Mechanick exercises: or the doctrine of handy-works. Applied to the arts of smithing joinery carpentry turning bricklayery. To which is added Mechanick dyalling: ... The third edition. By Joseph Moxon, ...

MECHANICK EXERCISES: OR, The Doctrine of Handy-Works.

Of SMITHING in General.

Definition.

SMITHING is an Art-Manual, by which an irregular Lump (or several Lumps) of Iron, is wrought into an intended Shape.

This Definition, needs no Explanation; therefore I shall proceed to give you an Account of the Tools a Smith uses; not but that (they being so common) I suppose you do already know them; but partly because they may require some precaution in setting them up fittest to your use; and partly because it be|hoves you to know the Names, Smiths call the several parts of them by; that when I name them in Smith's Language (as I shall oft have occa|sion to do in these Exercises) you may the easier understand them, as you read them.

Of setting up a Smith's Forge.

THE Hearth, or Fire-place of the Forge mark|ed A. (in Plate 1.) is to be built up from your floor with Brick about two foot and an half, or sometimes two foot nine Inches high, accord|ing to the purpose you design your Forge for; for if your Forge be intended for heavy work, your Hearth must lie lower than it need be for light

work, for easiness of management, and so broad as you think convenient: It may be built with hollow Arches underneath, to set several things out of the way. The Back of the Forge is built up|right to the top of the Ceiling, and inclosed o|ver the Fire-place with a Hovel, which ends in a Chimney to carry away the Smoak, as B. In the back of the Forge against the Fire-place, is fixed a thick Iron Plate, and a taper Pipe in it about five Inches long, called a Tewel, or (as some call it) a Tewel-Iron marked *, which Pipe comes through the Back of the Forge, as at C. Into this taper Pipe or Tewel is placed the Nose, or Pipe of the Bellows. The Office of this Tewel, is only to pre|serve the Pipe of the Bellows, and the back of the Forge about the Fire-place from burning. Right against the Back is placed at about twenty Inches, or two foot distance, the Trough, and reaches commonly through the whole breadth of the Forge, and is as broad and deep as you think good, as at D. The Bellows is placed behind the Back of the Forge, and hath as aforesaid, its Pipe fitted into the Pipe of the Tewel, and hath one of its Boards fixed so that it move not upwards or downwards. At the Ear of the upper Bellows board is fastened a Rope, or sometimes a Thong of Leather, or an Iron Chain or Rod, as E; which reaches up to the Rocker, and is fastened there to the farther end of the Handle, as at F. This Han|dle is fastened a cross a Rock-staff, which moves between two Cheeks upon the Center-pins, in two Sockets, as at G. So that by drawing down this Handle, the moving Board of the Bellows ri|ses, and by a considerable weight set on the top of its upper Board sinks down again, and by this Agitation performs the Office of a pair of Bellows.

Of the Anvil.

THE shape of a Black Smith's Anvil I have inserted in this Figure, though it is some|times made with a Pike, or Bickern, or Beak-iron, at one end of it, whose use I shall shew you when I come to round hollow work. Its Face must be very flat and smooth, without Flaws, and so hard that a File will not touch it (as Smiths say, when a File will not cut, or race it.) The upper Plain A. is called the Face; it is commonly set upon a wooden Block, that it may stand very steady and solid, and about two foot high from the floor, or sometimes higher, according to the stature of the Person that is to work at it.

Of the Tongs.

THere are two sorts of Tongs used by Smiths; the one the Straight-nosed Tongs, used when the work is short, and somewhat flat, and gene|rally for all Plate Iron. The other Crooked-nos'd Tongs, to be used for the forging small Bars, or such thicker work, as will be held within the Returns of their Chaps. The Chaps are placed near the Joint, because, that considering the length of the Handles, they hold the Iron faster than they would do, were they placed farther from the Joint, as in the Fig. 3.4. A the Chaps, B the Joint, CC the Handles.

Of the Hammer, and the Sledge.

THere are several sorts of Hammers used by Black-Smiths; as first the Hand-hammer, which is sometimes bigger, or less, according to the Strength of the Work-man; but it is a Ham|mer of such weight, that it may be weilded, or governed, with one hand at the Anvil. Second|ly, the Up-hand Sledge, used by under-Workmen, when the Work is not of the largest, yet requires

help to batter, or draw it out; they use it with both their hands before them, and seldom lift their Hammer higher than their head. Thirdly, the About Sledge is the biggest Hammer of all, and is also used by under-Workmen, for the batter|ing, or drawing out of the largest Work; and then they hold the farther end of the Handle in both their Hands, and swinging the Sledge above their Heads, they at Arms end let fall as heavy a Blow as they can upon the Work. There is also another Hammer used by them, which they call a Rivetting-hammer. This is the smallest Hammer of all, and very rarely used at the Forge, unless your Work prove very small; but upon cold I|ron it is used for rivetting, or setting straight, or crooking small work. In Fig. 5. A the Face, B the Pen, C the Eye, D the Handle.

