Wichita eagle., 1886-11-11
~SSNiLIa~
9ailY eagle
MAKING LEAD PENCILS.
DAILY CONSUMPTION BY THE cOuN-
TRY ONE-oUARTER MILLION.

Separating the Graphite Dust Accordin.
to Eineness-sIixing the Clay and Fore
ing the Coil-The Wooden Case and
Filling 1t.
The consumption of lead pencils in this
country is estimated at 25O, 600 a day. This
Is at the rate Of one per day to every 100 Of
population, or about 5000, 600 a year.
Graphite, which is the softest substance dug
from the earth, is taken in the lump direct
from the mouth Of the mine to the reducing
mill. Here it is pulverized by stamps under
water, tho particles floating off with the
water through g series of tanks. It comes 10
the factory in Brooklyn in barrels, in the
form Of dust The powder is lusterless and
OF dizzy 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
to take pinch of it between the forefnger
and thumb it IS as evasive as quicksilver,
and the only sensation left is that the flesh is
smoother than before
The first process in manufacturing is to sep
arate the graphite dust further, according to
fineness 1t is mixed with sufficient 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 cOarseSt 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 rs heavy as
water and sinking in it If undisturbcd, has 50
far settled that the water discharged at the
top is nearly clear. After the flow is stopped
and the powder allowed 20 settle the clear
water Is withdrawn BY removing successfully,
beginning with the upper one, q number Of
plugs inserted in holes in the side OF each tub,
care being used not to agitate the contents SO
as to disturb the deposited dust This being
done properly, the deposit is removed through
the gates at the bottom Of each tub. The
separation is thus performed, by this ingen-
ious process of floating, more perfectly than
it could by any direct handling, dry treat
Inent being wholly inpracticable. For the
finest pencils the deposit from the last tub
only is used, but for ordinary and cheap
grades that from the two before the last viii
answer.
READY FOR THE CLAY.
The graphite is now ready for the clay.
This is q peculiar pipe clay, from Germany.
After being subjected to the floating process
the finest is mixed with the graphite, in pro-
portions varying according to the degree of
hardness required. The more clay used the
harder the pencil For medium 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 mixture is
fed to the grinding mills, which consist of two
fiat stones, about two feet in diameter, placed
horizontally. only the upper one running.
Between these the mass is ground Ike paint
for the finest pencils as many as twenty-four
times, thus securing the most perfect 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 IL becomes a thick
dough.
1t then goes to the forming press. This is
simply small vertical iron cylinder, having
"a solid plunger or piston driven by a screw.
\ plate is inserted in the bottom, having al
opening of the shape and size of the lead de-
sired, and the graphite is slowly forced |
through the hole, exactly as water is forced |
from q syringe, coiling itself round and round |
like coil OF wire on a board set beneath the |
press. The coil is taken UP at intervals, "rover
off straight by the hands into lengths suffi-
Gent for three leads, which are Strengthened
KID pIleT pressed ll.tC
by putting a cover over them. They are
finally hardened by placing them in q crucible
and baking in a kiln. The handling must be
done expeditiously, as the leads begin drying
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 WOODEN CASE.
The leads are 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, ab0tt seven inches long. and |
these are sawed into strips about three and a |
half inches wide and three-sixtcenths of an |
inch thick. The pencil consists of two parts |
glued together, with the lead between. Each |
strip is wide enough to make the halves of |
six pencils. The pencils are made six ut Il |
tine, and imperfect strips are pat together SO
as to make a full strip out OF the parts. |
When these boards (which are now ready for |
shaping reach the factory, they are first |
passed. into a continuous line. under a cutter
which cuts six little grooves, round or square, |
for the leads and snoo;hs the faces by the |
same stroks. The lead in the foreign pcscil |
lies wholly in one-half of the wood the other |
slip being put on as cover, as nearly every !
covers coming off and leaving an unpieas- |
antly fat surface; but the American method |
has the groove equally in each strip. Accord |
ingly the two strips are glued alike
Filling the leads is done by girls sitting at |
braSs-covercd tables. The first takes u groov- /
cd slip with her left hand and a bunch OF /
leads in her right. Spreading these out III her |
fingers Ike the sticks OF Il fan, she dexterous- |
" lays them in the grooves and passes the /
filled slip TO The girl at the left, who puts over
ii another slip which has just received n coat |
ing Of hot glue from a brush welded by 1
third Any two slips tit together, and the |
united pairs are laid in row and pressed to- |
gether in an iron frame by screw. and the !
row OF slips is left to dry. The rough oRds Of /
the slips and the projecting parts are Eext /
ground smooth against a wheel covered with 4
Sandpaper, and are then ready for che process
of separating and shaping, which Is done by !
machinery-~B. V. H." il Brooklyn Eagle /
Cosmopolitan Character of Bombay.
The cosmopolitan character OF Bombay IS
by missionary letter: Last week 1
n Greenlander called. seeking work. Tive
DAVIS after a man from Australia wrote rle
asking q favor \ few weeks ago 4 West In
dian came to attend to repairs on my house.
Last Sunday night preached 70 a conCreCa-
ton in which sat, side by side, a Russian from
the Baltic. and an Armenian from the foot Of
Mount Ararat Among my paTi>honeIS Ia
an Abyssinian Turks from the DardanelleS,
Greeks from the Adriatic, SeeIlee boy. from
Zanzibar NorweEians and South Africans