In point of fact he had chanced upon part of the library of Ashur-bani-pal, one of Assyria’s greatest kings; the library appears to have been stored partly in the northern palace, that of Ashur-bani-pal proper, and partly in the south-western palace built by Sennacherib; it was in the latter that the rooms referred to were found; the other half of this great library of the later Assyrian kings was subsequently unearthed by Rassam. The contents of these tablets, made of the finest clay and ranging from one to fifteen inches, are as varied as the tablets themselves. Some of them contain historical records, others astronomical reports, or mathematical calculations: there are also letters of a private and public character, but the majority of the tablets deal with astrology and medicine, both of which subjects were intimately connected in the mind of the Babylonian. Prayers, incantations, psalms and religious texts in general, formed a considerable part of this library, and as a large proportion of the “volumes” or tablets are not original works but copies from earlier Babylonian productions, the value of the library,—now known under the name of the “Kouyunjik collection,”—for the study of the religious and mythological conceptions of both the Babylonians and Assyrians is more than can be adequately estimated. Many of the tablets are bilingual, the ideographic Sumerian being provided with an Assyrian interlinear translation, and these, together with other tablets of the collection containing syllabaries in which the Sumerian value, the Assyrian name, and sometimes the Assyrian meaning of different signs are given, have been of the utmost use in the rediscovery of the languages of Mesopotamia. Layard also visited Babylonia, and began to excavate at Babylon and Nippur, but his Babylonian operations were not attended with the extraordinary success of his excavations at Nineveh and Calah. In 1851 a French expedition was sent out to Babylonia under Fresnel and Jules Oppert: they secured various relics from the ruined mounds of Babylon, among which may be especially mentioned a fine collection of coloured-brick fragments, but unfortunately all was lost through a mishap on the Tigris in 1855.