MECHANICK EXERCISES:
Or, the Doctrine ofHandy-works.Applied to the Art ofPrinting.
THere are two sorts ofPressesin use,viz.the old fashion and the new fashion; The old fashion is generally used here inEngland; but I think for no other reason, than because manyPress-menhave scarce Reason enough to distinguish between an excellently improved Invention, and a make-shift slovenly contrivance, practiced in the minority of this Art.
The New-fashion’dPressesare used generally throughout all theLow-Countries; yet because theOld-fashion’dPressesare used here inEngland(and for no other Reason) I have in Plate 3. given you a delineation of them; But though I give you a draft of them; yet the demensions of every particular Member I shall omit, referring those that think it worth their while, to theJoynersandSmithsthat work toPrinters: But I shall give a full description of the New-fashion’dPress, because it is not well known here inEngland; and if possible, I would for Publick benefit introduce it.
But before I proceed, I think it not amiss to let you know who was the Inventer of this New-fashion’dPress, accounting my self so much oblig’d to his Ingeniety for the curiosity of this contrivance, that should I pass by this oppertunity without nameing him, I should be injurious to his Memory.
It wasWillem Jansen BlaewofAmsterdam: a Man as well famous for good and greatPrinting, as for his manyAstronomicalandGeographicalexhibitions to the World. In his Youth he was bred up toJoynery, and having learn’d his Trade, betook himself (according to the mode ofHolland) to Travel, and his fortune leading him toDenmark, when the nobleTycho Brahewas about setting up hisAstronomical Observatory, was entertain’d into his service for the making his Mathematical-Instruments to Observe withal; in which Instrument-making he shew’d himself so intelligent and curious, that according to the general report of many of his personal acquaintance, all or most of theSyderal Observationsset forth inTycho’sname, he was intrusted to make, as well as the Instruments.
Image: Plate 4.
Plate 4.
And before these Observations were publish’d to the World,Tycho, to gratifyBlaew, gave him the Copies of them, with which he came away toAmsterdam, and betook himself to the making ofGlobes, according to those Observations. But as his Trade increased, he found it necessary to deal inGeographical MapsandBooksalso, and grew so curious inEngraving, that many of his bestGlobesandMapswereEngravedby his own Hands; and by his conversation inPrintingof Books at otherPrinting-houses, got such insight in this Art, that he set up aPrinting-houseof his own. And now finding inconveniencies in the obsolete Invention of thePress, He contrived a remedy to every inconvenience, and fabricated nine of these New-fashionedPresses, set them all on a row in hisPrinting-house, and call’d eachPressby the name of one of theMuses.
This short History of this excellent Man is, I confess forraign to my Title; But I hope my Reader will excuse the digression, considering it tends only to the commemoration of a Person that hath deserved well of Posterity, and whose worth without this small Monument, might else perhaps have slid into Oblivion.
ThePressis a Machine consisting of many Members; it is delineated in Plate 4.
a aTheFeet.b bTheCheeks.cTheCap.dTheWinter.eTheHead.fTheTill.g gTheHose. In the Cross-Iron of which, encompassing theSpindle, is theGarter.h h h hTheHookson theHosethePlattinhangs on.i k l m nTheSpindle.iPart of theWormbelow theHead, whose upper part lies in theNutin theHead.k lTheEyeof theSpindle.mTheShankof theSpindle.nThe Toe of the Spindle.o o o oThePlattintyed on theHooksof theHose.pTheBar.qTheHandleof theBar.r rTheHind-Posts.s sTheHind-Rails.t tTheWedgesof theTill.u uTheMortessesof theCheeks, in which theTennantsof theHeadplays.x x x x y yTheCarriage.x x x xThe outerFrameof theCarriage.y yTheWooden-Ribson which theIron-Ribsare fastned.zTheStayof theCarriage, or theStay.1. TheCoffin.2. TheGutter.3. ThePlanck.4. TheGallows.5. TheTinpans.6. TheFrisket.7. ThePoints.8. ThePoint-Screws.
All these several Members, by their Matter, Form and Position, do particularly contribute such an assistanceto the whole Machine, that it becomes an Engine managable and proper for its intended purpose.
