696 



PRINTING. 



tin- tympan and frisket, as will be seen in the figure, 

 jire attached to the frame. When the plattin is 

 ilrawn over the tympan, it comes into checks or 

 catches attached to side levers, which are linked 

 very ingeniously to the long lever, seen under the 

 table, one end of which is affixed to a crank at the 

 side, wrought by a winch or handle. These attach- 

 ments are made in such a way, that, by turning the 

 winch, motion is communicated through the levers 

 and links to the plattin, which is brought down; and 

 in this, as in the Stanhope, the motion is at first rapid 

 in the plattin, but slow when it comes upon the 

 tympan, so that the greatest mechanical effect is 

 produced. MrRuthven's press is now chiefly used 

 for what is called jobbing, or for impressions where 

 the form is small. 



In Fig. 4. we have given a perspective represen- 

 tation of Cogger's printing press, which, according 

 to Hansard, possesses considerable merit. Its supe- 

 riority over the Stanhope consists in the less liability 

 of the stapple to break, or that part in the Stan- 

 hope press which corresponds to the cheeks, head, 

 and winter in the common screw press. The 

 cheeks are pillars of malleable iron. On these pil- 

 lars cast iron tubes are dropped, which support the 

 winter ; above these there ar.e placed brass tubes, 

 which give a resting place to the levers that effect the 

 pressure. Above these the head is placed, all being 

 secured by screws which are seen at the top. The 

 plattin is made to descend by the action of levers 

 turning a bar round in a collar, on the top of which 

 there are two convex steel studs, acted on by in- 

 clined planes of varying inclinations, in order to 

 cause the motion during the descent of the plattin 

 to be at first rapid, and very slow at the termination, 

 where the greatest power is required. The most 

 important advantage of this press is, that it can in 

 no way affect the distance of the plattin from the 

 tympan by over application of power, and uniformity 

 of impression is the consequent result. 



In 1814, Mr G. Clymer of Philadelphia invented 

 a printing press, which has obtained great celebrity. 

 It. was introduced into England in 1818, and is 

 commonly denominated the Columbian Press. In 

 this press, as in the Ruthven, the power is obtained 

 solely by a system of levers, without the intervention 

 either of screws or inclined planes. By this press 

 a workman can pull a heavy form with much greater 

 ease than with any of the presses heretofore des- 

 cribed. Much mechanical ingenuity has been dis- 

 played in the arrangement of its several working 

 parts, and no printing press has received so much 

 aid in the improvement of its external appearance. 

 A representation of the Columbian press is given in 

 Fig. 5. The cheeks are connected at the bottom, 

 but not at the top. The top of the cheek in the 

 right hand side of the figure, serves as a fulcrum 

 for one end of a large lever which is seen inclining 

 downwards to the left. The left end of this lever 

 is attached to a link, working in an arbor in the 

 cheek, the lower end of which link is attached to 

 another cross link, which again is wrought by the 

 handle or bar, seen projecting towards the bottom 

 of the frisket. The principal lever at the top is 

 one of the second kind, its point of action being in 

 the middle, where it presses down the stapple of 

 the plattin, which stapple is a square rod of iron 

 descending through guides so as to maintain the 

 parallelism of the plattin. In order to raise the 

 plattin when the pull has been made, a weight is 

 placed on the top of the main lever between the 

 point of action in the centre and the fulcrum to the 

 right. In consequence of the strain arising from 

 the oblique action of the levers, it sometimes hap- 

 pens that the cheek on the left hand side of the 



figure breaks, a circumstance which can only be 

 attributed to a miscalculation of the strength of 

 materials on the part of the press maker. 



A very ingenious and effective press was invented 

 by Mr Hope of Jedburgh, in Scotland, which 

 may be regarded rather as an improvement upon 

 the press of earl Stanhope, than in the light of an 

 entirely new invention. The principal object aimeil 

 at in the construction of this press, is to bring the 

 system of levers twice into action, instead of once, 

 as in the presses heretofore described. This is ef- 

 fected by an additional forked lever attached to the 

 off side of the iron standard, and another connecting 

 rod leading round by the back of the press to the 

 inclined planes or sectors. Herein lies the chief 

 distinction between the Jedburgh press and the press 

 of Cogger ; the inclined planes of the former being 

 made of cast iron, and those of the latter of steel or 

 case hardened iron. Mr Hope has recently made 

 some modifications in his press, by which the in- 

 clined planes are dispensed with, and levers alone 

 employed, the principal advantage of which is, that 

 the new presses are much more durable, and more 

 easily repaired when they go wrong. Hope's press 

 is represented in Fig. 6. plate LXXVI. 



In Fig. 1. plate LXXVI I. we have given a per- 

 spective view of a press, the merit of inventing which 

 is claimed both by Mr Hope of Jedburgh and by 

 Mr Stafford of Bingham in Nottinghamshire. This 

 press resembles somewhat the press of Ruthven. 

 The table is stationary in this as in the Ruthven 

 press. The tympan and plattin are attached to each 

 other, and they must be raised and turned down 

 every time an impression is taken. When turned 

 down, the pressure is obtained by the action of a 

 screw and two levers, very ingeniously combined ; 

 but from the great weight of the plattin, it is im- 

 possible that this press can ever come into use where 

 forms are to be printed larger than foolscap. In- 

 deed, so far as utility is concerned this press is in- 

 ferior to the press of Ruthven, even for impressions 

 from small forms. 



Fig. 7. plate LXXVI., is a view of the Albion 

 press of Mr R. W. Cope, which exhibits some no- 

 velties in mechanism, and has been found superior 

 to most presses, especially for moderate sized forms. 

 The pull is not heavy, and from the excellent me- 

 chanical arrangementof the working parts, the strain 

 is so distributed as not to act very materially on any 



Eoint, and hence the press of Mr Cope is less lia- 

 le than any other press of equal power, to give 

 way. The pressure is given by a combination of 

 levers acted on by the bar handle, which in this 

 press is better situated than in the Columbian, being 

 attached to the near cheek, and consequently more 

 within the reach of the pressman. Another great 

 advantage connected with the bar handle is, that 

 the pull requires only about one quarter of a turn, 

 and consequently the impression is more speedily 

 taken by this press, than by the Columbian, and the 

 bar handle returns only so far as to clear the rise of 

 the tympan. The pressure is given by means of two 

 limbs forming a knee joint, and the action of the 

 levers brings this knee joint into a perpendicular 

 position, the under link pressing down the stapple 

 which carries the plattin. The stapple moves up 

 and down in a hollow cylinder. This is the first 

 instance in which such a contrivance has been in- 

 troduced into the mechanism of a printing press. 

 The parts are so few and so judiciously arranged, 

 that there is little friction, or liability to wear or 

 go wrong. An improved modification of this press 

 was made the subject of a patent by Messrs Slier- 

 win and Cope. It is denominated the Imperial 

 press, and is much esteemed among printers. 



