{"id":1057,"date":"2015-03-30T01:00:32","date_gmt":"2015-03-30T01:00:32","guid":{"rendered":"http:\/\/blog.lib.uiowa.edu\/eng\/?p=1057"},"modified":"2015-04-02T15:31:32","modified_gmt":"2015-04-02T20:31:32","slug":"get-the-lead-out","status":"publish","type":"post","link":"https:\/\/blog.lib.uiowa.edu\/eng\/get-the-lead-out\/","title":{"rendered":"Get the Lead Out"},"content":{"rendered":"

\"Ticonderoga<\/a>“Eeyore was saying to himself, “This writing business. Pencils and what-not. Over-rated, if you ask me. Silly stuff. Nothing in it.<\/em>” — Winnie the Pooh.<\/p>\n

A long time ago, in a far away place, before apps and texts and even typewriters, pencils were used to convey the written word.\u00a0As you purchase\u00a0a new box of Ticonderogas to mark\u00a0your bubble answer sheet, consider the invention of the pencil.<\/p>\n

History<\/h2>\n

Pencils are made with graphite. Therefore,\u00a0graphite mining had to exist before the pencil was created. The first graphite was mined at Seathwaite Fell in Cumbria, England in 1564. Since graphite has similar properties to lead, it was first called, “plumbago,” derived from the Latin word for lead ore. The first pencils were\u00a0produced\u00a0by sawing the graphite into sheets, shaping the graphite\u00a0sheets into square rods, and inserting the graphite rods into\u00a0a wood casement. However, the first pencils were fragile\u00a0because the\u00a0graphite broke easily.<\/p>\n

Patent<\/h2>\n

\"H.L.<\/a>To prevent the graphite from breaking, French chemist, Nicolas-Jacques Cont\u00e9, discovered the process of mixing the graphite with clay. The soft material was pressed into sticks and kiln-fired. At which point, the dry graphite & clay rod\u00a0was inserted into a wooden case. By varying the ratio of graphite to clay,\u00a0Cont\u00e9 discovered that he could\u00a0manufacture a\u00a0pencil\u00a0for a specific hardness to differentiate the\u00a0marks\u00a0on\u00a0paper. For example, No.2 pencils are popular because of its midrange hardness which leaves dark marks without smudging. No.1 is the softest graphite and leaves a darker, smudgier mark , and No.3 pencils leave a fainter mark. Cont\u00e9’s 1795\u00a0patent\u00a0is the basic process for manufacturing pencils\u00a0today.<\/p>\n

To learn more about the manufacturing of pencils, watch this video from the Science Channel,\u00a0How It’s Made : Pencils<\/a>.<\/p>\n