Fastening clothes and accessories may seem too simple to be the focus of an important innovation. Indeed, visitors to World Expo 1893 Chicago may have seen Whitcomb Judson’s “Clasp Locker” on display without realising how this device would be the predecessor of an overlooked everyday innovation: the zipper.

85 years ago today, Expo 1935 Brussels opened its doors to visitors from all over Europe and the world. Here are a few facts about the World Expo that you might not have known:

Widely known as La Ville Lumière or the ‘City of Lights’, Paris is famed for its streetlights, first tested in the late 18th century and which became a symbol of the city during the Belle Époque. It was when the whole world was in Paris, during World Expo 1878, that one of the most advanced forms of electrical lighting of its time – the Yablochkov candle – made its debut.

Alfred Heller, dean of American Expo writers, died in December 2019 at the age of 90. Alf had attended almost every Expo since his first, the 1939-40 Golden Gate International Exposition in his native San Francisco. He was a mentor to many of us who write on the subject. From 1981 to 1995, he published World Fair magazine, and he authored his personal memoir of Expo history and his observations, “World’s Fairs and the End of Progress: An Insider’s View,” published in 1999.

Taking place in the world’s largest economy and in midst of the second industrial revolution, World Expo 1904 St. Louis introduced many new technologies and innovations to the public. One of these innovations was the X-ray machine, a fledgling technology that has revolutionised healthcare.