I wonder how many of you have read this one. The American title, at least of the International Polygonics edition that I have, leaves out the word old, but the stories are the same, and they're classic stuff. Baroness Orczy is best known, probably for The Scarlet Pimpernel, but the stories collected here are what make her important in the mystery field.
The Old Man in the Corner sits in the A. B. C. tea room, tying and untying complex knots in a piece of string. While he does so, he talks about unsolved crimes to a young reporter. He's the very model of the armchair detective as he lays out the facts and produces the solutions, all based on things he has read an observed. He has no interest in bringing anyone to justice. He cares only about the crime and the solution, and his credo is that "There is no such thing as a mystery in connection with any crime provided intelligence is brought to bear upon its investigation." Murder, robberies, and forgeries that the police can't figure out are all clear to the Old Man.
Poe and Doyle came before Baroness Orczy, but nobody who's interested in the history of the mystery genre should overlook this collection. It's dated, sure. It might even seem quaint, but in going over the stories again, I found myself enjoying them just as much as ever. Give them a try and see what you think.