Page:History of the Indian Archipelago Vol 3.djvu/469

 ARTICLES OF EXPOIITATIOX. 45.1 These incumbent materials vary a little in differ- ent situations, but not materially. Immediately under the last stratum occurs the bed or stream of tin ore, disseminated in coarse fragments of granite, and other primitive rocks, and of various degrees of depth. The disappearance of the bed of ore is constantly indicated by a stratum of pure white friable clay. * The tin ore of Banca is common tin ore, or tbu sto7ie, an oxide of tin, and its most common colour is reddish-brown. From this account of the geog- nostic situation of tin we shall be prepared to un- derstand the nature of the processes pursued for converting it into metal. The process of mining is wonderfully simple, easy, and cheap. A tin mme is nothing else than a large oblong pit, made by excavating the ground in a perpendicular di- rection, to a depth of from 15 to ^5 feet, to re- move the superincumbent strata of sand and clay and get at the ore. The first opening is seldom above 100 feet in length, and if the ore is discovered to lie below the usual depth, the situation in the present abundance of mineral will be neglected for a more favourable one. The mines are divided into lai'ge and smally called respectively in the language of the country kolong and Iculit. It is in the first
 * Callc.l_,by the Chinese miners Kon^sek.