4. No construction of bricks, either crude or kiln-dried, could have sufficient solidity without the help of some kind of cement, to make them adhere firmly together. This also the lowlands of Chaldea and Babylonia yield in sufficient quantity and of various qualities. While in the early structures a kind of sticky red clay or loam is used, mixed with chopped straw, bitumen or pitch is substituted at a later period, which substance, being applied hot, adheres so firmly to the bricks, that pieces of these are broken off when an attempt is made to procure a fragment of the cement. This valuable article was brought down by water from Is on the Euphrates (now called Hit), where abundant springs of bitumen are to this day in activity. Calcareous earth—i.e., earth strongly mixed with lime—being very plentiful to the west of the lower Euphrates, towards the Arabian frontier, the Babylonians of the latest times learned to make of it a white mortar which, for lightness and strength, has never been surpassed.
(Perrot and Chipiez.)
5. All the essential materials for plain but durable constructions being thus procurable on the spot or in the immediate neighborhood, the next important point was the selection of proper sites for raising these constructions, which were to serve purposes of defence as well as of worship and royal majesty. A rocky eminence, inaccessible on one or several sides, or at least a hill, a knoll somewhat elevated above the surrounding plain, have usually been chosen wherever such existed. But this was not the case in Chaldea. There, as far as eye can see, not the slightest undulation breaks the dead flatness of the land. Yet there, more than anywhere else, an elevated position was desirable, if only as a protection from the unhealthy exhalations of a vast tract of swamps, and from the intolerable nuisance of swarms of aggressive and venomous insects, which infest the entire river region during the long summer season. Safety from the attacks of the numerous roaming tribes which ranged the country in every direction before it was definitely settled and organized, was also not among the last considerations. So, what nature had refused, the cunning and labor of man had to supply. Artificial hills or platforms were constructed, of enormous size and great height—from thirty to fifty, even sixty feet, and on their flat summits the buildings were raised. These platforms sometimes supported only one palace, sometimes, as in the case of the immense mounds of Koyunjik and Nimrud in Assyria, their surface had room for several, built by successive kings. Of course such huge piles could not be entirely executed in solid masonry, even of crude bricks. These were generally mixed with earth and rubbish of all kinds, in more or less regular, alternate layers, the bricks being laid in clay. But the outward facing was in all cases of baked brick. The platform of the principal mound which marks the place of ancient Ur, (now called Mugheir),[H] is faced with a wall ten feet thick, of red kiln-dried bricks, cemented with bitumen. In Assyria, where stone was not scarce, the sides of the platform were even more frequently "protected by massive stone-masonry, carried perpendicularly from the natural ground to a height somewhat exceeding that of the platform, and either made plain at the top, or else crowned into stone battlements cut into gradines."[I]
10.—MOUND OF NIMRUD.
(Hommel.)
6. Some mounds are considerably higher than the others and of a peculiar shape, almost like a pyramid, that is, ending in a point from which it slopes down rapidly on all sides. Such is the pyramidal mound of Nimrud, which Layard describes as being so striking and picturesque an object as you approach the ruins from any point of the plain.[J] Such also is the still more picturesque mound of Borsip (now Birs Nimrud) near Babylon, the largest of this kind.[K] These mounds are the remains of peculiar constructions, called Ziggurats, composed of several platforms piled one on the other, each square in shape and somewhat smaller than the preceding one; the topmost platform supported a temple or sanctuary, which by these means was raised far above the dwellings of men, a constant reminder not less eloquent than the exhortation in some of our religious services: "Lift up your hearts!" Of these heavenward pointing towers, which were also used as observatories by the Chaldeans, great lovers of the starry heavens, that of Borsip, once composed of seven stages, is the loftiest; it measures over 150 feet in perpendicular height.
