Five Weeks in a Balloon

Five Weeks in a Balloon
Title page of a Hetzel edition
Author(s)	Jules Verne
Original title	Cinq semaines en ballon
Translator	William Lackland
Illustrator	Édouard Riou and Henri de Montaut
Country	France
Language	French
Series	The Extraordinary Voyages #1
Genre(s)	Adventure novel
Publisher	Pierre-Jules Hetzel
Publication date	1863
Published in English	1869
Media type	Print (Hardback)
ISBN	N/A
Followed by	The Adventures of Captain Hatteras

Five Weeks in a Balloon, or, Journeys and Discoveries in Africa by Three Englishmen (French: Cinq semaines en ballon) is an adventure novel by Jules Verne.

It is the first Verne novel in which he perfected the "ingredients" of his later work, skillfully mixing a plot full of adventure and twists that hold the reader's interest with passages of technical, geographic, and historic description. The book gives readers a glimpse of the exploration of Africa, which was still not completely known to Europeans of the time, with explorers traveling all over the continent in search of its secrets.

Public interest in fanciful tales of African exploration was at its height, and the book was an instant hit; it made Verne financially independent and got him a contract with Jules Hetzel's publishing house, which put out several dozen more works of his for over forty years afterward.

Plot summary

A scholar and explorer, Dr. Samuel Ferguson, accompanied by his manservant Joe and his friend professional hunter Richard "Dick" Kennedy, sets out to travel across the African continent — still not fully explored — with the help of a hot-air balloon filled with hydrogen. He has invented a mechanism that, by eliminating the need to release gas or throw ballast overboard to control his altitude, allows very long trips to be taken. This voyage is meant to link together the voyages of Sir Richard Burton and John Hanning Speke in East Africa with those of Heinrich Barth in the regions of the Sahara and Chad. The trip begins in Zanzibar on the east coast, and passes across Lake Victoria, Lake Chad, Agadez, Timbuktu, Djenné and Ségou to St Louis in modern day Senegal on the west coast. The book describes the unknown interior of Africa near modern day Central African Republic as a desert, when it is actually savanna.

Map of the trip described in the book from the east to the west coast of Africa.

A good deal of the initial exploration is to focus on the finding of the source of the Nile, an event that occurs in chapter 18 (out of 43). The second leg is to link up the other explorers. There are numerous scenes of adventure, composed of either a conflict with a native or a conflict with the environment. Some examples include:

• Rescuing of a missionary from a tribe that was preparing to sacrifice him.
• Running out of water while stranded, windless, over the Sahara.
• An attack on the balloon by condors, leading to a dramatic action as Joe leaps out of the balloon.
• The actions taken to rescue Joe later.
• Narrowly escaping the remnants of a militant army as the balloon dwindles to nothingness with the loss of hydrogen.

In all these adventures, the protagonists overcome by continued perseverance more than anything else. The novel is filled with coincidental moments where trouble is avoided because wind catches up at just the right time, or the characters look in just the right direction. There are frequent references to a higher power watching out for them, as tidy an explanation as any.

The balloon itself ultimately fails before the end, but makes it far enough across to get the protagonists to friendly lands, and eventually back to England, therefore succeeding in the expedition. The story abruptly ends after the African trip, with only a brief synopsis of what follows.

Inconsistent scientific/technological reference

The description of the apparatus used to heat the hydrogen gas in the balloon is deeply flawed. Jules Verne states that it uses a powerful electric battery to electrolyze water into hydrogen and oxygen, and then burns resulting hydrogen in a blow-pipe. He also says that the apparatus weighs 700 pounds (including the battery) and it is able to process 25 gallons of water. This is physically impossible. Even using state-of-the-art 21st century batteries (e.g. lithium-ion batteries) and assuming zero losses, one needs over 4000 pounds of batteries to electrolyze that much water.^[1] This number should be increased by at least a factor of five if authentic mid-19th century batteries are to be used. It would have been far more realistic simply to electrolyze the water up front and to load a tank of compressed hydrogen onto the balloon (electrolysis of that quantity of water produces less than 25 pounds of hydrogen).

Further, it would have been more efficient to use the energy contained in the battery to heat the gas directly. Electrolysis of water is not 100% efficient. So some of the energy contained in the battery is wasted and the heat generated by burning the obtained hydrogen is less than the heat that could have been obtained by simply using a resistance connected to the battery. In fact, Verne implies that the described device is a perpetual motion machine, since he implies that greater energy can be obtained by electrolysis than could have been obtained from the battery directly: if this were true, then the obtained hydrogen could be used to boil water to create steam to power an electrical generator to create more electricity for the battery. This may have been a deliberate joke by Verne.

Though the novel goes into great detail with much of the calculations involving the lift power of the hydrogen balloon, and how to obtain the proper amount of volume through changes in temperature, there are gaps in the logic. The balloon rises up when heated, and lowers as it is allowed to cool. This pattern is used as numerous plot points and is shown to be a somewhat quick process of cooling. At night, however, there is little mention of them maintaining the temperature through the night. Another gap in the scientific logic is the lack of reference to the effect of atmospheric temperature on the balloon itself, though the temperature is referenced as affecting the heating coil.

