ends of it, is made two Iron _Half-joynts_ to contain a Pin of about
a quarter of an Inch over, which Pin entring this _half-joynt_, and a
_match Half-joynt_ made upon the _Frisket_, serves for the _Frisket_ to
move truly upon.
In the middle of each long _Rail_ of the _Tympan_, is made through the
top and bottom an Hole half an Inch square, for the square Shanks of
the _Point-Screws_ to fit into.
The like Holes are also made in the _Tympan_, at one third part of
its length from the Fore-end or _Frisket-joynt_, to place the _Point
Screws_ in; when a _Twelves_, _Eighteens_, &c. is wrought.
Into the Inner-side of this _Tympan_ is fitted the _Inner-Tympan_,
whose three sides are also made of Wood, and its fourth side of
Iron, as the _Tympan_, but without _joynts_; it is made so much
shorter than the _Outer-Tympan_, that the outer edge of the Iron of
the _Inner-Tympan_ may lye within the inner edge of the Iron on the
_Outer-Tympan_; and it is made so much narrower than the inside
of the _Tympan_, that a convenient room may be allowed to paste a
_Vellom_ between the inside of the _Tympan_, and the outside of the
_Inner-Tympan_.
About the middle, through the hither-side of the _Inner-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 the
_Inner-Tympan_, which three quarters of an Inch Pin fits into a round
hole made in the inner-side of the _Tympan_, to gage and fit the
_Inner-Tympan_ right into the _Tympan_; for then by the help of an Iron
turning _Clasp_ on the further side the _Tympan_, the _Inner-Tympan_ is
kept firmly down and in its position.
¶. 11. _Of the_ Inck-Block, Slice, Brayer, _and_ Catch _of the_ Bar,
_marked_ c d e f _in_ Plate 7.
To the _Rail_ between the hither _Cheek_ and _Hind-Post_ is fastned
the _Inck-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 the _Inck-Block_. It is
described in Plate 7. at c.
The _Brayer_ marked _a_ is made of _Beech_: It is turned round on the
sides, and flat on the bottom, its length is 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 the _Inck_ on
the _Inck-Block_ well together.
The _Slice_ is a little thin Iron _Shovel_ about three or four Inches
broad, and five Inches long; it hath an Handle to it of about seven
Inches long. Near the _Shovel_ through 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.
The _Catch_ of the _Bar_ described 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 the _Bar_ may by its _Spring_ fly
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 further _Cheek_ of
the _Press_; so that the _Catch_ may be Screwed close to the _Cheek_,
as shall further be spoken to hereafter.
¶. 12. _Of the Iron-work, and first of the_ Spindle _marked_ A _in
Plate_ 8.
From the Top to the _Toe_ of the _Spindle_, _viz._ from _a_ to _b_
is sixteen Inches and a half, the length of the Cilinder the _Worms_
are cut upon is three Inches and a quarter, and the diameter of that
Cilinder two Inches and a quarter; between the bottom of the _Worms_
and top of the Cube one Inch and an half; the Cube marked _c c c c_ is
two Inches and three quarters, the square _Eye_ at _d_ in the middle of
the Cube is an Inch and a quarter through all the sides of the Cube;
one Inch under the Cube at _e_ is the _Neck_ of the _Spindle_, whose
diameter is two Inches, It is one Inch between the two shoulders,
_viz._ the upper and under shoulders of the _Neck_ at _e e_, so that
the Cilinder of the _Neck_ is one Inch long; the very bottom of the
_Spindle_ at _b_ is called the _Toe_, it is made of an Hemispherical
form, and about one Inch in diameter; This _Toe_ should be made of
_Steel_, and well Temper’d, that by long or careless usage, the point
of pressure wear not towards one side of the _Toe_, but may remain in
the Axis of the _Spindle_.
[Illustration: _Plate 8._]
§. 11. _Of the_ Worms _of the_ Spindle.
I promised at the latter end of _Numb._ 2. to give a more copious
account than there I did of making _Worms_, when I came to exercise
upon _Printing-Press Spindles_; and being now arrived to it, I shall
here make good my promise.
¶. 1. The _Worms_ for _Printing-Press Spindles_ must be projected with
such a declivity, as that they may come down at an assigned progress of
the _Bar_.
