Why, you might ask, would anyone discuss ballooning in a serious history of science? It’s just a hobby.
Well, first of all, ballooning was and still is a really interesting conquest of one aspect of the physical world; second, balloons remain an important tool in the study of weather, though they now go unmanned.
Ballooning means using a vehicle that is inflated and floats. Airplanes, which are heavier than air, came after the balloons.
Principles and limitations
A balloon can be floated with hot air, which is cheap but inevitably cools; otherwise, balloons use some gas that is lighter than air. Hydrogen and several other gases are fairly cheap candidates, but they’re also flammable, so they’re dangerous. Helium is safe but expensive.
When hot air is used, the balloon loses altitude gradually and naturally as the air cools. If you take a heater up with you (and don’t set fire to the balloon) you can easily change altitude by letting the air cool or by re-heating it. This is nice because you can sometimes find a different wind direction by changing altitudes; on the other hand, sometimes you can’t — all these first experiments were done before much was understood about high-altitude world-wide winds such as the jet stream. It was incredibly risky, but on the other hand, that’s how we learned what was up there, and some people have more curiosity than prudence, perhaps due to an oversupply of serotonin.
When a light gas is used, the balloon only comes down when the gas leaks out. You gain altitude by dropping ballast – a few bags of sand work well and can be emptied little by little; and you lose altitude by letting the gas out. Eventually, someone struck on the idea of building a valve into the balloon. Keep in mind that there’s always a danger in riding a balloon which goes where the wind takes it, rather than in a direction you can plan, so you want maximum control over altitude at least.
Tethered balloons were a fashionable amusement for a while; they give their passengers a good, unobstructed view of the world, and, compared to building the Eiffel Tower or the Empire State Building, they were (and still are) a relatively a cheap way to get up pretty high and view an awesome landscape.
In time, horizontal, torpedo-shaped balloons, called dirigibles, were developed. These could be steered, and were soon adapted for commercial use, even for international travel, including circumnavigating the world. Inevitably, however, one burned, bringing the commercial dirigible flight to an ignominious end.
Rozier balloons use both hot air and gas (in separate compartments) to get the advantages of cheap hot air for altitude control, and helium for lift. Rosier himself crashed while trying to cross the English Channel, but modern long flights in balloons use his idea – hot air is cheap and allows easy ups and downs; the light gases are more expensive, but they provide lift as long as you can keep them from leaking.
History of ballooning
The Kongming Lantern was developed in China, a few centuries B.C. It is basically a candle attached to a small air pocket – the candle keeps the air hot for as long as it burns. The invention is attributed to Zhuge Liang, who lived in the 3rd century AD, but it seems clear that the little device was around long before that. In any case, the lanterns were made of bamboo and oiled rice paper and were used for signaling; then, being pretty, they were used for festivals. Not a good plan for a dry climate, of course — it’s dangerous if the balloon comes down before the fire dies — but obviously a very pretty sight if all goes well.
Ahem: the history
In 1710, Father Bartolomeu de Guzmao of Sao Paulo Brazil, visiting in Lisbon for his education, made a large paper balloon which had a clay fireplace inside and which lifted off in the presence of the king of Portugal. Since he was inside a building, the servants quickly attacked the balloon, lest it set fire to the curtains. Within a year, the good father himself took a short flight which ended in a minor crash. He survived the crash, but his reputation was never the same. Still, he was the first man to go so high. Those Portuguese!
In 1766, Henry Cavendish produced hydrogen, which is lighter than air, and Joseph Black immediately suggested the possibility of a manned balloon. The race was on to get into the sky. Because it was difficult and expensive to make hydrogen Cavendish’s way, the use of hydrogen waited until people learned to obtain it by electrolysis of water; then it was relatively easy and cheap.
