Book forty-one: Mr. Popper's Penguins by Richard and Florence Atwater

When Mr. Popper writes to Admiral Drake at the South Pole, he never anticipates a reply, and he certainly never would have guessed that Drake would send him a flightless bird. The already strapped family isn't sure how to make ends meet during the winter months but when that one bird becomes a dozen penguins, Popper's idea has the family going on an across-the-country vacation with the penguins earning their keep.

41 down plus 11 to go. (Let's face it. I'm totally not going to hit the mark again. Dang.)