The improved printing press, invented by Lord Stanhope, the first of which was completed in 1800, is made altogether of iron. The platten is of the full size of the sheet of paper to be printed, and the work is done at a single pull. The requisite power is obtained by a combination of levers, so adjusted that the platten is brought down rapidly in the first instance, before any pressure is required, and when it comes to bear upon the types, the levers act with the greatest possible mechanical advantage, so that the handle moves through the space of a foot, whilst the platten descends only the twentieth part of an inch. By this means a large sheet of paper can be printed off by a single pull, and with more impression and greater sharpness than by two pulls with a wooden press. Great as was this improvement in the printing press, its action was still very slow, compared with the rapidity of printing we are now accustomed to, it being considered quick work, with a small Stanhope press, to print 500 sheets an hour. The author remembers to have seen the _Globe_ newspaper printed by an old wooden press in 1820; and, about the same time, the London _Courier_, by a Stanhope press. In order to supply the large demand for the latter paper, it was then customary to print off three pages early in the day, and to set up the types for the fourth page, containing the latest news, three or four times, and to print it at as many separate presses. The pressmen could thus, by great exertion, perfect the printing, when three presses were used, at the rate of 1,500 an hour. The _Times_ newspaper, which greatly exceeds the size of the _Courier_, is now printed by a machine at the rate of 13,000 an hour. The invention of printing machines was preceded by the manufacture of inking rollers, to supersede the pelt balls for distributing the ink over the types. Earl Stanhope had endeavoured in vain to construct inking rollers, for which purpose he tried skins and pelts of various kinds, but the seam proved an obstacle that he could not overcome. In 1808, a "new elastic composition ball for printing," which consisted principally of treacle and glue, to serve as a substitute for pelts, was invented by Mr. Edward Dyas, a man of great original genius, the parish clerk of Madeley, in Shropshire. These balls were first introduced into the extensive printing office of the late Mr. Edward Houlston, of Wellington, where they were for some time exclusively used, and that printing-office consequently became celebrated for the excellence of its work. A similar composition was some years afterwards cast in the form of rollers, upon a hollow core of wood, by the late Mr. Harrild; and these rollers have proved a far more cleanly and more expeditious mode of inking the types than the balls. These inking rollers supplied an essential want in the working of Printing Machines.