Lithographic Printing Press

Lithographic Printing Press

Lithographic Printing l~ress, gT: produced complete ; at least, the only preparation for the press which, it requires is the trimming of the superfl...

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Lithographic Printing l~ress,

gT:

produced complete ; at least, the only preparation for the press which, it requires is the trimming of the superfluous edges, which is,done by~ a circular saw with great celerity. The b a c k o f t h e plate i s a s s m o o t h as the slab of metal from which it received its impression, a n d thus the planing process in stereotyping is now done away. The w h o l e operation is perfectly clean, and may be conducted and compl.eted .in less than an hour, while by the ordinary process the period varies from ten to twelve hours, liable to the breaking, splitting, or warping of the stucco matrices, risks which are unknown in the new card-process. Plates may be produced by this process as distinct and clear as any that have been cast fl'om stucco. As many as a dozen casts may be taken from the same card. Glasgow Prae. Mee. & Eng.Mag.

Lithographic Printing Press. All attempts which have heretofore been made to apply to lithography the principle of machinery, introduced in typographic printing about twenty years ago, have been unsuccessfill, as it was ibund impossible to obtain by a machine-press the same precision and. regularity of pressure as by the common hand.press. M. Nicolle has not only made a machine so peri~ct as to give impressions as good as those obtained by hand ;--he has gone fm'ther, for the impressions throw~ off by his machine are superior to those obtained by the ordinary process now in use, whilst in point of rapidity the Improvement is so great as to be almost incredible. ]3y the common lithographic process, not more than from 200 to ~50 good impressions of designsl or about I00O copies of lithographic writing can be obtained in twelve hours; by this new machine, which is also worked by hand, as many as 2,000 of the former and 2o,000 of the latter can be obtained within the same period of time.The machine occupies but a small space; the ink-rollers are so arranged that the supply as they pass over the stone is regularly distributed, the paper is laid upon the stone by machinery~ and, when printed, thrown off without having any person to l a y or~ and take off, and thus the expense of working is reduced at the same time that the products are so greatly multiplied. The most extra0r.' dinary part of tile machine, however, is that which provides for the wetting of the stone for each impression. By the ordinary system, the printer is compelled after every impression to moisten the stone with a wet sponge. This is an operation that requires great care, but which, notwithstanding, gradually affects the drawing, and before a Ihousand copies are taken off the delicacy of the outlines is ahnost destroyed. M. Nieoile has imagined a means of wetting the ston% which, to use a French expression, ,, tient au merveilleux." With a force-pump of his own invention, and by three or four strokes o f the piston, he extracts the moisture fl'om tile atmospher% and throws R upon the stone in the form of a fine dew, so that the application o f lhe hand is avoided, and there is great economy of time. I'his pump is fixed over the ston% and the piston is rapidly worked by the m a chine. When we were present~ this apparatus was not ciuite C0m-

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Meetta~ics, Phgsies, and Chemislry.

pleted, and was not, therefore, attached to the machine; but we s a w the pump at work by the hand, and could have no reasonable d o u b t of its perfect success when affixed to the machinery. Tile air of the printing-room would necessarily soon lose its moistare by the repeated application of the exhausting process; but Ihe moisture may easily b e kept up by tile simple use of a small charcoal stove and an evaporating dish filled with water. M. Nicolle has patents in France and ill England tot his invention. London Athenaeum.

Proceedi~tgs q/lhe Society for the Encouragement of Nalionttl Indust~ff, 19aris. Sillin• of May ~8, 1845. T R A N S L A T I ' ; I ) F O R q ' l l ~ IIOUltNAI, OF TII/'I FllA.~t~KLIIq I N S T I T U T I ' ; ,

ELr:cTPo'rrpr.' Er,'(~I~AVr,XGs.--M. Philif)pe, of' Rouen, exhibited a n electrotype copy of an old and much esteemed engraving by Wille, representing the wandering minstrels, bearing the date of 1764. It was accompanied by two proofs, one from the original plate and t h e other from the copy. tte also deposited a sealed description of tile methods he had found to be most advantageous for the re-product ion by electricity of copperplate ctlgravings of every size, and also of the means he had employed lo prolong, lbr an indefinite period, the eIficiency of the rollers used in printing calicoes, &c. by a re-deposite of metal upon their surfaces. It appears from the i~fformation furnished by M. Philippe, that his plates are composed of three different qualities of copper; the engraved side is composed of a thick layer of copper, as hard as sleel; it can, therefore, furnish a large number of impressions without injury. T h e n a layer of medium hardness, and last a layer of pertectly malleable copper. The superposition of these layers allows the plate to sustain without injury the action of the press. If it becomes curved by t h e iutensisty of the pressure, it is easily straigh(ened by passing through the press in an inverled position ; this can be done as often as required without the plate undergoing the least alteralion. M. Philippe remarked, that the re-produced engraving had b e e n obtained in fourteen days by the action of four pair of the carbon battery of Bunsen. After two years' experiments and practice, he asserts lhat he is able to re-produce geographical charts engraved o n copper fl'om the original plates, without the latter undergoing the slightest injury. MANL'I.'AC'I'IrF.t: oF SUGAR I.'IlO~IBE:ETS.~r~I. Payen remarked that fears had been entertained by many, as to the prosperity of the m a n nfactnre of the' beet root sugar, since tile establishment of a progressive impost on don)estie sugars; but on account of the improvements receutly introduced into the manufacture, all such fears have b e e n dissipated, und there is now no doubt that under eqnal imposts, beet sugar can sustain, in oar own market, the competition of that from the colonies. The establishment of the impost had, it is trne, oecasioned the stoppage of many establishments ; but these eilher had not been conducted