The paper is now not in sheets, but in a long web like a web of cloth. It passes between felt-covered rollers to press out all the water possible, then over steam-heated cylinders to be dried, finally going between cold iron rollers to be made smooth, and is wound on a reel, trimmed and cut into sheets of whatever size is desired. The finest note papers are
not finished in this way, but are partly dried, passed through a vat of thin glue, any excess being squeezed off by rollers, then cut into sheets, and hung up to dry thoroughly at their leisure.
Paper made of properly prepared linen and cotton is by far the best, but there are so many new uses for paper that there are not rags enough in the world to make nearly what is needed. There are scores of newspapers and magazines where there used to be one; and as for paper bags and cartons and boxes, there is no limit to their number and variety. A single manufacturer of pens and pencils calls for four thousand different sorts and sizes of boxes. School-children's use of paper instead of slates, the fashion of wrapping Christmas gifts in white tissue, and the invention of the low-priced cameras have increased enormously the amount of paper called for. In the attempt to supply the demand all sorts of materials have been used, such as hemp, old rope, peat, the stems of flax, straw, the Spanish and African esparto grass, and especially wood; but much more paper is made of wood than of all the rest together. Poplar, gum, and chestnut trees, and especially those trees which bear cones, such as the spruce, fir, balsam, and pine are used. There are two methods of manufacturing wood pulp; the mechanical, by grinding up the wood, and the chemical, by treating it chemically. By the mechanical method the wood is pressed against a large grindstone which revolves at a high speed. As fast as the wood is ground off, it is washed away by a
current of water, and strained through a shaking sieve and a revolving screen which drives out part of the water by centrifugal force. In a great vat of pulp a drum covered with wire cloth revolves, and on it a thin sheet of pulp settles. Felting, pressed against this sheet, carries it onward through rolls. The sheets are pressed between coarse sacking. Such paper is very poor stuff. In its manufacture the fiber of the wood is so ground up that it has little strength. It is used for cardboard, cartons, and packing-papers. Unfortunately, it is also used for newspapers; and while it is a good thing for some of them to drop to pieces, it is a great loss not to have the others permanent. When we wish to know what people thought about any event fifty years ago, we can look back to the papers of that time; but when people fifty years from now wish to learn what we thought, many of the newspapers will have fallen to pieces long before that time.
Courtesy S. D. Warren Co.
WHERE RAGS BECOME PAPER
The vat where the rags cook and turn over, and the big room where the web of finished paper is passed through rollers and cut into a neat pile of trimmed sheets.
There is, however, a method called the "sulphite process," used principally in treating the coniferous woods, by which a much better paper can be made. In all plants there is a substance called "cellulose." This is what gives strength to their stems. The wood is chipped and put into digesters large enough to hold twenty tons, and is steam-cooked together with bisulphite of magnesium or calcium for seven or eight hours. Another method used for cooking such woods as poplar and gum, is to boil the wood in caustic soda, which destroys everything except the cellulose. Wood paper of one kind or another
is used for all daily papers and for most books. Whether the best wood paper will last as long as the best rag paper, time only can tell.