A US Public Health Service worker measures samples of air pollution form the American Steel and Wire Company's zinc works in Donora during a four day test © Bettmann/Getty Images
1948 - Killer smog descends on Donora
The 14,000 residents of Donora, Pennsylvania wake up to a thick yellow smog containing sulphuric acid, nitrogen dioxide and fluorine, amongst other poisonous gases that would last for five days. Over half of the town’s population became ill and 70 were killed.
The nearby zinc plant was held largely responsible as its toxic emissions had already wiped out all plant life within half a mile. The event caused nationwide concern and is often cited as the trigger for the eventual passing of the clean air act in 1970, and is immortalised by the museum in Donora with the slogan: “Clean Air Started Here”.
1873 - First patent filed for modern barbed wire
Joseph Glidden files the first patent for his new design of a wire fence with fixed barbs, nicknamed “The Winner”. Prior to its invention the leading barbed fencing was the far less catchy “The Wooden Strip with Metallic Points”, which had limited success. Upon successful demonstrations of the effectiveness of barbed wire in Texas, the cheap production cost and durability of the barbed wire eventually lead to global adoption and popularity, revolutionising cattle farming practices.
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