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bastions, two toises thick, consistin'; ofsolid good earth well pressed together,covered and supported with fascines,having likewise banquettes behind themsutiiciently high to conceal the soldiers’teiits. If water could be conveyed, ordrawn into the ditch from any adjacentrivulet, or river, the security would hegreater. When the lines of entrench-ment are thrown up with an intentionto maintain the ground any length oftime, a covert-way must he made, whichshould be regularly fenced with palisades.

There is another species of field for-tification, which is resorted to in orderto keep up a communication betweentwo places; in which case great caremust be taken to prevent the lines frombeing enfiladed in any quarter; and ifthey should be exposed in that manner,no time ought to he lost in strengtheningthe weak . points by constructing re-doubts, or small forts. The defence ofthese redoubts and forts must be en-trusted to small arms and musketry,but not to cannon; as the range of thelatter is always too extensive to preventan enemy’s close approaches to the linesof communication from their field works,or forts. Necessary drains must bemade to let out the water that collects,as it would otherwise destroy the works,drown the sentries, and cut oflf all com-munication with the main body.

When a position is taken upon a steeprock, nr eminence extremely difficult otaccess, the lines which surround it donot absolutely require ditches for theirsafety, as the parapet and banquettemay probably be sufficient; hut if anyvulnerable or weak part be observed,every effort should be used to get at aspring, and to fill up an excavation infront of it, to prevent surprizes. An ableengineer will be particularly careful, indrawing his plan of communication, toascertain the exact points whereby theymay be protected by an enfilade fromone fort to another; so that if the enemyshould make a lodgment any where, hewill not be able to maintain his position,on account of his being flanked byother works.

Field works, or small forts, are gene-rally constructed in places, the preser-vation of which is judged to be indis-pensably necessary. Such, for instance,are necks of land that stretch into amarsh, and are surrounded by it; thepassage of a road, tetes de ponts, or

heads of bridges, and other objects ofsimilar importance in offensive or de-fensive operations. On these occasionsthe shape and size of the constructionmust depend upon the nature of theground, the importance of the under-taking, and on the number of men bywhich the works are to be garrisoned.

Many forts in field fortification arebuilt in triangular forms; some aresquare, some starred, or en etoile, someas redoubts, in the shape of detni-lunes,others in crown, or horn-work, andothers again in the figures of tenailles,or queues d’hirondelle.

When the object of defence is a wind-mill, a castle, or a small dweliing-house,the first step to be taken is to select aspot of ground upon which you are tobuild the field-work, so as to check andprevent the enemy’s approaches. Inorder to do this effectually, the shapeand adjacent parts of the building mustbe closely attended to, and the work bethrown up without exposing it to a rearattack; but if the place to he defended,stand alone, and he not supported by anyditch or eminence on its flanks, or in itsrear, you must then fortify it all round.The earth which is dug out of the ditchwill serve to raise the rampart, or para-pet. Salient angles, distributed at equaldistances in the shape of bastions, mustbe erected with good flanks to protectand cover the intrenchment. If, on ac-count of the ground, the work shouldnot be much raised, the parapet must befraised, in order to prevent the enemyfrom attempting an easy assault.

An engineer from Piedmont, who hasproposed some new methods in fieldfortification, is decidedly against stoneand masonry, in the construction ofparapets and field works. His reason isself-evident; for, as he justly observes,the scattered pieces which must natu-rally be thrown about in all directionsby the demolishing of the walls in thedischarge of heavy cannon, would domore mischief than the cannon itself.

It is frequently found necessary tofortify a bridge ; the means adopted forthis purpose must depend entirely uponthe size and current of the river. If thestream should be broad and navigable,and so far from the fortress, that it can-not be defended by the ordnance of thetown or fortified place, in that case, a*large retrenchment, resembling a placeof arms,must be constructed,withstrong