Books used to look more like rolled charts than the rectangular stack of pages we associate with the word 'book' today. Writing was only found on the inner side of the scroll.
From the Manual of Classical Literature by Johann Eshenburg:
[S]everal strips or leaves of the parchment or paper were glued to each other at the ends, either before or after the writing...The whole was then wound upon a rod, or cylinder, which was ordinarily made of wood or ivory, and had at both ends projecting ornaments, knobs or the like. The title was written on the back of the protocol visible after the winding of the roll, or on a small separate strip attached to the edge of the roll. The book itself, or whole roll, was encompassed with bands, or enclosed in a case.
There was said to have existed in the library at Constantinople, 'an ancient manuscript of Homer, on a roll of parchment one hundred and twenty feet in length, the intestines, as it was tabled, of a prodigious serpent.'—Gibbon, Dec. and Fall of Rom. Emp. ch. liii, (N. York, 1822, vol. v. p. 3G7).A king of Pergamos is credited with introducing the shape of books as we know them today.
