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:''This article is about the handwriting instrument. For other uses, see Pencil (disambiguation) . A pencil is a Writing or Drawing instrument consisting of a thin stick of Pigment (usually Graphite , but can also be coloured pigment or Charcoal ) and Clay , usually encased in a thin wood cylinder though paper and plastic sheaths are also used. Pencils are distinct from Pen s, which use a liquid marking material. HISTORY The Archetypal pencil may have been the Ancient Roman stylus, which was a thin metal stick, often made of Lead and used for scratching on Papyrus , a form of early paper. The word ''pencil'' comes from the Latin word ''pencillus'' which means "little tail." Some time prior to 1565 (some sources say as early as 1500), an enormous deposit of Graphite was discovered at the site of Seathwaite Fell near Borrowdale , Cumbria , England . The locals found that it was very useful for marking Sheep . This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. This was and remains the only deposit of graphite ever found in this solid form. Chemistry was in its infancy and the substance was thought to be a form of lead. Consequently, it was called ''plumbago'' (Latin for "lead ore")12. The black core of pencils is still sometimes referred to as "lead," even though it never contained the Element lead. The value of graphite was soon realized to be enormous, mainly because it could be used to line the moulds for Cannon balls, and the mines were taken over by the Crown and guarded. Graphite had to be smuggled out for use in pencils. Because graphite is soft, it requires some form of case. Graphite sticks were at first wrapped in string or in Sheepskin for stability. The news of the usefulness of these early pencils spread far and wide, attracting the attentions of artists all over the "known world." Although deposits of graphite had been found in other parts of the world, they were not of the same purity and quality as the Borrowdale find, and had to be crushed to remove the impurities, leaving only graphite powder. England continued to enjoy a Monopoly on the production of pencils until a method of reconstituting the graphite powder was found. The distinctively square English pencils continued to be made with sticks cut from natural graphite into the 1860s . Today, the town of Keswick , near the original findings of block graphite, has a pencil Museum . The first attempt to manufacture graphite sticks from powdered graphite was in Nuremberg , Germany , in 1662 . It used a mixture of graphite, Sulphur , and Antimony . Though usable, they were inferior to the English pencils. It was the Italians who first thought of Wood en holders. An Italian couple in particular, named Simonio and Lyndiana Bernacotti, were believed to be the ones to create the first blueprints for the modern carpentry pencil for the purpose of marking their carpentry pieces; however, their version was instead a flat, oval, more compact type of pencil. They did this at first by hollowing out a stick of Juniper wood. Shortly thereafter, a superior technique was discovered: two wooden halves were carved, a graphite stick inserted, and the two halves then glued together—essentially the same method in use to this day. English and German pencils were not available to the French during the Napoleonic Wars . It took the efforts of an officer in Napoleon 's army to change this. In 1795 Nicholas Jacques Conté discovered a method of mixing powdered graphite with Clay and forming the mixture into rods that were then fired in a Kiln . By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied. This method of manufacture which had been earlier discovered by the Austrian Joseph Hardtmuth of Koh-I-Noor in 1790 remains in present use. American colonists imported pencils from Europe until after the American Revolution . Benjamin Franklin advertised pencils for sale in his ''Pennsylvania Gazette'' in 1729, and George Washington used a three-inch pencil when he surveyed the Ohio Territory in 1762. It is said that William Munroe, a cabinetmaker in Concord, Massachusetts , made the first American wood pencils in 1812. This was not the only pencil-making in Concord. According to Henry Petroski , Transcendentalist philosopher Henry David Thoreau discovered how to make a good pencil out of inferior graphite using clay as the binder; this invention was prompted by his father's pencil factory in Concord, which employed graphite found in New Hampshire in 1821 by Charles Dunbar. Munroe's method of making pencils was painstakingly slow, and in the neighboring town of Acton , a pencil