Of the Vice.

THE Vice must be set up very firmly that it shake not, and stand upright with its Chaps, parallel or range with your Work-bench; because square filing, is a great piece of good Work|manship in a Smith; and should the Vice not stand upright, and range with the Work-bench, the Chaps pinching upon two square sides, would make the top side of your work either lean to|wards you, or from you; and consequently you filing (as a good Workman ought to do) upon the flat, or Horizontal Plain of your work, would take off more of that Angle, or Edge, which ri|ses higher than the Plain, and less off that Edge, that lies lower than the Plain; so that one Angle being higher, or lower, than the other, your work instead of being filed Square, would be filed Squa|re-wise, when you shall have filed all its flat sides, and that more or less, according to the leaning of the Chaps of your Vice. AA the Face, hath its

two ends in a straight Line with the middle of its Face, or Plain. B the Chaps must be cut with a Bastard Cut▪ and very well tempered; C the Screw Pin, cut with a square strong Worm. D the Nut, or Screw Box, hath also a square Worm, and is brazed into the round Box. E the Spring must be made of good Steel, and very well temper'd: Where note that the wider the two ends of the Spring stand asunder, the wider it throws the Chaps of the Vice open. F the Foot must be straight, and therefore will be the stronger to bear good heavy blows upon the work screwed in the Chaps of the Vice, that it neither bow, or tremble.

Of the Hand-Vice.

OF the Hand-Vice are two Sorts, one is called the Broad Chapt Hand-Vice, the other the Square Nos'd Hand-Vice. The Office of the Hand-Vice, is to hold small work in, that may require often turning about; it is held in the left hand, and each part of your work turned upwards successively, that you have occasion to file with your right. The Square-nos'd Hand-Vice is sel|dom used, but for filing small Globulous Work, as the Heads of Pins that round off towards the Edges, &c. And that because the Chaps do not stand shouldering in the way, but that the flat of the File may the better come at the Edges. Their Chaps must be cut as the Vice aforesaid, and well tempered.

Of the Plyers.

PLyers are of two Sorts, Flat Nos'd, and Round Nos'd. Their Office is to hold, and fasten upon all small work, and to fit it in its place. The Round Nos'd Plyers are used for turning, or bowing Wyer, or small Plate, into a circular Form. The Chaps of the Fla•• N••s'd Plyes, must

also be cut and temper'd, as the Chaps of the Vice. A the Nose, B the Chaps, C the Joint, DD the Handles.

Of the Drill, and Drill-Bow.

DRills are used for the making such Holes as Punches will not conveniently serve for; as a piece of work that hath already its Shape, and must have an hole, or more, made in it. Here the force of a Punch, will set your work out of order and shape, because it will both bat|ter the Surface of the Iron, and stretch its Sides out: The shank of a Key also, or some such long Hole, the Punch cannot strike, because the Shank is not forged with substance sufficient; but the Drill, tho' your work be filed and po|lish'd, never batters or stretches it, but cuts a true round Hole, just in the point you first place it. You must have several Sizes of Drills, according as your work may require. The shape in Fig. 8. is enough to shew the Fashion of it; but it must be made of good Steel, and well temper'd. A the Point, AB the Shank, C the Drill-barrel: Where note, that the bigger the Drill-barrel is, the easier it runs about, but less swift.

And as you must be provided with several Drills, so you may sometimes require more than one Drill-bow, or at least, several Drill-strings; the strongest Strings for the largest Drills, and the smallest Strings for the smallest Drills: But you must remember, that whether you use a small or strong String, you keep your Drill-Bow straining your String pretty stiff, or else your String will not carry your Barrel briskly about. But your String and Bow, must both be accommodated to the Size of your Drill; and if both, or either, be too strong, they will break, or bend your Drill; or if too weak, they will not carry about the Bar|rel, as aforesaid.

The Drill-Plate, or Breast-Plate, is only a piece of flat Iron, fixt upon a flat Board, which Iron hath an hole punched a little way into it, to set the blunt end of the Shank of the Drill in, when you drill a hole: Workmen instead of it, many times use the Hammer, into which they prick a hole a little way on the side of it, and so set the Hammer against their Breast.

Of the Screw-Plate, and its Taps.

THE Screw-Plate is a Plate of Steel well tem|per'd, with several holes in it, each less than other, and in those Holes are Threds grooved inwards; into which Grooves, fit the respective Taps that belong to them. The Taps that belong to them, are commonly made tapering towards the Point, as Fig. 7. shews. But these tapering Taps, will not serve for some sorts of works, as I shall shew in its proper place.

