The circular wave that arises on the surface of the water enclosed in a struck vessel ends along that line which was there created by the motion of its mover.

Every moving body that generates a reflection ends its course along the line of incidence.

This happens because the incident motion is of greater power than the reflected motion, and that which is more powerful has more durability than the less powerful.

The motion of the incident body will be more powerful than its reflected motion, because the percussion of the incidence made upon the dense object diminishes part of the impetus joined to that body. This diminution does not leave the reflected motion as powerful as the incident one was said to be; although at every degree of motion the impetus of the body diminishes of itself even without percussion against something dense, and it remains true that such percussion diminishes it far more. For if you measure the motion that such a body would have made without incidence, and measure the motions born of many bounces up and down, the motion continued along one same course will be longer than that which is so many times interrupted by the incidences, even though the beginning of the impetus in each of them were of power equal among themselves.