The Barcode Began as Morse Code Drawn in Beach Sand

Picture a young engineer sitting on the sand at Miami Beach, at the end of the 1940s, letting the warm grains run through his fingers. He is thinking about Morse code, which he learned as a Boy Scout. Then he pokes four fingers into the sand and pulls them towards himself. Four lines appear, and with them an idea that now beeps at shop tills around the world.

How lines in the sand became a code

The puzzle had started in Philadelphia in 1948. According to IBM's own history, a graduate student at the Drexel Institute of Technology overheard a supermarket executive pleading with a dean for a way to record automatically what shoppers bought. He shared the problem with a friend and fellow student, who was so taken with it that he went off to his grandfather's flat in Miami to think. Morse code turned out to be the key. On the beach he saw that dots and dashes could become narrow lines and wide lines, and that a machine could read those with light.

Then, as he later told it, he swept the lines round into a circle. A round code, like a small bull's-eye, could be read whichever way a package was facing. The two friends applied for a patent on 20 October 1949 and received it in 1952, under the unglamorous title Classifying Apparatus and Method. The patent, US 2,612,994, shows both versions: a pattern of straight lines, and a target of concentric black and white circles.

Why it waited a quarter of a century

The idea was sound, but the machines of the day were not ready. Smithsonian Magazine describes the home-built prototype: it needed a powerful 500-watt bulb, the setup was the size of a desk, and it worked, up to a point. IBM records that the inventors eventually sold their patent for 15,000 dollars. The code got its second chance in 1970, when grocery companies asked for proposals for a shared product code. An IBM engineer set the bull's-eye aside, because it smeared when printed, and offered a rectangle of 30 black and 29 white lines that a laser could read from any direction. With a few small changes, the trade adopted it in 1973.

1. 1948 A supermarket executive asks a Philadelphia college for a faster checkout
2. 20 October 1949 Two friends apply for a patent on a code of lines and circles
3. 1952 The patent is granted
4. 1973 The grocery trade adopts a rectangular code of black and white lines
5. 26 June 1974 The first pack of chewing gum is scanned in Troy, Ohio

The first beep

Just after eight in the morning on 26 June 1974, at a Marsh supermarket in Troy, Ohio, a cashier passed a multipack of Wrigley's Juicy Fruit chewing gum over a brand-new scanner. The till rang up 67 cents. The shopper was no ordinary customer: he was the supermarket chain's own head of research and development, and the lines in the sand had finally reached the checkout.

What people often get wrong

Three things. The first is that the gum was grabbed at random. The man who bought it said later that this was not a lucky dip: he chose chewing gum because nobody had been sure a barcode could be printed on something so small. The second is that the famous pack sits in a museum case. Smithsonian Magazine corrected its own article in 2017 to say that the Smithsonian did not collect the gum, and that only a facsimile was once on display. The third is that the barcode was always a block of stripes. The version its inventors settled on was round, and the familiar rectangle arrived more than twenty years later.

Today, by IBM's count, barcodes are scanned about 6 billion times a day. Every one of those beeps goes back to the same small thought: a dot can be a thin line and a dash can be a thick one. Most things drawn in beach sand are gone by the next tide. This one just took a quarter of a century to come in.