The assigned progress may be various, and yet the _Spindle_ do its
office: For if the _Cheeks_ of the _Press_ stand wide assunder, the
sweep or progress of the same _Bar_ will 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 the _Spindle_, in the _Nut_,
the _Toe_ does and ought to come down two Inches and an half; but the
_Spindle_ in work seldom makes above one quarter of a Revolution at
one _Pull_, 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 the _Press_, subject to squeeze
between the Mortesses of the _Winter_ and the Mortesses the _Head_
works in; and every Joynt between these are subject to squeeze by the
force of a _Pull_. As first, The _Winter_ may squeeze down into its
Mortess one third part of the thickness of a _Scabbord_. (Allowing a
_Scabbord_ to be half a _Nomparel_ thick.) Secondly, The _Ribs_ squeeze
closer to the _Winter_ one _Scabbord_. Thirdly, The _Iron-Ribs_ to
the Wooden _Ribs_ one _Scabbord_. Fourthly, The _Cramp-Irons_ to the
_Planck_ of the _Coffin_ one _Scabbord_. Fifthly, The _Planck_ it self
half a _Scabbord_. Sixthly, The _Stone_ to the _Planck_ one _Scabbord_.
Seventhly, The _Form_ to the _Stone_ half a _Scabbord_. Eighthly, The
_Justifyers_ in the Mortess of the _Head_ three _Scabbords_. Ninthly,
The _Nut_ in the _Head_ one _Scabbord_. Tenthly, The _Paper_, _Tympans_
and _Blankets_ two _Scabbords_. Eleventhly, Play for the Irons of the
_Tympans_ four _Scabbords_. Altogether make fifteen _Scabbords_ and one
third part of a _Scabbord_ thick, which (as aforesaid) by allowing two
_Scabbords_ to make a _Nomparel_, and as I shewed in _Vol._ 2. _Numb._
2. §. 2. One hundred and fifty _Nomparels_ to make one Foot, gives
twelve and an half _Nomparels_ for an Inch, and consequently twenty
five _Scabbords_ for an Inch; so by proportion, fifteen _Scabbords_ and
one third part of a _Scabbord_, gives five eighth parts of an Inch, and
a very small matter more, which is just so much as the _Toe_ of the
_Spindle_ comes down in a quarter of a Revolution.
This is the Reason that the coming down of the _Toe_ ought 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 the
_Tympans_ so high, that it would be troublesom and tedious for the
_Press-man_ to _Run_ them under the _Plattin_, unless the _Cheeks_
stood wider assunder, and consequently every sweep of the _Bar_ in a
_Pull_ exceed a quarter of a Revolution, which would be both laborious
for the _Press-man_, and would hinder his usual riddance of Work.
I shew’d in _Numb._ 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, these _Printing-Press Screws_ are 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 the _Spindle_, on any part of the
_Cilinder_, and there make a small mark with a fine _Prick-Punch_, and
in an exact Perpendicular to this mark make another small mark on the
top of the Cilinder, and laying a straight _Ruler_ on these two marks,
draw a straight line through them, and continue that line almost as low
as the Cube of the _Spindle_. 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 the _Screw_ as 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 the _Spindle_.
This is the Rule and Measure that ought to be observ’d for ordinary
_Presses_: But if for some by-reasons the aforesaid Measure of two
Inches and an half must be varied, then the varied Measure must be set
off from the top of the Cilinder, and working with that varied Measure
as hath been directed, the _Toe_ of the _Spindle_ will 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 the _Spindle_
will Rise more or less for the number of _Worms_ winding about the
Cilinder; for they think, or at least by tradition are taught to say,
that a _Three-Worm’d Spindle_ comes faster and lower down than a
_four-Worm’d Spindle_: But the opinion is false; for if a _Spindle_
were made but with a _Single-Worm_, and should have this Measure,
_viz._ Two Inches and an half set off from the top, and a _Worm_ cut 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 six _Worms_, &c. cut
in the same Measure: For indeed, the numbers of _Worms_ are only made
to preserve the _Worms_ of the _Spindle_ and _Nut_ from wearing each
other out the faster; for if the whole stress of a _Pull_ should bear
against the Sholder of a single _Worm_, it would wear and shake in the
_Nut_ sooner by half than if the stress should be borne by the Sholders
of two _Worms_; and so proportionably for three, four, five _Worms_,
_&c._
But the reason why four _Worms_ are generally made upon the _Spindle_,
is because the Diameters of the _Spindle_ are generally of this
propos’d size; and therefore a convenient strength of Mettal may be had
on this size for four _Worms_; But should the Diameter of the _Spindle_
be smaller, as they sometimes are when the _Press_ is designed for
small Work, only three _Worms_ will be a properer number than four;
because when the Diameter is small, the thickness of the _Worms_ would
also prove small, and by the stress of a _Pull_ would be more subject
to break or tear the _Worms_ either of the _Spindle_ or _Nut_.
