35. The power-press first used in this country, was invented, in 1823, by Mr. Treadwell, a scientific mechanic, of Boston, who was originally a watch-maker by trade. It acts on the same principle with the hand press, and is equal to three of these of the best construction. Daniel Fanshaw, who first applied steam to printing in the United States, introduced several of these presses into New-York, in 1826. Messrs. Adams and Tufts, of Boston, have each invented a power-press which act on the same principle with Mr. Treadwell's. 36. The presses noticed in the preceding paragraph, are used chiefly in printing books and periodicals requiring moderate speed in their production. But they do not answer the purposes of the daily press in large cities, where from twenty thousand to sixty thousand impressions of a single paper are required every day. To supply this immense demand of the public was the original aim of the inventors of power-presses in England. The first attempt to construct a printing machine was made, in 1790, by William Nicholson, of London; but his machine was never brought into use. The next attempt was made by Mr. Konig, an ingenious German, who but partially succeeded. The first really useful machine was constructed by Messrs. Applegate and Cowper. 37. The machines used in this country are modifications of that originally invented by Mr. Napier, of England. The paper is brought in contact with the form of types by means of a cylinder, while the form is passing underneath it. The press is constructed with one or two cylinders. A double cylinder press will give from 4000 to 6000 impressions an hour. The improvements on this press were made by Robert Hoe & Co., who have permitted Mr. Napier to introduce them into his press in England. [Illustration] THE TYPE-FOUNDER. 1. The types cast by the type-founder are oblong square pieces of metal, each having, on one end of it, a letter or character, in relief. The metal of which these important instruments are composed, is commonly an alloy consisting principally of lead and antimony, in the proportion of about five parts of the former to one of the latter. This alloy melts at a low temperature, and receives and retains with accuracy the shape of the mould. Several hundred pounds of type-metal are prepared at a time, and cast into bars filled with notches, that they may be easily broken into pieces, when about to be applied to use. 2. In making types, the letter or character is first formed, by means of gravers and other tools, on the end of a steel punch. With this instrument, a _matrix_ is formed, by driving it into a piece of copper of suitable size. A punch and matrix are required for every character used in printing. A metallic mould for the body of the type is also made; and, that the workman may handle it without burning his hands, it is surrounded with a portion of wood. The mould is composed of two parts, which can be closed and separated with the greatest facility.