The Shelleys traveled to the Reuss during the Swiss journey; it is
described in History of a Six
Weeks' Tour:
Reuss is exceedingly rapid, and we descended several falls, one of more
than eight feet. There is something very delicious in the sensation, when
at one moment you are at the top of a fall of water, and before the second
has expired you are at the bottom, still rushing on with the impulse which
the descent has given.