ABSTRACT
The first important step towards the possibility of a printing machine was made, when for these inking balls was substituted a cylindrical roller, mounted on handles. The body of the roller is of wood, but it is thickly coated with a composition which unites the qualities of elasticity, softness, and readiness to take up the ink and distribute it evenly over the types. The machines used for lithographic printing by steam power are almost identical in their general arrangement with that just described, which may be taken as a representative specimen of the modern printing machine. The various kinds of printing machines adapted to each description of work are too numerous to admit of even a passing; but those which have been described may fairly be considered as representing the leading principles of modern improvements.