And thus I hope I have performed the promise here I made at the latter
end of _Numb._ 2. Whither I refer you for the breadth, and reason of
the breadth of the _Worm_.
¶. 13. _Of the_ Bar _marked_ B _in_ Plate 8.
This _Bar_ is Iron, containing in length about two Foot eight Inches
and an half, from _a_ to _b_, and its greatest thickness, except the
Sholder, an Inch and a quarter; The end _a_ hath a Male-Screw about an
Inch Diameter and an Inch long, to which a _Nut_ with a Female-Screw
in it as at C is fitted. The Iron _Nut_ in which this Female-Screw is
made, must be very strong, _viz._ at least an Inch thick, and an Inch
and three quarters in Diameter; in two opposite sides of it is made
two Ears, which must also be very strong, because they must with heavy
blows be knock’t upon to draw the Sholder of the square shank on the
_Bar_, when the square Pin is in the _Eye_ of the _Spindle_ close and
steddy up to the Cube on the _Spindle_. The square Pin of the _Bar_
marked _c_ is made to fit just into the _Eye_, through the middle of
the Cube of the _Spindle_, on the hither end of this square Pin is made
a Sholder or stop to this square Pin, as at _d_. This Sholder must be
Filed exactly Flat on all its four insides, that they may be drawn
close and tight up to any flat side of the Cube on the _Spindle_; It
is two Inches square, that it may be drawn the firmer, and stop the
steddyer against any of the flat sides of the said Cube, when it is
hard drawn by the strength of the Female-Screw in the aforesaid _Nut_
at C. The thickness from _d_ to _e_ of this Sholder is about three
quarters of an Inch, and is Bevil’d off towards the _Handle_ of the
_Bar_ with a small Molding.
The substance of this _Bar_, as aforesaid, is about an Inch and a
quarter; but its Corners are all the way slatted down till within five
Inches of the end: And from these five Inches to the end, it is taper’d
away, that the _Wooden-Handle_ may be the stronger forced and fastned
upon it.
About four Inches off the Sholder, the _Bar_ is bowed beyond a right
Angle, yet not with an Angle, but a Bow, which therefore lies ready
to the _Press-man_’s Hand, that he may Catch at it to draw the
_Wooden-Handle_ of the _Bar_ within his reach.
This _Wooden-Handle_ with long Working grows oft loose; but then it
is with hard blows on the end of it forced on again, which oft splits
the _Wooden-Handle_ and loosens the square Pin at the other end of the
_Bar_, in the _Eye_ of the _Spindle_: To remedy which inconvenience, I
used this Help, _viz._ To weld a piece of a Curtain-Rod as long as the
_Wooden-Handle_ of the _Bar_, to the end of the Iron _Bar_, and made a
Male-screw at the other end with a Female-screw to fit it; Then I bored
an hole quite through the _Wooden-Handle_, and Turn’d the very end of
the _Wooden-Handle_ with a small hollow in it flat at the bottom, and
deep enough to bury the Iron-_Nut_ on the end of the Curtain-Rod, and
when this Curtain-Rod was put through the Hollow in the _Wooden-Handle_
and Screwed fast to it at the end, it kept the _Wooden-Handle_, from
flying off; Or if it loosened, by twisting the _Nut_ once or twice more
about, it was fastned again.
¶. 14. _Of the_ Hose, Garter, _and_ Hose-Hooks.
The _Hose_ are the upright Irons in Plate 8. at _a a_, They are about
three quarters of an Inch square, both their ends have Male-screws on
them; The lower end is fitted into a square Hole made at the parting of
the _Hose-Hooks_, which by a square _Nut_ with a Female-screw in it, is
Screwed tight up to them; Their upper ends are let into square Holes
made at the ends of the _Garter_, and by _Nuts_ with Female-Screws in
them, and Ears to turn them about as at _l l_ are drawn up higher, if
the _Plattin-Cords_ are too loose; or else let down lower if they are
too tight: These upper Screws are called the _Hose-Screws_.
