Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1914-04-22
BATTLES SCIENCE.
Why Hot Steel Is Tempered by
a Sudden Cooling.
SLOW cooLINo:KEEPsIT SOFT

SLOW C00LING.KEEPS IT SOFT
Vet The Dusys Grain Of Man Cannot
Succeed In Reasoning Out Why This
u -Ths. Mystsrious Properties
Exhibited BY Water, Tin and Glass.
Here is, Q. fact. known to .everybody.
which is as mysterious as would be
the actual appearance Of a ghost. BY
which I mean that the fundamental ex-
PLANTATION Of the phenomenon ts about
a. 4far beyonds%our reach in the one
case as in the other. . Mint
The fact to which i referSis tho pro-
ductien Of tempered steel by quenching
IN. cold water. If hot steel is cooled
very slowly it becomes soft and cannot
takea cutting edge, but II 1t ia cooled
suddenly It becomes very hard and can
be ground into Keen swords. knives
and cutting tools.
Now. why the difference? Have you
ever thought about that question? II
you have NOT, many a man Of science
has; and has been puzzled over It.
Here IL another related mystery. If
you heat an old Japanese sword. which
for centuries has retained its capacity
to slice of a head at a blow. or to
opens swift passage for the soul Of
the Victim Of the harakirf mania, to
the temperature Of boiling water it
gradually. softens and loses the keen.
ness that once made it 80 formidable.
It IL the same steel, but 1t. too, seems
to have lost ito soul. At a tempera.
ture Of $50 degrees centigrade the
hardened steel commits harakiri in a
few minutes. Surely there is some
thing strange in that,
Then consider this: At zero tempera-
turey water changesSfrom a liquid and
suddenly becomes solid. But IL you put
the water In a vase and carefully pro
'tect it from dust you may cool it as
much as 20 degrees below. zero and yet
1t will not freeze, But now shake the
vase or drop in q bit of ice, and the
water Immediately solidi6es!
l owe the collection Of these facts to
a paper by Professor James n Wal.
ton, Jr., Of Wisconsin university. The
explanation which he gives is that sub
stances like the hardened steel and the
unfreezing water are in. q state Of
Suspended: change" That accounts
for the phenomena. but in a certain
sense they remain mysterious. Just as
life is mysterious. III
Many substances possess the same
curious characteristics. Professor WAL
ton says that IL q TASK containing So
dunn acetate. which has been cooled
below it's natural freezing point with
ont solidifying. is opened in q room
dusttof the solid acetate the
fine particles Of the latter dropping into
the flask will cause the whole contents
to solidify.
Tin is a very. strange metal with re.
gard to this state of suspended change
or "metastabihty." A severe winter cold
will sometimes cause 1t to lose it's
n cr0mDle.
Objects made of tin. sometimes IN.
dereo such change and are then said
be suffering from :.'thne tin disease"
The contact Of diseased tin with
hard tin is capable OF setting
up the transformation.
Glass. Professor Walton informs us.
IL IAN undercooled substance"-tha is,
it Is In a metastable condition. If old
glass tubes through which water has
frequently passed are heated the glass
crystallizes and loses Its transparency.
All substances in this state are liable
to change, and the change. under prop
conditions. may be sudden. Hard.
ened steel Is in a similar category. If
It were as perishable as tin It could not
be safely used for many purposes for
which 1t is habituallyS employed. For
tunately steel exhibits great resistance
to change OF state utter it has been
tempered. Transformation h retarded
or arrested.
docs steel slowly return to the sta
Bile form and thus grow softer" asks
Professor. Walton. and then answers:
That We do not know; We can only
say that IL such a change does take
place. hundreds Of years are necessary
bring it about"
The same ancient Japanese swords, (
when heated, as before, describ-
ed. become soft, retain all their hard.
ness If carefully preserved.
1t ia evidently Of the highest i'm
portance to the practical world that
10 investigating these things
and discovering the way and the cir
cumstances in which the changes come
about, even If it has not unveiled the
underlying mystery Of their cause
Garrett P. Serviss in New York Jour
nal. III X
Correct Interpretation Essential.
Many Of, the most beautiful pieces
of poetry IN literature would seem un. !
interesting and 6at If read BY a bad
In the same way a good re-
viii make attractive a poem
whose BEAUTIES are not so apparent.
. 0ne painter will light up each little
beauty In bis pictures until the small.
EST detail IL attractive and strikes the
Eye It Is only the mediocrity whose