Suppose that you were Champollion, and that you were examining a stack of papyrus sheets, all covered with hieroglyphics. Suddenly you came across a picture of a man with a saw. "Very well," you would say, "that means of course that a farmer went out to cut down a tree." Then you take another papyrus. It tells the story of a queen who had died at the age of eighty-two. In the midst of a sentence appears the picture of the man with the saw. Queens of eighty-two do not handle saws. The picture therefore must mean something else. But what?
That is the riddle which the Frenchman finally solved. He discovered that the Egyptians were the first to use what we now call "phonetic writing"—a system of characters which reproduce the "sound" (or phone) of the spoken word and which make it possible for us to translate all our spoken words into a written form, with the help of only a few dots and dashes and pothooks.
Let us return for a moment to the little fellow with the saw. The word "saw" either means a certain tool which you will find in a carpenter's shop, or it means the past tense of the verb "to see."
This is what had happened to the word during the course of centuries. First of all it had meant only the particular tool which it represented. Then that meaning had been lost and it had become the past participle of a verb. After several hundred years, the Egyptians lost sight of both these meanings and the picture 
came to stand for a single letter, the letter S. A short sentence will show you what I mean. Here is a modern English sentence as it would have been written in hieroglyphics. 
