[68] See the seventeenth century Atlases of Blaeu, Janssons, and others, the modern maps prepared by Grassellini and others about 1840-50 (some on the scale 1:4,000), and in particular the Atlante geografico of Attilio Zuccagni-Orlandini (Firenze, 1844), and the recent town-maps of various Italian cities (mostly about 1:10,500).  Different maps of the same town sometimes differ much in their detail.  The Italian Government maps of the largest scale (1:25,000) are small for our present purpose and have been issued mainly for northern Italy.

The evidence of the streets needs, however, to be checked in every case.  It would be rash to assume a Roman origin for an Italian town simply because its streets are old and their plan rectangular.  There are many rectangular towns of mediaeval or modern origin.  Such is Terra Nova, near the ancient Gela in Sicily, built by Frederick Stupor Mundi early in the thirteenth century.  Such, too, Livorno, built by the Medici in the sixteenth century.  Such, too, the many little military colonies of the Italian Republics, dotted over parts of northern and middle Italy.  Often it is easy to prove that, despite their chess-board plans, these towns do not stand on Roman sites.  Often the inquiry leads into regions remote from the study of ancient history.

Fortunately, enough examples can be identified as Roman to serve our purpose.  Some of these occur in the Lombardy plain where, both under the Republic and at the outset of the Empire, many ‘coloniae’ were planted full-grown and where town-life on the Roman model was otherwise developed.  Not all these towns survive to-day; not all of the survivors retain clear traces of their Roman town-plan; in nine cases, at least, the streets seem unmistakably to follow Roman lines.  Four of the nine date from early days; in the late third and the early second centuries (218-183 B.C.), Piacenza, Bologna, Parma, and Modena, were built as new towns with the rank of ‘colonia’.  The first three of these were later refounded, about 40-20 B.C.—­whether their streets were then laid out afresh is an open question—­and Turin and Brescia were added.  In addition, Verona, Pavia, and Como won municipal status in or before this later date, though when or how they came to be laid out symmetrically is not certain.[69] And there are other less certain examples.

[69] Milan (Mediolanium), once the chief Roman town of north Italy, is usually stated to preserve to-day no trace of Roman street-planning.  But the line of the Via Manzoni, Via Margherita, and Via Nerino (cutting the Ambrosian Library) seems really to represent one of its main streets, and the line of the Fulcorino and Corso di Porta Romana the other, while one or two traces of ‘insulae’ can be detected near the Ambrosian Library.  The town was destroyed in A.D. 539 and again in 1162, and more survivals cannot be expected.

Other instances, but not so many, may be quoted from