111 STRAND

processes. LAdter another careful examination and cleaning, the wax mould is mmmcersed in the first plating bath, where 1t reccives, by chemical action; a very thin first Copper. g bath, which 15 a large tank full of a I(n1)1(1(1111“—]001\111“ fluid, wherein the mould, with many othus B suspcn(lcd from rods lard across the top. A dvnamo buzzes furi- ously at the head of this tank, and dispatehes clectrienty through its contents, hiberating thercfrom minute particles of copper, and attachimg them to the thin film ahmd\ de-

posited. "The entire process might be gone through in this bath, hut the chemical deposit 1s precipitated first for the sake of quickness, Some few hours of this mmersion lTeaves a bright shell of copper, as thick as fairly stout writing-paper, upon the mould. This Tatter 1s then carefully washed away in hot water, and there remains an exact and delicate foae

seile 0 thin copper of the original page of

type.

But before this can be printed from it must be *backed up.” Another carcful examin- ation is the preliminary to this process, which consists in pouring upon the bhack of the copper shell a quantity of molten metal - principally Tead—to a thickness of about a lifth of an inch, so as to make up asolid plate, with the pnntmg surface in copper. The rough cdges

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coat of Next it goes into the copper-deposit-

of this plate are trimmed off

Q1 CL0S. (03

with a fine circular saw, and another maching shaves 1t to the proper thickness. Then a skilled workman closcly serutinizes the plate for any incquality of surface caused by heat, cte., and cleverly beats it up perfee t]) flat

after which another machine s called into requisition, which shaves the cdges exactly

still another machine down the plate to the exact thickness required a can take off an almost trans- parent shaving hall the thickness of tissue paper. Then o very exact piece of mechanism bhevels the edges precisely to o the correcet angle required o fit the cylinder whereupon he plate 15 to be fixed for printing. After this, heing placed upon a flexible ])IC(L‘ of steel, the 15 brought between the jaws

sqquare and to size s fimally shaves mathematically machie which

of the shaper, which, bemg heated by gas and anr blast, close to"ctlwc and blmg

it to the curve to it printing cylinder. Then the plate s finally examined for mimute defects, and, if found satisfactory, is sent to do its work. Such are the processes - 1 addition to some other smaller and subsidiary ones not neces- sary tooexplam - through which the metal surface from which this page s printed went before even approaching the printing machine. At any stage of the operations, even the final cxamination, a defeet not casily remedied mvolves the casting aside of the plate and

proper upon the

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Cpne STRAND JMACGAZINE PRINTING ROOM.