It must be remembered that, previous to this, archæologists had no clear notion of the order or relative position of the products of different ages and races, and the same confusion extended to the terremare. For instance, at Castelnuovo, Chierici seemed puzzled at finding, underneath a Bronze Age terramara, indications of an older period. At Campeggine, on the other hand, objects of the early Iron Age appeared, but chiefly in the upper strata, while Etruscan remains had been recognised in several instances. Another point to which Chierici's attention was directed was the frequency with which rectangular enclosures were disposed so as to have their four sides facing the cardinal points; and this orientation within certain limits, varying, it would seem, according to the direction of the sunrise when the settlement was founded, he considered also applicable to all the terramara villages. On this point see also Helbig. (B. 308.) In his famous theory of the structure of the terramara villages (B. 206) Chierici conceived the idea that they had been constructed over artificial basins to which a running stream was made to flow so as to convert the _bacino_ into a pool of water. This pool was surrounded by an earthen dyke inside of which a wooden platform was erected on piles and covered with a layer of clay. Huts were then erected over this platform at regular intervals, and the refuse from them was thrown, by means of holes here and there, into the space below. The water entering at one side of the enclosure made its exit at the opposite side. Thus the space below the platform was more or less occupied with water, and the _débris_ thrown into it became arranged into sedimentary strata, and so continued to accumulate until the entire space was filled up. When the accumulation of _débris_ reached this extent it became necessary to elevate their floorings, and this was done by repeating the same process at a higher level; and in this manner Chierici accounted for the successive platforms and palafittes which were to be met with in the terramara beds.