Karl Baedeker took over a publishing house in 1832 and built his series of travel guides. He traveled himself every summer and checked sights, prices and distances. The best-known story about him: while climbing Milan Cathedral, he stopped every twenty steps and moved a dried pea from his waistcoat pocket to his trouser pocket. On the way down he counted again to check.
The story has no known primary source. A 2009 article by the Protestant press service tells it as fact but gives no reference.