a shot from which will not merely pierce or bore the thickest iron plate, but which will break the plates into pieces, or else tear them from their fastenings and carry them bodily with it into the ship.

Prior to the use of gunpowder for breaching purposes the masonry of fortified places was not covered by the interposition of any screen between it and the direction of attack; but as soon as a force was discovered by means of which cannot-shot could be projected against the walls of castles, it became indispensable to raise a screen of earth before these walls whenever a battery could be established within the distance at which the masonry could be reached with sufficient force and accuracy for it to be destroyed by the process of battering. This limit of distance being soon learned by experience, all masonry that could not be reached by accurate firing was still left uncovered, while in front of all liable to be destroyed by battering a mound of earth for which this cover was necessary varied with the advances made in the construction of ordnance and the manufacture of gunpowder. The following extract from a standard authority on the subject of sieges presents the general idea clearly:

In the sixteenth and beginning of the seventeenth centuries the art of disposing the different works of a fortress to cover each other, and to be covered by the glacis from the view of an enemy from without, was either unknown or not attended to. The small quantity of artillery in use, its unwieldiness, and the great expense and difficulty of bringing it up, occasioned but little to be used at siege, and the chief care in fortifying towns was by height of situation and lofty walls to render them secure from escalade, and all places built prior to that period are invariably of such construction. The simplicity of the places to be attacked gave the same character to the operation itself, and everything was thus effect by desperate courage without the aid of science; but as the use of artillery became more common, and large quantities of it were used at sieges, such exposed walls could no longer oppose a moderate resistance, even to the imperfect mode of attack then in use, land to restore an equality to the defense it became necessary to screen them from fire.

Coming to the memorable and somewhat recent date of the sieges of the Peninsular war of Wellington, the following cases may be cited:

At the second siege of Badajos fourteen brass 24-pounders breached the outer face of the castle-wall at the distance of 800 yards in about eight hours. The earth behind the wall was left standing when the wall peeled away. Before this earth could be reduced to a slope the approach of a succoring force made it necessary to abandon the siege.

At the third siege of Badajos breaching batteries were established against the face of one bastion and the flank of another at a distance of 500 to 600 yards. The batteries being on a hill, nearly the whole height of the scarp-walls could be seen by them. The garrison, however, constructed an earthen counterguard in front of one, land so covered the lower part of the wall from the besieging projectiles. The batteries were armed with twelve 24-pounder and fourteen 18-pounder brass guns.

By over two days" battering the wall was cut through and the clay behind visible.

The third day's firing cut away the earthen parapet, and the breaches were regarded as in a state to be assaulted. Fourteen of the guns were then turned on the exposed scarp of a curtin, which came down in two hours" firing, being extremely bad masonry. The extent of front of the three breaches opened was above 500 feet, the greater part of which was as good as can be formed. The assault on the breaches failed, but the place was carried by escalade by other columns.