Midway between the big forts, at a distance of a quarter of a mile from
each, is a block house of two stories with the upper story of wood,
overhanging the lower foundation of mud. These are placed at right
angles to the railroad, instead of facing it, as do the forts.

Between each block house and each fort are three little forts of mud
and planks, surrounded by a ditch. They look something like a farmer's
ice house as we see it at home, and they are about as hot inside as the
other is cold. They hold five men, and are within hailing distance of
one another. Back of them are three rows of stout wooden stakes, with
barbed wire stretching from one row to the other, interlacing and
crossing and running in and out above and below, like an intricate
cat's cradle of wire.

One can judge how closely knit it is by the fact that to every twelve
yards of posts there are four hundred and fifty yards of wire fencing.
The forts are most completely equipped in their way, but twelve men in
the jungle would find it quite easy to keep twelve men securely
imprisoned in one of them for an indefinite length of time.

The walls are about twelve feet high, with a cellar below and a vault
above the cellar. The roof of the vault forms a platform, around which
the four walls rise to the height of a man's shoulder. There are
loopholes for rifles in the sides of the vault, and where the platform
joins the walls. These latter allow the men in the fort to fire down
almost directly upon the head of any one who comes up close to the wall
of the fort, where, without these holes in the floor, it would be
impossible to fire on him except by leaning far over the rampart.