Page:Cyclopaedia, Chambers - Volume 2.djvu/500

 PRI

( 877 )

PRI

Office of the Fre£man, or Pr i n t i n g, properly fo call 'd.

To work off the Form thus prepared and corrected by the Compofitor, there are three things required, Taper, Ink, anda-?re/i.

To fit the F apcr for ufe, it is to be firft wet or moiften'd, by dipping feveral Sheets together in Water ; thefe are afterwards laid in a heap over one another; and to make 'em take the Water equally, are all prefs'd clofe down with a Weight a-top. As to the degree of wetting, it muft be according to the Quality of the Paper, and the Size of the Letter ; fmall Letters, and ft iff Faper, requiring molt wetting.

The Printer's Ink is of two kinds, black and red. The lilt occafionaUy ul'ed in Title-Pages, Calendars, igc. the firft for the Body of Books. The Compofition of each, tho' now reckon'd no part of the Printer's Bufinefs, but ufually futnifh'd 'em by other hands, is as follows.

Method of making the PaiNTiNO-7«ij.

For Hack Ink : An hundred Pounds of Nut, or Linfeed- Oil being reduced, by boiling, to the Confluence of a Sy tup, is cleans'd and putity'd by throwing into it two Pounds of coarfe Bread, and about a dozen Onions. They then boil thirty or thitiy-five Pounds of Turpentine, a-part, till fuch time as they find, upon its cooling on Paper, that it breaks clean, like Glafs, without pulvetizing ; for if it pulverize eafily, 'tis a fign it is burnt. The Oil and Turpentine thus prepared, the firft is gently pour'd, half cold, into the lat- tet ; and the two llirr'd together with a Stick till they be well mixed ; after which, the Compofition, which is call'd the Vatnifb, is fet by, to be ufed occafionaUy.

Now, to proceed to make Ink, they take a quantity of this Mixtute, and add to it a certain quantity of Lamp- black ; working it up with a kind of wooden Mullet, or grayer, till the whole be incorporated and reduced into a kind of Pulp ; which is the Ink for ufe.

Where, Note, that its Thicknefs or Strength are always to be proportion'd to that of the Paper and the Warmth of the Weather ; flrong Paper and hot Weather requiring ilrong Ink : and that the Strength or Weaknefs of the Ink depends on the greater or lefs degree of Coclion of the Yarnifh.

For red Ink : They ufe the fame Materials as for black, excepting that inffead of Lamp-black they add a proper Quantity of Vermillion. Some hold, that by mixing and incorporating the bignefs of a Nut of Fifh-glue, or Brandy, or the White of an Egg with the Ink j the Vermillion ac- quires a greater Luitre.

The Ink is applied upon the Forms by Sails, which are a kind of wooden Funnels, the Cavities whereof are fur- nifh'd with Wool, covet'd with Leather nailed to the Wood. One of thefe the Prefs-man takes in each Hand, and ap- plying them on the Ink-block, to charge 'em with Ink, he rubs one again!! t'other to diftribute the Ink equally ; and, at laft, fmears over the Form by beating or dabbing 'em feveral times over the whole Face thereof: This leaves the Form in a condition to be pafs'd under the Prefs, with the moiften'd Paper laid thereon.

2l!£ Pm N T I N G-Pfe/S.

The Friulixg-Frefs (reprefented Tab. Miscellany, fig. 8.) is a very compiex Machine J its two principal Parts, each whereof confifts of feveral others, are the Body of the Prefs, which ferves to give the Pinch or Stroke for the Impteffion ; and the Carriage, on which the Form is laid to undergo the fame.

The Sody confifts of two Ilrong Cheeks bb, placed perpendicularly, and join'd together by four crofs Pieces or Planks.

The firff Plank c c, call'd the Cap of the Prefs, is fixed, and ferves to keep the two Cheeks together at the due diftance, at top : The fecond d d, call'd the Bead, is moveable ; being fuflain'd by two Iron-Pins or long Bolts, that pafs the Cap : In this Plank is fix'd a Female-Screw or Wcrm, with a brafs Nut, fuflain'd by two port Solts which keep it up : The third Plank ee, call'd the Shelves, ferves to keep Heady a Patt call'd the Hofe, in which the Spindle (to be fpoke of hereafter) is enclofed : The fourth Plank//, call'd the Winter, is moveable 5 it bears the Carriage, and fuflains the Effort of the Prefs beneath, as the Head does above ; each giving way a little, the one upwards, the other downwards, to make the Pull the eafier.

The Spindle gg, is an upright piece of Iron pointed with Steel, of different Dimenfions ; having a Male-Screw which goes into the Female of the Head aboutfour Inches. Thro' the Eyeh, of this Spindle, is rivetted the Bar, by which the Prefs-man works the Prefs.

