The Swiss Family Robinson is an educational book for children, in the style of Robinson Crusoe (hence the name). I have to say that while it's a fun adventure story, anyone with even a vague comprehension of geography, flora and fauna will find it ridiculous. Or, at least, the collection of the most useful plants and animals across the world on one island will be considered ridiculous. But, it is a fantasy, so one should make allowances. What I really find difficult to stomach is the dialogue. I don't care when it was written, why it was written or any of that, people just don't talk like that. Especially not six-year-old boys. I'm willing to overlook some things, but there comes a point when my disbelief cannot be suspended any further. 
 It's a fun classic that should definitely be read, but don't expect something believable (unless you're under ten).