But because the smallness of this altogether-Draft may obscure the plain appearance of many of these Parts; Therefore I shall give you a more particular description, and large delineation of every Member in thePress: And first of the Wooden-work: Where,Note, that all the Fram’d Wooden-work of aPressis made of Good, Fine, Clean, Well-season’dOak.
TheFeet(markeda ain Plate 5.) are two Foot nine Inches and an half long, five Inches deep; and six Inches broad, and have their outsides Tryed to a true square, as was taught,Numb.5. §. 15. It hath (for ornament sake) its two ends bevil’d away in a Molding, from its upper-side to its lower, about four Inches within the ends; about four Inches and three quarters within each end of each Foot is made in the middle of the Breadth of the upper-side of the Foot a Mortess two Inches wide, to receive theTennantsof the lower end of theCheek, and theTennantof the lower end of theHind-Post: The Mortess for theCheekis eight Inches long,viz.the Breadth of theCheek: And the Mortess for the Hind-Post is four Inches long,viz.the square of theHind-Post.
TheCheeks(markedb bin Plate 5.) are five Foot and ten Inches long (besides theTennantsof the topand bottom) eight Inches broad, and four Inches and an half thick. All its Sides are tryed square to one another. It hath aTennantat either end, its lowerTennantmarkedato enter the Fore-end of the Foot, runs through the middle of the Breadth of theCheek, which therefore is made to fit the Mortess in theFoot, and is about four Inches long, and therefore reaches within an Inch of the bottom of theFoot; But theTennantat the upper end of theCheekmarkeda, is cut athwart the breadth of theCheek, and therefore can have but four Inches and an half of Breadth, and its thickness is two Inches, Its length is four Inches; so that it reaches into the Mortess in theCap, within half an Inch of the Top.
In the lower end-Tennantis two holes bored, within an Inch and an half of either side, and within an Inch and an half of the Sholder, with a three quarter InchAugure, to be pin’d into theFeetwith an Iron Pin.
In the middle of the upperTennant, and within an Inch and an half of the Sholder, is bored another hole, to Pin theTennantinto theCap, also with an Iron Pin.
Betweenb ctwo Foot and half an Inch, and three Foot seven Inches of the Bottom-Sholder of theTennant,viz.from the top of theWinterto the under Sholder theTillrests upon, is cut flat away into the thickness of theCheek, three Inches in the Inside of theCheek; so that in that place theCheekremains but an Inch and an half thick: And theCheeksare thus widened in this place, as well because the DuftailTennantsof theWintermay go in between them, as alsothat theCarriageandCoffinmay be made the wider.
Even with the lower Sholder of this flat cutting-in, is made a Duftail Mortess as atd, to reach eight Inches and an half,viz.the depth of theWinterbelow the said Sholder. This Mortess is three Inches wide on the inside theCheek, and three Inches deep; But towards the inside theCheek, the Mortess widens in a straight line from the said three Inches to five Inches, and so becomes a Duftail Mortess. Into this Duftail Mortess is fitted a DuftailTennant, made at each end of theWinter.
Two Inches above the aforesaid Cutting-in, is another cutting-in of the same depth, from the Inside theCheekas ate. This cutting-in is but one Inch broad at the farther side theCheek, and an Inch and a quarter on the hither-side theCheek. The under-side of this Cutting-in, is straight through theCheek,viz.Square to the sides of theCheek: But the upper-side of this Cutting-in, is not square through theCheeks, But (as aforesaid) is one quarter of an Inch higher on the fore-side theCheekthan it is on the further side; So that a Wedge of an Inch at one end, and an Inch and a quarter at the other end may fill this Cutting-in.
At an Inch within either side theCheek, and an Inch below this Cutting-in, as atf f, is made a small Mortess an Inch and an half wide, to which twoTennantsmust be fitted at the ends of theTill, so that theTennantsof theTillbeing slid in through the Cutting-in aforesaid, may fall into these Mortesses, and a Wedge being made fit to the Cutting-in, may press upon theTennantsof theTill, and force it down to keep it steddy in its place.
