The Bismarck tribune. [volume] (Bismarck, N.D.) 1916-current, 1917-11-19
American ..Aviators Won't Have
to Experiment While Flying =
g.. Over Enemy. .@:.s.
TWO PROBLEMS TO SOLVE
United States Bureau Of Standards
Has Devised q Way to Reproduce
the Conditions Found in High r.
Attitudes. ..-.}- L.

ards ia erecting a little greenish.gray
concrete building on the edge Of its
grounds where one Of the final chap.
ters of Americas preparations for
aerial warfare will be written. The
bureau declines to discuss what part
it will play in the final design Of the
new "Liberty air engine" which the
government is expected to mount on
II American alrplancs for use in the
european war. hut 1t has become
;nown that before the final design Of
his engine Is approved It must under
. !. few Anal tests in that little green
h-,.ray building. ~ .t;E4tts% T. 4 i
There will be determined. under con;
itions almost identical with condi'
.ons found ut various attitudes, Just
NV m airplane engine performs
hen it gets so high that the mir gets
.erceptihly thinner. 1t will be tested
n Il temperature down to freezing.
Bringing High Altitude Down. d
The bureau building Is tomblike
tructure, full Of delicate instruments
.hich will have the effect Of bringing
ne skies down to the earth, insofar
. airplane conditions are concerned.
t is impractical to send an engineer
loft to watch the engine perform up
here, 50 the bureau plans to brina
lie skies TO the engine. r;,,..,u ..r,
Ever since the European war began
the aviat0rs. Of the warning nations
have been flying to astonishing heights
n the clear air OF France. Attitudes
Vt 10000 feet are quite commonplace
ard 2O.OM-f0ot flights no longer ex
cite wonder. Aviators must go NJ
high, and they must have engines thai
will take them there, 80 the engine
designers have been experimenting fol
the last three years with an engine
that won't "smother" when 1t gets Int
thin air. &s.
So fnr the allies have been unable
for various reasons, to make absolute
" accurate tests. An engineer can g
aloft in a plane, hut he can't load II
a ton or two Of apparatus also AM
test out sparkling efficiency, compress
sion density, horsepower delivery ant
nll the other things that he should do
Being confronted with the neccssit!
of making such tests, the bureau o
standards experts figured out
method.
The Two Problems.
First, they argued. they must know
inst what an airplane does at al
altitude. say of 10000 feet. An engine
that will perform perfectly at 10'Vt
feet has a tricky habit Of stumbling
and missing ignition when 1t gets an
other 10000 feet higher, and the ex
pcrts wanted to observe all It's all
mcnts at that height.
Second, they wanted some sort o.
a mechanical arrangement which
would rermlt them to test untriet
types Of engines under conditions sim
liar to conditions very high aloft. ant
to approve or condemn the perform
ance Of these untried types.
So they set to work to build = con
crete. tomb.like structure, about Il
feet long by 6 feet wide and 6h fee
high. This concrete chamber was 81
constructed that it could be made
vacuum II necessary. The walls are
2 inches thick and tarred on the out
side. They needed thick walls be
cause at 10000 feet altitude the all
pressure Is about seven pounds to thu
souare inch-about half the pressure
ut sen level. That meant that wher
the scientists got to duplicating Ill
pressure at 10000 feet the walls hac
to support m outside pressure of oil
equal to eight pounds to the square
inch. II the walls were not built thicl
they would crush in like paper.
Either Hot Or Cold.
Then complete heating and re
frigerating plant was installed so that
when the four or six big fans which
IRE to whlrl the air over the engine al
I'D niles on hour start their gale !,
will he down to the temperature tina,
one finds thousands Of feet up.
Into this air chamber they expect
to put the engine type that Is to~be
tested. mounted so that it can tilt for
ward. backward or sidewise, just as II
would behave in the air.
As soon Is everything II ready taf