I did a lot of research on this a few years ago and made a nice handout on
it. I have included the text below for your info. Sorry that I could not
attach the nicely formatted page, but at least you have the information if
you want it - by the way - cool pencil facts at the bottom of the section.
All about the
In ancient Rome, scribes wrote on papyrus (an early form of paper from
Egypt) with a thin metal rod called a stylus, which left a light but
readable mark. Other early styluses were made of lead. Today we still call
the core of a pencil the "lead" even though it is made from nontoxic
Graphite came into widespread use following the discovery of a large
graphite deposit in Borrowdale, England in 1564. Graphite left a darker mark
than lead, making it ideal for use by writers and artists, but was so soft
and brittle that it required a holder. At first, sticks of graphite were
wrapped in string. Later, the graphite was inserted into wooden sticks that
had been hollowed-out by hand!
The hardness or softness of these pencils was dependent on the quality or
purity of the graphite, and so was difficult - or impossible - to control.
Different methods of refining and mixing of graphite were experimented with
over the years, but it was not until about 1795 that a Frenchman,
Nicolas-Jacques Cont?, developed a process for making pencil leads that is
still in use today. The process, known as the Cont? Process, involves the
mixing of finely powdered graphite with finely ground clay particles and
shaping and baking the mixture. By controlling the ratio of clay to
graphite, varying degrees of hardness can be obtained, as well as fairly
consistent and reproducible quality from batch to batch.
By the beginning of the twentieth century, a combination letter-number
system had been established and was in use by nearly all European pencil
makers, and was also used for some American-made pencils. This system is
still in use today, and provides for a wide range of grades, usually
consisting of the series:
9H, 8H, ... , 2H, H, F, HB, B, 2B, ... , 8B, 9B
where 9H (Hardness) is the hardest, 9B (Blackness) is the softest. The
letter "F" is also used to indicate that the pencil sharpens to a fine pont.
At the same time, a number-only system was in use, particularly in the U.S.,
which is still in use. The list below indicates approximate equivalents
between the two systems:
#1 --- B, #2 --- HB, #2? --- F, #3 --- H, #4 --2H
The common #2, or HB grade pencil in the middle of the range, is considered
to be the preferred grade for general purpose writing. Harder pencils are
most often used for drafting purposes, while softer grades are usually
preferred by artists.
Pencils have been painted yellow ever since the 1890s. And that bright
colour isn't just so you can find them on your desk more easily! During the
1800s, the best graphite in the world came from China. American pencil
makers wanted a special way to tell people that their pencils contained
Chinese graphite. In China, the colour yellow is associated with royalty and
respect. American pencil manufacturers began painting their pencils bright
yellow to communicate this "regal" feeling and association with China.
The typical pencil can draw a line 56.3 kilometers ( 35 miles) long!
The average pencil can be sharpened 17 times.
You can write about 45 000 words with a pencil.
Each year, more than 14 billion pencils are produced.
300 000 pencils can be made from a sizeable tree.
Until 1876 almost all pencils were square . Then hexagonal, round and other
shapes began to appear.