founded upon some of Dürer's principles, have been adopted, and may be studied in the works of defence of Coblentz. In all such works masonry defences or casemated buildings assume a character of the highest importance, but it should not be forgotten that masonry can never resist the effects of a concentrated fire of heavy guns, and can be considered safe only when protected by earthen masks or couvre-faces. The Maximilian towers of the defences of Lintz are no longer approved by modern engineers, and in closing the harbor of Sebastopol against approach by sinking a large portion of their own fleet, the Russians exhibited their distrust of masonry defences when opposed to ships. And this distrust is not to be wondered at when it is remembered that, to bring the guns forward enough to afford them latinto, and greatly weakened. This great defect of masonry defences, and the evils of smoke in close casemates, are well known to engineers. In the earliest periods of Italian fortification, the necessity of increasing the active power of the flanks beyond that afforded by their length was strongly felt; and retired flanks, rising one above the other, were adopted, as well as casemated flanks admitting two or more tiers of guns, thus obtaining, as in Montalembert's System, a greater number of guns by extending the battery vertically. At first sight this appears an obvious mode of acquiring a superiority over the attack, in which the batteries can only be extended laterally, but in practice the retired flanks were soon found to be untenable, while the front flanks were complete shell-traps, and the casemates were practically useless from the difficulty of clearing the smoke from them. The systems of Montalembert partake of the same defects; and however imposing the appearance of several successive tiers of guns may be, it should be remembered that, covered by a mask, they can only be partially used when the enemy is at a considerable distance, and that exposed to view they can be easily destroyed at 2500 yards by the guns of attack of the calibres now in Several writers have proposed systems based upon principles similar to those of Montalembert, but it is perhaps sufficient here to mention the work of Don Jose Herrera Garcia (Teoria Analytica de la Fortificacion Permanente), as it is unquestionably the most remarkable development of the tower system of defence. Garcia proposes several successive lines of massive casemated buildings or towers, of an egg-shape, connected together with casemated curtains. The towers are surmounted by parapets, which at the ends next the enemy are broken into a series of smaller curves, and are retired or independent of the exterior wall or scarp. As each of these towers is defensible of itself, the work of forcing a way through three lines of them would be most formidable, but the expense of such a system would be enormous.

Having traced the history of bastioned defence to the high state of perfection it attained, a summary of other systems will complete the subject. It has been shown that no sooner had the Italians invented the Bastioned System of defence than it found in every country persons who devoted themselves to the improvement of its details,-in France, Errard, Pagan, and Vauban; in the Netherlands, Freitag and Coehorn; and in Germany, Speckle, who was at least equal to any of the others. Germany, however justly iteral training, the walls of casemated batteries must be cut prided itself on Speckle, has gone back to Dürer, and has adopted from him the system of flanking defence, which depends on casemated galleries, and caponnières or casemated works placed across the ditches. Yet, notwithstanding this, it is remarkable that the Germans have taken much of their works from a French officer-the celebrated Marc René, Marquis de Montalembert, who in 1776 published his celebrated work, Perpendicular Fortification, or an Essay on Several Methods of Fortifying a straight line, a triangle, a square, and all polygons of any number of sides, giving to their defence a perpendicular direction; also, Methods of improving Existing Defences and rendering them much stronger; also, Redoubts, Forts, and Field Intrenchments, of a New Construction, in 11 quarto volumes, with 165 large plates,-a work which must be considered the source from which all the modern "inventions" in this branch of Fortification have been derived. Referring back to earlier German writers, it appears that Rimpler in 1673 proposed a system which is a combination of bastions with tenailles, and that Landsberg in 1712 proposed a purely tenaille system; but both these adhere to earthen ramparts and parapets, the first with revetments, the second without them, and their systems are little more than extensions of Field Fortification. But Montalembert, in his Tenaille System, replaces the simple revetment at the re-entering angles with casemated works in two stages, thus affording direct fire, both of artillery and musketry, for the defence of the ditches and faces of the redans, the remaining portion of the trace being occupied by an earthen couvre-face work, with a detached loopholed gallery in front of it, evidently the prototype of Carnot's detached revetment. The reentering casemates are calculated to hold 24 guns in two tiers. Behind the couvre-face is the body of the place of the redan, being also fronted by a casemated gallery, and separated from the couvre-face by an inner wet-ditch. In this system, then, the defence by musketry as well as by artillery is from two levels, the upper at a moderate height above the bottom of the ditch, and not, as in the old Italian systems, at the high level of the crest of the parapet. At the gorge of each redan is placed a formidable casemated tower; whilst in front of the main ditch there is a general couvre-face provided with casemated galleries, a second or advanced ditch, places of arms in front of the re-entering angles, a covered-way, and a glacis.

