Ceredo advance. [volume] (Ceredo, W. Va.) 1885-1939, 1886-08-19
LEAD PENCILS.
The American and Foreign Process
Of Making Them.
DAILY Consumption by This Country. n
Quarter OF "a MILLION Graphite and Its
observation-disclosures the Coll
flllnE the Leads.

frliIng the Leads.
Inc CONSUMPTION of lead pencils I'm
this country is estimated at $50. 900 a
day. This is at the rate of one per dav
TO every 160 of population. or about
'S,Ooo,ooo year. Graphite. which is
the soitest substance dug from the
earth, is taken in the lump direct from
inc mouth of the mine to the reducing
mill. Here il is pulvcrizod by stamps
under water, the PARTICLES floating of
with the water through a ,eries of
tanks. IL comes to the factory in bar
relS, IN the form of dust The powder
Is lusfcrless and OF "A dingy color 1t
Is inner and softer than any -four. and
can be taken up in the hand lust AS
water can, but is hardly retained more
easily than water is. II one ATTEMPTS
To take pinch of it between the fore
hnger and thumb it is as evasive as
quicksilver, and the only sensation left
i That the flesh is smoother than be-
fore.
The first process in manufacturing is
TO separate the graphite dust further.
W niltntN>. II Il mixed with
s"lhcieht water to run very freely, and
Is then turned into hopper, from
Which the water runs slowly through
series of tubs. The coarsest and
heaviest PARTICLES settle to the bottom
of the first tub. the next coars-
est and heaviest in the next. and so
on. the movement of the water being
made very gentle. On reaching the
last tub the powder, being twice -
heavy as water and sinking in it if I'M
disturbed, has so far settled that the
water discharged at the top is nearly
clear After the How is stopped and
the powder allowed TO settle the clear
water Is Withdrawn by removing sue
ccSslvely, beginning with the upper
one, number of plugs inserted i'm
holes I'm the side of each tub, care be-
ing used not To agitate the contents so
rs TO disturb the deposited dust. This
being done properly, the deposit is
removed through the gates at the bot
tom of each tub. The separation i
thus performed, by this ingenious
process of floating more perfectly
Than 1t could be by any direct handling.
airy treatment being wholly imprac-
ticablc. For the finest pencils the de-
post from the last tub only is used.
but for ordinary and cheap grades that
from the two before the last will an
swcr
The graphite is now ready for the
Clay. This is peculiar pipe clav.
from Germany. Al er being subjected
10 the hoating process, the finest is
mixed with the graphite. in proper
uons varying according To the degree
OF hardness required. The more clay
hn Ii. 81
dunn grades the proportion is about
sven parts clay to ten graphite by
we ght The graphite and clay are
mixed together with water. TO the CON
sistency OF thick cream. and the MKT
ure is fed TO the grinding-mills, which
consist of two flat stones about two
feet in diameter. placed horizontally.
only the upper one running. Between
these the mass is ground like paint. for
the finest pencils Is many as twenty
lour times. thus securing the most per
l"ct strength. uniformity, and freeness
from grit IN the leads. After UfindiuO
the mass Is incloscd i'm stout canvas
bags, and the clear water forced
out by hydraulic pressure until il be-
comes thick dough II then goes to
the forming-press. This is simply a
small vertical iron cylinder. having a
solid plungcr or piston driven by n
srrrw. plat" is inserted i'm the bot
tom, having an opening OF the shane
and size of the lead desired. and the
graphite is slowly forced through the
hole. exactly ~ water is forced through
Syringe. cOiling itself round and
round like coil of wire on board
set beneath toe press. The coil is taken
up 90 intervals rove on straight by
the hands into lengths sufficient for
three leads, which are Strengthened
ont laid in order on board. and
pressed llat by putting o cover over
UcW They are finally hardened by
placing them in q cruciblc aud baking
% kiln The handling must be- done
cNrodiuOusly. a- thc leads begin dry
Ing Immediately and become brittle II,
they dry; but on first issuing from the
press they are so plastic that knots
may be tied loosely In them
The leads are now ready for their
wooden case. For The cheapest pencil
pine d, used. Tor the common grades an
ordinary quality of rcd cedar At tho
saw mills the cedar Is cut into
blocks about seven inches long
and these are sawed into strips about
three aud half inches wide
aud thrco--ixternths 81 an inch
thick The pencil consists Of two part.
glued together with the lead be-
tw' en- Each strip is wide enough m
make The balyr. Of SIS pencils The
pcncil- are made six 40 time. and
imperfect strips are put together 30 "A,
~ mako full strip out Of the parts.
W hen those boari. (Which are now
ready for -haping) reach the factory
thcN are first passed in "a cDufiuuou,
linn under e cutter. which cuts So,
l'tlo grooves, round or square. for tho
ioads. and .mOothcs the faces by the
same stroke. The lead in the foreign
pencil Iirs wholly in one-half Of III,
wood, Che other Slip being put on AZ Z
cover. as nearly every body has found
occasion TO know by The covers com
in@ oh and leaving an unplcasantly na.
rincc but the American method Ia.
groove equally in each strip Accord
Wsiy Che twp strips are glued alike.