Here we see remains a square Sholder or substance of Wood between two Cuttings-in; But the under corner of this square Sholder is for Ornament sake Bevil’d away and wrought into anOgee.
At two Inches above the last Cutting-in, is another Cutting-in, but this Cutting-in goes not quite through the breadth of theCheek, but stops at an Inch and an half within the further side theCheek; So that above theTilland itsWedgeis another Sholder or substance of Wood, whose upper Corner is also Bevil’d away, and wrought to a Molding as the former.
The last Cutting-in is markedg, and is eight Inches and a quarter above the Sholder of theTill, that it may easily contain the depth of theHead; The substance remaining is markedh. This Cutting-in is made as deep into the thickness of theCheekas the former Cuttings-in are,viz.three Inches; and the reason theCheekis cut in here, is, that theCheeksmay be wide enough in this place to receive theHead, and itsTennants, without un-doing theCapandWinter.
Just above this Cutting-in is made a square Mortess in the middle of theCheek, as ati, it is eight Inches long, and two Inches and an half wide, for theTennantof theHeadto play in.
Image: Plate 5.
Plate 5.
Upon the fore-side of theCheekis (for Ornament sake) laid a Molding through the whole length of theCheek(a square at the Top and Bottom an Inch deep excepted) it is laid on the outer side, and therefore can be but an Inch broad; Because the Cuttings-in on the inside leaves the substance of Stuff but anInch and an half thick, and should the Moldings be made broader, it would be interrupted in the several Cuttings in, or else a square of a quarter of an Inch on either side the Molding could not be allowed, which would be ungraceful.
TheCapis three Foot and one Inch long, four Inches and an half deep, and nine Inches and an half broad; But its fore-side is cut away underneath to eight Inches,Viz.the breadth of theCheeks. Three quarters of an Inch above the bottom of theCap, is a smallFacia, which stands even with the thickness of theCheeks; Half an Inch above that a Bead-Molding, projecting half an Inch over theFacia. Two Inches above that a broadFacia, also even with the thickness of theCheeks; and an Inch and a quarter above that is the upper Molding made projecting an Inch and an half over the twoFacia’s aforesaid, and the thickness of theCheeks.
Each end of theCapprojects three Inches quarter and half quarter over theCheeks, partly for Ornament, but more especially that substance may be left on either end beyond the Mortesses in the Cap; and these two ends have the same Molding laid on them that the fore-side of theCaphath.
Within two Inches and half quarter of either end, on the under-side theCapis made a square Mortess two Inches wide, and four Inches and an half long,viz.the thickness of theCheekinwards, as ata a, to receive the TopTennantsof theCheeks; which TopTennantsare with an Iron Pin (made tapering of about three quarters of an Inch thick) pin’d into the Mortess of theCap, to keep theCheekssteddy in their position.
The Length of theWinterbesides theTennants, is one Foot nine Inches and one quarter of an Inch; The Breadth of theWintereight Inches,viz.the Breadth of theCheek, and its depth nine Inches; all its sides are tryed square; But its two ends hath each a Duftail-Tennantmade through the whole depth of theWinter, to fit and fall into the Duftail Mortesses made in theCheeks: These Duftail-Tennantsare intended to do the Office of aSummer, Because the spreading of the ends of these twoTennantsinto the spreading of the Mortesses in theCheeks, keeps the twoCheeksin a due distance, and hinders them from flying assunder.
But yet I think it very convenient to have aSummeralso, the more firmly and surer to keep theCheekstogether; ThisSummeris only a RailTennanted, and let into Mortesses made in the inside of theCheeks, and Screwed to them as the Rails described,Numb.15. §. 4. are Screwed into the Stiles of theCase-Frame; Its depth four Inches and an half, and its breadth eight Inches,viz.the breadth of theCheeks.
The length of theHeadbesides theTennantat either end, is one Foot nine Inches and one quarter of an Inch; The breadth eight Inches and an half, and its depth eight Inches. The Top, Bottom and Hind-sides are tryed Square, but the fore-side projects half an Inch over the Range of the fore-sides of theCheeks; in which Projecture is cut a Table with a hollow Molding about it, two Inches distant from all the sides of the fore-side of theHead: ItsTennantsare three Inches Broad, and are cut down at either end, from the top to the bottom of theHead, and made fit to the Mortesses in theCheeks, that they may slide tight, and yet play in them.
