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Wednesday, June 8, 2005

Reading List: Tom Swift and His Airship

Appleton, Victor. Tom Swift and His Airship. Bedford, MA: Applewood Books, [1910] 1992. ISBN 1-55709-177-3.
Following his adventures on land and lake, in this third volume of the Tom Swift series, our hero takes to the air in his hybrid dirigible/airplane, the Red Cloud. (When this book was written, within a decade of the Wright Brothers' first flight, "airship" referred to any flying craft, lighter or heavier than air.) Along the way he survives a forest fire, thunderstorm, flying bullets, false accusation of a crime, and an irritable schoolmarm not amused by having an airship crash into her girls' school, and solves the crime, bags the perpetrators, and clears his good name. Bless my seltzer bottle--never get on the wrong side of Mr. Wakefield Damon!

Apart from the arm-waving about new inventions which is the prerogative of the science fiction writer, Victor Appleton is generally quite careful about the technical details--All American Boys in the early 20th century knew their machinery and would be all over a scribbler who didn't understand how a carburetor worked! Here, however, he misunderstands lighter than air flight. He describes the Red Cloud as supported by a rigid aluminium gas container filled with "a secret gas, made partly of hydrogen, being very light and powerful". But since the only thing that matters in generating lift is the weight of the air displaced compared to the weight of the gas displacing it, and since hydrogen is the lightest of elements (can't have fewer than one proton, mate!), then any mixture of hydrogen with anything else would have less lift than hydrogen alone. (You might mix hydrogen with helium to obtain a nonflammable gas lighter than pure helium--something suggested by Arthur C. Clarke a few years ago--but here Tom's secret gas is claimed to have more lift than hydrogen, and the question of flammability is never raised. Also, the gas is produced on demand by a "gas generator". That rules out helium as a component, as it is far too noble to form compounds.) Later, Tom increases the lift on the ship by raising the pressure in the gas cells: "when an increased pressure of the vapor was used the ship was almost as buoyant as before" (chapter 21). But increasing the pressure of any gas in a fixed volume cell reduces the lift, as it increases the weight of the gas within without displacing any additional air. One could make this work by assuming a gas cell with a flexible bladder which permitted the volume occupied by the lift gas to expand and contract as desired, the rest being filled with ambient air, but even then the pressure of the lift gas would not increase, but simply stay the same as atmospheric pressure as more air was displaced. Feel free to berate me for belabouring such a minor technical quibble in a 95 year old story, but I figure that Tom Swift fans probably, like myself, enjoy working out this kind of stuff. The fact that this is only such item I noticed is a testament to the extent Appleton sweated the details.

I read the electronic edition of this novel published in the Tom Swift and His Pocket Library collection at this site on my PalmOS PDA in random moments of downtime over a month or so. I've posted an updated electronic edition which corrects typographical errors I spotted while reading the yarn.

Posted at June 8, 2005 23:57