The Polygonal System may, however, be considered as springing directly from Dürer's work of the same name, only in this system the simple earthen ramparts of Dürer are replaced by a combination of casemated towers, casemated galleries, and earthen couvre faces. In Dürer's polygon the sides were straight or unbroken, but in Montalembert's the centre was thrown back and formed into an Italian bastioned trace, the faces flanking the faces of the caponnière. In forts which formed a triangle or square Montalembert was rich in resources, though the massive casemated tower, casemated galleries, and earthen couvre-faces were the essential elements of all. In France, the views of Montalembert have never been received with enthusiasm, though Cherbourg is fortified in conformity to them, and it was even alleged that the corps du genie was indisposed to receive instruction from an officer of another arm; but it is more reasonable to suppose that the cherished name of Vauban has induced its officers to direct their attention rather to the improvement of the Bastioned System, which they have certainly carried to perfection, than to the development of a system depending on such different principles. In Germany, on the contrary, Speckle is less known than Vanban, and though probably a thought of Dürer may not have entered into the question, Montalembert's Systems,

use.

The system of the Swedish general Virgin belongs to the bastioned systems, but it is mentioned here in contrast to Garcia's, as it disperses in the defences separate bastioned forts, of a form somewhat approaching to Rimpler's, and covered by outworks so arranged as to secure the inner works from injury until the enemy has effected his lodgment upon them. These forts are surrounded on all sides by ditches, and connected together by secure communications. Ingenious as Virgin's system is, it is manifest that though the loss of one fort would not insure the fall of the others, it would at least render all the interior space inclosed by the line of forts untenable, and place the town, the arsenal, or other public buildings, at the mercy of the besiegers. This may be said of all detached forts, and it must be again laid down as a maxim that the ultimate value of such forts, as a means of securing an important object, depends on an inner line of defence of a nature to resist any sudden attack or coup-de-main. Detached forts may be, for the purpose of keeping an enemy at a distance, more effectual than a simple continuous line, but they cease to be of use if an enemy can pass them and attack a defective interior line behind, incapable of resisting a coup-de

main.

It has been well stated by the French translator of Zastrow, that the reduction of a place may be considered as a certain amount of work to be performed, the magnitude of which depends on various elements, amongst which the dis position and nature of the works constitute the most important; and that the attack has to perform this work in a certain time, and with certain means, amongst which the principal elements are the quantity of heavy artillery, and

How then should a capital be fortified? The answer is, that it should be so fortified that it may be safe from bombardment and from blockade, and that its defences may be beyond the control of its inhabitants.

the nature of the ground over which the approaches must | electrical science, Napoleon said that a great capital is the be carried. When, therefore, it is said that a work forti-native place of the flower of the nation, the central point fied on Vauban's first system would fall on the twenty- of public opinion, and the general dépôt; and he added eighth day, on Cormontaigne's, with a cavalier entrench- that it is the greatest of absurdities to leave so importment in the bastion, on the thirty-first,-it must be remem- ant a place destitute of immediate defence. bered that this implies the possibility of complete investment, and of steadily advancing the approaches over soil easily worked by the sapper; but that if the investment be incomplete, if the ground be rocky, and every inch have to be gained by hard and incessant toil, protracting the time during which the sapper is uncovered, and therefore greatly adding to the daily losses in the trenches, such periods may readily be extended to twice or three times their ordinary length. INTRENCHED CAMPS.

It would not be proper to leave the subject without a brief description of intrenched camps, especially as they have an important bearing upon the defence of capitals, with which this article closes.

These objects may be attained by two methods,-first by constructing a circle of detached forts round the capital, and at such a distance in advance of it as shall render investment impossible, or, secondly, by forming a cordon of intrenched camps far in advance of the capital, making at the same time such arrangements as shall facilitate the rapid concentration of troops in any of them.

With respect to these two methods there is much difference of opinion, and eminent military authorities may be cited in support of one or the other according to the bias of the writer. Nevertheless it may be safely asserted that the value of either is dependent upon the number and quality of the troops available for its service. If the troops be few, or insufficiently trained and poor in quality, then it would be proper to have recourse to a system of detached forts round and not far in advance of the capital, and so disposed that they may, in a measure at least, be manned by local auxiliary levies. If, on the other hand, the troops be fully equipped, thoroughly trained and disciplined, with high power of manoeuvring, then, even though inferior in number, it may be advisable to have recourse to a cordon of intrenched camps.

