Research Balloons: Exploring Hidden Worlds

ISBN: 9780822515852

出版社: Lerner Pub Group

出版年: Jul-88

页数: 64

定价: 45.00

装帧: 简装

内容简介

Inventing
the Balloon
For centuries??? humans have been fas-
cinated with the idea of flying. Some
people designed wings to be attached
to a person s arms. Others watched
smoke rise from fires and thought there
must be a way for them to rise with it.
These people tried to build balloons.
Finally??? in 1783??? two brothers in
France successfully built and launched
a balloon. Joseph Montgolfier and his
younger brother??? Jacques-Etienne??? were
paper makers in Annonay??? France. They
often talked about constructing a large???
paper globe that would float passengers
above the earth. The Montgolfiers
thought that smoke was a kind of
lighter-than-air gas??? so they decided to
raise their balloon with smoke from
burning rags. Actually??? smoke rises be-
cause air warmed by fire is lighter than
the surrounding cooler air. Therefore???
a balloon full of hot air will rise until
thinner air at higher altitudes can no
longer push up on the balloon or until
the balloon s hot air cools enough to
make it too heavy to stay aloft.
Although people in earlier centuries
tried to construct balloons--and the
Incas or Chinese may have succeeded
in launching them--the Montgolfiers
are credited with inventing the balloon.
They received a good deal of public
attention because both they and their
rival??? Jacques Charles??? wanted to be
the first to send up a balloon. The
Montgolfiers won the race to fly on
June 5??? 1783??? and their balloon s flight
--without passengers--was officially
witnessed and documented by the
Academy of Sciences.
On September 19??? 1783??? the Mont-
golfiers flew their invention--later
called a motztgolfier or a hot-air bal-
loon-before King Louis XVI and his
court in Versailles. On this second flight???
the balloon carried three passengers--
a sheep??? a duck??? and a rooster. The
balloon measured 41 feet (12 meters)
in diameter and was 86 feet (26 m)
high. Floating to a height of 1???450 feet
(435 m)??? the balloon stayed in the air for
about 10 minutes. After the balloon s