The mines are operated in a crude, inefficient manner and scarcely two-thirds of the ore is recovered. The number of actual producers ranged from 183 in 1902, to 376 in 1906, but declined to 96 during the political troubles in 1908. The ore is sorted by hand and the low-grade material is washed in crude plants. From 20 to 25 per cent. of the exported material has been concentrated by washing. In 1902 there were 5,000 concessions, of which 3,750 were owned by 14 persons, each with 25 to 500 concessions; the remainder belonged to 300 peasants and small merchants. By 1912 a producers’ association had been formed to permit the owners to deal collectively with the exporters. Large investments had also been made by German capitalists in mines as well as in undeveloped territory. The Gelsenkirchen Gesellschaft, a German firm, had been formed partly for the purpose of mining but largely to purchase and export ore to Germany. In 1912, this firm, although it produced only a little ore, exported nearly one-third of the total. German groups also established necessary financial agencies to facilitate export of ore as well as to make loans to mine operators. In 1913, of 16 exporting firms, only 3 were Russian. The output of the mines of the Chiaturi district is hauled to Chiaturi (1.3 to 3.3 miles), loaded on narrow-gauge cars for transport to Sharopan (25 miles), and then reloaded on cars for shipment to Poti or Batum (107 miles), the ports of export. Large stocks ranging from 1,030,000 tons in 1912, to 1,525,000 tons in 1908, are kept at Chiaturi, Poti and Batum. From 1910 to 1912, the distribution of exports ranged as follows: Holland (for Germany), 30 to 43 per cent.; England, 22 to 23 per cent.; Belgium (largely for Germany), 15 to 21 per cent.; Germany (direct), 5 per cent.; France, 4 to 6 per cent.; United States, 4 to 10 per cent.; Austria, 4 to 10 per cent. About 1913, an export tax equal to 40 cents per long ton was levied by the Russian government. It is estimated that from 1848 to 1914, inclusive, this deposit yielded about 11,000,000 tons of washed ore of marketable grade. The maximum production of 1,300,000 tons was attained in 1913. Another important manganese mining region is the Nicopol district, in the Province of Ekaterinoslav, north of the Black Sea. In this district a bed of manganese oxides lies between clays and sandstone of Oligocene age. This bed is 1 to 5 feet thick, averaging nearly 3 feet. It is estimated to extend over an area of 20 square kilometers (7.5 square miles) and to contain 7,400,000 tons of manganese ore. The ore is mined and washed in a crude way to free it from the attached clay.