treatise L'architecture hydraulique, printed in France in 1737. The arrow is here used to illustrate the direction of the flow of water and of the water wheel's rotation. At about the same time, arrow symbols were used to indicate the flow of rivers in maps.

A trend toward abstraction, in which the arrow's fletching is removed, can be observed in the mid-to-late 19th century. The arrow can be seen in the work of Paul Klee. In a further refinement of the symbol, John