In forming the papyrus into books it was customary to use a long sheet or web of it, and roll it upon a stick, as is the custom in respect to maps at the present day. The writing was in columns, each of which formed a sort of page, the reader holding the ends of the roll in his two hands, and reading at the part which was open between them. Of course, as he advanced, he continually unrolled on one side, and rolled up upon the other. Rolls of parchment were often made in the same manner. The term _volume_ used in respect to modern books, had its origin in this ancient practice of writing upon long rolls. The modern practice is certainly much to be preferred, though the ancient one was far less inconvenient than might at first be supposed. The long sheet was rolled upon a wooden billet, which gave to the volume a certain firmness and solidity, and afforded it great protection. The ends of this roller projected beyond the edges of the sheet, and were terminated in knobs or bosses, which guarded in some measure the edges of the papyrus or of the parchment. The whole volume was also inclosed in a parchment case, on the outside of which the title of the work was conspicuously recorded. Many of these ancient rolls have been found at Herculaneum. For ink, various colored liquids were used, generally black, but sometimes red and sometimes green. The black ink was sometimes manufactured from a species of lampblack or ivory black, such as is often used in modern times for painting. Some specimens of the inkstands which were used in ancient times have been found at Herculaneum, and one of them contained ink, which though too thick to flow readily from the pen, it was still possible to write with. It was of about the consistence of oil. These rolls of papyrus and parchment, however, were only used for important writings which it was intended permanently to preserve. For ordinary occasions tablets of wax and other similar materials were used, upon which the writer traced the characters with the point of a steel instrument called a _style_. The head of the style was smooth and rounded, so that any words which the writer wished to erase might be obliterated by smoothing over again, with it, the wax on which they had been written.