The lower part of the Spindle paffes thro' the Shelves, being inclofed .n a fquarc wooden Frame i, call'd the Hofe ; and its Pomt works into the Ting, fix'd in a brafs Fan fup- ply d with Oil : which Tan is fix'd, an Iron Plate let into tnetop otite Flatten The Prefs-man, then, by pulling or turning the Bar fix d ,n the Bye by an Iron Key, prtffes upon a fquare fmooth Piece of Wood call'd the Flatten and enables it to comptefs the Form cover'd w,th the Paper, rympans, and its Blankets, which, in order hereto, are brought under the Flatten.

At each Corner of the Hofe, is an Iron- Hook fi.ften'd to thofe at each Comer of the Flatten, with Cords or Pack- thread very exact ly.

The Carriage I II I, which makes the fecond principal Member of the Prefs, is placed a foot below the Flatten, having its fore-part fupported by a wooden Prop m, call'd the Fore-flay, while the other refls on the Winter. On this Carnage, which fullains the Flank, are nail'd two long Iron-Bars or Ribs 0, and on the Flank are nail'd fhort pieces of Iron or Steel pp, call'd Cramp-Irons, equally tempered with tht Ribs, and which Hide upon 'em when the Frefs is turn'd in, or out.

Under the Carriage is fix'd a fmall piece of Iron call'd theSpit, with a double Wheel in the middle, round which Leather Girts are faflen'd, nail'd to each end of the Flank. To the outride of the Spit is fix'd a Handle, or Romcc, by which the Prefs-man turns the Plank in or out at pleafure.

Upon the Plank is a fquare wooden Frame, or Coffin q q, wherein is inclofed a Marble, or poli/h'd Stone, for the Form to be laid on : 'To this Coffin are faflen'd Leather Stay Girts, one on each fide ; which being again falten'd to the Cheeks of the Prefs, prevent the Plank from tunning too far out, when drawn from under the Flatten. On the fore-part of the Flank is a Gallows rr, which fetves to fuffain the Tympans, when taken ftom off the Form.

On the Ftont of the Coffin are three Frames much alike, tho' ferving for different purpofes.Wa. the two Tym- pans and Frisket : The tympans s s, are fquare, made of thtee Slips of very thin Wood, and a-top of a flip of Iron, ftill thinner, call'd a. Head-Band: That call'd theoutward 'Tympan is faflen'd with Iron Joints to the Coffin. They are both covet'd with Parchment; and between the two are placed Blankets, which ferve to make the Impreffion of the Flatten upon the Sutface of the Letters more equable ; as alfo to prevent the Letters from being broke by the Fotce of the Prefs. The Frisket 1 1, is all of Iron, very thin j faften'd i-top to the great or outward Tympan ; and fuflain'd by a flip of Wood hanging from the Cieli.ig, when open'd, to take out the printed Sheets, and put in others. It is alfo covet'd with Parchment, or Paper, cut in the ne- ceffary places, that the Sheet, which is between the great Tympan and Frisket, may receive the Ink, and that nothing may hurt the Matgins. On the Parchment of the great or outward Tympan it is, that the blank Sheet is laid to be printed.

To regulate the Margins, and make the Lines and Pages anfwer each other when printed on the other fide ; in The middle of the Wood in the fides of this Tympan are two Iron Points which make two Holes in the Sheet, to be pla- ced on the fame Pins when the Sheet is return'd for an Impreffion on the other fide, call'd the Reiteration.

Every thing now about the Tympans being prepared for printing, and the Prefs-man having ink'd, or beat his Form now placed on the Stone ; he brings the Tympans and Frif- ket down from the Gallows upon the Form ; and advancing the Flank under the Platten by means of the Spit- Handle, or Rounce, gives two Strokes or Fulls with the Ear ; and with the fame Handle turn'd the contrary way, brings back the Plank, to take out the printed Sheet, and put in a frefh one; and this he repeats till he have taken off the full Number of Sheets the Edition is to confill of.

One fide of the Sheet thus printed, 'tis remanded to the Frefs for the other ; and fo difpofed as that the Iron Points pafs thto' the Holes already made in the Sheer.

Sometimes 'tis required to cut the Frisket a-frefh, where the fecond fide h to be more or lefs full of Trinting than the firft ; as is frequently the cafe at the beginning and end- ing of Books, &c.

The Number of Sheets of the Edition being com- pleat, and the Form to be feparated, to reftore the Letters into the Cafes ; they firff wafh it in a boiling Lye to take out the Remains of the Ink, fcouringit with a Brufh, and then with fair Water. This done, it is carry 'd to a wooden Frame to be unlock'd, and the Furniture, i. e. the Sticks, He. taken off to difengage it from the Chafe. Then the Compofitor taking out feveral Lines at once upon a little wooden Ruler, he replaces each Letter in its proper Box, to be again ufed in the remainder of the Impreffion ■ which laft Operation they call Diftribiitiw.

10 O Bef.de