Coincident with these processes of urban expansion, we find, in many towns which can be connected with the later Republic or the Empire, examples of a definite type of town-planning. This type has obvious analogies with earlier Italy and with the town-planning of the Greek world, but is also in certain respects distinct from either. The town areas with which we have now to deal are small squares or oblongs; they are divided by two main streets into four parts and by other and parallel streets into square or oblong house-blocks ('insulae'), and the rectangular scheme is carried through with some geometrical precision. The 'insulae', whatever their shape--square or oblong--are fairly uniform throughout. Only, those which line the north side of the E. and W. street are often larger than the rest (pp. 88, 125).[58] The two main streets appear to follow some method of orientation connected with augural science. As a rule, one of them runs north and south, the other east and west, and now and again the latter street seems to point to the spot where the sun rises above the horizon on the dawn of some day important in the history of the town.[59] [58] Modern plans seem sometimes to imply that the 'insulae' which abutted on the walls were also abnormally large. That is because the corresponding modern blocks often include, with the original 'insula', the space between it and the wall, and also the wall itself which has been disused and built over. [59] See on this point some remarks by W. Barthel, _Bonner Jahrbücher_, cxx. 101-108. The public buildings of these towns are in general somewhat small and arranged with little attempt at processional or architectural splendour; they seldom dominate or even cross the scheme of streets. Open spaces are rare; the Forum, which corresponds to the Greek Agora, contains, like that, a paved open court, but this court is almost as much enclosed as the cloister of a mediaeval church or the quadrangle of a mediaeval college. Theatre and amphitheatre[60] might, no doubt, reach huge dimensions, but externally they were more often massive than ornamental and the amphitheatre often stood outside the city walls. Here and there a triumphal arch spanned a road where it approached a town, and provided the only architectural vista to be seen in most of these Roman towns. [60] In western Europe the provincial Roman amphitheatre averaged 45 x 70 yds. for its arena.