“Millions for Defense,” Miles J. Breuer, 1935 – Set in the Depression. A young scientist is forced to work for his hateful uncle at his bank, where the young man devises a contraption to foil bank robbers.
Comments: An sf story with a Depression-era, western, and “beleaguered scientist” feel to it all at once. Can be read as containing implied criticism of capitalism, banks. Everett Bleier, in The Gernsback Years, says this is not science fiction.
Author: Wikipedia: “Miles John Breuer (January 3, 1889 – October 14, 1945) was an American physician and science fiction writer.”