SOME FEATURES OF ROMAN FORTS 67 



giye information on this interesting point, though, this 

 camp (which is about 500 yards square, covered some 55 

 acres, and may have accommodated as many as 11,000 

 men) would seem to afford evidence of more than tem- 

 porary occupation. 



The very fact that at least three plans recently obtained 

 by careful survey (Melandra, Grellygaer and Newstead) ^i 

 have come out askew, can be fully explained if we assume 

 (as no doubt was the case) that the foundations were set 

 out and measured off in precisely the way described by 

 Polybius,^^ who was himself present at the destruction of 

 Carthage. We may perhaps stand at Melandra on the 

 very spot where the metator — acting possibly under the 

 eye of Agricola — placed the standard or the groma and 

 proceeded to make the necessary measurements. An error 

 of two degrees in setting off the right angle with the 

 groma would account for the skew appearance of the 

 Melandra survey. When once the cardo viaxiiaus and 

 the decumanus maximus were laid down, the method fol- 

 lowed in completing the plan would ensure that the error 

 would be repeated throughout. 



The other points in which the plan of a fort like 

 Melandra would seem to resemble that of the consular 

 camp are the rectangular shape, the existence of four 

 gates at points dividing the sides similarly, the lie of the 

 roads connecting them, and the shape of what we may call 

 for the moment the headquarters building; for the shape 

 of this building in practically all the forts more nearly 

 resembles the prsetorium of the Polybian than of the 

 Hyginian camp. The rounding of the corners is of course 

 a feature of the camps of the early empire, while the 



21. Perhaps Cardiff should be added. The plan of Brough is also out 

 of truth, but with less regularity. 



22. Polyb. Hist., vi. 27. 



