Once in a while, as I wheeled around some sharp bend, I could hear a sullen roar that plainly indicated the presence of falls below; but it seemed so far away that I paid but little attention to it.

I kept driving steadily along, enjoying the exhilaration of the rapid pace, when my attention was attracted by the report of a gun.

Looking up I saw a guarda civil, the gendarme of Spain, who held his carbine aloft and vigorously waved his hat with the other hand as I shot by.

The current increased and the roar below became more audible.

Going around another bend I saw a number of people on the bank waving their hats with a downward motion.