The _Garter_ (but more properly the _Coller_) marked _b b_, is the
round Hoop incompassing the flat Groove or Neck in the Shank of the
_Spindle_ at _e e_; This round Hoop is made of two half-round Hoops,
having in a Diametrical-line without the Hoop square Irons of the same
piece proceeding from them, and standing out as far as _g g_, These
Irons are so let into each other, that they comply and run Range with
the square Sholders at both ends, wherein square Holes are made at the
ends of the _Hose_. They are Screwed together with two small Screws, as
at _h h_.
The four _Hose-Hooks_ are marked _i i i i_, They proceed from two
Branches of an Iron Hoop at _k_ encompassing the lower end of the
_Spindle_, on either Corner of the Branch, and have notches filled
in their outer-sides as in the Figure, which notches are to contain
several Turns of _Whip-cord_ in each notch, which _Whip-cord_ being
also fastned to the _Hooks_ on the _Plattin_, holds the _Plattin_ tight
to the _Hooks_ of the _Hose_.
¶. 15. _Of the_ Ribs, _and_ Cramp-Irons.
The _Ribs_ are delineated in Plate 8. at E, they are made of
four square Irons the length of the _Wooden-Ribs_ and _End-Rails_,
_viz._ four Foot five Inches long, and three quarters of an Inch
square, only one end is batter’d to about a quarter of an Inch thick,
and about two Inches and an half broad, in which battering four or
five holes are Punch’t for the nailing it down to the _Hind-Rail_ of
the _Wooden-Ribs_. The Fore-end is also batter’d down as the Hind-end,
but bound downwards to a square, that it may be nailed down on the
outer-side of the _Fore-Rail_ of the _Wooden-Ribs_.
Into the bottom of these _Ribs_, within nine Inches of the middle, on
either side is made two Female-Duftails about three quarters of an Inch
broad, and half a quarter of an Inch thick, which Female-Duftails have
Male-Duftails as at _a a a a_ fitted stiff into them, about an Inch
and three quarters long; and these Male-Duftails have an hole punched
at either end, that when they are fitted into the Female-Duftails in
the _Ribs_, they may in these Holes be Nailed down the firmer to the
_Wooden-Ribs_.
[Illustration: _Plate 9._]
These _Ribs_ are to be between the upper and the under-side exactly
of an equal thickness, and both to lye exactly Horizontal in straight
lines; For irregularities will both Mount and Sink the _Cramp-Irons_,
and make them _Run_ rumbling upon the _Ribs_.
The upper-sides of these _Ribs_ must be purely Smooth-fil’d and
Pollish’d, and the edges a little Bevil’d roundish away, that they may
be somewhat Arching at the top; because then the _Cramp-Irons_ _Run_
more easily and ticklishly over them.
The _Cramp-Irons_ are marked F in Plate 8. They are an Inch and an half
long besides the Battering down at both ends as the _Ribs_ were; They
have three holes Punched in each Battering down, to Nail them to the
_Planck_ of the _Coffin_; They are about half an Inch deep, and one
quarter and an half thick; their upper-sides are smoothed and rounded
away as the _Ribs_.
¶. 16. _Of the_ Spindle _for the_ Rounce, _described in Plate_ 9. _at_
a.
The _Axis_ or _Spindle_ is a straight Bar of Iron about three quarters
of an Inch square, and is about three Inches longer than the whole
breadth of the Frame of the _Ribs_, _viz._ two Foot two Inches: The
farther end of it is Filed to a round Pin (as at _a_) three quarters
of an Inch long, and three quarters of an Inch in Diameter; the hither
end is filed away to such another round Pin, but is two Inches and a
quarter long (as at _b_); at an Inch and a quarter from this end is
Filed a Square Pin three quarters of an Inch long, and within half
an Inch of the end is Filed another round Pin, which hath another
Male-Screw on it, to which is fitted a square Iron _Nut_ with a
Female-Screw in it.
On the Square Pin is fitted a _Winch_ somewhat in form like a
Jack-winch, but much stronger; the _Eye_ of which is fitted upon the
Square aforesaid, and Screwed up tight with a Female-Screw. On the
straight Shank of this Winch is fitted the _Rounce_, marked _e_.
