"The Hardy Boys, What Happened at Midnight"...stays at Midnight? Copyright 1931.
The first chapter is entitled, "The Automat". I might have to read this one. Where are my rubber gloves?
Tom Sawyer Detective and Other Stories. Copyright 1924.
The "Other Stories" are "The Stolen White Elephant", "Some Rambling Notes of an Idle Excursion", "The Facts Concerning the Recent Carnival of Crime in Connecticut", "About Magnanimous-Incident Literature", and "Punch, Brothers, Punch". I'm guessing more than a few young boys were lured by the cover only to be disappointed in the content.
I found this used as a bookmark inside. They didn't get very far.