The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1913-11-13
BATTLES SCIENCE.
Why Hot Steel Is Tempered BY
a Sudden Cooling.
SLOW COOLING KEEPS It SOFT

SLOW COOLING KEEPS # SOFT
Vet the Busy 6rain Of Man Cannot
Succeed In Reasoning Out Why This
10 so-Ths Mysterious Properties
Exhibited BY Watsr. Tin and Glass.
Here is fact. known to everybody.
which Is as mysterious as would be
the actual. appearance Of q ghost BY
which mean that the fundamental ex-
PLANTATION Of the phenomenon IL about
as far beyond our reach In the one
case as In the other.
The fact to which refer Is the pro-
dnction Of tempered steel by qnenching
in cold water. II hot steel Is cooled
very slowly It becomes soft and cannot
tnke cutting edge. but II 1t Is cooled
suddenly 1t becomes very hard aud can
be ground into keen swords. knives
and cutting tools.
Now. why the difference? Have you
ever thought about that question: II
has. and has been puzzled over It.
Here is another related mystery. II
you heat an old Japanese sword. which
for centuries has retained its capacity
to slice uf head ut Il blow. or to
! open swift passage for the soul OF
the victim Of the llarakiri mania. to
the temperature uf boiling water Il
gradually softens and loses the keen
ness that once made II so formidable
1t is the same Steel hut 1t. too. seems
to have lost ,ts soul At u temprrn
tnre Of liO degrees rcntigrnde the
hardened steel commits ilnIakiri in q
few minutes Surely there Is some
thing strange In that,
Then consider this. At zero tempera.
ture WATER changes from a liquid and
suddenly bes'on,es solid Rmt II SOU put
the water in Il wise and carefully pro
tect 1t from dust you may euOl It as
mnch ax ~ degrees below zero and yet
II will not freeze! But now shake the
vase or drop in u t'It Of lee. and the
winter immediately soIidiiies!
owe the collection OF these facts to
| a paper. by Professor james 81 Wal.
ton. Jr.. OF Wisconsin university. The
explanation which he gives II that sub
stances ike the hardened steel and the
unfreezing water are In state of
suspended change" That accounts
| for the phenomena. but In u certain
| sense they remain mysterious, just us
life Is mysterious
Many substances possess the same
curious characteristics Professor Wal
ton says that II flask containing So
dunn acetate. which has been cooled
below It's natural freezing point with
| ont solidIfying. Is opened In RON
containing dust Of the solid acetate the
fine particles Ut the latter drBppiu. into
the flask will cause the whole contents
to solidify.
Tin is very strange metal with re-
/ gard to this state Of suspended change
or ''met:,stability" A severe winter cold
will sometimes cause IT to lose its
hardness and crumble.
Objects made Of tin sometimes nm.
derg0 sacl, change and are then said
4
The contact Of diseased tin with
bright. hard tin is capable of setting
up the transformation.
Glass. Professor Walton informs us,
Is IAN umlercooltd substance" = that Is,
II is in metastable condition II old
glass tubes through Which water has
frequently passed are heated the glass
crystallizes aud loses its transparency
All substances In this state are liable
to change. and the change. under prop
er conditions. may be sudden Hard
enetl steel is.in . similar category II
II were as perisllable MS tin It could not
be safely used for many purposes for
which II Is ilabituaIly employed For
tunately steel exhibits great resistance
to change OF state after 1t has been
tempered Transformation Is retnrtiesi
OF arrested
i Does steel slowly return to the sta.
BILE form and thus grow sufter!" asks
Professor Walton. and then answers:
THAT We do not know: we can only
say That II such a ciiange does take
place. hundreds Of years IRE necessary
to bring 1t about"
/ The same ancient Japanese swords
which. when heated. as before dexcrilD.
I'd. become soft, retain all their hnrd
hess II carefully preserved
/ It Is evidently of the highest i'm
portance to the practical world that
science is Investigating these things
and discovering the way and the cir.
cumstances In which the changes coint
about. even II II has not unveiled the
underlying mystery OF their cause. :
Garrett P Serviss In New York Jour
nal
i Correct Interpretation Essential.