[72] Some years ago many of the most valuable vineyards were destroyed by an insect pest known as the _phylloxera_, introduced from California. The trouble was overcome by replanting with American vines, the roots of which were immune to the pest. On these roots were grafted the choice French vines, the leaves and twigs of which were immune. In this manner the vineyards were restored with vines that are proof against attack, and the wine output has reached its normal amount. [73] It is cultivated as an ornamental tree in the Southern States and in California. [74] A small vein of coal occurs near Freiburg. [75] The St. Gotthard tunnel is almost nine and one-half miles long; the Arlberg tunnel is six and one-half miles in length. The tunnel now nearing completion under the Simplon Pass is more than twelve miles long. Five railways cross the northern frontier into Germany, and German commerce profits most by them. [76] Persian rugs are the finest. As a rule the designs are floral and many of them contain legendary history worked in fantastic but beautiful patterns. Among those of especial merit are the Kermanshah tree-of-life fabrics, now somewhat rare. The rugs of Tabriz and Shiraz are also of high value. In general, Persian fabrics are characterized by very fine weaving, a short pile, and elaborate designs. Turkoman rugs are usually a rich brown or maroon in color, and are apt to contain slightly elongated octagonal figures. The Bokhara and Khiva-Bokhara, or Afghan rugs, are the best examples. The Baluchistan rugs are usually very dark in color, with bright red designs and striped ends of cotton warp. Turkish rugs are made almost wholly in Asia Minor or Anatolia. Large carpets of American and European designs are made at Ushak and Smyrna. "Smyrna" rugs are made in Philadelphia. [77] The most valuable Kermanshah rug, now no longer made there, is the tree-of-life prayer-rug, an illustration of which is shown on p. 350. The design is emblematic of the story of the Garden of Eden. [78] In 1900 the aggregate value of the wheat exported to Great Britain was only L2,200. [79] Since the treaty of 1901, which forbids the importation of fire-arms, a number of large plants for the manufacture of fire-arms, smokeless powder, and fixed ammunition have been established on the lower Yangtze. [80] The islands are mainly in the belt of prevailing westerly winds. More rain, therefore, falls on the west than on the east coasts. [81] This region is also known us the Gold Coast. Formerly it furnished the chief British supply of gold, and the gold coin known as the "guinea" received its name from this circumstance. [82] This region was formerly comprised in the Boer republics, Orange Free State and South African Republic. In 1899 they declared war against Great Britain, with the result that they were defeated and annexed to that country--the former as Orange Colony, the latter as Transvaal Colony.