258 MARTIN RATTLER.

bed varies in thickness from one to four feet, and the
pebbles are of various kinds, but when there are
many of a species called esmerilo preto, the cascalho
is considered to be rich in diamonds.

Taking Martin round to the back of the shed,
Barney showed him a row of troughs, about three
feet square, close to the edge of a pond of water.
These troughs are called bacos. In front of each
stood a Negro slave up to the knees in water. Each
had a wooden plate, with which he dashed water
upon the rough cascalho as it was thrown into the
trough by another slave. By this means, and by
stirring it with a hoe, the earth and sand are washed
away. Two overseers were closely watching the
process, for it is during this part of the operation
that the largest diamonds are found. These overseers
were seated on elevated seats, each being armed with
a long leathern whip, to keep a sharp look out, for
the slaves are expert thieves.

After the cascalho had been thus purified it was
carefully removed to the shed to be finally washed.

Here seven slaves were seated on the side of a
small canal, about four feet broad, with their legs in
the water nearly up to their knees. This canal is
called the lavadeiva. Each man had a small wooden

platter, into which another slave, who stood behind