or of half-round timber, but often bed directly on top of the wall. These principals are crossed by stout sawed laths, and upon these are laid the common heavy ridge and furrow tiles, whose appearance is so familiarly characteristic of Italy, and so much more picturesque, than constructively good. These tiles are from ¾ to 1¼ inch thick, each course from 18 to 24 inches long, and they are frequently laid dry, and not secured down in any way but by their own great weight, except at the ridges, where the ridge tiles are cemented down in mortar. Roofing of this character weighs very little less than an equal surface of the flooring just described.
Framed roofing of large span and squared timber is not common in churches, &c., which are usually vaulted with brick or stone, dome'd or groined.
It will thus be remarked that in the construction of the more important buildings, the mass and inertia, of walls, floors, and roofs are enormous, while the bond and connection of each of these, and of all to the others, is loose and imperfect.
It is in the medieval towns and villages of the interior provinces, however, that these conditions are still more evident. Nothing can be more striking than the general appearance of these ancient abodes. They are almost without exception perched upon the summits and steep flanks of precipitous "collines," usually rounded conoidal hills of limestone, sometimes abrupt and rocky elevations, whose slopes and shelves are occupied and their craggy heights crowned by the houses, built out to the very edge of the precipice, with no windows or doors looking outwards, or, if any, high up and inaccessible to any
