Actually - hieroglyphics are able to be read both ways horizontally and downwards - the direction is indicated by the direction in which the symbols are facing - the birds are usually the easiest to tell. This enables them to be be written on all sorts of objects for ceremonial/magical purposes.
You can read hieroglyphs left to right, vise versa, and sometimes up and down (this occurs most likely on carcoutches). It depends on which direction the glyphs are facing. Usually the bird glyphs faced left, so you read that left-to-right. If the bird faced right then vise versa. Just have to look at the glyphs around it to know...
TRUST THE EXPERT: Hieroglyphics CAN be written from all suggested ways. (Up to down, left to right, and right to left) However, the Egyptians themselves preferred to write right to left-- thats the way the wrote them automatically. They only wrote the other ways for artistic purposes.
I think you've both got mistaken...western books ARE read from left to right, unless gothgirl7 knew that Egyptian hieroglyphics are meant to be read from right to left...anyway, i would like to share this: Chinese texts ran from right to left and were arranged vertically downwards by columns in the ancient times (not sure about Japanese). Hence, what passed for the "back" of the book by western "standard" was actually the front cover.