mill owner named Ebenezer Wood set out to automate the process at his own pencil mill located at Nashoba Brook along the old Davis Road. He used the first circular saw in pencil production. He constructed the first hexagon- and octagon-shaped pencil cases that we have today. Ebenezer did not patent his invention and shared his techniques with whoever asked. One of those was Eberhard Faber of New York, who became the leader in pencil production. Joseph Dixon , an inventor and entrepreneur involved with the Tantiusques granite Mine in Sturbridge, Massachusetts , developed a means to Mass Produce pencils. By 1870 , The Joseph Dixon Crucible Company was the world’s largest dealer and consumer of graphite and later became the contemporary Dixon Ticonderoga pencil and art supplies company. Dixon Ticonderoga Company Tantiusques Graphite Mine MANUFACTURE Modern pencils are made industrially by mixing finely ground graphite and clay powders, adding water, forming long Spaghetti -like strings, and firing them in a Kiln . The resulting strings are dipped in Oil or molten Wax , which seeps into the tiny holes of the material, resulting in smoother writing. A juniper or Incense-cedar plank with several long parallel grooves is cut to make something called a slat, and the graphite/clay strings are inserted into the grooves. Another grooved plank is glued on top, and the whole thing is then cut into individual pencils, which are then varnished or painted. GRADING & CLASSIFICATION Many pencils across the world and almost all in Europe are graded on the European system using a continuüm from "H" (for hardness) to "B" (for blackness), as well as "F" (for fine point). The standard writing pencil is graded HB. According to Petrosky this system might have been developed in the early 1900s by Brookman (an English pencil maker) which used "B" for black and "H" for hard; a pencil's grade was described by a sequence or successive Hs or Bs such as '''BB''' and '''BBB''' for successively softer leads, and '''HH''' and '''HHH''' for successively harder ones.Petrosky 1990, page 157. Today a set of pencils ranging from a very hard, light-marking pencil to a very soft, black-marking pencil usually ranges from hardest to softest as follows. Today few companies produce the entire range of pencils grades. Koh-i-noor offers 20 grades from 10H to 8B (for its 1500 series)http://www.koh-i-noor.cz/main/main.php?pageid=3211&lang=4&=&filter=&cat=24&position=30 Koh-i-noor Catalog: Graphite Pencis; Derwent produces also 20 different grades (from 9B to 9H--for its Graphic pencils) http://www.pencils.co.uk/products/derwent.aspx?sid=3&p=1 Derwent Graphic, retrieved Aug 21, 2007 but Staedtler produces only 16 (from 8B to 6H--for its Mars Lumograph pencils)http://www.staedtler.com/Mars_Lumograph_gb.Staedtler?ActiveID=2213 Staedtler Mars Lumograph Pencils, retrieved Aug 21, 2007. The main market for such wide range of grades are artists who are interested in creating a full range of tones from light gray to black; while engineers prefer harder pencils which allow for a greater control in the shape of the lead. This is reflected in the way pencils are packaged and marketed. For example, for its Graphic pencils Derwent offers three packages of 12 pencils each: Technical (with hard grades from B to 9H), Sketching (with soft grades 9B to H), and Designer (with medium grades 6B to 4H). Another common method uses numbers to designated the grade of a pencil. It was originally created by Conté and adopted in the United States by Thoreau in the 19th centuryPetrosky claims that Conté used integer numbers that started at 1, with higher numbers indicating softer leads, while Thoreau used higher numbers to designate harder leads (Petrosky, 1990, page 157). It is believed that Thoreau developed independently his method of mixing clay and graphite, and his use of numbers to designate grades is evidence that he was at least aware of Conté methods and tried to reverse engineer them. Thoreau offered pencils graduated from 1 to 4 in the middle 1800s (Petrosky, 1990, page 119), see also .. The following table shows approximate equivalences between the different systems Petrosky, 1990, page 230):
