The two most important human inventions are perhaps Speech and Writing. In no adequate way could man fully express his mental activities except by speech: nor could he adequately record them except by writing. And to some extent the development of the two ran a parallel course, for just as early Speech is largely an imitation of natural sounds (Onomatopœia), so early Writing is probably, in the first instance, entirely from pictures (pictograms), which from the need of acceleration became worn down to simpler forms, and finally to letters; the sense similarly declining from the plain or derivative ideas arising from pictures, to mere syllables with no intrinsic meaning, and finally to simple sounds corresponding to letters. But even this latest stage was reached in the Valley of the Nile by, or not long after, 3000 B.C., as is testified by a stelè representing the cult of Send, a king of the second Egyptian Dynasty (now in the Ashmolean Museum at Oxford), in which the letters S, N, D occur in a cartouche; while in 1750 the North American Indians used pictograms, and the practice is not yet extinct, for we use the symbol ☞ [Sidenote: Early Libraries.] As soon as Writing occurs in a portable form, whether as cylinders of baked clay in Assyria, or as tablets of bark, wood or wax, or as sheets of parchment or paper, there is a volume, and there is the possibility of a collection of books which forms a Library. The earliest library of which a plan can be reconstructed was discovered at Nineveh by Layard and dates from about 700 B.C. Of early Egyptian libraries no trace has been found; but under the Macedonian dynasty of the Ptolemies the great library at Alexandria in Egypt was founded about 285 B.C. About libraries in Greece information is very scant until the time of Euripides (fifth century B.C.) In Italy, the earliest public library was founded soon after 39 B.C. by C. Asinius Pollio, and under Augustus at least two more were instituted at Rome; and by the fourth century at least twenty-five or so were there erected, but all of them are stated to have been closed down, “bybliothecis sepulcrorum ritu in perpetuum clausis” (_Ammianus Marcellinus_). Of course these public libraries had been preceded by private collections, of which records are few and far between.