The first step in the growth of the book was taken when memory aids were invented. Sometimes we tie a knot in a handkerchief to help us to remember something. Now, it was just by tying knots that primitive man first lent assistance to the memory. The first material book was doubtless a series of knots well represented by the quipu (Fig. 2) of the ancient Peruvians. This curious-looking book was written (tied) by one known as the officer of the knots. It contains an account of the strength of the Peruvian army, although it is confessed that its exact meaning cannot be made out. It was not intended to be read by any one who was not a keeper of the knots. Books made of knots were used by nearly all the ancient peoples of South America and by some of those of Asia. Akin to the knotted cord is the notched stick, which is still used in Australia by the savages to assist the memory of one who has a message to carry. Figure 3 shows a variety of such message-sticks. The lowest one—a crooked branch of a tree—contains an invitation to a dancing party. The notches are read by the messenger. The notched stick as an aid to memory is not confined to savage races. Many a highly civilized baker has kept his accounts by making notches in sticks and so has many a modern dairyman, as he has delivered milk from door to door.
Memory aids were followed by picture-writing. To express thought by means of pictures is an instinct shared alike by the lowest savage and the most enlightened people. All over the earth we find examples of early picture-writing. A beloved chief had died, a fierce battle had been fought, an exciting chase had occurred: promptly the event was pictured on a stone or on the skin of some animal. Pages might be filled with illustrations of these primitive picture-books, but we must be content with a single specimen (Fig. 4). This was found painted on a rock in California: "We selected this as a camping place, but we have found nothing," say the human figures f, g, h, i. The upturned palms say plainly, "nothing, nothing." "One of our comrades (d) has died of starvation," say the three lank figures at c pointing to their own lean bodies. "We deeply mourn his loss," says the sorrow-stricken a. "We have gone northward," says j, his distinguished arm extended to the north.
FIG. 4.—PICTURE WRITING.
Practice in picture-making was bound to lead to shorter methods of expressing ideas. It was soon found that reduced pictures, or picture-signs, would suffice to express ideas. Thus, if the idea of sorrow was to be expressed it was not necessary to draw an elaborate picture of a sorrowful looking man like a in Figure 4; a weeping eye would express the idea just as well. Instead of numerous figures (e, f, g, h, i) weeping and saying, "nothing here," a single pair of empty palms would say the same thing just as clearly. In this way a pair of clasped hands came to mean "friendship"; two trees meant "a forest"; a calf running toward water meant "thirst." These picture-signs, of course, assumed the form in which they could be most easily and rapidly drawn. The weeping eye became
; the pair of extended palms
; the forest
