In 1928, Otto Frederick Rohwedder gave the world the invention that all future inventions would be cheekily compared to: sliced bread. His revolutionary bread-slicing machine made such an impact that it inspired the popular idiom “the best thing since sliced bread”, which we still use even today. Despite the idiom, we aren’t quite as impressed these days by sliced bread — however, it’s still an apt example of the many inventions that not only defined one of the 20th century’s most dynamic decades but revolutionised the world.

A bread slicer in use, 1930.

The 1920s were a time of change and prosperity. Jazz ruled, hemlines rose, and Western countries like the United States experienced an economic boom of epic proportions. In all aspects of life, things were changing, and they were changing fast.

It was an exciting time. Society was shifting and innovation was booming, with advancements in technology, science, and entertainment rolling out one after another. Post-WWI prosperity allowed many people to live comfortably with cash to burn on consumer goods, and the retail market blossomed with gadgets. Scientific discoveries saved more lives than ever, and technological breakthroughs turned science fiction into reality. The Twenties were Roaring, all right.

The Jazz Age gave us everything from world-shaking scientific breakthroughs to household devices that simply made life more comfortable. The decade’s technological discoveries were among the most important of the 20th century, such as the first liquid-fueled rocket, which ushered in the Space Age. Other inventions focused on efficiency, comfort, and entertainment — hair dryers, sunglasses, BandAids, and even cheeseburgers were all born in the 20s. If you think those are the bee’s knees, take a look at a few of the decade-defining, world-changing technologies and inventions that revolutionised the world during the 1920s.

Antibiotics

Antibiotics have saved countless lives, curing infections that would have been deadly only a century ago—and we have Alexander Fleming’s messiness to thank for it. On September 3 1928, the Scottish professor returned to his laboratory after a family vacation. Fleming, who wasn’t known for being especially tidy, had left stacks of staphylococci-drenched glass plates sitting on a bench. While sorting them, he noticed that a fungus had contaminated one of the cultures, forming a staph-free area. Reacting with a simple “That’s funny,” Fleming showed his assistant and got to work studying the mystery mould. He discovered that this “mould juice”, as he called it, was able to destroy a variety of bacteria. He soon renamed the mould juice, dubbing it penicillin (a bit of a shame, really—mold juice has such a nice ring to it), which today is well-known as the first true antibiotic. Surprisingly, scientists in Fleming’s time weren’t interested in his discovery. Research on the magical mould juice didn’t take off until the 1940s after he had more or less given up on it. Happily, Fleming’s work was recognised, and he was granted a Nobel Prize in 1945. Better late than never, right?

Radio broadcast

The history of radio in a broad sense goes all the way back to the 19th century, with a variety of innovations and discoveries all contributing to its development. Radio was used for wartime communication and amateur broadcasts in the early 1900s, but the radio, or radio broadcast as a commercial medium, didn’t take off until the 1920s when radio receivers became common. The first licensed commercial radio station, KDKA, was developed by Henry P. Davis on November 2, 1920, and the first commercial broadcast was Davis reading the results of the US Presidential election. Over the next decade, radio stations began popping up all over the world. The new medium, which made immediate mass communication available for the first time, shook things up. Newspapers feared the decline of the printed page and bought their own stations, advertisers immediately jumped on board, and society fell in love with the entertainment programs that gave them news, drama programs, and music.

Walk into any grocery store today and you’ll find aisles upon aisles of frozen food, ready to be popped into the oven and eaten within minutes. Whether that’s a great thing for modern society is debatable, but it was certainly a huge deal back in the 20s and had a major effect on future Western eating habits. Frozen foods were developed by Clarence Birdseye, an American who travelled to northern Canada in the 1910s for business and observed the process of freezing food by natives. After some experimentation, he founded a company and patented his process of flash-freezing fish packed into cartons. In 1929, he sold his company and patents for $22 million, and large-scale production began in 1930. It was a hit with consumers for its efficiency and for making out-of-season foods available year round.

Pop-up toaster

The pop-up toaster isn’t the most prolific invention of all time, but it’s a perfect example of the many time-saving household items that hit the market in the 20s. Before the first electric toaster was developed in the 1890s, toast wasn’t a quick snack. A toast-lover had to hold bread over an open flame using tongs or a wire toasting frame. Even when using an electric toaster, toast still had to be manually flipped—and, of course, it was a fire hazard. The pop-up toaster solved these problems, letting hungry people everywhere set a timer, toast both sides of the bread, and not have to worry (as much) about kitchen fires. Invented in 1919 by Charles Strite, the first commercially available electric pop-up toaster, the Model 1-A-1 Toastmaster, hit kitchens in 1925—three years before sliced bread.

Before the development of insulin, diabetes was a death sentence. Doctors knew the disease was related to sugar and would prescribe strict diets, but there wasn’t much else that they could do. In 1920, Frederick Banting had a moment of clarity and jotted a note: “Ligate pancreatic ducts of the dog. Keep dogs alive till acini degenerate leaving islets. Try to isolate internal secretion of these and relieve glycosuria.” What looks like gibberish to you and me was the final breakthrough in a series of research milestones in the study of diabetes. Banting took his hypothesis to J.J.R. Macleod, Professor of Physiology at the University of Toronto, who, despite being sceptical, gave him lab space, ten dogs, and two assistants (who flipped a coin to see who would end up as the only assistant). Banting experimented with his idea, refining and purifying the drug until he decided it was ready for clinical tests. On January 11 1922, 14-year-old Leonard Thompson became the first patient treated with insulin. The boy had a severe allergic reaction, and Banting worked for the next 12 days to perfect the injection, giving it another go on January 23. This time, it was a complete success. What happened next went down in history as one of the medicine’s most miraculous moments: Banting and his team made the rounds in a hospital, injecting children who were dying from diabetes. The children awoke from their comas, greeted by their overjoyed families. No wonder Banting and Macleod won the 1923 Nobel Prize for medicine!

Are these technological developments the cat’s pyjamas, or what? Between penicillin and sliced bread, we can safely say that it was a great decade for discovery. If you know of any other great inventions and technologies of the 1920s, let us know about them in the comments!