POSEN AND STRASBURG. 
485 
The escarp walls are, for the most part, “ detached;” only where—as at the 
angles of the polygon—a plunging power of musketry fire was to be re¬ 
tained, the rampart has been kept close np to the demi-revetment. The 
counterscarp has a gallery along its whole length, and smaller galleries and 
caponnieres are freely supplied to any corners in need of them. From the 
counterscarp gallery is carried forward a system of countermines, the details 
and extent of which are judiciously kept secret, whereby the proper moral 
effect of such occult defences must come to be enhanced, both in current 
repute and on occasion of actual trial. 
So far the regular Prussian system; what Posen showed peculiarly its 
own was the extreme development of the caponniere. These works, pro¬ 
longed inwardly right through the rampart of the enceinte until they flanked 
its reverse slopes, widened sufficiently to afford roomy open spaces in their 
interior (large enough, indeed, for the ordinary parades of their garrisons), 
topped with earthen parapets commanding all the adjacent works, and com¬ 
pleted for self-defence by small musketry caponnieres in front and by the 
almost bastion-front tracing of their gorge walls—the rampart being kept 
separate from them by cuts across it to the depth of the main ditch, and 
retaining its communication with them only by the continuation of its 
detached escarp wall and by drawbridges—constituted a sort of chain of 
detached forts, which were merely connected by the adjusted joints of the 
enceinte: the latter, though considerably heightened at the angles, for 
command and against enfilade fire, being kept so narrow as to afford but a 
very unsatisfactory site for the lodgments of a besieger. 
Finally, the strength of the place was enhanced by the advanced fort of 
Yiniary. This work—connected indeed with the enceinte, yet complete in 
its own system of defence and surrounded by its own glacis, on a com¬ 
manding site, having its outward face composed of three fronts of the 
Prussian system (not quite so fully developed as those of the enceinte, being 
of earlier date), its flanks indented applications of the same principles, and its 
gorge closed with a casemated keep well capable of accommodating five or 
six thousand men;—holding, moreover, the control of extensive inundations 
which would isolate it from the rest of the fortress—was fit to fill the office 
either of a powerful detached fort against the earlier operations of a besieger, 
or of a citadel capable of independent defence after the reduction of the rest 
of the place. 
Of the advantages peculiar to the above method at the time of its intro¬ 
duction-—which consisted principally in its small subjection to enfilade fire, 
its force of direct commanding fire from the body of the place, its abundance 
of bomb-proof cover, and, more especially, its retention of the artillery 
command of the main ditch up to an advanced period of the regular attack 
-—the last (which needed for its exact evaluation the solution of the then, 
curious artillery question of how far several tiers of guns in casemates might 
be reducible by one tier in earthern counter-battery on the crest of the 
glacis—which solution, unmixed, the world is hardly likely to see since the 
introduction of curved fire from rifled guns—and which, whilst fully effective 
against attempts of accelerated siege, appeared to retain but little validity in 
the face of advanced operations perseveringly pushed by means of regular 
mining attack) must be held to have undergone important modification by 
the influence of the enhanced powers of rifled artillery. The caponnieres, 
