The script of the ancient Egyptians is usually called hieroglyphs, from the Greek meaning "divine incised signs". The Egyptians themselves called it medu netjer "god's words". They believed that the god Thoth had invented writing. It is a pictographic script that is first used towards the end of the fourth millennium BC - in the early 1990s, some bone and ivory labels were found at Abydos with hieroglyphic inscriptions on them. They have been dated by Carbon 14 to 3400-3200 BC. The script remained in use until the fourth century AD, after which time its meaning was completely lost. It was not until the 19th century that the Frenchman Champollion deciphered the script with the help of the Rosetta Stone. The script has thousands of signs that can be divided into ideograms (which illustrate the word), phonograms (which have a certain sound) and determinatives (which further explain the meaning of a word). It is written without spaces or punctuation, in columns as well as lines. Only the consonants were important in written Egyptian - vowels were not written and as a result we no longer know what the language sounded like. A very few sounds have been reconstructed with the help of Coptic, the last phase of Ancient Egyptian which did write the vowels, and of Egyptian loan words in other ancient languages. In addition to the work-intensive hieroglyphs used on monuments, there was also a cursive version of the script called hieratic. This was more suitable for writing on papyrus and ostraca. At first the hieratic signs strongly resembled their corresponding hieroglyphs, but they were quickly simplified and the original signs were soon no longer recognizable. Hieratic remained in use until the third century AD. An even more cursive script developed out of hieratic, called Demotic. It was frequently used from the Late Period onward, mainly for administrative and legal documents. The profession of scribe was very respected and it was often favourably compared with other professions in the texts. For example, a scribe was better off than a metalworker in front of his smelting furnace, whose fingers were like the claws of a crocodile and who smelt of fish, at least according to the well-known "Satire of the Trades". The office of scribe usually passed from father to son. During the apprenticeship, a number of classical texts were learnt, for example the Story of Sinuhe. Many copies of and quotations from this story have survived. Thoth and Sheshat were the protective deities of scribes.