The mere fact of carrying on such campaigns and forming such political alliances is sufficient to show that the Hittites must have attained to an advanced state of civilization. But there is abundant proof that this was the case from other sources. They were a commercial people, and their capital, Carchemish, was for many centuries the great emporium of the caravan trade between the East and West. The products of the East, probably as far as Bactria and India, reached it from Babylon and Nineveh, and were forwarded by two great commercial routes, one to the south-west to Syria and Phoenicia, the other to the north-west through the pass of Karakol, to Sardis and the Mediterranean. The commercial importance of Carchemish is attested by the fact that its silver mina became the standard of value at Babylon, and throughout the whole of Western Asia. The Hittites were also great miners, working the silver mines of the Taurus on an extensive scale, and having a plentiful supply of bronze and other metals, as is shown by the large number of chariots attached to their armies from the earliest times. They were also a literary people, and had invented a system of hieroglyphic writing of their own, distinct alike from that of Egypt and from the cuneiform characters of the Accadians. Inscriptions in these peculiar characters, associated with sculptures in a style of art different from that of either Egypt or Chaldæa, but representing figures identical in dress and features with those of Hittites in the Egyptian monuments, have been found over a wide extent of Asia Minor, at Hamath and Aleppo; Boghaz-Keni and Eyuk in Cappadocia; at the pass of Karakol near Sardis, and at various other places. Several of those attributed by the Greeks to Sesostris or to fabulous passages of their own mythology, have been proved to be Hittite, as, for instance, the figure carved on the rocks of Mount Sipylos, near Ephesus, and said to be that of Niobe, is proved to be a sitting figure of the great goddess of Carchemish. For a long time these inscriptions were an enigma to philologists, but the researches of Professor Sayce and other scholars have quite recently thrown much light on the subject, and enabled us partially to decipher some of them, and the recent discovery of papyri at Tel-el-Amara written partly in the Hittite language in cuneiform characters, removes all doubt as to its nature and affinities.