The Jersey City news. (Jersey City [N.J.]) 1889-1906, 1896-01-16
Value OF PLUMBAG0.
Interesting Talk to the Teach
ers' Association by Mr..
John A. Walker.

The Teachers Association held a very
enthusiastic meeting yesterday afternoon
in the High School Building on Bay street.
The following officers were elected for the
ensuing term:-J. H. Brensinger. Presi-
dent: P. S. Hulsizer. First Vice-President;
Mrs. S. C.. Marvin, Second Vice-President:
Miss N. G. Dutch. Treasurer: Miss j. NJ.
Lewis, Financial Secretary; Miss Scott.
Recording Secretary.
An excellent programme followed. Master
HysIop sang delightfully."-, and Miss Car
oiyn Paddock delighted everybody with
her excellent recitations.
Mr.. John A. Walker. President of the
Dixon Crucible Company. gave the teach
ers a most entertaining and instructive
talk on graphite and it's uses. The min
eral. he said, known ~colloquially as
sblacklead' and chemically as plumbago,
cropped out in every quarter of the globe.
Ihe bases OF supply Were, however, in few
places. The Island of Ceylon, off Hin
dostan. furnishes the largest expectation.
Here the supply is inexhaustible. and it is
the leading industry of the island. Ticon-
t hey later ter pi sagp' Mr.. Walker Naa m'a aaId. lF waa
the same as the Cingalese variety with
of the rock.
Bavaria next furnishes a large supply,
but 1t is not pure graphite. The mineral
here IS what biologists term graphite
senoro, said Mr.. Walker. in Mexico,
furnishes also a bountiful supply of
sssehntiy. and the mineral IS Largely assIps used
for lead pencils.
Speaking chemically. graphite is
higher the percentage Of carbon" Mr..
giossy mineral 1T Selon ssY' to. the coal cal
ertles as the diamond. The difference be-
tween the opaque graphite and the trans
parent b%rillianey Of the precious stone
stones. Graphite occurs in Archaic rocks,
and as those are the. lowest in the struc-
tnre Of the earth's crust, it is, there
stances. The SPECULATION IS s0T that s eS-
IRENE. heat distilled pure carbon in a
volatile state Where lumps are with
and filled the pockets of the rock with
pure carbon. Where the rock had been
porous the carbon particles sank into n
became part of the works,
Leaving the chemical analysis and scien-
tific description Of the mineral. Mr..
ak dng,,s sPok Re Ct IL the great uses to which It
principal use, he said. was in the manu-
fscture of crucibles. Melting pots Of
plumbago. he said, hav revolutionized
Clay melting pots. before the discovery
Of graphite. We're formerly used, only to
be destroyed at one melting. A graphite
nickel, to G in steel. n s. to 50 in Com
position metals. Thus the Introduction Of
graphite has changed the whole system of
This valuable mineral was first used
for crucibles by an American, a resident
of Salem, Mass. Now graphite crucibles
are used the world over.
lead pencils. The old system WHY Was e = saw u
the leads out Of convenient blocks of
It remained for a Frenchman,
Conte, to find out a method for purify
putting the particles together again with
a binding material. The grades Of hard
and soft in pencils are caused by the
more graphite and less clay, and 4 hard
pencil has more clay and less graphite.
In his way the writing world, and that
means everybody is dependent on gra-
phite.
AZ an anti-friction agent, graphite Is
extremely valuable. It is the best solid
anti-friction agent known to the metal
lurgical world and has grown to be a
Wherever a wheel turnsAfrom a locomo-
tive. or. gear wheel, to the smallest
wheels where. great friction is felt, graph
is of inestimable value in this respect
ard Is used in all kinds If machinery.
another use for graphite is as q pig
4pEut 1t IS indestruetfble by fire, insen-
FSIpieNto variations of heat and cold and
lf6t9fS aprotectjye coat, the best known
8aS piHfnent for roofs and ether sur
f8E949 where pigments are nece ssary,
efa8h} lfa's said NJ 3 W Saqee ~ceal feg + e
The nest confuctor known II IS used in
eHFTy efentE1c plant In rods 1r for resist
ance purposes to graduate the degrees
fhs row az electric nuiI. III this re-
spact II has nj rixal and no approach to
exeu cenapstitor.