objects of the berm, it was' in some way available to subserve
the purpose of defence. It certainly made undermining of the
vallum very difficult, and the use of a battering ram from the
opposite side of the ditch a virtual impossibility. Perhaps
it was also furnished with defensive obstacles, and may
have had a palisade or a row of tribuli1 set along the front
of it. It may have been taken advantage of as a species of out-
work or defensive platform. On these possibilities, nevertheless,
it must be owned that our excavations throw no direct light. No
trace of any structure or article of any kind has been detected
in the berm, although surface woodwork might easily dis-
appear, and the absence of such indications proves nothing.
5. The Fosse.
A passage quoted2 from Hyginus describes two leading kinds
of ditches used in Roman fortification—the fastigate and the
Punic. The fastigate had both its sides sloping so as to meet
in a point at the bottom. The Punic had the counterscarp as
nearly as might be perpendicular,3 whilst the slope of the scarp
was the same as in the fastigate fosse. Apparently the fastigate
or V-shaped type was most in vogue. A curious passage4 in
1 Vegetius, iii. 24. a calthrop is an obstacle fixed in
Tribulus autem est ex quattuor palis front, made of four stakes, so that
confixum propugnaeulum quod quoquo whatever way you throw it it stands
modoabjeceristribusradiis stat et erecto on three legs, and with the fourth erect
quarto infestum est. is an annoyance to the enemy.
- Supra, p. 29.
3 It is at least an odd speculation whether the name Punic was not given
becatise of the bad faith which a perpendicular-sided ditch would be almost
certain to show. There seems to be no evidence (except this word) that the
Carthaginians made their fosses thus, and there is direct evidence of Phoenician
custom to the contrary. When by the labour of many nationalities the canal of
Xerxes was being out across an isthmus in Thrace, all the other peoples dug their
allotted portions with perpendicular sides. Not so the Phumicians, who were wiser,
as the sequel showed. " With all, except the Phoenicians, the sides of the excava-
tion falliug in gave them double labour: for as the trench at top and bottom was
made of the same dimensions, this accident could not fail to happen to them : but
the Phoenicians who show their ingenuity in all other works displayed it more
particularly in this : for they excavated that portion of the ground which had
fallen by lot to their share, making the opening of the trench at top double the
breadth of what the canal was wanted to be : as the work proceeded downward,
they drew the two sides nearer and nearer, so that when they reached the proper
depth their portion of the work was equal in width to that of the others."
Herodotus, vii. 23.
4 Vegetius, iii. 8. "Imparem enirn numerum observari mos est."