Evening star., 1933-06-26

is called "superheat At night the g
the superheat approaches zero. Often
that is. the gas becomes slightly cooler
These temperature effects are very
important in both balloons and powered
airships, because the gas expands when
its temperature is raised, and it conse-
ouently displaces more air and increases
the lift of the balloon. When the gas
heats up in the sun and expands the
balloon will want to rise and will do
so unless checked by valving gas out
through the valve in top of the balloon.
As the balloon rises the gas will ex-
pand because CT the more rarefled air
outside and lower barometric pressure.
The balloon will rise until the gas
has expanded enough to fill the en-
velope completely full. This point is
called pressure height" Any further
rise above this point will cause gas
to spill out Of the appendix" an open
Eventually enough gas will be lost in
this way to overcome the balloons
static 'lightness" and she will level
off"
Use Usual Controls
In the stratosphere flight the usual
controls of valving and ballast will be
employed. We will throw ballast to go
up. valve to 60 down. Obviously, valv-
ing checks ascent and throwing ballast
checks descent. The ballast used will
be sand and metallic dust. At least
$50 pounds of metallic ballast will be-
come available from one of the cosmic
ray instruments. This instrument IS
buried in approximately that much
lead dust, which may be released as
ballast once the instrument has record
ed its testimony.
Suspension lines for the gondola will
take off from the balloon at about
the go degrees south latitude" par
allel-which is the easiest way of de-
scribing the location of the catenary
band around the balloon below the
equator" There will be 1913 take-of
points The suspension lines will lead
down to the load ring, a circular metal
lie ring about feet in diameter, for
the concentration of loads. The metal
gondola will be suspended from this
load ring, the top of the ball being
about feet below the ring.
At low attitudes one or both men,
bers of the crew will stand on top OF
the ball and inside of the load ring.
This will constitute kind of poop"
deck. At about $4,000 feet altitude,
where the atmospheric pressure is
about 6 that on the surface. the crew
will 90 below into the ball and close
the alright matches, just as sub
marines crew goes below and battens
down all matches before dive.
Seek Right Weather.
We will wait for right weather condi-
tions before we take of from Soldier
Field. This Is not because of any par
ticular hazard in doing otherwise, but
because perfect weather conditions are
essential for the most successful collec-
ton of scientific data. including cos
mic ray observations. We will take OF
about midnight and loM at open
hatch" attitudes. which will be some
where below $4,000 feet, until sunrise.
Then the sun will suck us up. We will
hit pressure height at the tropopause-
about 5000 feet. The balloon will be
very f1abby at the take-off, as it will
be only about 20 per cent full. We will
get the maximum altitude in early aft
ernoon, then start down and land either
just before sunset or some time during
the night.
In landing it is probable we shall pull
out our rip panel" The rip panel is
toward the top side of the balloon. A
stout pull will rip the panel wide open,
allowing ~as to escape quickly and per-
mitting IN immediate landing when
close to the ground. The rip panel is
often employed in conventional balloon
hops.
In order to insure the best possible
conditions for the fight, we will have
a radio station and meteorological per-
sonnel at Soldier Field several days in
advance of the flight Complete weather
maps of North America will be drawn
twice a day from information supplied
by the Navy radio station at Arlington,
Va. and from $50 Weather Bureau sta
tions We will also run frequent up
per air soundings with sounding bal
looms.
All in all, this stratosphere flight from
the Worlds Fair promises to be most
interesting project.
Copyright 1888 by North American News
paper Alliance.l