From Popular Science Monthly, 1916.

From the University of Illinois's 1912 yearbook.

From The Gazelle's Ears by Corey Ford and illustrated by Frueh, 1926.

From the United States Naval Academy's 1909 yearbook.

From the University of Toronto's 1950 yearbook.

From Life Magazine, 1925.  [Via Jonathan Caws-Elwitt]

From Machines and the Men Who Made the World of Industry by Gertrude Hartman, 1939.

From the United States Naval Academy's 1925 yearbook.

Simple landlord remover.  From Life Magazine, 1921.

From Purdue University's 1910 yearbook.

From Great Inventors and Their Inventions by Frank Bachman, 1918.

From Black and White Budget, 1901.

From Fate Magazine, 1953.

From Children of the Dawn by Evan Davies and illustrated by Cyril Cowell, 1938.

From the University of Illinois's 1912 yearbook.

From the University of Illinois's 1912 yearbook.

At first glance, we thought this was a portable keyhole, and the inventor mentions having lost a keyhole once.  But it's actually practical — an illuminated and magnetized key for finding a lock in the dark.  The text notes that the inventor looks over his glasses to keep the lenses from wearing out, which sounds silly at first ... until one recalls that some corrective lenses actually do weaken the eyes over time, so avoiding them would in fact lengthen the life of the prescription.  As for the claim that the invention also cures hay fever, dusts the piano, makes vacations easy, and does away with sea sickness, we'll give the inventor the benefit of the doubt.  From the Duluth Herald, 1911.

Here's a precursor to the "Find My" apps.  The talking collar-button, from Life Magazine, 1921.  [Via Jonathan Caws-Elwitt]

From The Old Line, 1934.

From Purple Parrot, 1929.