Blast furnaces are apparatuses that extract metal from ore by removing oxygen from metal oxide. These tall, cylindrical smelting furnaces are fed from the top with a mix of ore, coke, and a flux, commonly limestone, while preheated compressed air is introduced under pressure from the bottom. As the contents become molten, the metal sinks and impurities, called slag, float to the top. Blast furnaces were first used in China more than 2,000 years ago. When did they appear in Europe?
Back in the day
By the 1970s, Leonardo da Vinci's 15th-century mural masterpiece, The Last Supper, was badly deteriorated. Italian officials then undertook a major restoration project to permanently stabilize the painting and reverse the damage. The painting's original form was determined using original sketches and scientific tests, including infrared reflectoscopy and microscopic core-samples. The restoration took 21 years, and the painting was put back on display in 1999. Where is it located?
Born on a day like today
Moore was an Irish poet who achieved prominence in his day not only for his poetry but also for his love of Ireland and personal charm. He is remembered today for Irish Melodies, a group of lyrics published between 1808 and 1834 and set to music by Sir John Stevenson and others. Moore was friends with Percy Bysshe Shelley and Lord Byron, and his biography of Byron is among his best prose works. Byron left Moore his memoirs, but Moore later destroyed them. Who persuaded him to do it?