Evening star. [volume] (Washington, D.C.) 1854-1972, 1910-11-24


able to determine the properties of such
mundane stuff
Spectroscope Is as common SUI
Useful Instrument. s s@r mn,,e tue
able 70 go triliionS OF mics into spacs
and catch rays of lisEt whiei, tell him
what kinds of matter are found in the
star which he is studying. The old-fash-
toned prism through which a ray of light
looked like rainbow is the :.ilplest
form of the spectroscope. With lis in
.strument minerals have been fo,. I'd in
the stars before they were discovG. cd in
the earth. In the arts the spectroscope is
used in the analysis Of sugar: i; is USED
TO show the exact moment when iron is
converted into steel when in the con-
verter, and is great aid in the detection
OF aduiterantS i'll foods. 1t is i'm these
fields that the americans have made the
best use OF the spectroscope. 1t also will!
inform its owner whether the thousandth
part of a grain or dried blood is OF HUI
man animal origin. When the chemist
goes into court and swears positively that
Il certain red splotch i'm the evidence is
human blood he predicates his oath upon
HE spectroscopic analysis.
The accuracy of weighing Instruments
Il no less remarkable than those which
measure length, heat or other qualities.
Scales of such extreme senSitiveness have
been devised in America that they will
register a difference of one-iive-huRdredth
of u miliigram. We get an idea of what
TINS means by the following 'iliIStrat ion
II two weights OF common shape each
weigfng two pounds, were placed on
ono side of the scales. and two others
exactly like them were placed in identical
positions on the her side there would
nc perfect balance. But il on one side
one weight should be put on top Of the
other. the bare two inches of difference
~ the distance of that weight from the
cchtcr OF the Garth would cause the
S"aies to register the difference in weight
In other words. refined are these bal
ances that thc% will tell the difference in
T:;Sa OF a two-pound block OF steel
when moved two inches farther from or
nearer 10. tae center o. the Garth
Even i'm the machine shop one comes
across instruments Of remarkable ire
cision. There
Infnitesimal Distances are many
Arc Measured. ~ N e $
which the difference OF thousandth
part OF an inch world be the difference
between success and failure. Therefore.
micronieters OF unusual deIicacy are re-
ouired. Some of these possess SCI VS. of
forty turns to Inc inch and there is d
scale like that on combination lock
which registers the twenty-fifth part of a
t;;rn. Thus the machinist. by the urn
irs of a little screw, is able TO tell TO the
"De-hundred- thousandth part of an inch
whether his work is accurate or not The
practicabiiity OF this knowledge is shown
by the fact that the main difficulty Watt
experienced in inventng the steam en-
zine was in getting a cylinder and piston
mead tight enough 10 hold steam and vet
permit the back and forth motion of the
piston.
Science. however does not REQUIRE ONLY
delicate Instruments. Some of the apra-
"atus must be as powerful as the other
Instruments are delicate For instance
the huge equiiateral telescope must be
operated by hydrauic methods and must
Cdnflcnse the light gathered on a twenty
six-inch glass into little thread of light
which will pass through a pin hole
There must be measuring machines which
VIII register a pressure of million
pounds the ono hand or the efYort
required 20 crack nut or break an esp-
SHE'LL on the other There must be net,-
odS OF producing cold Of such intensity
tha' hydrogen gas may be TRANSFORMER
into a liquid ard then frozen into solid
Ice Such temperature extended over
the earth 5 surface would transform IT'S
entire atmosphere into liquid air and then
freeze it solid as block of ice
On the other hand. the scientist must
make a heat so intense that steel hollis
like teakettte
produces neat That and passes of
VIII p~;l GIL into gas like
The steam from
the kettle. Not content with that heat
Re has forced tie notch still nigher--,o
.TJ degrees. which is twice as not as
t. Necessary 20 boil steel. Every known
sGEs.ln.e wells Under such q Eeat. Iron