In the under-side of theHeadis cut a square Hole, (as ata,) about four Inches square, and three Inches and an half deep, into which theBrass-Nutis to be fitted: And to keep thisNutin its place (lest the weight of it should make it fall out) is made on either side the square hole, at about half an Inch distance from it, (as atb b) a square Hole quite through the Top and Bottom of theHeadabout three quarters of an Inch wide; and into this square Hole is fitted a square piece of Iron to reach quite through theHead, having at its under-end a Hook turned square to claspe upon the under-side of theNut; and on its upper end a Male-Screw reaching about an Inch above the upper-side of theHead, which by the help of a Female-screw made in an IronNut, with Ears to it to turn it about draws theClaspat the bottom of the IronShankclose against theNut, and so keeps it from falling out.
In the middle of the wide square Hole that theNutis let into, is bored a round Hole through the top of theHead, of about three quarters of an Inch wide, for thePress-manto pourOylin at so oft as theNutandSpindleshall wantOyling.
At three Inches from either end of theHead(as atc c) is bored a Hole quite through the top and bottom of theHead, which holes have their under ends squar’d about two Inches upwards, and these squares are made so wide as to receive a square Bar of Iron three quarters of an Inch square; But the other part of these Holes remain round: Into these Holes two Irons are fitted called theScrews.
The Shanks of theseScrewsare made so long as to reach through theHeadand through theCap: At the upper end of these Shanks is made Male-screws, and to these Male-screws, Iron Female-screws are fitted with two Ears to twist them the easier about.
So much of these Iron-Shanks as are to lye in the square Hole of theHeadaforesaid, are also squared to fit those square Holes, that when they are fitted and put into the Holes in theHead; they may not twist about.
To the lower ends of these Iron-Shanks are made two Square, Flat Heads, which are let into and buried in the under-side of theHead; And upon the Sholders of those two Flat Heads, rests the weight of theHeadof thePress; And by theScrewsat the upper end of the Shanks are hung upon the upper-side of theCap, and Screwed up or let down as occasion requires.
Image: Plate 6.
Plate 6.
TheTillis a Board about one Inch thick, and is as theHeadandWinter, one Foot nine Inches and a quarter long, besides theTennantsat either end; Its Breadth is the Breadth of theCheeks,viz.eight Inches; It hath twoTennantsat either end as ata a a a, each of them about an Inch and an half long, and an Inch and an half broad, and are made at an Inch distance from the fore and Back-side, so that a space of two Inches is contained in the middle of the ends between the twoTennants; theseTennantsare to be laid in the Mortesses in theCheeksdelineated atf fin Plate 5. and described in this §. 10. ¶. 2.
In its middle it hath a round Hole about two Inches and an half wide, as atb, for the Shank of theSpindleto pass through.
At seven Inches and a quarter from either end, and in the middle between the fore and Back-side, is made two square Holes through theTill, as atc c, for the IronHoseto pass through.
At one Foot distance from the Hind-sides of theCheeksare placed upright twoHind-Posts, they are three Foot and four Inches long besides theTennants, whichTennantsare to be placed in the Mortesses in the hinder-ends of theFeet; Their thickness is four Inches on every side, and every side is tryed square;But within eight Inches of the top is turned a round Ball with a Button on it, and a Neck under it, and under that Neck a straight Plinth or Base: This turn’d work on the top is only for Ornament sake.
There are sixRailsfitted into theseHind-Posts, two behind markeda b, one of them standing with its upper-side at two Inches below the turned Work, the other having its upper-side lying level with the upper-side of theWinter.
These twoRailsare each of themTennantedat either end, and are made so long, that the outsides of theHind-Postsmay stand Range or even with the outer-sides of theCheeks; TheseTennantsat either end are let into Mortesses made in the insides of theHind-Posts, and Pin’d up with half Inch wooden Pins, Glewed in, as was shewn Vol. 1.Numb.5. §. 17. Because the twoHind-Postsneed not be separated for any alteration of thePress.
