484 
POSEN AND STRASBURG. 
general conclusion as to what are the points which the Prussians consider 
most urgent in the present fortificational situation. 
The surface of the country about Posen being of that formation which has 
been termed,, in recent geology, quaternary (that is, the sand and gravel 
deposits above the tertiary), offers but little feature decisively available for 
the purposes of the military engineer. Its long plains and sandy swellings 
attain neither to particular limitation nor prominence, except where modelled 
into some shape by the river and its small affluents. The streams have, 
indeed, been taken advantage of in the scheme of defence, and prepared to 
serve as obstacles and for inundation, as far as practicable; and the most 
considerable knoll declared by the river (having a command of somewhat 
more than 100 ft. over its valley) was occupied, as the first step necessary 
for securing the position, by the powerful self-maintenant fort of Yiniary; 
yet there remain fully two-thirds of the circumference of the place innocent 
of natural qualification for defence, and thus a fair field for the exhibition 
of the art, pure and simple, of fortification. 
The fortress proper, enclosing the city and large military depots, is of 
somewhat circular general disposition, with diameters varying between 2000 
and 3000 yds. Its main body lies on the western side of the river (which 
here runs nearly from south to north); that part of it which lies east of the 
river having much less frontage and depth, and containing but little of 
importance;* yet the eastern portion of the enceinte is composed of fronts 
of the same construction as those of the western, and its flanks receive 
support across the river from the projecting extremities of the latter—espe¬ 
cially from that on the north, which constitutes Fort Yiniary. These fronts 
may be supposed to have expressed, at the time of their construction, the 
protest of the Prussian Engineers against the self-proferent saliencies and 
angularities of the bastion systems, in recognition of the increasing power of 
siege artillery. Their trace runs very nearly straight from angle to angle of 
the polygon (retaining but the merest rudimentary expression of flanks in 
certain slight undulations of the parapet opposite to the ditches of the 
ravelin), and the defence of the main ditch is committed to peculiar and 
mighty caponnieres, which cross it perpendicularly in the centre of each 
front, and which, carrying their two and even three tiers of guns below the 
level of the superior crests in front of them, are designed to retain the 
artillery command, in their proper sphere, up to a very advanced period of 
the attack. These caponnieres have their ends towards the country covered 
by ravelins, which, whilst reaching with their salients about as far forward 
as those of the modern bastion trace, yet offer less length of face. to the 
action of enfilading batteries, being based on a straight and not a re¬ 
entering main line of rampart; and the usual covered way runs round the 
whole—distinguished, however, by the provision of bomb-proof block¬ 
houses, or small casemated barracks, in the salient and re-entering places of 
arms, covering the heads of the communications, and themselves covered 
from horizontal fire by the glacis. A casemated work of the same nature, but 
stronger, is constructed in the gorge of the ravelin, giving close defence to the 
interior of the latter, as well as additional cover to the head of the caponniere. 
* Unless the cathedral be excepted. It has, however, little architectural merit or antiquarian 
interest ; only its title and the custody of some reputed relics commend it to notice. 