An intrenched camp is a position, prepared beforehand, in which an inferior army rests in security from the attack of a superior army, and from which it may operate upon the communications of such superior army, or in which a Deaten army takes refuge for the purpose of reorganization. The position selected for an intrenched camp is usually around the capital, or around an important city, or on an important line of communication. The position should therefore contain sufficient space to receive the army for which it is constructed, to contain ample supplies of all kinds, and to keep an enemy beyond bombarding distance not only from the city, but from the camping-grounds within it. An intrenched camp should consist of a chain of in- Generally, if circumstances admit of its adoption, the dependent forts, with, wherever practicable, a strong inner second method is the better, especially if the camps are work; the forts should be as large as possible, and disposed disposed at such intervals that an enemy in force cannot in a right or slightly convex line. No fort should have pass between them, and at such distance from the capital undue prominence over the others, as such a fort would be that, if driven out of them, there is still time left to fall a source of weakness, inasmuch as it might be attacked by back and take up some inner position upon which to deitself, and being further removed from the centre of deliver a decisive battle. The capital though well covered by fensive operations would be more difficult to succor. The the camps, would take no part in the active defence, and camp should be traversed by free and easy communications; would not be attacked after the fall of one of them, while and if it have an interior work, that work should command the occupants of the camps could fight with no apprehenthe whole of the interior. It should also possess facilities sion of the populace rising in their rear, a danger to be apfor passing rapidly from the defensive to the offensive, and prehended from the most patient of people, as they become sufficient interior space for the execution of such manoeuvres pinched by the privations and miseries of a siege. as are necessary for the defence of the position.

FORTIFICATION OF CAPITALS.

Whether capitals, as capitals, should be fortified has given rise to much difference of opinion; but all authorities are agreed that the capitals of highly centralized countries must be fortified. In such countries the principal resources of the state, both public and private, are collected in the capital; in it is placed the centre of government, and from it administration and organization radiate. Such a capital is truly the heart of the nation; a deadly blow to it stops the national circulation, and national paralysis may and will probably follow. Take, for example, England, perhaps the most highly centralized of countries. Can it be doubted that an enemy in possession of London could exact what terms he pleased? Upon this point the commissioners appointed to consider the defences of the United Kingdom say,-"There can be no doubt that the main object of an enemy invading the country would be to push for the capital, in the hope that, if he succeeded in obtaining command of it, such a disaster would result in our buying him off upon any terms he might think it expedient to exact." This was written in 1860, but within eleven years its general truthfulness was thoroughly established by the fall of Paris, when the exactions of the Germans were only limited by the ability of the French to comply with them. It is then scarcely too much to say that the fall of London would result in the downfall of England. Speaking of the general confusion and ruin which the presence of a hostile army on British soil must produce, Lord Overstone said: "The occupation of London by an invading army! . . . I cannot contemplate or trace to its consequences such a supposition." And he might well say so; not England only, but the cause of civilization throughout the world would be shattered by such an occupation.

At a time when capitals were by no means the national centres which they have since become, owing to the development of the means of locomotion, and to the discoveries of

In practice it will almost always happen that a combination of the two methods will be adopted; but whatever method be adopted it will generally be inadvisable to surround the capital, more especially if large, with a close enceinte. If, however, it have such an enceinte, the works of which the enceinte is composed should be provided with strong interior defence. In all large cities there is a considerable cosmopolitan and vagrant element, possessed of no property, and having no interest in the maintenance of order, whose contact with the soldiery may be attended with deplorable results, inasmuch as it must tend to lessen the bands of discipline, to destroy the habits of obedience, and to weaken those feelings of devotion and self-restraint which are more than ever necessary under the privations of a close siege.

Against this view it may be urged that the enceinte constructed round Paris in 1840 prevented its falling into the hands of the Prussians after the battle of Chatillon. This may be true; but in estimating the value of this enceinte it should be borne in mind that 236,000 Prussians were sufficient to shut up in it, and eventually reduce by famine, a garrison of 300,000 men, and it is certain that the absence of interior defences in that enceinte permitted a mere handful of communists to make themselves masters of Paris and its fortifications, and to force back the regular troops upon Versailles. Generally, however, the rapid growth of the population in very large cities precludes a close enceinte. Indeed the enormous extent of very large capitals, and the very long range of present artillery, render the fortification of them so costly that, in elaborating any scheme for their defence, cost must enter largely into calculation, and must materially modify theoretical and scientific conclusions.

But however elaborately the capital may be fortified, the full effect of the expenditure upon its fortifications is not obtained unless other strong places are formed in appropriate positions in relation to it; for if the capital only be fortified, defence will cease with its fall. It is asserted upon the authority of official documents that the French would