Evening star. [volume] (Washington, D.C.) 1854-1972, 1942-01-06
Of Stors, Men
And Atoms
Notebook Of Science Progress
In Laboratory, Field
And Study
BIZ Thomas r. Henri.

And Study
By Thomas r. Henry.
Parachute jumping is . relatively safe
occupation.
Such is the testimony of Its. william
j. Tobin. Laurence j. Cohen and John T.
Vandover Of the Army Medical Corps
in q report to the American Medical
Association on the injuries in training
sustained to date by American soldiers.
During the past year, up tos August /,
there had been 1890 training jumps, In
which 121 men were injured. Only 81,
however, were hurt seriously enough to
require hospital attention. One was
killed when, in . jump from $50 feet.
both his main and emergency para
chutes failed to open completely.
The majority Of the injuries reported
by the Army doctors were bone fractures,
due to rough landings. The wind has
proved the main hazard to the jumper,
they say. II cross wind currents are
strong the increased swaying Of the
parachute will cause the jumper to
strike the ground unevenly. II one of
the ankles hits the ground first and the
wind is on the parachutist's side, . vio-
lent steering force may be developed
sufncient to break the ankle joint.
OSCILLATION Of the parachute due to in
experience of the jumper also may be
dangerous, they point out. Wind cur
rents within 200 feet of the ground are
most treacherous, they explain. because
at that level the parachutist must pre-
pare to land. Another danger is rough
ground. II one foot lands at one level
and another at lower level or higher
level there results an unequal distribu-
ton Of weight.
One curious accident has occurred
in the training program. the doctors
report. The parachutist jumped in the
usual manner from . plane travelling at
approximately 120 miles an hour. His
chute opened prematurely and became
hooked on the tail Of the plane, where
he remained suspended for about 10
minutes. During this time he was spun
around at terrific speed. Just before
losing consciousness he had the presence
OF mind to open his emergency chute.
This opening had suficient force to tear
him away from the plane, but in doing
so violently wrenched his left hip Joint.
Although accidents to date have been
few the Army doctors say, they probably
will be much reduced in the future by
improved training methods. During the
course OF ground training, they explain,
there are two types Of jumps-the plat
form and tower Jumps The platform
jumps are made from levels Of 4, s and II
feet. but the latter height has been gen.
orally discarded because OF several in
juries sustained by green recruits.
In this phase of training the jumper,
with harness attached. attempts to sim
ulate what actually takes place when he
lands during q parachute jump He is
taught the method of landing to take up
shock. The instructions are to land
equally on the balls of the two feet 70
that this shock. which is transmitted
through the ankles, knees, legs and hips,
may be partially absorbed. A man is
supposed to land with the legs shoulder
width apart, the ankles held firmly, but
not rigidly, and to fall forward in q roll,
so that the shock may be broken at the
knees and ankles.
Two types OF tower jumps are used,
In one, known as the harness" or con-
troI jump. the student is attached to
the harness with an open chute con-
trolled by cables. He is allowed to fall
through $50 feet and lands on q rubber
steel spring mattress. The other Is
known as the free-tower jump in which
the jumper is hoisted to the top Of a
tower $50 feet high in an open chute and
then dropped. This exactly Stimulates a
parachute jump.
A cold meter" has just been reported
to the American Medical Association,
Tested in one Of New York's largest
department stores and in subways, rail-
way cars. factories and hospitals by two
Cornell Medical College doctors, it prom
1ses to measure the likelihood of CATCH
ing cold in given environment.
It Is based, according to the report Of
Drs. John c. Torrey and Michael Lake,
on device known as the Wells air CEN
trifuge. which collects large samples Of
air from which it is possible to isolate
and cultivate bacteria.
Bacteria do not cause colds. Most
types Of those maladies are believed to
be due to enthusiastically minute living
particles, filterable viruses, which con-
stantly are present in the air but which
could be detected only with extreme
difficulty, If at all.
Drs. Torrey and Lake found, however.
that the prevalence Of colds among the
employees Of the department store, Of
which careful records were kept, varies
with the prevalence in the atmosphere
Of bug" which can be isolated and
counted. It is known as the alpha
hemolytic streptococcus." It is present
In most persons mouths and threats
most Of the time and is the prevalent
organism thrown into the air by respira-
ton. Closely associated with 1t Is the
slightly different gamma hemolytic
streptococcus." and Drs. Torrey and Lake
found that there correlations with cold
prevalence were slightly better when the
numbers Of both types were combined.
PSYCHOLOGISTS long have had q rough
test Of the purity Of drinking water
supphes-the prevalence of q micro
scopic organism known as Esch. coli.
Presence OF other disease causing germs
IS assumed II this bug is found In con-
siderable numbers.
The streptococci count, the two ex-