With a small allowance, Bob Fulton wants to make each bottle of soda pop last longer so creates a device (which blows up) and creates a gell/liquid which removes friction. Naturally the government claims it theirs.
Found this in my fifth grade teacher's collection before she discarded half of it, and have been kicking myself for not asking for it ever since.
I first read this when it was new and back then I'd have given it a five star rating. As an adult I'm a little less taken by it- there's a great idea in it, and a lot of imagination, but the style is a little stiff- and the espionage aspect is dated. Still a good read though, and the illustrations are fun - by a young Gahan Wilson no less! The final message still seems accurate: give people a choice between advanced technology and cheap candy, and they'll choose cheap candy.
I read this book while in Elementary school. I thoroughly enjoyed the inventive tinkering, the surprise discovery and alternate use, the benefit of the discovery to the world and the awareness of the unintended consequences, not to mention the rational solution to those consequences. I have not read this from an adult perspective, yet.