The twoSide-Railson either side thePressareTennantedat each end, and let into Mortesses made in theCheeksandHind-Posts, so as they may stand Range with the outer-sides of theCheeksandHind-Posts; But theTennantsthat enter the Mortesses in theCheeksare not pin’d in with Wooden Pins, and Glewed, because they may be taken assunder if need be; But are Pin’d in with Iron Pins, made a little tapering towards the entring end, so as they may be driven back when occasion serves to alter thePress: And theTennantsthat enter the Mortesses in theHind-Postsare fastned in by a Female-screw, let in near the end of theRail, which receives a Male-screw thrust through theHind-Posts, even as I shew’d in
TheRibslye within a Frame of four Foot five Inches long, one Foot eleven Inches broad; its twoEnd-Railsone Inch and an half thick, itsSide-Railstwo Inches and an half thick; and the breadth of theSideandEnd-Railstwo Inches and an half. But theSide-Railsare cut away in the inside an Inch and an half towards the outer-sides of theRails, and an Inch deep towards the Bottom sides of theRails, so that a squareCheekon eitherSide-Railremains. This cutting down of theOuter-Railsof theFrameis made, because the Planck of theCarriagebeing but one Foot eight Inches and an half broad, may easily slide, and yet be gaged between theseCheeksof theRail, that theCramp-IronsNailed under theCarriage Planckjoggle not on either side off theRibs, as shall more fully be shewn in the next §.
Between the twoSide-Railsare framed into the twoEnd-Railsthe twoWooden-Ribstwo Inches and an half broad, and an Inch and an half thick; they are placed each at an equal distance from eachSide-Rail, and also at the same distance between themselves. Upon these twoRibsare fast Nailed down theIron-Ribs, of which more shall be said when I come to speak of the Iron-work.
ThePlanckof theCarriageis an Elm-Planck an Inch and an half thick, four Foot long, and one Foot eight Inches and three quarters broad; upon thisPlanckat its fore-end is firmly Nailed down a square Frame two Foot four Inches long, one Foot ten Inches broad, and the thickness of its Sides two Inches and an half square; This Frame is called theCoffin, and in it theStoneisBedded.
Upon each of the four Corners of thisCoffinis let in and fastned down a square Iron Plate as ata a a a, with Return Sides about six Inches long each side, half a quarter of an Inch thick, and two Inches and a quarter broad; upon the upper outer-sides of each of these Plates is fastned down to them with two or three Rivets through each side, another strong Iron half an Inch deep, and whose outer Angles only are square, but the Inner-Angles are obtuse, as being sloped away from the Inner-Angle towards the farther end of each inner-side, so as theQuoinsmay do the Office of a Wedge between each inner-side and theChase.
Image: Plate 7.
Plate 7.
The Plates of these Corners (as I said) are let in on the outer Angles of the upper-side of the Frame of theCoffin, so as the upper-sides of the Plates lye even with it, and are Nailed down, or indeed rather Rivetted down through the bottom and top-sides of the Frame of theCoffin, because then the upper-sides of the Holes in the Iron Plates being squareBored (that is, made wider on the upper-side of the Plate, as I shall shew when I come to the making ofMathematical Instruments) the ends of the Shanks of the Iron Pins may be so battered into the Square-boring, that the whole Superficies of the Plate when thus Rivetted shall be smooth, which else with the exturberancies of Nail-heads would hinder the free sliding of theQuoins.
At the hinder end of the Frame of theCoffinare fastned either with strong Nails, Rivets, or rather Screws, two IronHalf-Joynts, as atb b, which having an Iron Pin of almost half an Inch over put through them, and twoMatch-half-Joyntsfastned on the Frame of theTympan, these twoMatch-half-Joyntsmoving upon the Iron Pin aforesaid, as on anAxis, keeps theTinpanso truly gaged, that it always falls down upon theFormin the place, and so keepsRegistergood, as shall further be shewed in proper place.
