Dodge City times. [volume] (Dodge City, Kan.) 1876-1892, 1886-08-26
LEAD PENCILS.
The American and Foreign Process
of Making Them.
Daily Consumption by This Country, a
Quarter of a Million-Graphite and Its
Observation-Disclosures the Coil
Filling the Leads,


The consumption OF lead-pencils il
this country is estimated at 25O. 900
day. This is at the rate of one per da,
to every 100 of population. or abou
"S'oOo'ooo 4 year. Graphite, which i
the softest substance dug from tn,
earth, is taken in the lump direct from
the mouth of the mine to the reducing
mill. Here il is pulverized by stamp
under water, the particles floating OF
with the water through series O
tanks, 1t comes to the factory in bar
rcls, in the form of dust The powde,
is lusterlcss and of a dingy color Il
Is liner and softer than any Hour. anC
can be taken up in the hand Just a.
water can, but is hardly retained NOR,
easily than water is. If one attempt.
to take pinch of it between the fore
1nger and thumb it is as evasiyc n,
quicksilver, and the only sensation LEFT
Is that the flesh is smoother than be.
fore
The first process In manufacturing i,
to separate the graphite dust further
according to iinencss. It's mixed with
sufficient water to run very freely. and
is then turned into a hopper, from,
winch the water runs SLOWLY through
n 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 baino
made very gentle. On reaching the
last tuS the powder, being twice AS
heavy as water and sinking in it if un-
disturbed, has so far settled that the
water discharged at the top is nearly
clear. After the flow 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water is withdrawn by removing sue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 in
hoIes I'm the side of each tub, care be-
Tag 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 is
thus performed, by this ingenious
process of floating" more perfectly
than it could be by any direct handlinc.
dry treatment being wholly imprac-
ticable. 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
swer
The graphite is now ready for the
clay. This is peculiar pipe clay,
from Germany. After being subjected
to the floating process, the finest is
mixed with the graphite, in proper
tons varying according TO the degree
OF hardness required. The more clay
used the harder the pencil For me-
dun grades the proportion is about
seven parts clay to ten graphite by
weight 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 as many rs twenty
four times, thus securing the most per-
feet strength. uniformity, and freeness
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
solid plunger or piston driven by a
screw. A plate is inserted in the bot
tom, having an opening of the shape
and size of the lead desired, and the
graphite is slowly forced through the
hole. exactly as water is forced through
a syringe, coiling itself round and
round like a coil of wire on a board
set beneath the press. The coil is taken
up at intervals, rove off straight by
the hands into lengths sufficient for
three leads, which are Strengthened |
out. laid in order on a board, and |
pressed flat by putting q cover over
them. They are finally hardened by |
placing them in crucible and baking |
in kiln. The handling must be done |
expeditiously, as the leads begin dry
ing Immediately 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
ordinary 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-siyteenths of an inch
thick. The pencil consists of :wo 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 Mt time, and
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 cutter. which cuts SIX
little grooves, round or square, for the
leads, and smoothcs 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 a
cover, rs nearly every body has found
occasion to know by the covers COM
ing of and leaving an unplcasantly flat
surface; but the American method has
groove equally in each strip. Accord
ingly the two strips are glued alike.