Pencil, a derivative of the Latin word
pencillus for "little tail," originally described a small, fine,
pointed brush.
N. J. Conte, in 1795, successfully produced pencils, after the
later famed Faber family of Nuremberg, Germany, failed to do so, by
using a pulverized graphite base to create a substandard,
crude prototype of a pencil. Conte's method, the basic recipe used
by all pencil manufacturers today, differed from the failed Faber
fiasco, as he ground graphite, mixed it with certain types of clay,
pressed the "dough" into sticks, and finished them in a kiln. The
Faber family followed suit, and achieved the fame and fortune
that previously eluded it.
The recipe used by modern pencil manufacturers, calls for dried,
ground graphite, a form of carbon, mixed with clay and water in
varying proportions. Pencils made with more clay produce a harder
pencil, and, conversely, pencils made with more graphite produce a
softer pencil. In either case, the ingredients are mixed until they
reach a doughy consistency, then pass through a forming press, which
presses the dough into a "pencil thin," smooth, glossy rope. After
workers straighten the rope, they cut it into the desired lengths,
and bake them in industrial ovens.
While the mixture is prepared and baked, workers prepare the
casing that will house the lead. They shape the wooden casings, made
from either red cedar or pine, into halves, and carve grooves in
them to encase the graphite-based leads. The workers then carefully
insert the finished leads into the grooves, glue the two wooden
halves together, run the resulting slats through a saw that cuts
them into single pencils, and finish them with a shaping machine
that smoothes the pencils' surfaces.
Modern pencils come in over 350 flavors, each designed for a
specific use, and may be purchased in over 72 colors. "Black
pencils," graphite-based pencils, come in 19 degrees of hardness and
of intensity. Specialty pencil leads are crafted to write on
surfaces such as cloth, cellophane, plastics, and movie film.
Architects, engineers, and those doing out door construction work
primarily purchase these specialty leads, as they possess non-fade,
weatherproof qualities. The versatility of Conte's brainchild, the
pencil, makes it the essential, indispensable tool of these
trades.
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note:
graphite :石墨
follow suit:
效仿
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