The Lancaster ledger. [volume] (Lancaster, S.C.) 1852-1905, 1856-04-16
Hllsttllullruus.
LEAD PENCIL-MANUFACTpRE,
ETC. :.

As an implement With the uses ofwhch
wo are so familiar, there is probably none
whose origin, the materials requisite to
construction, and the mode ofmanufacture
are 50 little known, rs the Black-Lcad
Pencil. .t-. :.
Plumbago, a substance commonly. call
ed black-lead, is a carbrret Of iron-a
combination of carbon and iron-found in
masses Of calcareous earth, beds Of quartz,
&c-varying in size from pea upwards.
In North Carolina, mine was discovered
some years since, in which this mineral
was found in large solid lamps, often
weighing hundreds of pounds. 1t is in
combustb!e and being easily worked, has
been extensively used as .Inetalic paint
mixed with oil, and roofs and out houses
coated with it. AS it hardens It's power OF
absorption of moisture is lost, and conse
quently it retards decay. When pure, its
composition is nine ten.l,s carbon and one.
tenth iron.
At what period pencils were first made
from this mineral Is not known. The ear.
liest record being In the year 1886, at
which date we find mention in work is.
sued by Sir John Pettus. entitled F7eta
Minor. Speaking of black lead he says
"Of late it is curiously formed into cases
of deal and cedar, aud so sold as dry pen.
ellis, something more useful than pen and
ink"
The Partisan mode Of treating the min.
eral, where ii is not encascd, is as follows
The plumbago is frs, pu!per,zcd, then
mixed with pure clap, also powdered, the
proportion of clay being governed by the
hardness of the pencil desircd-the ave
rage is about equal parts of each ingreii
ent 1t Is now thoroughly ground and
subsequently wetted to the consistency OF
paste. Form is then given to it by pres
sing it into grooves. When the paste has
had time to dry somewhat it is put with
the monld into heated oven when the
lead slirinks sufficiently to fill from the
grooves. These leads are now Sc, upright
in crucible and covered with powdered
charcoal, or fine saLd, and thus covered,
are heated, the harder the pencil the great.
er the degree Of heat required.
The cedar Of which cases are formed is
first sawed into long pIanks and suhse,
quently in rods. Grooves are then cut ont
ny the aid of macl,inery-cach of which
receives layer ofthe lead. The minera.
is cut into rods the size of the grooves into
which it is inserted. The two halves of
the case are now glued together aud fin.
'shed 10y being turned in cylindrical
shape.
Pencil points Were first used about the
year 1920, at which time 4 Mr.. Mordan
invented what was termed .',he ver.pon-
ted Pencil-case." 1t was similar to that in
use at the present day; merely "a slider,
acted upon by screw, protesting forward
n little cylinder of k.Iead." These
points" are formed by passing the mins.
raj, after being cut into square rods,
through holes in steel pla:e-,he first
one is octanagal, the other two giving a
cylindrical form to the point.
From their general and increasing use,
The manufacture of these minute convent.
enees has grown to be one of great im,,or.
tance owing to the amount Of capital in
vested, the number Of persons employed,
and the practicability Of the article in all
its multi,udinous forms.