generally redoubts, built with a view to containing garrisons strong enough to hold their own, in case the connecting parapet was abandoned and the infantry force withdrawn.
In this they differed from the rebel batteries south of the Appomattox
, which with few exceptions were open to the rear, and could not be held if the line was broken at any one point.
The entrenchments on both sides were built of the red loamy clay found in the eastern parts of Maryland
, a soil peculiarly adapted for earthworks, as it is easily dug, and stands well when formed into slopes.
The parapets were several feet thick and ten or twelve feet high; the faces were carefully traversed, and some of the guns had shields for protection against rifle-shots, made of three thicknesses of plank nailed together, and fitted over the breech in front of the sight, a slit being cut in the shield, in which the gun was laid.
The revetments were almost always of logs, laid horizontally, and parallel with the crest of the parapet.
The chevaux de frise were constructed of square logs, with holes through which the spikes were passed, after which the lengths were lashed together.
Covered ways, starting from tunnels under the parapet, gave access to the line of rifle-pits, which was sometimes only twenty-five or thirty yards outside.
Immediately in front of Petersburg
, where the hostile pickets were very close, and the riflefiring was continuous day and night, the men laid large logs of wood along the top of the parapet or rifle-pits, and out of the under side a small hole was cut, through which they were able to keep up a sharp fire without being often hit.