And it would be very dangerous to light a fire in the nacelle under a balloon filled with hydrogen.

Further, in Chapter 41, the load carried is progressively reduced in order to allow the balloon to rise higher and higher. But in fact a single load reduction would have been sufficient, because at that point the lift of the balloon would have exceeded the weight and it would have continued to rise until the volume of gas was reduced. (The density of air decreases with increasing altitude, thus reducing the lift at constant balloon volume, but the balloon would expand proportionately, due to decreasing air pressure, thus maintaining constant total lift.)

In Chapter 26, it says the doctor takes the balloon up to five miles (8 km). Later, in Chapter 29, in order to get over Mount Mendif, the doctor "by means of a temperature increased to one hundred and eighty degrees, gave the balloon a fresh ascensional force of nearly sixteen hundred pounds, and it went up to an elevation of more than eight thousand feet" which is noted as being "the greatest height attained during the journey." If this is meant to imply that the doctor went eight thousand feet above Mount Mendif, at a height greater than five miles (8 km), Jules Verne would have greatly underestimated the drop in temperature and how much heat would have been required to keep the balloon at that height for any length of time.

At the time when the book was first written, lands to the north and northwest of Lake Victoria were still poorly known to Europeans. Jules Verne makes a few inaccurate predictions here, such as placing the source of the Nile river at 2°40′N (instead of 0°45′N); claiming that this source is just over 90 miles (140 km) from of Gondokoro (the actual distance is closer to 300 miles); not mentioning Lake Albert at all (it was not discovered by Europeans until after the publication of the book). Much of the geography described further in the book is completely fictional. For example, coordinates given for the "desert oasis" in chapter 27 correspond to a location in a savanna region of southern Chad, less than twenty miles (32 km) from a big river.

Similarities to later novels

Five Weeks has a handful of similarities to the novel Journey to the Center of the Earth. There is the same sort of conjecture from current scientific ideas and what Verne puts forth as the actual truth (though Five Weeks is far more successful, assuming there is any attempt at accuracy with Journey). The party of three characters is similarly divided into the Doctor, the doubtful companion who initially balks at the journey, and the servant who is quite able. In both novels, Purdey rifles are referenced. In both novels, there is an episode of despair categorized by thirst.

Film adaptations

• 1961 - Flight of the Lost Balloon USA directed by Nathan Juran and starring Marshall Thompson. Due to pressure from Irwin Allen and 20th Century Fox all references to Jules Verne were dropped from the film.^[2]
• 1962 - Five Weeks in a Balloon, USA, directed by Irwin Allen and starring Red Buttons, Fabian, Barbara Eden, Sir Cedric Hardwicke, Peter Lorre, Richard Haydn, Barbara Luna (see Five Weeks in a Balloon at the Internet Movie Database)
• 1975 - Viaje Fantástico en Globo, Mexico, directed by René Cardona Jr and starring Hugo Stiglitz (see Viaje Fantástico en Globo at the Internet Movie Database)

Notes

1. ^ A lithium-ion battery stores 160Wh/Kg, see [1]. The electric power required to electrolyze hydrogen equivalent in energy content to 1.04 US gallons of gasoline is about 33 kWh, assuming perfect efficiency, see [2] and [3]. The resulting quantity of gas has an energy content of about 38 kWh (137 MJ), see Gasoline#Energy_content (note that this is more than the energy that was input, which is not possible according to the laws of conservation of energy--as noted above the estimate for the energy required to electrolyze the water assumed 100% efficiency, which is not realistic). The energy required to heat hydrogen is 14.3 joules per gram per degree, see Specific_heat#Heat_capacity. The total energy stored in 300 Kg of lithium-ion batteries would be about 48kWh, which could theoretically electrolyze hydrogen containing 55 kWh (198 MJ). This would be sufficient to heat about 275 kilos of hydrogen by 50 degrees. The specific volume of hydrogen is about 12 m3/Kg at 1 atmosphere and 20 degrees, see [4]. The balloon described by Verne had a volume of 90 thousand cubic feet (2548 m3), see chapter 7 of his book. So it would require about 212 Kg of hydrogen to fill the balloon completely; Verne states that the hydrogen weighed about 125 Kg, which is consistent with starting with a balloon that was only half-full, in order to allow for expansion. Given that the energy contained in the battery could only heat the 125 Kg of hydrogen by 50 degrees twice, it is clear that there was nowhere near enough energy in the battery to sustain a five week flight, and this because the gas would cool over time and would need to be heated many times over (not to mention the fact that Verne states that the hydrogen was heated by more than 100 degrees more than once--again, well beyond the capacity of even a modern high-performance battery).
2. ^ p.234 Taves, Brian, Michaluk, Stephen & Baxter, Edward The Jules Verne Encyclopedia Scarecrow Press, 1996

External links

• Works related to Five Weeks in a Balloon at Wikisource
• Five Weeks in a Balloon at Project Gutenberg
• Cinq semaines en ballon at Project Gutenberg (French)