Guess what were the inventions of the Roaring Twenties...
A lot was happening then. Here's some listing: traffic lights, hair dryer, lie detector, cotton swabs (which now after 100 years will finally be banned altogether), cheeseburger, pop-up toaster, bubble gum, penicillin, electric razor and even the Jukebox, invented by The Automatic Music Instrument Company in 1927. It was originally called "juke joint" until the word Jukebox came into use in the 1940's.
One more invention: sunglasses. And I do not mean the Chinese smoky-quartz predecessors of the 12th century. The modern sunglasses became popular, especially among the film stars, in the early 1920's. They were made from celluloid and were first mass-produced by Sam Foster in 1929.
Now what would summer be without the sunglasses! The sunbeams would blind your eyes all the time. And even more important: it would be impossible to maintain that mysterious diva elegance if everybody could see your eyes!
If you don't believe me... well, just ask Audrey.