Some of my happiest memories as a child are of reading the old children's books I found at houses and in the libraries of my school and camp. Musty smelling, filled with deco and nouveau style pictures of girls in strange costumes, they were a tangible link to the past. Not merely because some child had held that book in 1920, but because to read the popular fiction of another era is to take at least a few halting steps into its foreign mental world.So when I see old children's books--and by "old" I mean "pre-1960"--I often buy them. I love having the companions of my childhood to hand. I've always enjoyed the prospect of having more space to really take up collecting.Apparently, I can forget about that. Congress has apparently outlawed my hobby. Nor is this merely ideological hysteria. I just checked Amazon, and while there are still some old books for sale, it looks as if there are a lot fewer than there used to be.