The Anderson intelligencer. [volume] (Anderson Court House, S.C.) 1860-1914, 1899-07-05
ARE MADE OF GRAPHITE.
Lead Docs Not Enter Into the Com
position of Pencils.


The first thing to be said about lead
pencils is that they are not lead pencils
at all. Once upon time sticks of lead
were used for making marks on paper
and wood, and the name has survived,
though nowadays all the pencils are
filled with graphite. or plumbago. This
mineral is found in only a few places in
the world-in Cumberland, England,
along the Laurentian ranges in the
province OF Quebec and at Ticonderoga.
VT. The largest mines on this conti-
ncnt are at the latter place.
The graphite is taken in the lump
from the mines and carried to the re-
ducing mill. where it is ground or pull
verized in stamp mills under water.
The fine particles of graphite float away
with tie water through number Of
tanks. collecting at the bottom of these
reservoirs. 1t is packed in barrels in
the form of dust and sent to the factory,
where tens of thousands Of lead pencils
are turned ont every day. The pulver-
lied graphite is go fine that; it really is
dust, dingy in color and smooth and
oily to the touclI 1t is divided into va
rious grades Of fineness by f1oating it on
water from one tank to another. The
coarse dust sinks to the bottom OF the
first tank, the next finer to the bottom
of the second tank, and so On down the
line, the finest powder for the finest
+1,. 1o,t
In another series Of tanks the German
pipe clay, which is mixed with graphite
to secure the 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,
being ground together between stones,
and the hardness of the pencil is secured
by increasing the proportion of clay in
the mixture.
For the medium grades seven paris
by weight of clay are mixed with ten
parts of graphite After the graphite
and clay are ground together the mix
ture is put in canvas bags and the wa
ter is squeezed out under Il hydraulic
press, leaving mass the consistency
of putty. The plaster is placed in L
forming press. which is a small iron
cylinder, III which solid plunger OF
piston works MP and down. A steel
plate having 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 continuous
thread of wire of graphite. As long as
! this thread is moist it is pliable, but it
becomes brittle when dry, so it is han
died rapidly. It is cut into three lead
lengths, Strengthened out and then
hardened in "a crucible over coal lire.
The leads when taken from the crucl-
bles are ready for the wood, which is
pine for cheap pencils and cedar for
more expensive ones. When the strips
of wood are received at the factory,
they are run through machine which
cuts in each one six grooves, round or
square. and ut the same time smooths
the face of the wood.
The filing cf the strips is done 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 she fills the six grooves with
leads Next to her sits another girl,
who takes the filled strips and quickly
and neatly lays on another grooved
strip which has just been coated with
hot glue by third girl The filled and
glued strips are piled upon each other
and put in press, where they are left
to dry. The ends Of the strip are evened
off under sandpaper wheel, and then
the strips are fed into 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 is done with
liquid dyes after which the pencils are
sent through the vanishing machine. =
School and Home.