IELTS Academic Reading Practice Test 25: Passage 1

Every day, billions of products are scanned at checkouts, in warehouses and in hospitals around the world, each identified in a fraction of a second by a pattern of black and white stripes. The barcode is so familiar that it is easy to forget how recent it is, and how long it took to succeed. The idea was patented in the early 1950s, yet some twenty years passed before a barcode was first tested in a shop, and several more before most retailers were persuaded that the technology was worth the investment.

The story began in 1948 in Philadelphia, when Bernard Silver, a graduate student at the Drexel Institute of Technology, overheard the president of a local chain of food stores asking one of the institute's deans to develop a way of recording product information automatically at the checkout. The dean was not interested, but Silver mentioned the conversation to a friend, Norman Joseph Woodland, a recent graduate who was teaching at the institute. The pair's first attempt used ink that glowed under ultraviolet light, but the ink faded too quickly and was expensive to print.

Convinced that the idea could work, Woodland left his job and moved to his grandfather's apartment in Florida to think about the problem. His breakthrough came, according to his own account, while he was sitting on the beach. He had learned Morse code as a Boy Scout, and he began to draw its dots and dashes in the sand with his fingers. Pulling them downwards, he found that he had produced a series of thin and thick lines, which could represent information in the same way. Because a product might pass a reader at any angle, the pair also devised a version in which the lines formed a set of circles, rather like a target, so that it could be read from any direction. A patent covering both designs was granted in 1952.

Turning the idea into a working machine proved far harder. The inventors built a reader that used a 500-watt light bulb and a sensitive tube originally designed to read the soundtracks of films. The device worked, but it was far too large and expensive to be used in a shop. Electronic computers were still rare and enormously costly, and there was no cheap way to process the information. The pair eventually sold their patent to the electronics company Philco for 15,000 dollars, and it was later sold on to another firm, RCA. Woodland had by then joined the computer company IBM, and Silver died in 1963, long before the invention became widespread.

Two developments in the 1960s changed the situation. The first was the laser, demonstrated in 1960, which could produce a narrow, intense beam of light far better suited to reading codes than an ordinary bulb. The second was the arrival of smaller and cheaper computers. Meanwhile, the railways of North America tried a different system, attaching labels with coloured stripes to the sides of freight wagons so that they could be identified automatically. The scheme was adopted across the industry in the late 1960s but abandoned within about ten years, largely because the labels became too dirty to be read reliably.

Supermarkets, meanwhile, were facing rising labour costs and wanted faster checkouts. In 1972, RCA tested a version of the circular code at a supermarket in Cincinnati, but the circles tended to smudge during printing, which made them difficult to read. The following year, a committee representing the grocery industry chose a rectangular design developed at IBM, where Woodland was then working, as the standard for the whole industry. It became known as the Universal Product Code. On 26 June 1974, at a supermarket in Troy, Ohio, a packet of chewing gum became the first product to be sold using the new system.

Even then, success was not immediate. Installing scanners was expensive, and stores saw little point in buying them until most products carried a code, while manufacturers were reluctant to print codes until enough stores could read them. In the mid-1970s, one business magazine even described the supermarket scanner as a failure. It was only in the early 1980s, as more stores installed scanners and discovered the value of the information they produced, that the barcode spread rapidly. Retailers could now see exactly which products were selling, and when, and they used this knowledge to manage their stock and to negotiate with suppliers. Woodland lived to see his idea used across the world, and in 1992 he received the National Medal of Technology from the President of the United States. Today the barcode has many descendants, including the square QR code, invented in Japan in 1994 to keep track of car parts.