国产热热热精品,亚洲视频久久】日韩,三级婷婷在线久久,99人妻精品视频,精品九热人人肉肉在线,AV东京热一区二区,91po在线视频观看,久久激情宗合,青青草黄色手机视频

您現(xiàn)在的位置: Language Tips> Easy English> Odd Question  
 





 
誰發(fā)明了鉛筆
[ 2008-01-22 13:59 ]

鉛筆是大家從小用到大的東西。不知道你用鉛筆的時候有沒有想過它到底是怎么來的。想了解一下鉛筆是誰發(fā)明的和怎么制作的嗎?趕快看看下面這篇文章吧!

Pencil, a derivative of the Latin word pencillus for "little tail," originally described a small, fine, pointed brush.

N. J. Conte, in 1795, successfully produced pencils, after the later famed Faber family of Nuremberg, Germany, failed to do so, by using apulverizedgraphite base to create a substandard, crude prototype of a pencil. Conte's method, the basic recipe used by all pencil manufacturers today, differed from the failed Faber fiasco, as he groundgraphite, mixed it with certain types of clay, pressed the "dough" into sticks, and finished them in akiln. The Faber family followed suit, and achieved the fame and fortune that previously eluded it.

The recipe used by modern pencil manufacturers, calls for dried, ground graphite, a form of carbon, mixed with clay and water in varying proportions. Pencils made with more clay produce a harder pencil, and, conversely, pencils made with more graphite produce a softer pencil. In either case, the ingredients are mixed until they reach adoughyconsistency, and then pass through a forming press, which presses the dough into a pencil thin, smooth, glossy rope. After workers straighten the rope they cut it into the desired lengths, and bake them in industrial ovens.

While the mixture is prepared and baked, workers prepare the casing that will house the lead. They shape the wooden casings, made from either red cedar or pine, into halves, and carve grooves in them to encase the graphite-based leads. The workers then carefully insert the finished leads into the grooves, glue the two wooden halves together, run the resulting slats through a saw that cuts them into single pencils, and finish them with a shaping machine that smoothes the pencils' surfaces.

Modern pencils come in over 350 varieties; each designed for a specific use, and may be purchased in over 72 colors. Black pencils, or graphite-based pencils, come in 19 degrees of hardness and of intensity. Specialty pencil leads are crafted to write on surfaces such as cloth, cellophane, plastics, and movie film. Architects, engineers, and those doing outdoor construction work primarily purchase these specialty leads, as they possess non-fade, weatherproof qualities. The versatility of Conte's brainchild, the pencil, makes it the essential, indispensable tool of these trades.

pulverize: 研磨成粉

graphite: 石墨

kiln: 窯,干燥爐

doughy: 面團似的

(來源:coolquiz.com 英語點津 Annabel 編輯)

我想了解更多 趣味百科知識
 
 
相關(guān)文章 Related Stories
 
 
 

本頻道最新推薦

     
  誰發(fā)明了鉛筆
  I can fly!
  Hey! Let me have a look!
  昆蟲能被掐死嗎
  I believe I can fly!

論壇熱貼

     
  pee park
  狗不理譯成“Go Believe”?
  to my 2007
  《康定情歌》有誰可以譯出韻味來?
  被宰了
  破罐子破摔




温泉县| 法库县| 辛集市| 盐城市| 汶上县| 郎溪县| 张家口市| 高淳县| 缙云县| 邢台市| 嘉黎县| 岳池县| 安徽省| 柞水县| 庆云县| 嵊州市| 神木县| 诸暨市| 青海省| 胶南市| 富蕴县| 福建省| 永靖县| 海阳市| 建水县| 绥芬河市| 余庆县| 阿荣旗| 安乡县| 万全县| 临颍县| 达尔| 西丰县| 新田县| 囊谦县| 建昌县| 柘城县| 威信县| 离岛区| 扎鲁特旗| 上饶市|