_Cover for Guns._--Some degree of cover for guns, in addition to the
shield, is always desirable. If the gun stands on the natural surface
of the ground, the cover is called an epaulment. In that case a bank
is thrown up in front of the gun, about 1 ft. high in the centre, and
3 ft. 6 in. high at the ends. On either side of the gun and close up
to the bank is a small pit for the gunners. The rest of the earth for
the epaulment is got from a trench in front. If the gun is sunk, the
shelter is called a gun-pit.
In this case there is no bank immediately in front of the gun. Shelter
can be got more quickly with a pit than an epaulment, but it is
generally undesirable to break the surface of the ground.
Obstacles.
The commonest forms of _obstacle_ now used are _abatis_ and _wire
entanglements_. Fig. 93 shows a well-finished type of abatis. The
branches are stripped and pointed, and the butts are buried and pegged
firmly down. Wire entanglement may be added to this with advantage. An
abatis should be protected from artillery fire, which is sometimes
done by placing it in a shallow excavation with the earth thrown up in
front of it.
[Illustration: From _Mil. Engineering: Field Defences_, by permission
of the Controller H.M. Stationery Office.