Behind theCoffinis Nailed on to its outside, a Quarter, as atc cthis Quarter is about three Inches longer than the breadth of theCoffin, it hath all its sides two Inches over, and three of them square; but its upper-side is hollowed round to a Groove or Gutter an Inch and an half over. This Gutter is so Nailed on, that its hither end standing about an Inch higher than its further end, the Water that descends from theTympanfalling into it is carried away on the farther side theCoffinby the declivity of the farther end of the Gutter, and so keeps the Planck of theCarriageneat and cleanly, and preserves it from rotting.
Parallel to the outer-sides of the hind part of the Planck of theCarriage, at three Inches distance from either side, is Nailed down on the upper-side of the Planck two Female-Duftail Grooves, into which is fitted (so as they may slide) two Male-Duftails made on the two Feet of theGallows(as atd d) that theTinpanrests upon; and by the sliding forward or backward of these Duftail Feet, the heighth of theTinpanis raised or depressed according to the Reason or Fancy of thePress-man.
At three Inches from the hinder Rail of theCoffin, in the middle, between both sides of the Planck, is cut an Hole four Inches square (as ate e) and upon the hither and farther side of this Hole is fastned down on each side aStudmade of Wood (as atf f) and in the middle of these twoStudsis made a round Hole about half an Inch over, to receive the two round ends of an Iron Pin; which Iron Pin, though its ends be round, is through the middle of the Shank square, and upon that square is fitted a roundWooden-RowlerorBarrel, with a Shoulder on either side it, to contain so much of theGirtas shall be rowled upon it; And to one end of theRowleris fastned an IronCircleorWheel, having on its edgeTeethcut to stop against aClicker, when theRowlerwith an Iron Pin is turned about to strain theGirt.
TheTympanis a square Frame, three sides whereof are Wood, and the fourth Iron. Its width is oneFoot eight Inches, its length two Foot two Inches; the breadth of the wooden Sides an Inch and an half, and the depth one Inch.
On its short Wooden-side,viz.its Hind-end, at the two Corners is Rivetted an IronMatch-Joynt, to be pinned on to anotherHalf-joyntfastned on theHind-Railof theCoffin.
The other end,viz.the Fore-end of theTympanis made of Iron, with a squareSocketat either end for the Wooden ends of theTympanto fit and fasten into. This Iron is somewhat thinner and narrower than an ordinary Window-Casement.
Upon the outer edge of this Iron, about an Inch and an half off the ends of it, is made two IronHalf-joyntsto contain a Pin of about a quarter of an Inch over, which Pin entring thishalf-joynt, and amatch Half-joyntmade upon theFrisket, serves for theFrisketto move truly upon.
In the middle of each longRailof theTympan, is made through the top and bottom an Hole half an Inch square, for the square Shanks of thePoint-Screwsto fit into.
The like Holes are also made in theTympan, at one third part of its length from the Fore-end orFrisket-joynt, to place thePoint Screwsin; when aTwelves,Eighteens, &c. is wrought.
Into the Inner-side of thisTympanis fitted theInner-Tympan, whose three sides are also made of Wood, and its fourth side of Iron, as theTympan, but withoutjoynts; it is made so much shorter than theOuter-Tympan, that the outer edge of the Iron of theInner-Tympanmay lye within the inner edge of the Iron on theOuter-Tympan;and it is made so much narrower than the inside of theTympan, that a convenient room may be allowed to paste aVellombetween the inside of theTympan, and the outside of theInner-Tympan.
About the middle, through the hither-side of theInner-Tympan, is let in and fastned an Iron Pin about a quarter of an Inch over, and stands out three quarters of an Inch upon the hither outside of theInner-Tympan, which three quarters of an Inch Pin fits into a round hole made in the inner-side of theTympan, to gage and fit theInner-Tympanright into theTympan; for then by the help of an Iron turningClaspon the further side theTympan, theInner-Tympanis kept firmly down and in its position.
To theRailbetween the hitherCheekandHind-Postis fastned theInck-Block, which is a Beechen-board about thirteen Inches long, nine Inches broad, and commonly about two Inches thick, and hath the left-hand outer corner of it cut away; it is Railed in on its farther and hinder-sides, and a little above half the hither-side, with Wainscot-Board about three quarters of an Inch thick, and two Inches and an half above the upper-side the board of theInck-Block. It is described in Plate 7. at c.
