The sun. [volume] (New York [N.Y.]) 1833-1916, 1906-07-15
MORE MICA USED.
Once Seen Chiefly in the stove Now Em-
ployed to ~Insulate Electric Wires.

Once Seen Chiefly In the StOye-NOw EN-
plOyed to Insulate Electric Wires.
There was a time when mica, or isinglase
as IL was far more commonly called, was
familiar in one limited use in every house
hold in which there was a parlor or a sitting
room stove, thin, transparent sheets of this
mineral being set in the stove door. Through
the aisinglass," not ~destructible when
subjected to heat, as glass would have
been, the glow Of the fire within could be
| seen.
With long use the mica might become
smoked up and paque OF 1t might become
married and broken. Then the head Of the
household would get and set into the stove
door fresh isinglass, from the stove dealers,
while the fragments OF the old were very
were likely to be surprised to find into how
much thinner sheets still the thin old pieces
from the stove door could be divided. As q
matter Of fact mica Is divisible into sheets
one two-thousandth Of an inch In thickness.
Now there are many. who don't know
people born and raised in houses that are
heated by steam, in which no stoves are
used for heating purposes; but while
the number OF these Is large and all the
time growing, the number Of people who
yet use stoves is larger still; and 90 while
hllS0 iihay LoN PoCcCu OLoASiy Jul " b10
sight and mind of many who once knew
1t In this use, and in this use only, the prep
aration Of 1t for stove Use still constitutes
q regular branch Of the mica trade; and
thus n Of the old uses Of mica still con-
tinues.
The chief use to which mica is now
put is enc not dreamed Of until within a
comparatively few years. namely, as an
insulating material In tho construction Of
electrical APPARATUS, for which purpose its
800 q --I ----
ing, and far larger than in any. use to
which it Ind ever before been put.
Mica IL now used also for making ohim-
neys for ~inoandescent gas lamps placed
where they would be exposed to drafts, or
out Of doors, subject to the weather. Mica
candle shades, and it Is used for making
fancy boxes, and in place OF glass, for cover
ing the labels on drawers, as in n desk
Ground up mica ia row used In the manu-
facture OF lubricants and Of fertilizers,
and of dynamite. and in other forms it is
used for boiler coverings.
Mica wal long used fer windows and for
lanterns, and It is still ueed in lanterns
where such use would be advantageous.
It Is used in place Of glass In spectacles worn
lamps. and 1t has been In the past or still
ID put I o Various other including ornamental,
uses; but among it's various modern uses the
chief is in its application to electrical ma
chinery. For this the mica is cut into hum
dreds of different shapes and sizes.
India lie the chief source of the worlds
supply OF mica, with Canada next, the United
States next, and Brazil and other, countries
folio wing. Mica, from one source and
another, ranges in color from white or trans
parent, through various shades TO black.
In the formations in which II exists II IL
found In more or less scattering deposits,
or In pockets. It's value depends, with
regard TO the usas to which it may be put,
on its color, it's freedom from impurities
and the size OF the sheets that can he OBJ
tanned from II.
Now this snciently known mineral, for
many years put TO varied though ON
pa~ratively limited uses, finds more extcn-
awe use THAI ever in pplioatlons peculiarly
modern.