The best material for armour plates is, however, again prominently under consideration; so great an increase in penetration was obtained with chilled iron shot that the manufacture of steel projectiles was stopped as far back as 1866. Great advances have since taken place in the processes by which steel is made, and steel projectiles of great penetrating power have recently been under trial; by the use, too, of prismatic powder disposed in cartridges with a definite amount of air space, by which the combustion is rendered more gradual and more thorough, a far higher velocity is obtained with a materially diminished strain upon the chamber of the gun. This has rendered it possible to enlarge the chambers of the heavy guns and to increase their lengths by several calibres, with a resulting increase in energy of about one-third, so that a plate which would keep out a projectile of 800 lb weight from a 38-ton gun will now barely keep out a projectile of 400 lb from an 18-ton gun. It is not impossible, however, that by a combination of iron and steel the resistance of armour may be again brought up to the penetrating power of projectiles. During this consideration many curious and unexpected results have been obtained, but they have not been reduced to such a form at present as to modify what is stated above. The whole question is, however, full of interest, and will, it may be anticipated, receive considerable development before long.

ARMAMENT OF FORTRESSES.

The Systems of Fortification having been briefly described, it is right to say a few words here respecting the means of defending a place after it has been fortified. It is difficult to lay down exact rules as to the proportion of ordnance, ammunition, and stores of all kinds required for the defence of a fortified place, seeing they must necessarily vary according to the particular situation of each fortress, the system on which its works have been constructed, and the species of attack to which it may be exposed. If, for example, one of the sides be covered by a morass, swamp, or other obstruction which it is difficult or perhaps impossible to surmount, it must be obvious that a smaller proportion of artillery will be required than if the fortress were equally accessible on every side; and, on the other hand, a maritime fortress, accessible at all points, will necessarily require for its defence a larger proportion of ordnance than if it were only assailable on one or a few of these points. Where every front is equally exposed to attack, all must be equally prepared.

On this subject, however, certain maxims have been established, of which the following appear to be the most important. First, the proportion of ordnance, ammunition, and stores should never exceed the quantity necessary for a brave and resolute defence. Secondly, those fronts which are considered the most exposed to attack should be the most completely armed, whilst a partial armament of the remaining fronts may suffice. Thirdly, to the front to be attacked the following pieces of ordnance should be allotted, viz., to each Bastion, 1 for the salient, 5 for each face, 3 for each flank; to the Ravelin, 5 for each face; to the Lunette, 3 for each face, and a few pieces for the places of arms in the covered-way;-so that if one front be completely armed, the proportion of orduance will be

and 6 for the places of arms,-in all a total of 39 pieces for the front. This proportion is less than has been fixed by many authorities, but the range and accuracy of guns has so increased since the introduction of rifled ordnance that it will be necessary to provide a traverse for every gun on the most exposed faces, and this, while it affords security to the artillery, materially diminishes the space available for mounting guns. It may be thought by some that this arrangement provides too much traverse shelter, but a few well-protected and well-served guns are better than double the number in exposed positions. Fourthly, when a place is exposed to attack on two contiguous fronts, the armament of each should be augmented one-half; when it is threatened with attack on detached fronts, the armament should be doubled. Fifthly, each of the other fronts should merely be provided with such a proportion as to secure it against insult. From this it inay be assumed that a hexagon having only one front liable to attack should be completely armed on the two adjoining fronts, and that about seven guns per bastion and seven per outwork will be sufficient for the remaining fronts, and that a total of 178 pieces of ordnance will be sufficient for a hexagon.

The next consideration is the proportion which the several kinds of ordnance should bear to one another. Ordnance of the higher calibres is not the only ordnance which ought to be employed; in many cases medium and light guns are more efficacious; for when only troops or working parties are to be fired at, light guns will answer every purpose; their range is nearly equal to that of larger guns, and they are more manageable and may be worked with greater-rapidity. Short guns of heavy calibre which throw heavy charges of case and shrapnel are best adapted for the flanks; and, generally, the largest or heaviest ordnance should only be employed to destroy the besiegers' batteries and dismount their guns. The light guns, as they can casily be withdrawn, should be placed in the covered-way, in the places of arms, and in the outworks of every description. The heavy guns and mortars, which are not so easily moved, should be within the body of the place, and as they require largo charges of ammunition, they should be less frequently used, and only upon urgent occasions. A judicious economy of ammunition is a duty incumbent upon every commandant of a fortified place. The conduct of General Chassé in the defence of the citadel of Antwerp was a model in this respect. From the commencement till the close of the attack, scarcely a single shot was needlessly expended by the garrison.

