I loved the Great Brain books when I was a kid, but I'd never read this one. It was published posthumously in 1995. It's another of my library sale finds.
The books are each a series of short stories about J.D., his older brother Tom, and their family. Tom is the one known as the great brain, and as J.D. points out, he also has a money-loving heart. Every time Tom comes up with another idea to make money, it seems J.D. ends up broke--but never bored.
When I was a kid, I thought Tom's swindling was hilarious. As an adult, I'm a lot less amused. Tom's kind of a jerk. I actually disliked the first story, where Tom orders a bunch of soap to resell and talks J.D. into selling it and paying Tom for the privilege. But the later stories are a lot better. Tom helps figure out the actual events when a Paiute Indian is accused of stealing a rifle, and he engineers the downfall of a man running a dogfighting ring. Best of all, in the last chapter Tom gets his comeuppance from an unexpected source.
The stories are mostly funny, but they're also interesting since they're set in the last year of the 19th century. Fitzgerald wrote the books based on his own childhood memories. The writing is simple but clear, and J.D. is a nice guy even if he is a little too willing to let Tom walk all over him.