On the ragstone the soil is occasionally thin and much mixed with small portions of sand and stone; but in some situations the ragstone has a thick covering of clay loam, which is most suitable for the production of hops and fruits.
In this were found large numbers of inscribed clay tablets (it is estimated that upward of 40,000 tablets and fragments have been excavated in this mound alone), dating from the middle of the 3rd millennium B.C. onward into the Persian period, partly temple archives, partly school exercises and text-books, partly mathematical tables, with a considerable number of documents of a more distinctly literary character.
The fertility of a soil is dependent upon a number of factors, some of which, such as the addition of fertilizers or manures, increase the stock of available food materials in the soil (see Manure), while others, such as application of clay or humus, chiefly influence the fertility of the land by improving its physical texture.
The Falkland Islands consist entirely, so far as is known, of the older Palaeozoic rocks, Lower Devonian or Upper Silurian, slightly metamorphosed and a good deal crumpled and distorted, in the low grounds clay slate and soft sandstone, and on the ridges hardened sandstone passing into the conspicuous white quartzites.
As it descends it reaches a part of the kiln where the temperature is higher; here the carbonic acid of the carbonate of lime, and the combined water of the clay are driven off, and the resulting lime begins to act chemically on the dehydrated clay.
Thick; the lower part of this is mainly fireclay and sandstone, the upper part is weathered clay with thin layers of brown coal and shale.
During the campaign Crawford was stricken with paralysis, and when the electoral vote was cast Jackson received 99, Adams 84, Crawford 41, and Clay 37.
While the ruins of Calah were remarkably rich in monumental material, enamelled bricks, bronze and ivory objects and the like, they yielded few of the inscribed clay tablets found in such great numbers at Nineveh and various Babylonian sites.
The lakes were small at first, and each had its own outlet at the lowest depression in -the height of land to the south; but as the ice melted back, neighboring lakes became confluent at the level of the lowest outlet of the group; the outflowing streams grew in the same proportion and eroded a broad channel across the height of land and far down stream, while the lake waters built sand reefs or carved shore cliffs along their margin, and laid down sheets of clay on their floors.
Its walls are lofty and supported by buttress bastions with loopholed turrets at intervals; the fortifications, however, are but of hard clay and are much out of repair.