Professor Challenger

The mighty Professor Challenger was introduced to the world in 1912.  This was in Sir Arthur Conan Doyle's groundbreaking The Lost World. He is the exact opposite of Doyle's most famous creation, Sherlock Holmes.  A team up between these two characters would have been fun.  Too bad Doyle didn't do that, though that sort of thing rarely happened back then.  The only crossover I can think of is when Tarzan went to Pellucider.  And that was still mostly a Tarzan story.

I would think the five Challenger stories are now in the public domain, since they are well over a hundred years old.  I want to read them.  Doyle himself is a fascinating figure.  These two characters are incredibly science based, and yet Doyle was a spiritualist, going to seances and such stuff.