121. South American you look at the physical map of South America (Fig. 279), you will see that there is a long western highland in that continent, as there is in North America. Here, too, the Spaniards found that the Indians had much gold and silver. Because the Spaniards wanted this gold and silver, they conquered the country and made slaves of the Indians. They put them to work in the mines, and took the gold and silver and sent it to Spain. The mines are still worked.
122. Gold in North America.—Much gold is found in the mountains of California and in Alaska. Some of it is mined by dredges driven by electricity. Often where rock containing precious metals has been worn down or broken up, little pieces of gold are found in the sand and gravel in the stream beds. In Alaska and in the British territory in the upper Yukon River valley, the miners sometimes get the grains of gold out of the sand by panning it. (Fig. 124.) This is done by taking some sand and water out cf a stream and stirring it around in a pan like a wash basin, until the heavy gold settles to the bottom.
Then the sand is carefully washed out and the miner can get a few grains of gold.
The miners first found the gold of Cali fornia and the Pacific States in stream beds. Later, they found the ore rock with gold in it, from which the streams had carried the gold after having broken up the rock into sand, dirt, and the particles of gold. The gold-containing rock is called a mother lode, because the gold grains in the stream bed came from it, arid, one might say, are its children. The rock of these mother lodes can be crushed fine and the gold removed. Expensive machinery and much work are needed. Sometimes the buildings around a mine are so large that they look almost like a whole village or town under one roof.
123. African gold off in South Africa, at a place called Johan nesburg, are some of the richest gold mines in the world. Softie of these mines are a mile deep. They are owned by English men, but most of the work is done by black men who come there from Central Africa. (See Fig. 425.)