3.] To give the rings additional strength, the sides have a slight concave curve and, still further to resist external pressure, the shafts are filled from bottom to top with a loose mass of broken pottery.

At the top the shaft contracts rapidly by means of a ring of a peculiar shape, and above this ring are a series of perforated bricks leading up to the top of the mound, the surface of which is so arranged as to conduct the rain-water into these orifices.

For the still more effectual drainage of the mound, the top-piece of the shaft immediately below the perforated bricks, and also the first rings, are full of small holes to admit any stray moisture; and besides this, for the space of a foot every way, the shafts are surrounded with broken pottery, so that the real diameter of each drain is as much as four feet.

By these arrangements the piles have been kept perfectly dry; and the consequence is the preservation, to the present day, not only of the utensils and ornaments placed in the tombs, but of the very skeletons themselves, which are seen perfect on opening a tomb, though they generally crumble to dust at the first touch.
The skill of the Chaldaeans as potters has received considerable illustration in the foregoing pages.

No ordinary ingenuity was needed to model and bake the large vases, and still larger covers, which were the ordinary receptacles of the Chaldaean dead.