Miss Pickerell is taking her identical twin nephews and her cow to the city to visit the circus and the Atomic Energy Museum. They are traveling downstream in a steam boat and Miss Pickerell is rather put out because the cow was put in the hold with a bunch or annoying rocks. The rocks were ballast. But, when the owner of the boat found that there was a cow aboard, he put into shore and dumped Miss Pickerell and the cow off in a small village. There's an atomic energy research facility near by. Also, the town sherif is trying to prospect for uranium. Miss Pickerell gets involved with both, the sheriff and the research facility, and eventually figures out that there were stores of uranium back in the mountain near where she lives (the source of the steam boat's ballast).
So, we learn all about atomic energy, radioactive decay, how geiger counters work, cosmic ray background radiation, radio-carbon dating, and so forth. A fun way to (re)learn some science.
Given that the book came out in 1953, views favoring atomic energy were pretty highly boosted. Those old atoms were to power our future. We know these days that nuclear power is not so easy. The safety issues are much more difficult and expensive to deal with than we'd imagined back in the olden days (the real problem primarily is waste disposal, I believe, and no one wants to pay for that, neither the profiteers nor the taxpayers).
But, none-the-less, knowing about basic scientific issues is always a good thing. Even if some of the political and economic issues change, the basic science remains steadfast. We've become rather an anti-science society, which doesn't bode well for our futures. It fair boggles my mind that we had well over a dozen people running for President a few months ago, none of whom had even a vague clue about the nature of science. They all seemed to think scientific investigation is merely a matter of opinion. It seems that a good place for those ignoramuses to begin to understand the nature of scientific investigation would be some Miss Pickerell.