Page:The New International Encyclopædia 1st ed. v. 10.djvu/831

IOWA. lands of the principal rivers; the principal tract is the Missouri Bottoms, 150 miles long, and from a to 20 miles wide. This is, of course, the richest soil of the State, but is, nevertheless, rivaled by the drift soil. The latter consists of a fine loamy mixture of clay and sand, with a little gravel. It is of almost inexhaustible richness, and scarcely needs fertilizing. It covers by far the greater part of the State. The loess is a fine yellowish sand highly charged with carbonate of lime. It is found in various parts of the State, generally along the margins of the various drift areas, and is generally considered to be of glacial origin.

For flora and fauna, see.

. Owing to the heavy covering of drift, a thorough geological survey of Iowa is attended with diliiculties. Nevertheless our knowledge of the rock formations is fairly complete. In more than three-fourths of the State the surface consists of Paleozoic rocks appearing in parallel belts running northwest to southeast. Beginning at the northeastern corner, there is a narrow belt of Cambrian formation consisting of Potsdam sandstone; then follow the Silurian, Devonian, and the Lower and Upper Carboniferous formations, the latter occupying the southwest corner of the State. The northwestern part is covered by extensive Cretaceous beds deposited across and over the belts of the older strata. Finally, in the extreme northwest corner there are outcroppings of metamorphosed rock of the Algonkian period, known as Sioux quartzite, the oldest formation in the State. Over the entire surface, with the exception of a small driftless area in the northeastern corner, is a deposit of glacial drift from a few inches to several hundred feet in thickness. It consists mainly of fine rock fragments with but few boulders and pebbles. The limits of the various drift sheets, the older in the south and the later in the north, are clearly defined, although there are no typical moraines.

The most valuable of Iowa's mineral resources are the extensive bituminous coal beds found in the southeastern quarter of the State. Lead and zinc ores have been mined in considerable quantities in the Galena limestone of the Lower Silurian formation of the northeast. Extensive deposits of gypsum are also found, and various other minerals occur in smaller quantities, limonite iron ore being the only metallic deposit besides lead which seems at all promising. The limestones of the Devonian and Upper Silurian formations furnish an inexhaustible supply of building-stone of the finest quality.

. Bituminous coal is extensively mined in the eastern part of the State. An average of over 10,000 men are employed annually in the industry. In the early part of the decade 1890-1900, the production averaged a little in excess of 4,000,000 tons annually, but in the latter years of that period it exceeded 5,000,000 tons annually. The value of the product at the mine in 1900 was $6,968,866. Only one State west of the Mississippi River, Colorado, exceeds Iowa in the value of its coal output. The coal-fields are of great importance, not only to the State, but to the northwest region. Increasing quantities of limestone are quarried in the State, the value of the annual output having nearly doubled in the decade 1890-1900, being estimated in the latter year at $800,000. Clays suitable for brick manufacture are abundant and are extensively utilized. Small quantities of zinc and gypsum are mined.

. Iowa is preëminently an agricultural State, and in the census year 1900 exceeded every other State in the value of farm products. Of its total land area, 97.4 per cent. is included in farms, and of this, 86.5 per cent. is improved. In neither of these respects was Iowa exceeded in 1900. The average size of farms decreased decidedly between 1850 and 1880, but increased again during the two succeeding decades, the average number of acres per farm in 1900 being 151.2. In the northwestern part of the State the average was much in excess of this figure, exceeding 200 acres in a few counties. There are indications of a considerable decrease in the number of farm laborers as compared with the number of owners and tenants since the census year 1880. For the succeeding two decades the number of farms operated by tenants increased 80.5 per cent., as compared with an increase of only 5.5 per cent. for the farms operated by owners. The increase in the number of rented farms was wholly on the part of those rented according to the cash system, the number of these being five times greater in 1900 than in 1880, and constituting 19.5 per cent. of the total number of farms, while the farms rented on shares were but 15.4 per cent. of the total. The soil is well drained, producing abundantly without the aid of artificial fertilizers. The greater certainty of the rainfall exempts the State from crop failures such as occur in the States farther west. There are only two or three States which rival Iowa in the production of cereals. Nearly one-half of its entire land surface is devoted to these products. The State is noted especially for its corn crops, the acreage for which amounts to over one-fourth of its total area, and contributes about one-half of the total value for all crops. Every decade in the State's history shows an increase in the acreage and production of this crop, the largest gain being in the decade 1870-80. The crop is grown most extensively in the central and southwestern counties. Oats rank next in importance, with about one-half the acreage and one-third the value of corn. The State usually takes first place in the production of this cereal. Like corn, each census has shown a large gain over the preceding. The crop is grown most extensively in the northern part of the State. The attention given to wheat is in marked contrast with that given to corn and oats. In 1880 it was five times as great as in 1890. There has since been a revival in the cultivation of wheat, the increase during the decade 1890-1900 being nearly threefold. It is raised most extensively in the northern and northwestern counties. The State ranks second in the production of barley, this crop also being most extensively grown in the northern part. Less important cereals are rye and buckwheat. Flaxseed is also grown. The large stock interests of the State make heavy demands upon hay and forage crops, and the State ranks second in the acreage devoted to these products. The area devoted to them continued to increase rapidly until 1890, but in the following decade it fell off 15.4 per cent. The soil is well adapted to vegetables, and the State ranks second in the production of Irish potatoes. The fruit