I don't remember their titles (they're at my parents' house), but we have several. Some generic with a few plate drawings. Some illustrated. Some focused on one subject. It was not that you learned something particular, more that you know stuff existed.

I now like the fact that they, as books, are frozen in time. And that their knowledge is well packaged and consistent. Unless you're a researcher, you don't need the latest. And as a child, the clear writings and the great illustrations was key to internalize the knowledge.