On the eastern side of Shansí the rocks are made up of ancient formations or deposits of the Silurian age, presenting a series of peaks, passes and ranges that render travel very difficult down to the Plain. By these outlying ranges the province is isolated from Chihlí, as no useful water communication exists. This coal and iron formation is probably the largest in the world, and when railroads open it up to easy access it can be readily worked along the water-courses. The northern part of the province is drained through the rivers ending at Tientsin. This elevated region cannot be artificially irrigated, and when the rainfall is too small or too late, the people suffer from famine. The northern and southern prefectures exhibit great diversity in their animal, mineral, and vegetable productions. Some of the favorite imperial hunting-grounds are in the north; from the coal, iron, cinnabar, copper, marble, lapis-lazuli, jasper, salt, and other minerals which it affords, the inhabitants gain much of their wealth. The principal grains are wheat and millet, a large variety of vegetables and fruits, such as persimmons, pears, dates and grapes. The rivers are not large, and almost every one of them is a tributary of the Yellow River. The Făn ho, about 300 miles long, is the most important, and empties into it near the south-western corner of the province, after draining the central section. East of this stream, as far as the headwaters of those rivers flowing into Chihlí, extends an undulating table-land, having a general altitude of 3,000 feet above the Plain. South of it runs the river Kiang, also an affluent of the Yellow River, and near this, in Kiai chau, is a remarkable deposit of salt in a shallow lake (18 miles long and 3 broad), which is surrounded by a high wall. The salt is evaporated in the sun under government direction, the product bringing in a large revenue; the adjacent town of Lung-tsüen, containing 80,000 inhabitants, is devoted to the business. Salt has been obtained from this region for two thousand years; the water in some of the springs is only brackish, and used in culinary operations. There are two smaller lakes nearer the Yellow River. The iron obtained in the lower plateau, in the south-east near Tsih chau, is from clay iron-ore and spathic ore with hematite, which occurs in limestone strata at the bottom of the coal formations. It is extracted in a rude manner, but the produce is equal to any iron in the world, while its price is only about two cents a pound. The working and transportation of coal and iron employ myriads of people, though they are miserably paid. The province barely supplies its own cotton, but woollen garments and sheepskins are produced to make up the demand for clothing.