the oldest and simplest books were made of narrow bamboo ⺮ slats vertically arranged with spaces in between 間 and connected with string; k. were written in vertical order and many sketches of things oblong and horizontal, were placed vertically. The slats were drawn up into scrolls held in the left hand; the right hand was used for writing or pulling the scroll while reading. This is the origin of the top-bottom right-left order in writing