The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1925-11-18

balloon on Oct. 10, 17o3, near Paris.
The balloon was captive" being
fastened to the ground by q long
cable. Five weeks later on Nov. 21,
De Rozier and the Marquis
d'Arlandes scared from the ground
without a cable, the first men to
navigate the air in freedom. They
remained UP rs minutes, drifting
about five miles with the wind.
Furnaces Under Bags
From that time on balloon ascents
became increasingly common In
ventors learned how TO hang small
furnaces below the mouths of fire
balloons, 80 as to keep UP the sup
ply of hot air and make longer trips
possible. But the greatest develop
ment came in the gas balloon, which
soon replaced entirely it's elder
brother. "a sdE
Long before any successful ex-
periments were made with balloons
men had discussed the problem OF
flying. Some believed It possible to
hold themselves up with wings like
bird, but the majority OF scientists
thought the answer could only be
found in "lighter-thanair" machines.
The difficulty lay in finding a sub
stance suitable for Initiating ballons-
The success of the Montgolher ex-
pertinent was really an accident, for
the brothers believed It was smoke
that made their linen bag rise. It
was not until later that hot air was
recognized as the true source Of
theirN power. Air expands when
heated, so that a cubic foot of hot
air is lighter than a cubic foot OF
cold air. The difference in weight
between the hot air inside the old
fire ballon and the same amount Of
cold air was great enough to offset
the weight OF the ballon and pas
sengers. The difficulty lay in keep
ing the air hot. When the fuel for
the furnace was exhausted there
was nothing to do but come down.
Hydrogen Light Gas
What was needed was a gas that
should be lighter than air, no mat.
ter what its temperature Hydrogen
possesses this quality to the high
est degree, being fourteen times
lighter than air. Although some
balloonists use the cheaper coal gas,
it was not long before hydrogen be-
came the standard.
The fire balloon could be made 10
rise and fan by regulating the heat
Of the furnace. For the gas balloon.
however, It was necessary to de-
wise a valve which would release a
part of the gas when the aeronaut
wished to descend. To enable the
balloon to rise to higher levels, bags
Of fine sand were carried as a bal
last and emptied over the side, as
needed.
AS soon as the balloon was suffi-
GENTLY improved science seized upon
il as a means of exploring the upper
reaches of the atmosphere to ascer-
tain the variations OF temperature
and air pressure. 1t was in this
manner that Prof. A. Berson and Or.
r. ]. Surfing of Berlin, Germany,
rose on June so. 1901, 10 a height
Of 35, 440 feet. At high levels bal.
loonists find the atmosphere so rart,
lied that it is hard to breathe, while
the corresponding degree in air pres.
sure causes dangerous arrangements
of blood circulation. Indeed, many
sky explorers have died IN their bal
looms, and these two German bal
loonists, even though they were
equipped with oxygen tanks for
breathing were unconscious during
part Of their trip.
To obtain scientific information
without these great risks, investi-
gators hit upon the scheme Of send.
ing up self-recording apparatus. such
as thermometers, etc, i'm small bal
looms which carried no passengers.
One Of these sounding balloons"
reached q height OF 125,505 feet
(23.3S miles,, and brought back tho
information that at this tremendous
| height the temperature was GO de-
grees below zero and the pressure
only 1.25Oth Of what it is at sea
| level.
The difficulty in reaching these
great attitudes is not so much due
to the inability Of the balloon to
float in the highly rarefied atmos-
phere, as to the fact that when the
exterior pressure is so much re.
duced the gas bag tends to expand
and burst. This obstacle has been
overcome by sending up sounding
balloons Of India-rubber with a
parachute attached which will bring
the instruments back TO earth safely
after the balloon itself has reached
its maximum height and exploded.