The various graphite pencil grades are achieved by altering the proportion of graphite to clay: the more clay the harder the pencilhttp://www.staedtler.com/upload/graphite_video_eng_16461.mpg "Staedtler Pencil", video, retrieved Aug 21, 2007.Petrosky, 1990)http://www.pencils.co.uk/heritage.aspx?id=6&sid=1 Derwent Manufacturing Process, retrieved Aug 21, 2007. Two pencils of the same grade but different manufactures will not necessarily make a mark of identical tone nor have the same hardnessPetrosky claims that pencil grades vary "depending upon the manufacturer, when the penils are made, and the source of graphite and clay. One analyst found that graphitic carbon content, for example, to vary from about 30 to about 65 in a variety of different pencils bearing the same designation." Petrosky, 1990, page 229. Even though the known natural deposits of pure graphite are tapped out, it is still possible to write the way Englishmen did centuries ago, without clay or wax additives that leave oily stains on paper. Chemical supply companies commonly sell 99.995% pure graphite rods in 3 mm and 6 mm diameters. Various coatings are rated using the pencil hardness test. These coatings are used for paint, plastics and coatings for furniture. Below is a list of ratings for a variety of coatings. Type of coatings: Pencil Hardness Catalyzed polyester: 9H Catalyzed polyurethane: 9H Catalyzed Modified Acrylic polyurethane: 4H Catalyzed Acrylic polyurethane: 2H Water-based polyurethane: 3H Low VOC Catalyzed lacquer hrs : 2H Low VOC lacquer: 3H Urethane/Nitrocellulose lacquer [24 hrs}: F COLOUR OF PENCILS The majority of pencils made in the the trademark is now owned by Sanfordhttp://timberlines.blogspot.com/2005/08/mongolized.html Timberlines Blog "Mongolized" Aug 31, 2005, retrieved Aug 23, 2007). Not all countries use yellow pencils, however; German pencils, for example, are often Green , based on the trademark colours of Faber-Castell , a major German stationery company. Pencils are commonly round, Hexagonal or sometimes Triangular in section. PENCILS IN SPACE An Urban Legend in circulation since the 1970s (and told on a 2002 episode of '' The West Wing '') tells of NASA spending large sums of money, typically in the millions of dollars, to develop an instrument that would write in space (a Space Pen ). The typical punch line is that either someone supposedly should have sent NASA a pencil, or that the Soviets used pencils. While considered humorous, the story is not true. ''The Write Stuff'', Snopes. January 16, 2007. In fact, graphite pencils were used on all Mercury and Gemini space flights, and were replaced by pressurized " Space Pens " (independently developed without NASA funding) after the Apollo 1 fire. Pencils are, in fact, still used in space, for example aboard the International Space Station . TYPES OF PENCILS According to the material used to make them
According to their use
According to their shape
Other types
MISCELLANEOUS Pencils are students' primary writing instruments. Due to this common usage, the pencil is a common cause of minor puncture injuries in young children. The tip of the lead may leave a grey mark inside the skin for years. This led to the Old Wives' Tale that the lead bits could be passed through the blood vessels into the brain, causing Mental Retardation in those with such a wound. But of course, pencil "lead" is graphite ( Carbon ) and not the chemical element Lead . Residual graphite from a pencil stick does not seem to be poisonous, and graphite is generally harmless if consumed. Graphite - Identification, toxicity, use, water pollution potential, ecological toxicity and regulatory information On March 30 , 1858 , Hymen Lipman received the first Patent for attaching an Eraser to the end of a pencilhttp://patft.uspto.gov/netacgi/nph-Parser?patentnumber=19783 US Patent 19783 Combination of Lead-Pencil and Eraser by L. Lipman. In 1862 Lipman sold his patent to Joseph Reckendorfer for $100,000, who went to sue Faber for infringement Petroski, Henry (1990). ''The Pencil: A History of Design and Circumstance''. New York: Alfred A. Knopf. ISBN 0-394-57422-2; ISBN 0-679-73415-5, page 171. In 1875 the Supreme Court of the United States ruled against Reckendorfer declaring the patent invalid http://supreme.justia.com/us/92/347/case.html Reckendorfer v. Faber 92 U.S. 347 (1875). There are also Mechanical Pencil s, which use mechanical methods to push lead through a hole at the end. The erasers are also removable (and thus replaceable), and usually cover a place to store replacement leads. Mechanical pencils are popular for their longevity and the fact that they never need sharpening. Lead types are based on thickness. Common sizes are 0.3, 0.5, 0.7, 0.9, 1.1, and 1.6 Millimetre s. The 2.0 mm size is commonly used in designing, artwork, and engineering, but is not commonly used outside these fields due to its high cost. This largest size usually cannot be sharpened in Pencil Sharpeners : a variety of devices are used, mostly abrasive. EXTERNAL LINKS
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