Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1886-09-09
LEAD PENCILS.
How They Arc Manulactured-Daily Com
sumption by the Country, 100000.

Graphite and Its Peculiarities-Mix
the Clay and Forcing the Coil.
The consumption OF lead-pencils in
this country is estimated at 100000 a
day. This, says the Brooklyn Eagle. is
at the rate of one per day to every 100
of population, or about 78,000,000 n
year. Graphite. which is the softcst
substance dug from the earth, is taken
in the lump direct from the mouth of
the mine to the reducng-mill. Here it
is pulyerized by stamps under water,
the particles floating off with the water
through serious of tanks. 1t comes to
the factory in barrels, in the form of
dust. The powder is lusterless and of
dingy color. 1t is finer and softer than
any flour, and can be taken up in the
hand just rs water can, but is hardly
retained more easily than water is. If
one attempts 10 take pinch of it be-
tween the foretinger and thumb, it is as
eyasive rs quicksilver, and the only SEN
sation left is that the flesh is smoother
than before
The first process in manufacturing is
to separate the graphite dust further,
according to tineness. 1t is mixed with
sufficient water to run very freely, and
is then turned into hopper, from which
the water runs slowly through a series
of tubs. The coarsest and heaviest par
tlcles settle to the bottom of the first tub,
the next coarsest and heaviest in the
next, and SO on. the movement of the
water being made very gentle. On reach
ing the last tub the powder, being twice
us heavy us water and sinking in it if
has so far settled that the
water discharged ut the top is nearly
clear. After the flow is stopped and the
powder allowed to settle the clear water
is withdrawn by removing successfully,
beginning with the upper one, q num-
Der of plugs inserted in holes in the side
OF each tub, care being used not to agi-
tate the contents so as to disturb the de-
posted dust. This being done properly,
the deposit is removed through the gates
at the bottom of each tub. The separa-
ton is thus performed, by this ingenious
process of ''foating,n more perfectly
than it could be by any direct handling,
dry treatment being wholly impractical
bic. For the finest pencils the desposit
from the last tub only is used, but for
ordinary and cheap grades that from the
two before the last will answer.
The graphite is now ready for the
clay This is a peculiar pipe clay, from
Germany. After being subjected to the
floating process, the finest is mixed with
the graphite, in proportions varying &C.
cording to the degree of hardness re-
CURED. The more clay used the harder
the pencil. For medium grades the pro-
portion is about seven parts clay to ten
graphite by weight. The graphite and
clay are mixed together with water, to
the consistency of thick cream, and the
mixture is fed to the grinding-mills,
which consist of two Hat stones about
two feet in diameter, placed horizontal
~, only the upper one running. Be-
tween these the mass is ground like
paint, for the finest pencils as many as
twenty-four times, thus securing the
most perfect strength, uniformity, and
from grit in the leads. After
grinding the mass is inclosed in stout
canvas bags, and the clear water forced
out by hydraulic pressure until it be-
comes thick dough. 1t then goes to
the forming press. This is simply small
vertical iron cylinder, having 4 solid
plunger or piston driven by screw. A
plate is inserted in the bottom, having
an opening of the shape aud size of tho
lead desired and the graphite is slowly
forced through the hole, exactly as water
Is forced through Il syringe. coiling it
self round and round like coil of wire
on Il board set beneath the press. The
coil is taken up at intervals, 'roye" off
straight by the hands into lengths suili-
Gent for three leads, which are straight
ened out, laid in order on board. and
pressed flat by putting q cover over
them. They are finally hardened by
placing them in a crucible and baking
in kiln. The handling must be done
eXpeditlousiy, as the leads begin drying
and become brittle as they
dry; but on first issuing from the press
they are so plastic that knots may be
tied loosely in them
The leads arc now ready for their
wooden case. For the cheapest pencil
pine is used. for the common grades an
quality of red cedar AT the
saw-mills the cedar is cut into blocks
about seven inches long, and these are
sawed into strips about three and half
inches wide and three-sixteenths of an
inch thick. The pencil consists of two
parts glued together, with the lead be-
tween. Each strip is wide enough to
make the halves of six pencils. The
pencils are made six at time. and inn
perfect strips are put together so as to
make full strip out OF the parts. When
these boards (Which are now ready for
shaping) reach the factory they are first
passed in a continuous line under a cut
ter, which cuts six little grooves, round
or square, for the leads, and smooths
the faces by the same stroke. The lead
in the foreign pencil lies wholly in one
half of the wood, the other slip being
put on as 4 cover, as nearly everybody
has found occasion to know by the COW
ers coming off and leaving an unpleas-
antly fiat surface; but the American
method has the glue equally in each
strip. Accordingly the two strips are
glued alike
Filling the leads is done By girls, sitting
at Grass covered tables. The first takes
a grooved slio with her left hand and a
bunch Of leads in her right Spreading
these out in her fingers like the sticks of
a fan. she dexterously lays them in the
grooves and passes the filed slip to the
girl at the left, who puts over it another
slip which has just received a coating of
hot glue from q brush welded by q
third. Any two slips fit together, and
the united pairs are laid in row and
pressed together in an iron frame by a
screw, and the row Of slips is left to dry.
The rough ends Of the slips and the pro-
jecting parts are next ground smooth
against n wheel covered with sand
paper. and are then ready for the most
and characteristic process Of
of separating and shaping.
The foreign maker Still makes each
pencil separately. His glued slip is one
pencil, and ne formerly shaped it by
hand, but now does that by a plane
driven back and forward by machinery.
Yet it is still one at time with him,
and after shaping his pencil be has to
smoother it with sand-paper. Not so
in the American factories. The work of
separating and shaping them is done
by the same operation of single ma
chine. The slips are fed one by one I'M
der a revolving cutter, which separates
and rounds them on one side by cutting