BASTION. 



BA'TAVI. 



their convexity towards the interior of the work. This seems to have 

 been devised to allow room for a few more men to fire over their para- 

 pets than a straight wall could afford, and to prevent the distant 

 batteries of the enemy from easily dismounting their artillery by 

 firing along the interior side of the parapet. On some occasions these 

 advantages may be worth obtaining, but as the soldier placed behind a 

 parapet always fires nearly in a direction perpendicular to its length, it 

 is evident that the curved flank may cause the lines of fire to tend 

 towards the right or left of the main ditch, and thus endanger the 

 safety of the defenders stationed in the neighbouring works. 



The desire of lessening the effect of what is called the enfilading 

 fire, or that which an enemy may direct along the interior side of any 

 parapet, has led Bousmard to give a small curvature to the faces of his 

 bastions, the concave part being towards the interior ; but it is evident 



that, by this construction, the lines of fire directed from the collateral 

 flank for the defence of the face, instead of grazing the latter in its 

 whole length, can only be tangents to the curve, each line of fire meet- 

 ing it in but one point. It is therefore probable that the injury 

 inflicted on the enemy would be found so much less than that arising 

 from the usual construction, as to neutralise entirely the advantage of 

 the diminished enfilade fire of the enemy. 



The destructive effect of this last mode of firing would be most 

 effectually prevented by the formation of semicircular bastions, 

 detached from the enceinte, in the manner proposed by Mr. Bordwine ; 

 but the ingenious author of that system is in consequence compelled to 

 abandon, in a great measure, the advantage of having the exterior of 

 his walls well defended from those which are in collateral situations. 

 The batteries however which he proposes to raise in the interior of his 



bastions cannot fail to produce a powerful defence towards the rear, 

 for the rampart of his enceinte. 



Fig. 1. The line A B represents one side of the polygon supposed to 

 inclose the town fortified. The semicircular work at A is half a round 



tower ; and A c is part of the curtain or connecting wall between two 

 such towers, according to the ancient manner of fortifying places ; 

 a c represents a sort of fausse Iraye, or elevation of earth, protecting 

 the ancient walls of a place ; D represents half a bastion constructed 



Kg. 2. 



60 feet to an incft. 



at the angle, A, of the polygon, according to the method of the first 

 Italian and French engineers, with an orillon and triple flank. The 

 pentagonal figure about B is the plan of a modern bastion, of which the 



Fig. 3 



part on the left of the capital B E represents what is called a hollow, 

 and that on the right a solid bastion. An imaginary line from / to </ I 

 'd the gorge, and the rampart, e f, is the curtain joining the right flank 



of one bastion to the left of the next. The space, r o E, is the mam 

 ditch ; and H and K are respectively the positions of a counter and 

 enfilading battery which might be constructed by the enemy to silenca 

 the fires from the triple flank of D. The outworks r, a, Q, KB, 

 [TENAILLE, CAPONNIEBE, RAVELIN, COVEBED-WAY, and GLACIS] will bo 

 described under those words. 



Fid 2 represents a section supposed to be made from B to L, perpen- 

 dicularly across the rampart on the left face of B, and the mam ditch 

 in its front. M and N are sections through the revetments, or walls 

 which support the earth on the sides of the ditch. 



In fn 3, v represents the plan of a detached bastion ; T is a tower 

 bastion at an angle of the polygon which surrounds the place. The 

 bastioned systems will be further treated under FORTIFICATION. 



(Vitruvius, De Architectural; Maggi, Delia, Fortificatwnc dclle Cilta ; 

 Errard, La Fortification redmte en art; De Ville, L' Ingcmeur Parfait ; 

 Vauban, CEums Militaires, par Foissac; Belidor, La Science dellrt'je- 

 nieur Fritach, V Architecture Militaire; Cormontaigne, (Enures Posl- 

 humes; Montalembert, La Fortification Pa-pendiculaire ; Bousmard, 

 Eaai General de Fortification ; St. Paul, Tmite Completde Portion ; 

 Savart Cours EUmentaire de Fortification; Mandar, De I Architecture 

 des Forteresses; Dufour, De la Fortification Permanente; Carnot, De la 

 Defense des Places Fortes; Col. Pasley, Course of leme n tar<. Fortifica- 

 tion; Malortie, Permanent Fortification ; Capt. Straith, A Treatise on 



BA'TAvi, or BATA'VI (the forms Vatavi, Badai, and Betavi also 

 occur in MSS. inscriptions), the name of the ancient inhabitants of 

 South Holland, and some adjacent parts. The Batavi were a Germanic 

 tribe of the race of the Catti, who, some time before the age of Caesar, 



