[78] and private houses as yet
unexplored. Beneath the chief streets were sewers, by which indeed
these streets were mainly traced.

[77] C. Promis, _Antichita di Aosta_ (Torino, 1862), with plan,
plate 3, dating from 1838; _Notizie degli Scavi_, 1899, p. 108,
with a later plan, but lacking a scale; Nissen, _Ital.
Landeskunde_, ii. 171.

[78] Durm _Baukunst der Roemer_, p. 458.

[Illustration: FIG. 16. AOSTA]

The whole was divided by a regular network of streets into rectangular
blocks. According to the latest plan of the site, there were sixteen
blocks, nearly identical in shape and averaging 145 x 180 yds. (5-1/2
acres). That, however, is an incredible area for single house-blocks,
and it is to be noted that Promis shows two further roads (A, A in
fig. 16). If these are survivals of other such roads, Aosta may have
contained thirty-two oblong 'insulae', each nearly 220 x 540 ft., or
even sixty-four smaller and squarer 'insulae', measuring half that
size.[79] Four gates gave entrance; those in the two longer sides
which face north-west and south-east, are curiously far from the
centre and indeed close to the south-western end of the town. It is,
of course, impossible to determine, without spade-work, which of the
recognizable buildings of Aosta date from the foundation of the place
in 25 B.C. But the general internal scheme and the symmetrical and
practically 'chess-board' pattern of streets must date from the first
foundation.[80]

[79] Promis, p. 140; his plan has no proper scale. There seems no
decisive evidence and the modern streets of Aosta do not help us.

[80] The town of Concordia in north-east Italy, where Augustus
planted a 'colonia', doubtless of discharged soldiers, is said to
have possessed a ground-plan of oblong blocks very like that of
Augusta Praetoria. But this plan rests mainly on the authority of
a workman who apparently did not know how to read or write (he is
described as 'analfabeta') and I therefore omit it here. See
_Notizie degli Scavi_, 1880, p. 412, and Plate XII (the text
gives no dimensions and the plan lacks a scale), and compare
1882, p. 426, and 1894, p. 399.

_Florence_ (fig. 17).

A yet more interesting instance of a Roman town-plan preserved in many
streets may be found in Florence.[81] In Roman times Florence was a
'colonia'. When this 'colonia' was planted is very doubtful. Perhaps
the age of Sulla (90-8