Ripley County democrat., 1917-11-02
UNIQUE TEST FOR
LIBERTY engine
American Avlators Won't Have
to Experiment While Flying
Over Enemy.
TWO PROBLEMS 70 SOLVE
United States Bureau OF Standards
Has Devised 4 Way to Reproduce
tho Conditions Found In High
Attitudes.

tho Conditions Found In High
Attitudes.
Washington.--The bureau Of stand
ards Is erecting a little greenish-gray
concrete building on the edge Of Its
grounds where one Of the final chap
tiers of Americas Preparations for
aerial warfare win be written. The
bureau declines to discuss what part
It win play In the final design of the
new Liberty air engine" which the
government Is expected to mount on
all American airplanes for use in the
European war, but II has become
known that before the final design Of
this engine Is approved 1t must under
20 q few final tests In that little green
ish-gray building.
There will be determined, under con-
ditions almost identical with condi-
tons found at various attitudes, just
how an airplane engine performs
whom It gets so high that the air gets
percephbly thinner. It will be tested
In d temperature down to freezing.
Bringing High Altitude Down.
The bureau building Is tomblike
structure full of delicate Instruments
(which win have the effect Of bringing
the skies down to the earth, insofar
as sirplane conditions are concerned.
II 10 impractical to send an engineer
aloft to watch the engine perform up
there, 90 the bureau plans to bring
the skies to the engine.
Ever since the European war began.
the aviators Of the warning nations
,hava been flying to astonishing heights
I'm the clear cir of France. Attitudes
of 10000 feet are quite commonplace.
and 2O,O00-foot flights no longer ex-
cite wonder. Aviators must 60 up
high. and they must have engines that
will take them there, so the engine
designers have been experimenting for
the last three years with an engine
that won't smother" when It gets into
thin air.
So far the allies have been unable,
for various reasons. to make absolute
ly accurate tests. An engineer can go
aloft In a plane, but he can't load In
a ton or two Of apparatus also and
test out sparkling efficiency, compress
sion density, horsepower delivery and
all the other things that he should do.
Being confronted with the necessity
of inaking such tests, the bureau Of
'standrds experts figured out q
methot.
The Two Problems.
Fir$, they argued, they must know
Just khat an airpiane does at an
altitule, say Of 10000 feet. An engine
that kill perform perfectly at 10000
feet lbs q tricky habit Of stumbling"
and Kissing ignition when 1t gets an
other10,OO0 feet higher. and the ex-
perts wanted to observe all its all
mentA at that height.
Sednd. they wanted some sort Of
mechanical arrangement which
would permit them to test untried
typesbf engines under conditions SIM
liar 4 conditions very high aloft, and
to APPROVE or condemn the perform
ance q these untried types.
SoIhey set to work to build q con-
cretd tomb-like structure, about 10
feet bng by 9 feet wide and 85h feet
high. This concrete chamber was so
consthcted that 1t could be made q
vaculh II necessary. The walls are
IL inhes thick and tarred on the out
side. They needed thick walls be-
causdat 10000 feet altitude the air
presste is about seven pounds to the
sQua1 inch--about half the pressure
at sci level. That meant that when
the dentists got to duplicating air
pressfe at 10000 feet the walls had
to SUPPORT an outside pressure Of air
equa1to eight pounds to the square
inch. Lf the walls were not built thick
they kould crush In like paper.
Either Hot or Cold.
Thh a complete heating and re-
frigetting plant was installed SO that
whedthe four or six big fans which
are whirl the air over the engine at
40 nles an hour start their gale It
will } down to the temperature that
! one hds thousands Of feet up.