Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-07-20
MICA Is THE STUFF
In These Days the World Could Hardly
Worry Along without 10.

In These Days the World Could Hardly
Worry Along without 10.
From the Chicago Dsily Inter-ocean-
Mica fills the interstices Of modern progress.
A few decades ago we were seeking practical
use and market for the output Of mica mines
already found; now we are seeking new mines
to supply the multifarious uses to which mica
can be applied. Thus the law Of necessity
changes in it's relation 10 all things.
Mica is now essential to the various un.< of
electricity as thh great force il necessary IL hu-
man progress. In all appliances for electrical
lighting and power the most important rectpro-
cal agent entering into their mechauis.u ia
mica All armatures are built ND with il. in
sulation, whether for dynaraos. motors. genera-
tors or transformers. Without its use ~ an
Insulation the core OF the armature would burn
out with n flash But by placing sheets of mica
between the thin sheets OF iron. which are SCI
cured to the shaft that runs through the drum
o. the armatnre, insulation becomes perfect.
linus armature OF even the largest generators
can be run for twenty-four continuous hours
without heating them more than so degrees
Fahrenheit above the temperature OF the sur
rounding air. BY this o. mica the lines Of
ioTee are dssipated, but do not lose any OF heir
electrical energy.
In all electrical safety appliances mica also
performs an important part as an insulstor.
To It's iniu.ible and indestrnctible nature rsucb
OF the success OF the rheostat can be ascribed
This wonderful mechanism, which is applied az
motor starter, a governor of speed, . re-
yersing switch and automatic safety switch.
is absolutely freproof aud can be subjectea to
a red beat without mechanical injury. THIS il
rendered possible by making the resistanoe Of
thin plates OF iron packed closely together. but
separated by mica.
Thus the lines Of force operate on the same
principle as the armature. Aside from lbese
important uses of mica in electrical apparstus
IL Is also applied TO a thousand minor ones
which make II the constant and willing servant
OF 'ne greatest power that man has turned to
intelligent subjagation.
Mica Is also important factor In many
branches OF manufacture and art Owing 70 lie
peculiar elasticity and toughness, qualities in
Wbien rs not excelled by anything natural or
sIlnclM. IL is used as an absorbent Of nitro
giscerine, and when SO used explosions BY
percussion are rendered almost impossible.
| Mniie 81 The same time nothing lie taken from
| tne energy OF the nitro-gycerine when ex-
| pioaed by Eliminates or similar device For
| sueh purpose the piumose mica is used, OF that
| IN winch the scales are arranged in feathery
| form.
The prismatic or foliated mica is also usea bx
passing il through a mill This vastly increases
the mica's bulk and forms masses Of brauIike
scales, translucent and beautiful The French
| silver holdings are also made with this ground
mica The unslterable nature of mica and the
TACT that IL entirely ressts the action of corro-
siye acids, smoke and dust make IL valuable
material for edifcial decoration. Il cah be
readily colored or metalizei and its trans-
parency preserves in all it's pristine beauty any,
thing to which IL Is applied. This ground mics
is only used as a lubricant and axle grease, sud
for such purposes has no superior except plum
bsgo. Coarsely pulverized ii is also used for
roofing material and as q ireprooing for iron
safes.
The rle.vaoa ~ ,,;.. 4, ~ ,,-So.. q. Z. ...x