306 FROM CORRIENTES TO HUMAITA.
guayans good service. From Cueva to Asuncion^ from 1865 to 1868, we shall find that they had but one plan for defence. They chose for their stand-point some place where the stream was narrowest and flowed the swiftest, also where the deepest water was from 45 to 150 yards off" their guns, and where a passing ship must expose her prow, broadside, and hull. They placed their guns at the toe of a horse- shoe-shaped clifi", a re-entering angle generally in the left, or eastern bank, whose high and regular wall shows the flood-mark. The cliff", a natural earthwork, varied from twenty to fifty feet ; the upper half was usually per- pendicular, and composed of stiff" clay and sand, assuming the natural angle below, and off"ering no facility for scaling. It was generally bounded north and south by carrisal and impassable jungle. The ojoen-gorged batteries extended all along the bank so as to sweep the stream up and down . they often aff"ected a crossing or converging fire, and some- times, as at Asuncion, where the current hugs the side, the guns could not be depressed, and the defenders had to depend upon musketry. On the Gran Chaco, or western side, they chose, if possible, a low marshy spit subject to inundation, and they felled the trees, so that the enemy was compelled to act upon open ground. Thus they obviated the danger of rifle-pits and artillery duels.
None of the works could be called permanent fortifica- tions. The Paraguayans ignored the bastion, or Italian system (of Turin, 1461) afterwards perfected by Vauban, and only in one place did they attempt the casemates of Albert Diirer (sixteenth century) ; hence the polygonal, or German system^ which afterwards became popular through- out Europe, was unknown. A redan, or a ravelin, to sweep the face of the curtain, was the height of their art in field fortification, and the heaviest gun was generally placed upon the apex.
