The palace first discovered, that of Khorsabad, had been built by King Sargon at Nineveh, the site of the capital of the Assyrian kings. The city was built on several eminences, and was encircled by a wall 25 to 30 miles[18] in length, in the form of a quadrilateral. The wall was composed of bricks on the exterior and of earth within. The dwellings of the city have disappeared leaving no traces, but we have recovered many palaces constructed by various kings of Assyria. Nineveh remained the residence of the kings down to the time that the Assyrian empire was destroyed by the Medes and Chaldeans. =Inscriptions on the Bricks.=--In these inscriptions every character is formed of a combination of signs shaped like an arrow or wedge, and this is the reason that this style of writing is termed cuneiform (Latin _cuneus_ and _forma_). To trace these signs the writer used a stylus with a triangular point; he pressed it into a tablet of soft clay which was afterwards baked to harden it and to make the impression permanent. In the palace of Assurbanipal a complete library of brick tablets has been found in which brick serves the purpose of paper. =Cuneiform Writing.=--For many years the cuneiform writing has occupied the labors of many scholars impatient to decipher it. It has been exceedingly difficult to read, for, in the first place, it served as the writing medium of five different languages--Assyrian, Susian, Mede, Chaldean, and Armenian, without counting the Old Persian--and there was no knowledge of these five languages. Then, too, it is very complicated, for several reasons: 1. It is composed at the same time of symbolic signs, each of which represents a word (sun, god, fish), and of syllabic signs, each of which represents a syllable. 2. There are nearly two hundred syllabic signs, much alike and easy to confuse. 3. The same sign is often the representation of a word and a syllable. 4. Often (and this is the hardest condition) the same sign is used to represent different syllables. Thus the same sign is sometimes read "ilou," and sometimes "an." This writing was difficult even for those who executed it. "A good half of the cuneiform monuments which we possess comprises guides (grammars, dictionaries, pictures), which enable us to decipher the other half, and which we consult just as Assyrian scholars did 2,500 years ago."[19] Cuneiform inscriptions have been solved in the same manner as the Egyptian hieroglyphics--there was an inscription in three languages--Assyrian, Mede, and Persian. The last gave the key to the other two.