by them. You see, the way the wind is now we can lay our course for the
Whittaker. That's a cruel sand, that is, and stretches out a long way
from a point lying away on the right there. Once past that we bear away
to the south-west, for we are then, so to speak, fairly in the course
of the river. There is many a ship has been cast away on the Whittaker.
Not that it is worse than other sands. There are scores of them lying
in the mouth of the river, and if it wasn't for the marks there would
be no sailing in or out."

"Who put up the marks?" Lionel asked.

"They are put up by men who make a business of it. There is one boat of
them sails backwards and forwards where the river begins to narrow
above Sheerness, and every ship that goes up or down pays them
something according to her size. Others cruise about with long poles,
putting them in the sands wherever one gets washed away. They have got
different marks on them. A single cross-piece, or two cross-pieces, or
a circle, or a diamond; so that each sand has got its own particular
mark. These are known to the masters of all ships that go up and down
the river, and so they can tell exactly where they are, and what course
to take. At night they anchor, for there would be no possibility of
finding the way up or down in the dark. I have heard tell from mariners
who have sailed abroad that there ain't a place anywhere with such
dangerous sands as those we have got here at the mouth of the Thames."

In the first three or four hours' sail Geoffrey and Lionel acquired
much nautical knowledge. They learned the difference between the
mainmast and the mizzen, found that all the strong ropes that kept the
masts erect and stiff were called stays, that the ropes that hoist
sails are called halliards, and that sheets is the name given to the