Bismarck weekly tribune. [volume] (Bismarck, Dakota [N.D.]) 1884-1943, 1896-09-18

PENCIL MAKING
GRAPHITE, PIPE CLAY AND WOOD
THE COMPONENT PARTS.

~ - NlNO VOOO
THE COMPONENT PARTS.
An Interesting Account Of How the Ma
terials Are Reduced and Put Into Shape.
Highly Perfected Machinery That Pro.
duces In Large Quantities.
The ''leads" of lead pencils are made of
q mixture of German pipe clay and "black
lead" which Is not lead, but graphite. But
the first pencils were made Of real lead,
and the nam has chung to ''lead'' pencils
ever since. Graphite, or plumbago, is near
ly a pure form of carbon, and most of the
pencils made IN this country use the
graphite mined at Ticonderoga. where
the only graphite mine Of any consequence
in the United States is located,
The graphite is taken in the lump from
the mines and carried to the reducing
mill, where 1t Is ground or pulverized in
stamp mills under water. The fine par
ticles of the graphite float away with the
water through a number Of tanks, collect
Ing at the bottom of these reservoirs.
1t Is packed in barrels in the form of
dust n sent to the factory, where tens OF
thousands of lead pencils ore turned out
every day.
The pulverized graphite is so fine that
1t really is a dust, dingy In color and
smooth and oily to the touch. It is divided
into various grades of flneness by floating
1t on water from one tank to another.
Thu coarse dust sinks to the bottom of
the first tank, the next finer to the bottom
of the second tank, and so on down tho line,
the finest powder for the finest pencils set
thing In the last tank.
In another series of tanks the German
pipe clay, which is mixed with graphite
to secure tho different grades of pencils,
from very soft to extra hard, is graded in
the same way, by floating. The finest clay
Is mixed with the finest graphite, and tho
hardness of the pencil is secured by increas-
Ing the proportion Of clay in the mixture.
Fol the medium grades seven parts by
+ weight of clay are mixed with ten parts of
graphite. The mixing is lone under a
grinding mill similar to that used for
mixing paint, and water is added to facili-
tate the mix. The grinding stones arc
about 2 feet in diameter, and only the I'D
per one revolvcs.
After the graphite and clay are ground
together the mixture is put in canvas bags,
and the water is squeezed out under a hy-
draulic press, leaving a mass the consist
ency of putty. This plaster material is
placed In the forming press, which is q
SMALL iron cylinder, in which Il solid plunger
or piston works up md down. A steel
plate having a hole the size and shape Of
the lead is put under the open end Of
the cylinder, and the plunger, pressing
down, forces the graphite through the hole,
making a continuous thread or wire Of
graphite. AS long as this thread is moist
1t is pliable, but it becomes brittle when
dry, so it is handled rapidly. It is cut into
three lead lengths, Strengthened out, and
then hardened in a crucible over a coal
fire. The leuds when taken from the cruel
BILE are ready for the wood.
Pine is used for the cheap pencils, an
ordinary quality of red cedar is used for
the medium priced pencils, but nothing but
the best Florida Key cedar is put nto the
best pencils.
The sawmills in Tampa, Fla, cut the
cedar into blocks about seven inches long,
and these are sawed into strips wide enough
for six pencils, but as pencils are made in
halves each strip Is only thick enough for
half a pencil.
When the strips are received at the fac
tory, they are run through a machine
which cuts in each one six grooves, round
or square, and at the same time smooths
the face Of the wood. Both strips are
grooved alike, for, unlike the European
made pencils, the American make has the
lead equally in each strip.
The filling of the strips is lone by girls.
The first one takes a grooved strip of wood
In her left hand and a bunch Of leads in
the right. She spreads the leads out fan
shape, and with one motion fills the six
grooves with leads.
Next to her sits another girl who takes
the filled strip and quickly and neatly u la
on it another grooved strip which has lust
been coated with hot glue by a third girl.
The filled n glued strips are piled up
on each other and put in q press, where
they are left to dry. The ends of the strips
are evened off under a sandpaper wheel,
and then the strips are fed into q machine
which cuts out the individual pencils,
shapes them and delivers them, smooth
and ready, for the color and polish in six
streams.
The coloring isdone in liquid dyes, after
which the pencils are sent through tine
vanishing machine. Then follows the
stamping and finishing, all lone by auto
matte machines, and finally the finished
pencils are packed around the oval, grooved
CLOCKS, tied, papered and shipped out.
The pencils are counted at various stages
of the making, and the counting is done
In a way as simple as it is accurate. The
counting board" is a board on which two
strips of wood are fastened the length Of
the board and about four inches apart.
In each strip are IA grooves. The work.
man grasps a handful of pencils and rubs
them over the board once or twice, leaving
a pencil in each groove.
In this WY he counts a gross Of pencils
in a few seconds and does it without a
mistake, for only IA pencils can be placed
on the board at one time, and if any
grooves are empty the workman notices
the mistake at nce.-Chicago Record.
His Weights.
A Canadian baker bought his butter in
! pound rolls from a farmer. Noticing that
these rolls looked rather small, he weighed
them, and found that they were all under