BLAST, and BLASTING. See [Mine] and [Mining].
BLINDS, in military affairs, are wooden frames, composed of 4 pieces, either flat or round, two of which are 6 feet long, and the others 3 or 4 feet, which serve as spars to fasten the two first together: the longest are pointed at both ends, and the two others are fastened towards the extremities of the former, at about 10 or 12 inches from their points, the whole forming a rectangular parallelogram, the long sides of which project beyond the other about 10 or 12 inches. Their use is to fix them either upright, or in a vertical position, against the sides of the trenches or saps, to sustain the earth. Their points at the bottom serve to fix them in the earth, and those at top to hold the fascines that are placed upon them; so that the sap or trench is formed into a kind of covered gallery, to secure the troops from stones and grenades.
The term Blind is also used to express a kind of hurdle, made of the branches of trees, behind which the soldiers, miners, or labourers, may carry on their work without being seen. See [Hurdle].
Blinds are sometimes only canvas stretched to obstruct the sight of the enemy. Sometimes they are planks set up, for which see [Mantlet]. Sometimes they are made of a kind of coarse basket-work; see [Gabions]. Sometimes of barrels, or sacks filled with earth. In short, they signify any thing that covers the labourers from the enemy.
Blind See [Orillon] and [Fortification].
| BLOCKADE, | - | |
| BLOCKADING, |
in military affairs, implies the surrounding a place with different bodies of troops, who shut up all the avenues on every side, and prevent every thing from going in or out of the place; this is usually effected by means of the cavalry. The design of the blockade is to oblige those who are shut up in the town, to consume all their provisions, and by that means to compel them to surrender for want of subsistence.
Hence it appears that a blockade must last a long time, when a place is well provided with necessaries; for which reason this method of reducing a town is seldom taken, but when there is reason to believe the magazines are unprovided, or sometimes when the nature or situation of the place permits not the approaches to be made, which are necessary to attack it in the usual way.
Maritime towns, which have a port, are in much the same case as other towns, when their port can be blocked up, and the besiegers are masters of the sea, and can prevent succours from being conveyed that way into the place.
To Blockade, or to block up a place, is to shut up all the avenues, so that it cannot receive any relief either of men or provisions, &c.