That is the signal used in Spain when you are desired to approach.

I misunderstood it, and thought it meant for me to take the other side, which I did and found I was in a current from which I could not extricate myself.

Another sharp, turn and the village of Puente del Arzobispo came into sight with the heavy spray from the falls rising high in the air.

The roar was like the deep rumbling of thunder when near at hand.

I paid no attention to the shouts of the people to stop, for I saw could not possibly get out of the current, so I exerted myself to pass the falls safely.