The roads _m_ are 6 braccia higher than the roads _p s_, and each
road must be 20 braccia wide and have 1/2 braccio slope from the
sides towards the middle; and in the middle let there be at every
braccio an opening, one braccio long and one finger wide, where the
rain water may run off into hollows made on the same level as _p s_.
And on each side at the extremity of the width of the said road let
there be an arcade, 6 braccia broad, on columns; and understand that
he who would go through the whole place by the high level streets
can use them for this purpose, and he who would go by the low level
can do the same. By the high streets no vehicles and similar objects
should circulate, but they are exclusively for the use of gentlemen.
The carts and burdens for the use and convenience of the inhabitants
have to go by the low ones. One house must turn its back to the
other, leaving the lower streets between them. Provisions, such as
wood, wine and such things are carried in by the doors _n_, and
privies, stables and other fetid matter must be emptied away
underground. From one arch to the next