Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-02-19

From Youths Instructor.
Pencils are instruments used in writing
They were, in early days. simply pieces Of
chalk. colored earth or soft stone About
the fourth century. b. c., hair pencils be-
gan to be used
These pencils were generally made of the
hair of the camel, sable. mink. goat or the
bristle of hogs. A few hairs in the center
Of the brush were longer than those sur
rounding them, thus giving the brush or
pencil a fine point.
The pencils most generally used at the
present time are black lead pencils.
The first account We have of their being
used in the form in which we now have
them was given by Mr.. Gesner, who speaks
of using lead pencils inclosed in wood
This was about the year 1860 He gives US
no clue as to how they were manufactured
The lead pencils of the present day con-
tain no lead whatever. but are composed of
a mineral substance called graphite or
plumbaSo, though doubtless they receive
their name from pieces Of lead having been
used originally in writing
The best graphite is found in the Cumber-
land mines, though some of quite good
quality has been found in Siberia and other
parts of the Russian empire Inferior quail
world.
Graphite is seldom free enough from sand
and other materials to be used in its crude
state. but ii is ground up and washed until
pOA HIS Washing IS accomplished by put
ting the ground graphite or plum ago into
large tanks Of water and allowing il to re-
main long enough to permit the cosrser
portions to settle The floating part cles
are then drawn off into another tank to
pass through the same process after
which it is passed to the third tank What
remains floating in the third tank is cam
pressed and used in the best grades of pen
els. and those portions which have sunk I'm
the second tank are used in the second
grade OF pencils, and so on. the coarser
parts being used for the poorer pencils
Clay is ground up ana washed in the
same manner, and is thorcuChly mixed
with the graphite. TO make il softer The
mixture is then prepared for use by two
processes. One is known as Erokeion' 5
method, which is to extract the air frnr,
the mixture and subject il to a heavy pres
sure. which leaves # in square blocks
These are then sawed into strips about one
sixteenth of an inch in thickness 1t is
then sawed the other way the same thick
ness. thus leaving the composition in strins
just the size used in pencils.
strips of wood are passed under a small
saw, which cuts groove in them lust the
size of the strips of lead" as the compost
ton is called.
The lead is placed in one of them and
another is inverted over il, and they arc
glued while i'm that position. Afterward
they are passed through a machine thai
rounds off the Corners. They are then
painted, lettered and are ready for use
n Frenchman by the name of Conte has
invented cylinder perforated with various
IL shaped holes. The clay and graphite are
preparei The same as in the Rrokedon
method and placed in this cylinder. In
which a heavy piston works. driving the
composition through the perforaticns in
the end.
The shreds are caught in small grooves in
boards. and ere dried in a warm room
Atterward they are subjected to a great
degree Of heat. The more graphite and the
less heat applied. TIE darker will be the
color of the pencil; while on the other hand
the more clay there is used. and the higher
the degree of heat. the lighter will be the
pencil.
The lead is then prepared for use ac-
cording to previous description.