north, and westward to the Pacific Ocean, was a Spanish province. A brief historical sketch of the discovery and occupation of this grand empire by the Spanish and French governments will be a fitting introduction to the history of the young and thriving State of Iowa, which, until the commencement of the present century, was a part of the Spanish possessions in America.

Early in the Spring of 1542, fifty years after Columbus discovered the New World, and one hundred and thirty years before the French missionaries discovered its upper waters, Ferdinand De Soto discovered the mouth of the Mississippi River at the mouth of the Washita. After the sudden death of De Soto, in May of the same year, his followers built a small vessel, and in July, 1543, descended the great river to the Gulf of Mexico.

In accordance with the usage of nations, under which title to the soil was claimed by right of discovery, Spain, having conquered Florida and discovered the Mississippi, claimed all the territory bordering on that river and the Gulf of Mexico. But it was also held by the European nations that, while discovery gave title, that title must be perfected by actual possession and occupation. Although Spain claimed the territory by right of first discovery, she made no effort to occupy it; by no permanent settlement had she perfected and held her title, and therefore had forfeited it when, at a later period, the Lower Mississippi Valley was re-discovered and occupied by France.

The unparalleled labors of the zealous French Jesuits of Canada in penetrating the unknown region of the West, commencing in 1611, form a history of no ordinary interest, but have no particular connection with the scope of the present work, until in the Fall of 1665. Pierre Claude Allouez, who had entered Lake Superior in September, and sailed along the southern coast in search of copper, had arrived at the great village of the Chippewas at Chegoincegon. Here a grand council of some ten or twelve of the principal Indian nations was held. The Pottawatomies of Lake Michigan, the Sacs and Foxes of the West, the Hurons from the North, the Illinois from the South, and the Sioux from the land of the prairie and wild rice, were all assembled there. The Illinois told

the story of their ancient glory and about the noble river on the banks of which they dwelt. The Sioux also told their white brother of the same great river, and Allouez promised to the assembled tribes the protection of the French nation against all their enemies, native or foreign.

The purpose of discovering the great river about which the Indian nations had given such glowing accounts appears to have originated with Marquette, in 1669. In the year previous, he and Claude Dablon had established the Mission of St. Mary's, the oldest white settlement within the present limits of the State of Michigan. Marquette was delayed in the execution of his great undertaking, and spent the interval in studying the language and habits of the Illinois Indians, among whom he expected to travel.

About this time, the French Government had determined to extend the dominion of France to the extreme western borders of Canada. Nicholas Perrot was sent as the agent of the government, to propose a grand council of the Indian nations, at St. Mary's.

When Perrot reached Green Bay, he extended the invitation far and near; and, escorted by Pottawatomies, repaired on a mission of peace and friendship to the Miamis, who occupied the region about the present location of Chicago.

In May, 1671, a great council of Indians gathered at the Falls of St. Mary, from all parts of the Northwest, from the head waters of the St. Lawrence, from the valley of the Mississippi and from the Red River of the North. Perrot met with them, and after grave consultation, formally announced to the assembled nations that their good French Father felt an abiding interest in their welfare, and had placed them all under the powerful protection of the French Government.

Marquette, during that same year, had gathered at Point St. Ignace the remn ants of one branch of the Hurons. This station, for a long series of

years, was considered the key to the unknown West.

The time was now auspicious for the consummation of Marquette's grand project. The successful termination of Perrot's mission, and the general friendliness of the native tribes, rendered the contemplated expedition much less perilous. But it was not until 1673 that the intrepid and enthusiastic priest was finally ready to depart on his daring and perilous journey to lands never trod by white men.

The Indians, who had gathered in large numbers to witness his departure, were astounded at the boldness of the proposed undertaking, and tried to discourage him, representing that the Indians of the Mississippi Valley were cruel and bloodthirsty, and would resent the intrusion of strangers upon their domain. The great river itself, they said, was the abode of terrible monsters, who could swallow both canoes and men.

But Marquette was not to be diverted from his purpose by these fearful reports. He assured his dusky friends that he was ready to make any sacrifice, even to lay down his life for the sacred cause in which he was engaged. He prayed with them; and having implored the blessing of God upon his undertaking, on the 13th day of May, 1673, with Joliet and five Canadian-French voyageurs, or boatmen, he left the mission on his daring journey. Ascending Green Bay and Fox River, these bold and enthusiastic pioneers of religion and discovery proceeded until they reached a Miami and Kickapoo village, where Marquette was delighted to find "a beautiful cross planted in the middle of the town, ornamented with white skins, red girdles and bows and arrows, which these good people had offered to the Great Manitou, or God, to thank Him for

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