Oil Refining
An important new industry, oil refining, grew after the Civil War. Crude oil, or petroleum -- a dark, thick ooze from the earth -- had been known for hundreds of years, but little use had ever been made of it. In the 1850s Samuel M. Kier, a manufacturer in western Pennsylvania, began collecting the oil from local seepages and refining it into kerosene. Refining, like smelting, is a process of removing impurities from a raw material. Kerosene was used to light lamps. It was a cheap substitute for whale oil, which was becoming harder to get. Soon there was a large demand for kerosene. People began to search for new supplies of petroleum. The first oil well was drilled by E. L. Drake, a retired railroad conductor. In 1859 he began drilling in Titusville, Pennsylvania. The whole venture seemed so impractical and foolish that onlookers called it Drakes Folly. But when he had drilled down about 70 feet , Drake struck oil. His well began to yield 20 barrels of crude oil a day. News of Drakes success brought oil prospectors to the scene. By the early 1860s these wildcatters were drilling for black gold all over western Pennsylvania. The boom rivaled the California gold rush of 1848 in its excitement and Wild West atmosphere. And it brought far more wealth to the prospectors than any gold rush. Crude oil could be refined into many products. For some years kerosene continued to be the principal one. It was sold in grocery stores and door-to-door. In the 1880s refiners learned how to make other petroleum products such as waxes and lubricating oils. Petroleum was not then used to make gasoline or heating oil.
浅谈动名词用法
定语从句详解(三)
小升初英语语法大全:名词化的形容词
星期的几种用法
小升初英语语法大全:情态动词must与have to的用法
小升初英语语法大全:具有连接作用的副词
动名词
分词的用法(三)
浅谈need用法
英语语法:部分否定的几种表示方法
小升初英语语法大全:延续性动词的用法特征
特殊的虚拟语气词:should
倒装,语法及例题
小升初英语语法大全:dare的两种用法
小学英语小升初语法巧记口诀
小升初英语语法大全:时间介词辨析(下)
小学英语语法学习:八种词性及用法
小升初必备语法:其他部分倒装
小升初英语语法大全:介词的分类
had better表示"最好"
小升初英语语法大全:情态动词如何表猜测
小升初英语语法大全:可以说asleep children吗?
代词比较辩异 one,that 和it
小升初英语语法大全:连系动词及系表结构
英语句子六大成分英语的句子
介词to的用法归纳
分词的用法(六)
定语从句详解
浅谈倒装句(六)
定语从句详解(二)
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |