PRESS

(Fr. pre e.) The machine by which books, . are printed. Very little improvement in the construction of this instrument took place from the first introduction of the art into Europe till the late Earl Stanhope applied the powers of his mind to the subject, and introduced a new pre of a decidedly superior construction. The old pre was made of wood, with an iron screw that had a bar fitted in it; to the lower end of this screw was attached, horizontally, a flat piece of wood, called the platen, which was brought down by means of the screw, and pre ed the paper upon the lace of the types; and thus the impre ion was obtained. This pre has, however, entirely given place to pre es made of iron. Lord Stanhoj)e's pre is constructed of iron, with a screw; but the bar is fixed to an upright spindle, to which a lever is attached connected with a second lever fixed to the top of the screw by a connecting bar. These two levers are placed at different angles to each other; and when the platen is brought down to the face of the types, and power is wanted, the two levers take such a position with each other so as to act with tlie greatest advantage, and thus an almost incredible acce ion of power is gained, which enables the pre man to print larger sheets of paper in a superior manner, with le labour, and with greater ease to himself. This pre maintains its superiority over all others. This great improvement in the printing pre that Lord Stanhope had accomplished excited other ingenious men to exert their abilities in attempts at further improvements; among whom was a Mr. George Clymer, an American, who brought forward an iron pre , called the Columbian pre , in which he discarded the screw, and obtained his power entirely by levers. This pre has great power, and consequently great strength, and is made of a sire to print larger sheets of paper than any other; but for the common run of printing it does not work so easy as the Stanhope pre . These two are looked upon as the best pre es. There are a variety of others which are great improvements upon the old construction, and which are held in estimation by printers, but the limits of this work will not admit of the details of their respective merits. The book pre , in the warehouse department, used for pre ing books previous to their delivery, is the common screw pre , with a perpendicular screw, and screwed down by means of an iron bar: it is. also used for pre ing paper, when wetted, previous to being printed on, for the purpose of making it in better condition for the proce ; and also in cylindrical or machine printing to cause it to lie flat, otherwise it is apt to wrinkle, particularly large sheets, in being carried round the cylinders upon a flat surface. In large establishments Brahmah's hydraulic [s. 985]