When most of us think about technology, we think of computers, smartphones, or 3D televisions. But technology can come in many different forms, and sometimes we can take past technological advances for granted. Take the pencil for example. This was once considered to be a revolutionary device that allowed us to record our ideas quickly and cleanly. How revolutionary was it? Well, it has been almost 460 years since the graphite pencil was first invented, and it can still be found in classrooms around the world. The earliest pencils were invented by the Romans, who used lead tubes to make markings on papyrus, an early form of paper. Even the name "pencil" comes from the Latin word penicillus, which means "little tail." Although pencils do not contain the chemical element lead nowadays, many people still refer to the graphite in modern pencils as "lead." The story of the modern pencil began in 1564, when a large deposit of pure graphite was discovered in England. People found that it was perfect for marking sheep, and later it began to be used on paper. At first, the graphite was wrapped in string or sheep skin, and it quickly became popular with artists throughout Europe. The Italians further modified the graphite by enclosing it in wood. They glued two wooden halves together around the graphite stick. This exceptional method is still in use today. Nowadays, there are many different types of pencils. They're all graded according to their hardness on a scale that ranges from 9H (very hard) to 9B (very soft). Some pencils have replaced the black graphite with colored graphite. Pencils are undoubtedly popular. How widespread are they? Over 14 billion pencils are manufactured around the world every year. As for the wood required to make all these pencils, a good-sized tree will produce around 300,000 pencils. What about the answer to that eternal question of how long of a line could one pencil draw? The experts have even figured that out. The answer is around 113 kilometers.
我們大多數人想到科技，總是會想到電腦、智慧型手機，或3D 立體電視。但是科技可以有許多種形式，有時我們容易將過去的科技發展視為理所當然。以鉛筆為例，鉛筆也曾經被視為一項革命性的工具，讓人類可以快速簡潔地把想法記錄下來。到底有多革命性？這個嘛，距離石墨鉛筆最初被發明已經快要460 年了，但至今仍能在全世界的教室裡看到它呢。 最早的鉛筆是由羅馬人所發明，他們用鉛管在早期的紙張「紙莎草紙」上做記號。而「pencil」這個字也是從拉丁文「penicillus」演變而來，意思是「小尾巴」。雖然今日的鉛筆並不含鉛這個化學元素，許多人還是把現代鉛筆所使用的石墨稱為「鉛」。 現代鉛筆可以回溯至1564 年，當時在英格蘭發現了一大片的純石墨礦床。大家發現石墨非常適合用在羊身上做記號，之後也開始於紙上書寫。一開始是用繩子或羊皮包裹石墨，迅速受到全歐洲藝術家的青睞。義大利人進一步改良用木頭包覆石墨，他們把兩片木頭夾住石墨條之後黏住，到現在鉛筆都還是採用這個妙法製作。 今日的鉛筆種類繁多，全部依照硬度分級，從極硬的9H 到極軟的9B。有的鉛筆不用黑色石墨改用彩色石墨。人們愛用鉛筆是無庸置疑的，它們到底有多普遍呢？每年全球的鉛筆產量超過140 億枝，至於製造這些鉛筆所消耗的木頭，一棵大樹大約可以製造30 萬枝鉛筆。 至於那個永遠都會被問到的問題：「一枝鉛筆可以畫多長的線？」到底有沒有答案？專家甚至都算出來了，答案就是「113 公里」。 | 
