第八章 The Industrial Revolution 工业革命
书迷正在阅读：神级扮演：从小丑开始、地下城之主、全球天选：开局觉醒百倍经验天赋、妖魔入侵：我成救世大剑仙、名侦探柯南续集、火影：等会，我先戴个写轮眼、神奇宝贝之无尽轮回、这个世界的穿越者有点多、异界游戏王之虚空变、潜伏火箭队，只为超梦
ted where coal was cheap at pit heads， opened up a great expansion in coal mining by allowing mines to go deeper. Despite their disadvantages， Newcomen engines were reliable and easy to maintain and continued to be used in the coalfields until the early decades of the 19th century. By 1729， when Newcomen died， his engines had spread to Hungary in 1722， Germany， Austria， and Sweden. A total of 110 are known to have been built by 1733 when the joint patent expired， of which 14 were abroad. In the 1770s， the engineer John Smeaton built some very large examples and introduced a number of improvements. A total of 1，454 engines had been built by 1800. ??A fundamental change in working pr