In 1783, the Montgolfier Brothers, who owned a paper company and could produce paper in massive quantities, took off from near Paris in a hot air balloon. The (their pilots, that is) went almost 6 miles (ten kilometers), keeping the air hot with a cast iron stove (Eek!) up there below the paper balloon, and feeding the fire with straw. (Are you kidding?!) They could not see each other from the opposite sides of the stove, and they couldn’t hear very well, either, so they had to shout. People on the ground heard their excited shouts, and assumed they were exclaiming about the view. In fact, one was saying, “Let’s get down; this is long enough,” and the other was shouting, “Don’t just stand there; put more straw in the fire.” Eventually they came down safely.
In December, another team, using hydrogen, took off, also from near Paris, and stayed in the sky for several hours. When they got down, one stepped out and so lightened the basket that the balloon immediately rose again to 10,000 feet. It was intensely cold, intensely solitary, and memorably scary, but the design included a valve that would let out the gas in case there was need of descent. He made his observations of barometric pressure, temperature, and wind, opened the valve, and came safely and gracefully down. He never went up again.
Two years later, the first sky disaster took place when a balloon crashed in Tullamore, Ireland, and set the town on fire. They lived and rebuilt with a phoenix as their seal. I don’t know who flew this, and I assume he died.
The first American flight was in 1793, with George Washington in attendance, and the first balloon that could be steered (what a concept!) was Henri Giffard’s balloon in 1852. It was launched in France, and here’s a link to a picture. It doesn’t look like something anyone could steer, but what do I know?
Obviously balloons had a potential reconnaissance value, and the military of every nation eyed them thoughtfully as soon as they began to look like something that might turn up in the other guy’s arsenal.
In America, at the first Battle of Bull Run (also called the first battle of Manasses) on July 21, 1861, the Union had a balloonist who, using flag signals, helped them direct their artillery fire to the precise location of the enemy headquarters. The Union lost that battle anyway, but they would have lost much worse without the balloon. Reconnaissance balloons were then towed along the Potomac for other battles, including Vicksburg and Sharpsburg. The Confederates also tried ballooning, but they couldn’t match the Union supplies.
There was some discussion of using balloons for dropping firebombs, but evidently that seemed ungentlemanly in those gracious days, so it didn’t happen until we got into a war where the values didn’t include gentlemanliness.
In the winter of 1944-45, the Japanese sent balloon firebombs riding the jet stream to the US. Automatic altitude sensors triggered gas escape if they got too high and sand leakage if they got too low. Only a tenth of the released balloons arrived – but out of 9,000, a tenth was plenty dangerous. It took a while to figure out where they were from, but geologists examined the sand that was used to control their altitude and recognized the mineral configuration of the Japanese coast. Little harm was done though some children were killed at a picnic, but the Americans realized that if bio-weapons were loaded on such craft, the damage would be incalculable and this was an active concern. American B-29s ruined the hydrogen generation plants, and the war came to an end before the next winter.
Balloons and dirigibles had the effect of whetting the appetite for true airplanes, whose concept, however, is actually somewhat different, being heavier than air, not lighter, and the first prize for this achievement goes to the Wright brothers. It is true that in France, in 1898, a Brazilian inventor named Alberto Santos-Dumont flew an untethered balloon craft around the Eiffel Tower and back to Parc Saint Cloud in thirty minutes. He won the first prize for manned and steered flight, so Brazilians credit him with accomplishing the first manned flight. Note that this was a dirigible, not a heavier-than-air craft.
After the Wright Brothers, ballooning diverged from the development of heavier-than-air craft. Dirigibles had a generation of commercial life, but the usual problems proved insurmountable: hot air does not last, helium is too expensive, other gases are too dangerous. A fellow named Zeppelin made several large dirigibles that worked commercially, crossing the Atlantic and even going round the world, but eventually, inevitably, disaster struck. The famous Hindenberg caught fire while landing; 35 of the 97 on board died, and that was the end of ballooning.
Well, not quite the end.
In the 1950’s, Ed Yost 50’s started modern ballooning as a sport, using rip-stop nylon and following the Rosier design of some hot air for altitude control and some gas for a reliable long life. New records for all aspects of ballooning were set year by year until, in 1999, the Breitling Orbiter 3 circumnavigated the world in 3 weeks.
Pass the serotonin.