formation of the Cambrian system. The minor ridges and depressions of the East Tennessee Valley consist of successive outcrops of Potsdam sandstone of the Cambrian, and Trenton limestone, shales, and dolomite belonging to the Lower Silurian age. The Lower Silurian strata pass under the Cumberland Plateau and Highland Rim, and reappear as the surface rock of the Central Basin, and again in the bottom of the Western Tennessee Valley. The plateau strata are Carboniferous, the Highland Rim being Sub-Carboniferous, while the Cumberland Plateau belongs to the Upper Carboniferous system. West of the Western Tennessee the Paleozoic strata disappear, and on their edges the Cretaceous and Tertiary strata rest unconformably. The Cretaceous outcrop is narrow, the greater part of the Western Plateau Slope being Tertiary. Between the bluffs and the Mississippi River the surface is of recent alluvial formation.
There are two great iron belts in the State, one occupying the western part of the Highland Rim, and the other stretching along the western slope of the Unaka Mountains. The ore is chiefly limonite, with some magnetite in the northeast. Copper occurs in the metamorphic rocks in the extreme southeastern corner of the State, and zinc and lead are found in various parts of the East Tennessee Valley. The coal measures of the Cumberland Plateau contain several seams of bituminous coal of workable thickness. Other minerals of importance are hydraulic limestone and marble of a good quality, as well as other building stones derived chiefly from the Silurian strata.
Mining. Tennessee is beginning to acquire considerable importance as a mining State. Coal is excavated in the mountain counties west of the Upper Tennessee River. For several years prior to 1899 the annual value of the coal output was about $2,300,000; subsequently it rose until in 1901 it was valued at $4,067,381, the amount being 3,633,290 short tons. Over 9000 men are employed. There were 404,017 short tons of coke manufactured in that year. The iron ore mined in 1901, 789,494 long tons, was an increase over former years and made the State sixth in rank. Of the total amount, 474,545 tons was brown hematite. The mining of phosphate rock began in 1894 and the output of 1901 was worth $1,192,090, which was less than in the previous year. The marble quarried in the State each year is usually worth between $300,000 and $400,000; in 1901, however, the amount rose to $494,637. The value of limestone quarried for that year was $330,927, a sum larger than usual. Clays found in the State are extensively utilized in the manufacture of brick and tile.
Agriculture. The State has a great diversity of physical conditions with a corresponding variation of soil and crops. The river valleys are generally fertile. The region known as the Central Basin contains a limestone soil of great fertility. In 1900 20,342,058 acres were included in farms, a little over half of this area being improved. While the farm area was but little greater in 1850 than in 1900, the improved area had almost doubled. The average size of farms decreased meanwhile from 261 acres to 90.6 acres. In 1900 12.6 per cent. of the farms were rented for cash, and 27.9 per cent. share rent, the latter having made a large gain during the decade ending with that year. Over one-seventh of the farms are operated by negroes, but only 22.4 per cent. of the negro farmers own their farms.
By far the largest and most valuable crop is corn, the acreage of which increased very considerably in the decade 1890-1900. Wheat is also an important cereal and much more than regained in the decade 1890-1900 what it had lost in the preceding decade. The cultivation of oats, the only other important cereal, has decreased. Cotton is one of the leading crops in the southwest corner of the State, and it is of much importance also in some of the northern counties. The area in hay and forage has increased more than threefold since 1880. Dry peas and sorghum cane are noteworthy products, as are also Irish and sweet potatoes. Peanuts are grown in large quantities in the Tennessee Valley. The climate is favorable to fruit culture, and in 1900 there were over 11,700,000 fruit trees, of which 7,700,000 were apple trees. There was a large increase in the number of all varieties of fruit trees in the decade ending with 1900. Of the 12,944 acres reported in small fruits in 1899, 11,548 acres were in strawberries. Watermelons and various vegetables are extensively raised. The following table is self-explanatory:
| CROP | 1900, acres |
1890, acres |
| Corn | 3,374,574 | 2,791,324 |
| Wheat | 1,426,112 | 877,361 |
| Oats | 235,313 | 588,138 |
| Rye | 16,556 | 26,443 |
| Hay and forage | 645,617 | 571,553 |
| Cotton | 623,137 | 747,471 |
| Tobacco | 71,849 | 51,471 |
| Peanuts | 19,534 | 16,244 |
| Dry peas | 82,841 | ............ |
| Potatoes | 27,103 | 36,992 |
| Sweet potatoes | 23,174 | 23,746 |
| Sorghum cane | 31,364 | 40,303 |
Stock-Raising. The number of cattle increased between 1870 and 1890, but decreased in the following decade. Both horses and mules increased in each decade from 1870 to 1900. Sheep, on the contrary, fell off in numbers. In 1899 $1,510,183 was received from sales of dairy products. The following table gives the number of stock for two census years:
| 1900 | 1890 | |
| Dairy cows | 321,676 | 345,311 |
| Other cattle | 590,507 | 620,028 |
| Horses | 352,388 | 311,842 |
| Mules and asses | 262,509 | 203,639 |
| Sheep | 307,804 | 540,996 |
| Swine | 1,976,984 | 1,922,912 |
Forests and Forest Products. Tennessee stood first among Southern States in 1900 in the value of its lumber products. It is estimated that the State contains 27,300 square miles of wooded area. Increased activity in the lumber industry began after 1880. The value of products more than doubled between 1890 and 1900. The value of planing mill products decreased during the same period.
Manufactures. Since 1880 the manufacturing industry has grown rapidly, the value of products increasing 95.2 per cent. in 1880-90, and 48.5 per cent. in the subsequent decade, the value in 1900 being $107,437,879. There were in
