书城教材教辅科学读本(英文原版)(套装1-6册)
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第72章 第一册(72)

"When the men get to the coal-bed, they don"t dig down any more. They begin to dig sideways through the coal itself. They dig out great wide roads, through nothing but coal.""But how do the men get down?" asked Norah. "What do they do with all that they dig out? They must dig up a lot of things before they reach the coal.""I thought you would ask that, Norah," said Fred. "I will tell you. The men put up a big engine at the top of the shaft. Then they make a great box, which they call a cage. It is big enough to hold a dozen men. The cage is held by very strong chains, and the engine lets it down and draws it up again.""I see," said his sister. "Sometimes it takes the men up and down. Sometimes it brings up the earth, and stones, and other things, they dig out. At last it brings up the coal.""Quite right, little girl," said both the boys.

"Now think," added Fred, "about the mine itself. As the men dig along their great main roads, they branch off from time to time. They cut out streets and lanes on all sides. It looks like a town under the ground.""Oh," said Norah, with a shudder. "What a dark, ugly place!"SUMMARY