Pencil

This article is about the handwriting tool. For other uses, see Pencil (disambiguation).

A selection of colored pencils.

A pencil is a handheld instrument containing an interior strip of solid material that is used to shove up anol and draw, usually on Paper. The marking material is most commonly graphite, typically contained inside a wooden sheath. However, other marking materials are used, such as charcoal or cosmetics (as in an eyebrow pencil). Colored pencils employ pigments, including those used in oil and watercolor paints. Pencils may also have an eraser or "rubber" attached to one end, typically by means of a metal ferrule. Unlike pencils, pens use a liquid marking material, ink.

History

Simple pencils.

The prototypical pencil may have been the ancient Roman stylus, which was a thin metal stick, often made of lead and used for scratching on papyrus. The word pencil comes from the Latin word penicillus 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 sawed 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 "acts like lead"). The black core of pencils is still called "lead", even though it does not contain the element lead.

The value of plumbago was soon realised 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 the plumbago was soft, it required some form of case. Plumbago 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. They used a mixture of graphite, sulfur and antimony. Though usable they were inferior to the English pencils.

File:Pencil manufacture.JPG

Pencil manufacturing

It was the Italians who first thought of wooden 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 cause of being able to mark 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 plumbago stick inserted, and the two halves then glued together—essentially the same method that is 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 which were then fired in a kiln. By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied (the more clay, the harder the pencil, and the lighter the color of the mark). This method of manufacture remains in use today.

America 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. If so, 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.

Manufacture

File:Artwork 2b to 6b.jpg

Artwork made using 2B–6B pencils.

Today, 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.

Many pencils, particularly those used by artists, are labelled on the European system using a scale from "H" (for hardness) to "B" (for blackness), as well as "F" (for fine point). The standard writing pencil is "HB". However, artist's pencils can vary widely in order to provide a range of marks for different visual effects on the page. A set of art pencils ranging from a very hard, light-marking pencil to a very soft, black-marking pencil usually ranges from hardest to softest as follows:

9H

8H

7H

6H

5H

4H

3H

2H

H

F

HB

B

2B

3B

4B

5B

6B

7B

8B

9B

Hardest

→

Medium

→

Softest

The American system, using numbers only, developed simultaneously with the following approximate equivalents to the European system.

Tone	U.S.		Europe
	#1	=	B
	#2	=	HB
	#2 ½ *	=	F
	#3	=	H
	#4	=	2H

* Also seen as 2 4/8, 2.5, 2 5/10, due to patent issues

Even though the 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 leaving oily stains on paper. Chemical supply companies commonly sell 99.995% pure graphite rods in 3 mm and 6 mm diameters. The largest commonly available mechanical pencils ("lead holders") take 2 mm leads.

Pencils in space

A story 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). This task is not as simple as it seems, as standard ballpoints and fountain pens require gravity in order to function. The typical punch line is that either someone sends NASA a pencil, or that the Soviets used pencils.

While humorous, the story is not true (See Snopes for details). Writing with a pencil produces graphite dust, which when weightless would float about the cabin. From there it could become a health risk by being inhaled by the astronauts, clog filters in the ventilation system, or even cause short-circuits by getting into switches and other electrical equipment.

Color of pencils

Pencils in the United States and Canada tend to be painted yellow on the outside. According to Henry Petroski, this tradition now extends to a majority of pencils worldwide, and began in 1890 when the L. & C. Hardtmuth Company of Austria-Hungary introduced their Koh-I-Noor brand, named after the famous diamond. It was intended to be the world's best and most expensive pencil, and at a time when most pencils were either painted in dark colors or not at all, the Koh-I-Noor was yellow. As well as simply being distinctive, the color may have been inspired by the Austro-Hungarian flag; it was also suggestive of the Orient, at a time when the best-quality graphite came from Siberia. Other companies then copied the yellow color so that their pencils would be associated with this high-quality brand, and chose brand names with explicit Oriental references, such as Mikado and Mongol.

Not all countries however use yellow pencils; German pencils, for example, are often green, based on the trademark colors of Faber-Castell, a major German stationary company.

common pencil colors
United States
Canada
Germany
India
Switzerland	File:RedPencil.jpg
United Kingdom

Shape of pencils

Most pencils today are hexagonal in cross-section. This shape is comfortable to hold, the pencil will come to a stop if rolling on a desk, and less wood is wasted in manufacturing than with a round pencil. Carpenter's pencils have a flattened shape, which also will not roll, and allows for a more precise positioning of the line drawn.

Miscellaneous

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 retardation in those with such a wound. Of course, pencil lead is graphite (carbon) and not the element lead, so it is not poisonous.

See also

• Ballpoint pen
• Dixon Ticonderoga
• Fountain pen
• Mechanical pencil
• Pencil case
• Pencil lead
• Pencil sharpener

References

• Petroski, Henry (1990). The Pencil: A History of Design and Circumstance. New York: Alfred A. Knopf. ISBN 0394574222; ISBN 0679734155.
• Petroski, Henry. H. D. Thoreau, Engineer. American Heritage of Invention and Technology, Vol. 5, No. 2, pp. 8-16.

External links

• paper and pencil
• The Pencil Pages – A website containing history, numbering systems, and other pencil information
• The Pencil Place – A pencil collecting website
• Pencil Revolution
• Pencil information More information about the pencils.
• The Cumberland Pencil Museum in Keswick
• History of pencils, pencil lead; details of modern pencil manufacture – An article from the American Chemical Society