中国华文教育网
四大发明 The Four Great Inventions
2009年09月03日 14:37

  四大发明

  造纸术

  西汉时期已经出现早期的植物纤维纸,但比较粗糙,书写不方便。东汉时的宦官蔡伦,改进了造纸方法,用树皮、麻头、破布和旧鱼网作原料,制造出既美观又便宜,并且书写方便的纸张,并使这种以麻为主要原料的纸得到推广,对书写起到了重要的推动作用。造纸术逐步推广开来,到了公元三、四世纪,纸取代竹简和丝帛成为中国的主要书写材料。

  指南针

  战国时,人们用天然磁石磨成“司南”,这是世界上最早的指南针,到今天已经有两千多年了。司南磁性较弱,指南效果比较差。

  到了宋朝,发明了人造磁铁,磁性比天然磁铁稳定。指南针的装置也有很大改进,人们发明了指南鱼、指南龟、水浮指南针等指南工具。

  在宋代,海外贸易非常发达。为了克服在海洋中航行的困难,到北宋末年,在航海上已经应用了指南针。南宋时还出现了将指南针安装在刻?度数和方位的圆盘上的罗盘针,使海上航行的人,在没有太阳的白天,没有月亮的夜晚,也能辨别方向。

  印刷术

  在人类文明发展史上,印刷术的地位非常重要。大约在隋朝的时候,雕版印刷术被发明了出来。但雕版印刷费时长,花钱多。

  毕升是北宋时一个聪明能干的印刷工人,熟悉雕版印书的情况,他想发明一种既省时省力又经济的印刷方法,创造了活字印刷。

  毕升发明的是泥活字。先在粘土制成的一个个小方块上刻出反字。制成一批后,就放在窑中烧硬成为陶字。排版时,在一块铁板上铺上一层用松香、蜡和纸灰混合的粉末,把一个个陶字排在有框的铁板上,然后把铁板放到火上加温,等粉末熔化后,用一块平板把字压平。铁板温度降低后,活字固定,就可以印刷了。印板中如果有错别字,可以随时更换,印完一板,活字拆了,铁板可以再用。

  毕升为印刷术的改进打下了基础,西夏有了木活字,明代改成铜活字,直到后来使用的铅活字。

  火药与火器

  中国古代有专门炼丹的人,他们中有人把硫磺、硝石、木炭放在一起烧炼,引起了燃烧和爆炸,人们把这三种物质的混合叫做“火药”。唐朝中期的书籍里记载了制成火药的方法。唐朝末年,火药开始用于军事。

  在宋代,火药得到了广泛使用,火药不仅被用在生活中,狩猎、开石、采石,制造爆竹和焰火,更多地被用在军事上。火器的制造技术也提高到了一个新的阶段。北宋制造的火药武器主要是燃烧性的、爆炸性的,如火箭、霹雳(pili)火球、蒺藜(jili)火球等。到了南宋,发明了管状火器,把火药装在竹筒里点火喷射。有一次,宋朝军队和蒙古军队打仗,宋军发明了管状“突火枪”,即把火药装在竹筒里,然后装上“子窠(ke)”。“子窠”和子弹的性质差不多,是用石子和铁块做的。这是世界上最早使用原始步枪。它的出现是火器制造历史上划时代的进步。

  The Technique of Making Paper

  A crude type of paper was used for writing on as early as in the Western Han Dynasty. It was made from plant fiber, and was rather rough. Cai Lun, a eunuch of the Eastern Han Dynasty, used tree bark, rags and old fishing nets as raw materials, and produced a smoother and more convenient type of paper. By the fourth century, paper had replaced bamboo slips and silk as the main material for writing on.

  The Invention of the Compass

  Natural magnets were used as crude compasses as early as in the Warring States Period. By the Song Dynasty, artificial magnets had been invented, whose magnetism was more stable than that of natural magnets. With such artificial magnets, compasses were developed and used for navigation, together with degree markings. This greatly stimulated maritime trade.

  The Technique of Printing

  Printing has played a very important role in the history of civilization. Woodblock printing was in use at the time of the Sui Dynasty. But it involved laborious and expensive processes.

  Bi Sheng of the Northern Song Dynasty determined to improve the printing technique, and he invented moveable type. He carved characters in reverse on blocks of clay, and baked the blocks in a kiln. The slugs of type were pressed onto a coating of rosin, wax and paper ash spread on an iron tray, which was then heated and cooled to fix the slugs. If there was a wrong character, it could easily be replaced, and the tray, slugs and coating could be used over and over again.

  In the Ming Dynasty, bronze type was invented, and later lead type was used.

  Gunpowder and Firearms

  Alchemists were the first people in ancient China to dabble in chemistry. In the search for "pills of immortality",it was found that a mixture of sulfur, saltpeter and charcoal could cause an explosion. This mixture was mainly used for making fireworks, until the Song Dynasty, when it began to be applied for military use. Fire arrows and bombs were made using gunpowder, and crude muskets were used with devastating effect against Mongolian invaders.

【来源:中国华文教育网】