<tt id="6hsgl"><pre id="6hsgl"><pre id="6hsgl"></pre></pre></tt>
          <nav id="6hsgl"><th id="6hsgl"></th></nav>
          国产免费网站看v片元遮挡,一亚洲一区二区中文字幕,波多野结衣一区二区免费视频,天天色综网,久久综合给合久久狠狠狠,男人的天堂av一二三区,午夜福利看片在线观看,亚洲中文字幕在线无码一区二区
          您現在的位置: Language Tips> Easy English> Odd Question  
           





           
          Who invented the pencil?
          [ 2005-04-25 07:30 ]
             
            Pencil
             
            Who invented the pencil?
          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 a pulverizedgraphitebase 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 ground graphite, mixed it with certain types of clay, pressed the "dough" into sticks, and finished them in a kiln. The Faber familyfollowed 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 a doughy consistency, 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 flavors, each designed for a specific use, and may be purchased in over 72 colors. "Black pencils," 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 out door 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.

           

          note:

           

           

          graphite :石墨

           


          follow suit: 效仿

           
           
          相關文章 Related Stories
           
           
           

          本頻道最新推薦

               
            為什么下雪時天氣暖
            You are the smartest fish I've ever seen!
            Dog burger
            為什么老了脾氣好
            飛蛾為什么撲火

          論壇熱貼

               
            開個題目大家扯:hotel & restaurant
            追求某人
            請教工商年檢如何翻譯
            How to translate “中國老字號”into English?
            "港股直通車"怎么翻譯?
            兩免一補怎么說?




          主站蜘蛛池模板: 午夜免费福利小电影| 九九热在线观看精品视频| 亚洲男人的天堂久久香蕉| 国内精品久久久久影院日本| 欧洲亚洲国内老熟女超碰| 久久久久久久综合日本| 国产精品视频第一第二区| 免费中文熟妇在线影片| 日韩精品亚洲专在线电影| 亚洲欧美乱综合图片区小说区 | 亚洲国产精品自在在线观看| 国产色无码专区在线观看 | 日本又黄又爽gif动态图| 国产高清国产精品国产专区| 性一交一乱一伦| 少妇肉欲系列1000篇| 国日韩精品一区二区三区| 亚洲AV无码破坏版在线观看| 久久碰国产一区二区三区| 天堂v亚洲国产v第一次| 日韩内射美女人妻一区二区三区| 忘忧草影视| 亚洲视频高清| 午夜成人无码免费看网站| 忘忧草在线观看日本| 中文字幕国产精品自拍| 国产精品国产精品偷麻豆| 国产欧美另类久久久精品不卡| 久久精品国产99久久无毒不卡 | 亚洲av优女天堂熟女久久| 成人无码潮喷在线观看 | 99riav国产精品视频| 无遮掩60分钟从头啪到尾| 中文字幕无码av不卡一区| 亚洲精品国产成人av蜜臀| 亚洲国产精品一区二区第一页| 99这里有精品视频视频| 九九热视频精品在线播放| 日本亚洲成人中文字幕| 日本熟妇人妻一区二区三区| 老司机导航亚洲精品导航|