TheBrayermarkedais made ofBeech: It is turned round on the sides, and flat on the bottom, its lengthis about three Inches, and its diameter about two Inches and an half; it hath an Handle to it about four Inches long. Its Office is to rub and mingle theInckon theInck-Blockwell together.
TheSliceis a little thin IronShovelabout three or four Inches broad, and five Inches long; it hath an Handle to it of about seven Inches long. Near theShovelthrough the Handle is fitted a small Iron of about two Inches long standing Perpendicular to both the sides of the Handle, and is about the thickness of a small Curtain-Rod. It is described at e.
TheCatchof theBardescribed at f is a piece of Wood two Inches thick, four Inches broad, and ten Inches long; The top of it is a little Bevil’d or Slop’d off, that theBarmay by itsSpringfly up the Bevil till it stick. This Bevil projects three Inches over its straight Shank, which reaches down to the bottom; in the middle of this Shank, through the fore and back-side, is a Mortess made from within an Inch of the Rounding to an Inch and an half of the bottom; This Mortess is three quarters of an Inch wide, and hath an Iron Pin with a Shoulder at one end fitted to it, so as it may slide from one end of the Mortess to the other. At the other end of the Iron Pin is made a Male-Screw which enters into a Female Iron Screw let into the furtherCheekof thePress; so that theCatchmay be Screwed close to theCheek, as shall further be spoken to hereafter.
From the Top to theToeof theSpindle,viz.fromatobis sixteen Inches and a half, the length of the Cilinder theWormsare cut upon is three Inches and a quarter, and the diameter of that Cilinder two Inches and a quarter; between the bottom of theWormsand top of the Cube one Inch and an half; the Cube markedc c c cis two Inches and three quarters, the squareEyeatdin the middle of the Cube is an Inch and a quarter through all the sides of the Cube; one Inch under the Cube ateis theNeckof theSpindle, whose diameter is two Inches, It is one Inch between the two shoulders,viz.the upper and under shoulders of theNeckate e, so that the Cilinder of theNeckis one Inch long; the very bottom of theSpindleatbis called theToe, it is made of an Hemispherical form, and about one Inch in diameter; ThisToeshould be made ofSteel, and well Temper’d, that by long or careless usage, the point of pressure wear not towards one side of theToe, but may remain in the Axis of theSpindle.
Image: Plate 8.
Plate 8.
I promised at the latter end ofNumb.2. to give a more copious account than there I did of makingWorms, when I came to exercise uponPrinting-Press Spindles; and being now arrived to it, I shall here make good my promise.
The assigned progress may be various, and yet theSpindledo its office: For if theCheeksof thePressstand wide assunder, the sweep or progress of the sameBarwill be greater than if they stand nearer together.
It is confirm’d upon good consideration and Reason as well as constant experience, that in a whole Revolution of theSpindle, in theNut, theToedoes and ought to come down two Inches and an half; but theSpindlein work seldom makes above one quarter of a Revolution at onePull, in which sweep it comes down but half an Inch and half a quarter of an Inch; and the reason to be given for this coming down, is the squeezing of the several parts in thePress, subject to squeeze between the Mortesses of theWinterand the Mortesses theHeadworks in; and every Joynt between these are subject to squeeze by the force of aPull. As first, TheWintermay squeeze down into its Mortess one third part of the thickness of aScabbord. (Allowing aScabbordto be half aNomparelthick.) Secondly, TheRibssqueeze closer totheWinteroneScabbord. Thirdly, TheIron-Ribsto the WoodenRibsoneScabbord. Fourthly, TheCramp-Ironsto thePlanckof theCoffinoneScabbord. Fifthly, ThePlanckit self half aScabbord. Sixthly, TheStoneto thePlanckoneScabbord. Seventhly, TheFormto theStonehalf aScabbord. Eighthly, TheJustifyersin the Mortess of theHeadthreeScabbords. Ninthly, TheNutin theHeadoneScabbord. Tenthly, ThePaper,TympansandBlanketstwoScabbords. Eleventhly, Play for the Irons of theTympansfourScabbords. Altogether make fifteenScabbordsand one third part of aScabbordthick, which (as aforesaid) by allowing twoScabbordsto make aNomparel, and as I shewed inVol.2.Numb.2. §. 2. One hundred and fiftyNomparelsto make one Foot, gives twelve and an halfNomparelsfor an Inch, and consequently twenty fiveScabbordsfor an Inch; so by proportion, fifteenScabbordsand one third part of aScabbord, gives five eighth parts of an Inch, and a very small matter more, which is just so much as theToeof theSpindlecomes down in a quarter of a Revolution.