ATTACK AND DEFENCE OF FORTIFIED PLACES.

Having brought the discussion of Permanent Fortifications to this point we may now consider the attack of fortified places, the general system of which was introduced and perfected by Vauban, so that it has ever since served as a model for the plans of his successors.

"La résolution des sieges," says the Marshal, "est une affaire de cabinet. Elle est une suite naturelle de la supériorité que l'on croit avoir sur ses ennemis; mais leur exécution étant une des plus sérieuses, des plus importantes, et des plus difficiles parties, elle demande aussi le plus de mésure et de circonspection." He then goes on to state that the success of sieges depends on several cir cumstances, such as "1. Du secret, sans lequel il est difficile de réussir; 2. Des forces que l'on a sur pied pour attaquer les places ennemis; car s'ils sont réunis, et aussi forts que nous, ils peuvent des ennemis, et défendre les siennes; 3. Do la disposition des nous empêcher d'en faire; 4. De l'état des magazins les plus à portée des lieux sur lesquels on peut entreprendre; 5. De la conjoncture des tems, parce que tous ne sont pas propres aux siéges, et qu'on peut; 6. Des fonds nécessaires à leurs dépenses; car l'argent rien n'étant plus ruineux que ceux d'hyver, on les doit éviter tant

est le nerf de la guerre, sans lai on ne sçauroit réussir en rien. Co

as necessary as the gun and the mortar to the success of a besieger. To render this intelligible to the general reader, a descriptive sketch of the progress of a modern attack, from the excellent work of Sir John Jones already referred to, is introduced here.

"The first operation of a besieger," says that able and experienced engineer, "is to establish a force able to cope with the garrison of the town to be attacked, at the distance of some hundreds of yards from its ramparts. This is effected by approaching the place secretly in the night with a body of men, part carrying entrenching tools, and the remainder armed. The former dig a trench in the ground parallel to the front to be attacked, and with the earth that comes out of the trench raise a bank on the side next to the enemy, whilst the latter remain formed in a recumbent posture, in readi ness to protect those at work, should the garrison sally out. During the night this trench and bank are made of sufficient depth and extent to cover from the missiles of the place the number of men requisite to cope with the garrison, and the besiegers remain in the trench during the following day, in despite of the fire or sorties of the besieged. This trench is afterwards widened and deepened, and the bank of earth raised, forming a covered road, called a parallel, which embraces all the fortifications to be attacked; and along this road, guns, waggons, and men securely and conveniently move, sheltered from the view and the missiles of the garrison. Batteries of guns and mortars are then constructed on the side of the road, to oppose the guns of the place, and in a short time, by superiority of fire, principally arising from situation, silence all those guns which bear on the works of the attack. After this ascendency is attained, the same species of covered road is, by certain rules of art, carried forward, till it passes over all the exterior defences of the place, and touches the main rampart wall at a spot where it has been previously beaten down by the fire of the batteries erected expressly for the purpose in the more advanced parts of the road.

"The besiegers' troops, being thus enabled to march in perfect security to the opening in the walls of the place, assault it in strong columns, and, being much more numerous than the garrison defending the breach, soon overcome them, the more easily as they are assisted by a fire of artillery and musketry directed on the garrison from portions of the road only a few yards from the breach, which fire can at that distance be maintained, without injury to the assailants, on the defenders of the breach until the very instant of personal contention. The first breach being carried, should the garrison have inner works, the covered road is by similar rules of art pushed forward through the opening, and advanced batteries are erected in it to overpower the remaining guns of the place; which effected, the road is again pushed forward, and the troops march in security to the assault of breaches made in a similar manner in those interior works, and invariably carry them with little loss. But as it is always an object to preserve the life of even a single soldier, so, when time is abundant, the loss of men attendant on the assault of breaches under these favourable circumstances may be avoided, by pushing up the covered road through the breach, without giving the assault, and thus, by art and labour, the strongest defences frequently fall without any exertion of open Sorce."

