Delightful three-dimensional representation of daily passenger numbers on Frankfurt’s streetcar lines in the early 20th century. Each strip of wood represents 4,000 passengers: the higher the wood, the more passengers on that section of line!

The figure is from Willard C. Brinton’s Graphic Methods for Presenting Facts, first published in 1914 and widely regarded as the first book on data visualization best practices. You can read the book on archive.org

Source: 100yrsofbrinton