My favorite reading is science fiction and fiction set in the early 1800s. Reading a novel set just after Waterloo (1811), I found an anachronism. A character postulates wearing 'asbestos underwear', which led me on a hunt for the invention of asbestos.
Asbestos turned out to be a natural mineral which has been known for thousands of years for its fire-retardant qualities. But the wide-spread use of asbestos in clothing did not begin until about 1850, when it was spun with wool yarn in mills. A person would not have benn using the term for clothing in 1812, thus it was an anachronism.