This is the Reason that the coming down of theToeought to be just thus much; for should it be less, the natural Spring that all these Joynts have, when they are unsqueez’d, would mount the Irons of theTympansso high, that it would be troublesom and tedious for thePress-mantoRunthem under thePlattin, unless theCheeksstood wider assunder, and consequently every sweep of theBarin aPullexceed a quarter of a Revolution, which would be both laborious for thePress-man, and would hinder his usual riddance of Work.
I shew’d inNumb.2.fol.31, 32, 33, 34, 35. the manner of making a Screw in general; but assigned it no particular Rise; which for the aforesaid reason, thesePrinting-Press Screwsare strictly bound to have: Therefore its assigned Rise being two Inches and an half in a Revolution, This measure must be set off upon the Cilindrick Shank, from the top towards the Cube of theSpindle, on any part of theCilinder, and there make a small mark with a finePrick-Punch, and in an exact Perpendicular to this mark make another small mark on the top of the Cilinder, and laying a straightRuleron these two marks, draw a straight line through them, and continue that line almost as low as the Cube of theSpindle. Then devide that portion of the straight line contained between the two marks into eight equal parts, and set off those equal parts from the two Inch and half mark upwards, and then downwards in the line so oft as you can: Devide also the Circumference of the Shank of the Cilinder into eight equal parts, and draw straight lines through each devision, parallel to the first upright line; and describe theScrewas you were directed in the afore-quoted place; so will you find that the revolution of every line so carried on about the Shank of the Cilinder, will be just two Inches and an half off the top of the Shank: which measure and manner of working may be continued downward to within an Inch and an half of the Cube of theSpindle. This is the Rule and Measure that ought to be observ’d for ordinaryPresses: But if for some by-reasons the aforesaid Measure of two Inches and an half must be varied, then the varied Measuremust be set off from the top of the Cilinder, and working with that varied Measure as hath been directed, theToeof theSpindlewill come down lower in a revolution if the varied Measure be longer, or not so low if the varied Measure be shorter.
There is a Notion vulgarly accepted among Workmen, that theSpindlewill Rise more or less for the number ofWormswinding about the Cilinder; for they think, or at least by tradition are taught to say, that aThree-Worm’d Spindlecomes faster and lower down than afour-Worm’d Spindle: But the opinion is false; for if aSpindlewere made but with aSingle-Worm, and should have this Measure,viz.Two Inches and an half set off from the top, and aWormcut to make a Revolution to this Measure, it would come down just as fast, and as low, as if there were two, three, four, five or sixWorms, &c. cut in the same Measure: For indeed, the numbers ofWormsare only made to preserve theWormsof theSpindleandNutfrom wearing each other out the faster; for if the whole stress of aPullshould bear against the Sholder of a singleWorm, it would wear and shake in theNutsooner by half than if the stress should be borne by the Sholders of twoWorms; and so proportionably for three, four, fiveWorms,&c.
But the reason why fourWormsare generally made upon theSpindle, is because the Diameters of theSpindleare generally of this propos’d size; and therefore a convenient strength of Mettal may be had on this size for fourWorms; But should the Diameter of theSpindlebe smaller, as they sometimes are when thePressis designed for small Work, only threeWormswill be a properer number than four; because when the Diameter is small, the thickness of theWormswould also prove small, and by the stress of aPullwould be more subject to break or tear theWormseither of theSpindleorNut.
And thus I hope I have performed the promise here I made at the latter end ofNumb.2. Whither I refer you for the breadth, and reason of the breadth of theWorm.