This is one Verne's paeans to the Scientific Man, and he pulls out all the stops. It's his version of Robin Crusoe and The Swiss Family Robinson but cast with 4 men and one boy of iron will and backbones of steel.

Verne threw in everything, escape from foes by balloon, intrepid and stalwart companions, dedicated manservant, loyal dog, engineer that was a veritable walking encyclopedia, narrow escapes, pirates, an unseen hand lending aid when all hope seemed lost, man's ability to create what he needs from his environment, harsh weather, a castaway and a volcano. Plus, the final chapter of Captain Nemo!

Verne's style isn't just to entertain, but also to educate the reader with as much of his world known at the time. He tells how the colonists carve out living conditions from the raw material and their own pluck, nerve, sinews and knowledge through his worldview. He explains to the reader in great detail about the physical characteristics of the island, how the colonists overcome their challenges and and other scientific fact he could fit in. Being a dork, I really this aspect of the book, while acknowledging this won't appeal to all readers.

Verne also pairs two big themes: the ability of man to carve out prosperity from nature, and nature's raw power which can overwhelm man's mightiest works.