These lines consist of bastions, intended for Infantry, and of curtains in the shape of trenches, so arranged that they can be easily crossed; in the middle of each curtain is a redan armed with guns, which flank the faces of the adjoining bastions, and at each end of the curtains is an opening of II yards for the passage of Cavalry.

436 workmen relieved every two, or at most four hours, can construct 262 yards of these lines in a single night, and consequently give cover to a battalion of 400 files.

The profile of the bastion A B requires for every 3 feet of trace an excavation of 176 cubic feet, the profile of the curtain CD, 84 cubic feet, and the profile of the battery a b, 90 cubic feet.

The length of parapet in two demi-bastions is 188 yards; it requires 344 men, 172 of whom have to pass on part of the earth and level it. The curtain, the length of which is 100 yards, requires only 92 men, all employed in excavating.

The curtains at the extreme ends of the intrenched line are each armed with fifteen pieces of ordnance, those in the centre have at most three.

In the profile of the battery a b, the line e d t indicates small trenches (rigoles), 4′ 3.2" wide, dug between the guns, so that the detachments may get under cover as soon as they have loaded. In front of these trenches the parapet is the same, but the profile of the ditch is reduced to the dimensions shown in Fig. 6.

'This arrangement,' says Laisné, 'has at once the advantages of continuous lines and of lines with intervals.'

In our opinion they could only be of use in protecting the camp if an Army were forced to shut itself up when it could no longer keep the field. Frederick II. was situated thus when he fortified, in four or five days, the camp of Buntzelwitz, within range of the guns of the fortress of Schweidnitz.

For intrenching a field of battle we much prefer the arrangement recommended by Colonel de Pidoll, in the Oestreichische

Militairische-Zeitschrift of 1868, which is very like that of Rogniat, and of which a partial application was made at Sa-. dowa. (See Fig. 9, Pl. 2.)

The ideas of the Austrian colonel may be summed up as follows:

The configuration of the ground and the disposition of the troops determine the choice of positions for the Artillery. In advance of these positions and clear of the line of fire of the guns, there should be cover for the Infantry.

This may be arranged by means of a bastioned intrenchment, the curtain of which is occupied by the Artillery, and the bastions of which serve to shelter the supporting troops.

The faces of the bastions are from 50 to 60 paces, and the flanks from 25 to 30 paces in length, so that each bastion can contain a company of from 150 to 180 men, drawn up in single rank and one pace apart.

In rear of each bastion is a blindage of the same profile, and about 70 paces in length, in the inner ditch of which is placed a company intended in the first place to relieve the men firing in the first line; secondly, to increase the fire (by means of groups of skirmishers) in those parts where the ground is not sufficiently swept by the bastions; thirdly, to form a line of skirmishers on the outer flanks; fourthly, to act as a support, and to detach small columns on the flanks of the battery; and lastly, to fire volleys when the first line is taken, and to defend the second line if the reserves are not too far off.

These works may be constructed in the space of a night, like those of Rogniat. The advantages they offer are as follow:They do not hinder the movements of the troops; they can be strengthened by degrees; they give the enemy no marked superiority when he has taken them; the riflemen placed in the bastions protect the Artillery from the fire of skirmishers, and are themselves protected by the fire of the guns.

In our opinion this arrangement, like that of Rogniat, has the

Brialment, Hasty Intrenchments

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2500 Paces

Henry S King & Co. 65 Cornhill. London.

P. III.

disadvantage that it forces the redoubts to assume a trace which has some of the defects of a bastioned front.

The object would be better arrived at if the two faces of each bastion were replaced by a single line, either straight or curved, joining the shoulders. (Fig. 10, Pl. 2.) This line would, in fact, give more fire in the direction from which the enemy's troops have to attack the bastions. The other arrangement certainly affords a better protection for the ground in front of the guns, but it is not over this ground that the assailants will advance. It is, in fact, in accordance with the principles of tactics to attack batteries in flank and in reverse, while skirmishers, properly covered or concealed, keep up a direct fire against them. Now attacks in flank and in reverse can only succeed after the bastions are taken. Therefore the ground in front of these works should be swept as effectually as possible.

Let us apply the above arrangements to the defence of a front occupied by a corps d'armée of 33,000 men, composed of 6 brigades of 6 battalions each, of 6 regiments of Cavalry of 4 squadrons each, of 12 field batteries and of 3 batteries of Horse Artillery, of 6 guns each.1

Let us suppose that this corps d'armée is occupying the right of the field of battle, and that it is resting on a small river, bordered by marshy meadows. (Pl. 3.)

The nature of the ground is such that by occupying a hill which extends from the wood to the river, the troops and batteries in the first line can see the ground in front of the position, and command the plain, in the centre of which is the village T.

The roads leaving this village cross the left of the position; the most important of them is paved, and leads to our Army's line of retreat. It is, then, probable that the enemy will attack

If we calculate the extent of the position at the rate of 3 ft. for twelve men, we obtain a total length of about 3,000 yards; this is the minimum, for in recent campaigns not more than six or eight men are reckoned for every 34 ft. in length of the position.