-water rivers, with gravel bottoms, change their channels
very gradually, and therefore one needs to learn them but once; but
piloting becomes another matter when you apply it to vast streams like
the Mississippi and the Missouri, whose alluvial banks cave and change
constantly, whose snags are always hunting up new quarters, whose
sandbars are never at rest, whose channels are for ever dodging and
shirking, and whose obstructions must be confronted in all nights and
all weathers without the aid of a single light-house or a single buoy;
for there is neither light nor buoy to be found anywhere in all this
three or four thousand miles of villainous river.{footnote [True at the
time referred to; not true now (1882).]} I feel justified in enlarging
upon this great science for the reason that I feel sure no one has ever
yet written a paragraph about it who had piloted a steamboat himself,
and so had a practical knowledge of the subject. If the theme were
hackneyed, I should be obliged to deal gently with the reader; but since
it is wholly new, I have felt at liberty to take up a considerable
degree of room with it.

When I had learned the name and position of every visible feature of the
river; when I had so mastered its shape that I could shut my eyes and
trace it from St. Louis to New Orleans; when I had learned to read the
face of the water as one would cull the news from the morning paper; and
finally, when I had trained my dull memory to treasure up an endless
array of soundings and crossing-marks, and keep fast hold of them, I
judged that my education was complete: so I got to tilting my cap to
the side of my head, and wearing a tooth-pick in my mouth at the wheel.
Mr. Bixby had his eye on these airs. One day he said--

'What is the height of that bank yonder, at Burgess's?'

'How can I tell, sir. It is three-quarters of a mile away.'

'Very poor eye--very poor. Take the glass.'

I took the glass, and presently said--'I can't tell. I suppose that that
bank is about a foot and a half high.'

'Foot and a half! That's a six-foot bank. How high was the bank along
here last trip?'

'I don't know; I never noticed.'

'You didn't? Well, you must always do it hereafter.'

'Why?'

'Because you'll have to know a good many things that it tells you. For
one thing, it tells you the stage of the river--tells you whether
there's more water or less in the river along here than there was last
trip.'

'The leads tell