The round ends of this _Axis_ are hung up in two Iron-Sockets (as at _c
c_) fastned with Nails (but more properly with Screws) on the outside
the Wooden Frame of the _Ribs_.
The _Girt-Barrel_ marked _d_ is Turned of a Piece of Maple or
Alder-wood, of such a length, that it may play easily between the two
Wooden _Ribs_; and of such a diameter, that in one revolution of it,
such a length of _Girt_ may wind about it as shall be equal to half the
length contained between the fore-end Iron of the _Tympan_, and the
inside of the Rail of the _Inner-Tympan_; because two Revolutions of
this _Barrel_ must move the _Carriage_ this length of space.
This _Barrel_ is fitted and fastned upon the Iron _Axis_, at such a
distance from either end, that it may move round between the Wooden
_Ribs_ aforesaid.
¶. 17. _Of the_ Press-Stone.
The _Press-Stone_ should be Marble, though sometimes Master _Printers_
make shift with Purbeck, either because they can buy them cheaper, or
else because they can neither distinguish them by their appearance, or
know their different worths.
Its thickness must be all the way throughout equal, and ought to be
within one half quarter of an Inch the depth of the inside of the
_Coffin_; because the matter it is _Bedded_ in will raise it high
enough. Its length and breadth must be about half an Inch less than the
length and breadth of the inside of the _Coffin_: Because _Justifiers_
of Wood, the length of every side, and almost the depth of the _Stone_,
must be thrust between the insides of the _Coffin_ and the outsides
of the _Stone_, to Wedge it tight and steddy in its place, after the
_Press-man_ has _Bedded_ it. Its upper-side, or Face must be exactly
straight and smooth.
I have given you this description of the _Press-Stone_, because
they are thus generally used in all _Printing-Houses_: But I have
had so much trouble, charge and vexation with the often breaking of
_Stones_, either through the carelesness or unskilfulness (or both) of
_Press-men_, that necessity compell’d me to consider how I might leave
them off; and now by long experience I have found, that a piece of
_Lignum-vitæ_ of the same size, and truly wrought, performs the office
of a _Stone_ in all respects as well as a _Stone_, and eases my mind,
of the trouble, charge and vexation aforesaid, though the first cost of
it be greater.
¶. 18. _Of the_ Plattin _marked_ d _in Plate_ 9.
The _Plattin_ is commonly made of Beechen-Planck, two Inches and an
half thick, its length about fourteen Inches, and its breadth about
nine Inches. Its sides are Tryed Square, and the Face or under-side
of the _Plattin_ Plained exactly straight and smooth. Near the four
Corners on the upper-side, it hath four Iron _Hooks_ as at _a a a a_,
whose Shanks are Wormed in.
In the middle of the upper-side is let in and fastned an Iron Plate
called the _Plattin-Plate_, as _b b b b_, a quarter of an Inch thick,
six Inches long, and four Inches broad; in the middle of this Plate
is made a square Iron Frame about half an Inch high, and half an Inch
broad, as at _c_. Into this square Frame is fitted the _Stud_ of the
_Plattin Pan_, so as it may stand steddy, and yet to be taken out and
put in as occasion may require.
The _Stud_ marked _d_, is about an Inch thick, and then spreads wider
and wider to the top (at _e e e e_) of it, till it becomes about two
Inches and an half wide; and the sides of this spreading being but
about half a quarter of an Inch thick makes the _Pan_. In the middle of
the bottom of this _Pan_ is a small Center hole Punch’d for the _Toe_
of the _Spindle_ to work in.
¶. 19. _Of the_ Points _and_ Point-Screws.
The Points are made of Iron Plates about the thickness of a Queen
_Elizabeth_ Shilling: It is delineated at e in Plate 9. which is
sufficient to shew the shape of it, at the end of this Plate, as at
_a_, stands upright the Point. This _Point_ is made of a piece of
small Wyer about a quarter and half quarter of an Inch high, and hath
its lower end Filed away to a small Shank about twice the length of
the thickness of the Plate; so that a Sholder may remain. This small
Shank is fitted into a small Hole made near the end of the Plate, and
Revetted on the other side, as was taught _Numb._ 2. _Fol._ 24. At the
other end of the Plate is filed a long square notch in the Plate as at
_b c_ quarter and half quarter Inch wide, to receive the square shank
of the _Point-Screws_.