Actually, I'm reading the Oxford World's Classics edition of The Complete Stalky & Co (which is the stories in Stalky & Co plus more stories with the same characters that were not in the original collection). I have to say, my reading experience is much better thanks to the footnotes in that edition.
In the stories, the boys often use slang when talking to each other, and although I can follow the gist of it, thanks to the footnotes I realize that they were making jokes using quotes from books that were popular at the time but that I'm not familiar with. Most of that would have gone over my head without the footnotes. (Although I have read Frederic W. Farrar's "Eric, or, Little by Little", so I found it quite funny how they ruthlessly mock that book.)
Which goes to show, although I'm a big fan of Project Gutenberg and similar public domain pages, just getting the free ebook from Project Gutenberg may not be the best alternative for some classics.
by farseer4