down the page till it came nearly low enough to meet the imprint. If we go back to the habits of the scribes it is easy to understand another point in the early history of books, their make-up into quires and the marking of these quires by signatures and catchwords. The word _quaire_ or _quire_ is a shortened form of the Latin _quaternio_, the name devised for four sheets of paper folded down the middle so as to form eight leaves. A gathering of five sheets making ten leaves was called a _quinternion_, and this, though it has yielded no modern word, was for generations such a popular form that _quinterniones_ was sometimes used as a general expression for manuscripts. Gatherings of three sheets, making six leaves, were called _terniones_; gatherings of two sheets, making four leaves, _duerniones_. A few, but only a few, books exist--nearly all of those which I have seen are either block-books or thin folios of poetry of the reign of Charles II--which are made up in single sheets not placed one within the other, but following consecutively. But the system of gathering from two to five or more sheets together into quires was practically universal both before and after the invention of printing, and this for the excellent reason that it reduced the quantity of sewing necessary in binding a book, and reduced also the risk of the sewing cutting through the paper or vellum, as it would be very likely to do if there were only a single thickness to resist it. When the scribe had arranged his quire or gathering he wrote first page by page on all the leaves on the left hand until he came to the middle of the quire, when he proceeded to write page by page on all the leaves on the right hand. Thus in a quire of four sheets the left half of the first sheet would be leaf 1, pages 1 and 2, and the right half would be leaf 8, pages 15 and 16, so that the same sheet formed the beginning and end of the quire. In the earliest printed books the quires were printed page by page exactly as the quires of a manuscript had been written. But early in the 'seventies (Peter Schoeffer can be proved to have adopted the practice between 1471 and September, 1474) the advantage was perceived of printing both the pages on the upper or lower side of a sheet at the same time, i.e. in a quaternion, page 16 together with page 1. As soon as a printer had learnt to print two folio pages together, it became easy to print four quarto pages, or eight octavo pages, or sixteen sextodecimo pages. In each case the amount of type to be printed at a pull would be approximately the same. It thus ceased to be disadvantageous to print small books, whereas so long as each page had to be pulled separately it was obviously wasteful to make that page a very small one.