Your Humble Blogger had enjoyed The Seven Professors of the Far North enough to be actually eager for its sequel, which I have now happily read. The Flight of the Silver Turtle has airships, villainous Nazis, and coded messages from long-dead inventors. It’s a hoot. It also has scenes where the intrepid youngsters Use Math and Science to achieve their goals, which comes off a bit Lesson Plan for me, but may well work in context.
A good two-book start for a series of old-fashioned juveniles. Excellent stuff.
Tolerabimus quod tolerare debemus,
-Vardibidian.