The tools employed in working the mines are an iron crow three feet in length, called tabah, a shovel called changkul, and a heavy iron mallet or hammer, the head of which is eighteen inches in length and as thick as a man's leg, with a handle in the middle. With this they beat the lumps of rock till they are reduced to powder, and the pounded mass is then put into a sledge or tray five or six feet long and one and a half broad, in the form of a boat, and thence named bidu. To this vessel a rope of iju is attached, by which they draw it when loaded out of the horizontal mine to the nearest place where they can meet with a supply of water, which alone is employed to separate the gold from the pulverized quartz. In the perpendicular mines the smooth or gravel-gold is often found near the surface, but in small quantities, improving as the workmen advance, and again often vanishing suddenly. This they say is most likely to be the case when after pursuing a poor vein they suddenly come to large lumps. When they have dug to the depth of four, six, or sometimes eight fathoms (which they do at a venture, the surface not affording any indications on which they can depend), they work horizontally, supporting the shaft with timbers; but to persons acquainted with the berg-werken of Germany or Hungary, these pits would hardly appear to merit the appellation of mines.* In Siberia however, as in Sumatra, the hills yield their gold by slightly working them. Sand is commonly met with at the depth of three or four fathoms, and beneath this a stratum of napal or steatite, which is considered as a sign that the metal is near; but the least fallible mark is a red stone, called batu kawi, lying in detached pieces. It is mostly found in red and white clay, and often adhering to small stones, as well as in homogeneous lumps. The gold is separated from the clay by means of water poured on a hollow board, in the management of which the persons employed are remarkably expert. (*Footnote. It has been observed to me that it is not so much the want of windlasses or machines (substitutes for which they are ready enough at contriving) that prevents excavation to a great depth as the apprehension of earthquakes, the effect of which has frequently been to overwhelm them before they could escape even from their shallow mines.)