Moreover, the key at the farther end of the line could be so arranged as to make an impression on a piece of paper that was slowly drawn under it by clockwork. Now if the man at one end of the line held his key down for only an instant, this impression would look like a dot. If he held it down longer, it would look like a short dash. Morse combined these dots and dashes into an alphabet. For instance, one dash meant the letter "t," and so on. For a time people only laughed at Morse. But at length Congress gave him enough money to build a line from Baltimore to Washington. It was opened in 1844, and proved to be a success from the beginning. Other lines were soon built, and the Morse system, greatly improved, is still in use. The telegraph made it possible to operate long lines of railroad, as all the trains could be managed from one office so that they would not run into one another. It also made it possible to communicate with people afar off and get an answer in an hour or so. For both these reasons the telegraph was very important and with the railroads did much to unite the people of the different portions of the country.
而且，在这根导线更远一端的键可用于在一张纸上留下压痕，这个压痕是通过钟表装置慢慢留在纸上。如果一个人在导线的一段按一下他的键，这个压痕就像一个点；如果他按下的时间更长一点，压痕看起来就像一个短虚线。摩尔斯将这些点和短虚线合并成一份字母表。例如，一个短虚线的意思是字母"t"等等。有一段时间人们只是嘲笑摩尔斯，但是，国会最终给他足够的钱让他在华盛顿和巴尔的摩之间拉起一条电报线路，这条线于1844年开通，自开通就被证明是一个成功之举。很快又有几条线路开通。经过大量改进的摩尔斯系统至今还在使用。电报使得长途火车的开通成为可能，因为所有的铁路都将通过电报归于一处领导，这将避免两辆火车撞在一起。也使得与远处的人联系并在一个小时左右收到回答成为可能。由于这些原因，电报非常重要，它和铁路一起为将美国各地的人统一在一起做出了巨大贡献。
322. The McCormick Reaper.
322．麦考密克收割机
Every great staple depends for its production on some particular tool. For instance, cotton was of slight importance until the invention of the cotton gin made it possible cheaply to separate the seed from the fiber.
每一种重要作物的产量都依赖于特定的工具，例如，在轧棉机使得将棉籽与棉纤维有可能轻易分离开来之前，棉花没有多大重要性；