"[The word _birm_ seems to have the same meaning as berme (Fr. _berme_), which, in Fortification, denotes a piece of ground of three, four, or five feet in width, left between the rampart and the moat or foss, designed to receive the ruins of the rampart, and prevent the earth from filling the foss."
"The _berme_, or _heel-path_, is the side of the canal opposite the tow-path; _basins_ are small coves in the canal where boats may lie over; _stop-lock_, a sort of quay; the _bit_, a timber-head at the bow of the boat."
"F G the berme, or place left to prevent the parapet from washing down into the ditch."