we perceived the secret of her moving impulse. She did
not drive herself up the river with paddles or propeller,
she pulled herself by hauling on a great chain.
This chain is laid in the bed of the river and is only
fastened at the two ends. It is seventy miles long.
It comes in over the boat's bow, passes around a drum,
and is payed out astern. She pulls on that chain,
and so drags herself up the river or down it. She has
neither bow or stern, strictly speaking, for she has a
long-bladed rudder on each end and she never turns around.
She uses both rudders all the time, and they are powerful
enough to enable her to turn to the right or the left
and steer around curves, in spite of the strong resistance
of the chain. I would not have believed that that impossible
thing could be done; but I saw it done, and therefore I
know that there is one impossible thing which CAN be done.
What miracle will man attempt next?

We met many big keel-boats on their way up, using sails,
mule power, and profanity--a tedious and laborious business.
A wire rope led from the foretopmast to the file of mules
on the tow-path a hundred yards ahead, and by dint
of much banging and swearing and urging, the detachment
of drivers managed to get a speed of two or three miles
an hour out of the mules against the stiff current.
The Neckar has always been used as a canal, and thus
has given employment to a great many men and animals;
but now that this steamboat is able, with a small crew
and a bushel or so of coal, to take nine keel-boats farther
up the river in one hour than thirty men and thirty mules