From this description it must be obvious that the most important object at a siege is to carry forward the covered road to the walls of the place, that all the other operations are secondary to and in furtherance of such an advance, and that hence the efficiency of armies at sieges depends upon their ability to complete the road at a small expense of life. But as this covered road advances, the difficulty increases. At its commencement, the work, being many hundred yards from the fortifications, can be performed by the common soldiers. But when the road or trench has arrived within a fair range of musketry from the place, then particular precautions are required; yet the work at this stage is not so difficult as to prevent its being executed by soldiers who have had a little previous training. At the last stage, when the approaches have been pushed close to the place, when to be seen is to be killed, when mine after mine blows up the head of the road, with the officers and men on the spot, when the space becomes so confined that little or no front of defence can be obtained, and when the enemy's grenadiers sally forth every moment to attack and deal out destruction to the workmen, then the work becomes truly hazardous, and can only be performed by selected brave men, called sappers, who have acquired the difficult and dangerous art from which they derive their

name.

An indispensable auxiliary to the sapper is the miner, who in the exercise of his art requires even greater skill, conduct, and courage. The duty of a miner at a siege is to accompany the sapper, to listen for and discover the enemy's miner at work, and to prevent his blowing up the head of the road, either by sinking a shaft down to and meeting him, in which case a subterranean couflict ensues, or by running a gallery close to that of his opponent, and forcing him to desist from working by means of suffocating compositions, and by various arts the knowledge of which he has acquired from experience. Without the aid of skilful miners, sappers would be unable to execute that part of the covered road forming the descent into the ditch, not to mention other operations in the progress of which the assistance of the miner is equally indispensable; and without their joint labours and steady co-operation, no besiegers' approaches would ever reach the walls of a fortress. In the British service they are blended into one honourable body, the Royal Engineers.

But a siege, though it calls for personal bravery, anremitting exertion, and extraordinary labour in all employed, if scientifically prosecuted, is certain in its progress and its result. More or less skill and exertion in the contending parties may prolong or abridge its duration; but the sapper and the miner, when skilfully directed and adequately sup ported, will ultimately surmount every obstacle. On the other hand, sieges undertaken by armies imperfectly sup plied with these auxiliaries are hazardous in the extremel The only chance of success consists in scrutinizing the exterior of the fortress, in order to discover some spot whence, from the irregularity of the ground, or fault of construction, the main escarp wall may be seen at a distance sufficiently great to enable the ordinary working parties to approach with the covered road, and there to establish batteries for breaching or forming an opening through it into the place. When this is effected, the troops advance to the assault of the breach, us in the 16th century, thus passing from the shelter of the covered road into the fire of the place at the moment when it becomes most powerful and destructivo; and as the fire of the besiegers' distant batteries is necessarily suspended during the assault, lest it should destroy the storming party, the garrison can with impunity mount the ramparts and employ every kind of weapon, missile, and instrument in their defence. All the chances are thus in favour of the besieged; for should the columns of attack, under these disadvantages, arrive in good order at the brink of the ditch, they must descend into it down a wall from 14 to 16 feet in depth, which cannot fail to break their order and throw them into confusion; and as no new formation can be attempted in a spot where death meets them in every shape, the assailants rush to the breach more like a rabble than a solid column. From this moment success hinges on the individual bravery of the officers and men, and the unshrinking firmness of the general commanding, in encouraging and supporting their efforts. But although these qualities, when united in a high degree, may, at a great sacrifice of life, enable the assailants to overcome all resistance, yet an assault of this nature, under ordinary circumstances, has almost always proved unsuccessful. Indeed, it may be laid down as the result of experience that, should an army unprovided with sappers and miners, and with the materials and means to render their services efficient, be opposed to a place fortified according to the modern system, with its walls completely covered, all the usual methods to reduce it would prove unavailing; no period of time nor sacrifice of men would be sufficient to purchase success, and the prudent course would be to decline an attempt pregnant with hazard, perhaps ruin.

"These considerations," says Sir John Jones, to whom we are indebted for the above account of the various modes of attacking