By 1872 two hundred and ninety-nine Fourdrinier machines were running in the United States alone. In the improved Fourdrinier machine or system, rags, or wood, or straw are ground or otherwise reduced to pulp, and then the pulp, when properly soaked and drained, is dumped into a regulating box, passing under a copper gate to regulate the amount and depth of feed, then carried along through strainers, screeners or dressers, to free the mass from clots and reduce it to the proper fineness, over an endless wire apron, spread evenly over this apron by a shaking motion, subjected to the action of a suction box by which the water is drawn off by air-suction pumps, carried between cloth-covered rollers which press and cohere it, carried on to a moving long felt blanket to further free it from moisture, and which continues to hold the sheet of pulp in form; then with the blanket through press rolls adjustable to a desired pressure and provided with means to remove therefrom adhering pulp and to arrest the progress of the paper if necessary; then through another set of compression rollers, when the condensed and matted pulp, now paper, is carried on to a second blanket, passed through a series of steam cylinders, where the web is partially dried, and again compressed, thence through another series of rollers and drying cylinders, which still further dry and stretch it, and now, finally completed, the sheet is wound on a receiving cylinder. The number of rollers and cylinders and the position and the length of the process to fully dry, compact, stretch and finish the sheet, may be, and are, varied greatly. If it is desired to impress on or into the paper water marks, letters, words, or ornamental matter, the paper in its moist stage, after it passes through the suction boxes, is passed under a “dandy” or fancy scrolled roll provided on its surface with the desired design. When it is desired to give it a smooth, glossy surface, the paper, after its completion, is passed through animal sizing material, and then between drying and smoothing rollers. Or this sizing may be applied to the pulp at the outset of the operation. Colouring material, when desired, is applied to the pulp, before pressing. By the use of machines under this system, a vast amount of material, cast-off rags, etc., before regarded as waste, was utilised for paper making. The modern discoveries of the chemists of the century as to the nature of fibres, best modes and materials for reducing them to pulp, and bleaching processes, have brought the art of paper making from wood and other fibrous materials to its present high and prosperous condition.