The possible total of 132 'insulae' was, however, diminished by the space needed for public buildings, though it is not easy to tell how great this space was in the original town.
Ultimately, as the excavations show, eight 'insulae' were taken up by the Forum, four by the Theatre, three by the various Baths, one by a Market, one by a Public Library, and one by a Christian church.

But some of these edifices were certainly not established till long after A.D.100 and the others, which must have existed from the first, were soon extended and enlarged.

A competent writer on the subject, Dr.
Barthel, allows seven blocks for public purposes in the original town, but this seems too little.

The blocks themselves measured on the average a square of 70 Roman feet (23 x 23 yards), and may have contained one, two, three, or even four houses apiece, but they have undergone so many changes that their original arrangements are not at all clear.

The streets which divided these blocks were 15 to 16 ft.
wide; the two main streets, which ran to the principal gates, were further widened by colonnades and paved with superior flagging.