These are the most Essential Tools used in the Black-Smith's Trade; but some accidental work, may require some accidental Tools, which, as they may fall in, I shall give you an account of in convenient place.

Of Forging in general.

I Think it needless to tell you how to make your Fire, or blow it, because they are both but Labourers work; nor how little, or big, it need to be, for your own reason will, by the Size of your work, teach you that; only let me tell you the Phrase Smiths use for [make the Fire] is, Blow up the Fire, or sometimes, Blow up the Coals.

When it is burning with the Iron in it, you must, with the Slice, clap the Coals upon the out-side close together, to keep the heat in the body of the Fire; and as oft as you find the Fire begin to break out, clap them close again, and

with the Washer dipt in Water, wet the out-side of the Fire to damp the out-side, as well to save Coals, as to strike the force of the Fire in|to the in-side, that your work may heat the sooner. But you ought oft to draw your work a little way out of the Fire, to see how it takes its Heat, and quickly thrust it in again, if it be not hot enough: For each purpose your work is de|signed to, ought to have a proper Heat suitable to that purpose, as I shall shew you in the several Heats of Iron: For if it be too cold, it will not feel the weight of the Hammer (as Smiths say, when it will not batter under the Hammer) and if it be too hot, it will Red-sear, that is, break, or crack under the Hammer, while it is working between hot and cold.

Of the several Heats Smiths take of their Iron.

THere are several degrees of Heats Smiths take of their Iron, each according to the purpose of their work. As first, a Blood-red Heat. Secondly, a White Flame Heat. Thirdly, a Spark|ling, or Welding Heat.

The Blood-red Heat is used when Iron hath al|ready its form and size, as sometimes square Bars, and Iron Plates, &c. have, but may want a little Hammering to smooth it. Use then the Face of your Hand-hammer, and with light flat Blows, hammer down the irregular Risings into the Body of your Iron, till it be smooth enough for the File. And note▪ that it behoves a good Workman, to hammer his Work as true as he can; for one quarter of an hour spent at the Forge, may save him an hours work at the Vice.

The Flame, or White Heat, is used when your Iron hath not its Form or Size, but must be for|ged into both; and then you must take a piece of Iron thick enough, and with the Pen of your

Hammer, (or sometimes, according to the size of your work, use two or three pair of hands with Sledges to) batter it out; or, as Workmen call it, to draw it out, till it comes to its breadth, and pretty near its shape; and so by several Heats, if your work require them, frame it into Form and Size; then with the Face of your Hand-hammer, smooth your work from the Dents the Pen made, as you did with a Blood-red Heat.

A Sparkling, or Welding-heat, is only used when you double up your Iron (as Smiths call it) to make it thick enough for your purpose, and so weld, or work in the doubling into one another, and make it become one entire lump; or it is used when you join several Bars of Iron toge|ther to make them thick enough for your pur|pose, and work them into one Bar; or else it is used when you are to join, or weld two pie|ces of Iron together end to end, to make them long enough; but, in this case, you must be very quick at the Forge; for when your two ends are throughout of a good Heat, and that the inside of the Iron be almost ready to Run, as well as the outside, you must very hastily snatch them both out of the Fire together, and (after you have with the Edge of your Hammer scraped off such Scales or Dirt as may hinder their incorporating) with your utmost diligence clap your left hand-piece, upon your right hand-piece, and with all speed (lest you lose some part of your good Heat) fall to Hammering them together, and work them soundly into one another: and this, if your Bars be large, will require another, or somtimes two or three pair of Hands besides your own to do: but if it be not throughly welded at the first Heat, you must reiterate your Heats so oft, till they be throughly welded; then with a Flame-heat (as

before) shape it, and afterwards smooth it with a Blood-red Heat. To make your Iron come the sooner to a Welding-heat, you must now and then with your Hearth-staff stir up the Fire, and throw up those Cinders the Iron may have run upon; for they will never burn well, but spoil the rest of the Coals; and take a little white Sand be|tween your Finger and your Thumb, and throw upon the heating Iron, then with your Slice, quickly clap the outside of your Fire down a|gain; and with your Washer dipt in Water, damp the outside of the Fire to keep the Heat in.

But you must take special Care that your I|ron burn not in the Fire, that is, that it do not run or melt; for then your Iron will be so brit|tle, that it will not endure Forging without breaking, and so hard, that a File will not touch it.

Some Smiths use to strew a little white Sand upon the Face of the Anvil also, when they are to hammer upon a Welding-heat; for they say it makes the Iron weld, or incorporate the better.

If through Mistake, or ill management, your Iron be too thin, or too narrow towards one of the ends; then if you have substance enough (and yet not too long) you may up-set it, that is, take a Flame-heat, and set the heated end up|right upon the Anvil, and hammer upon the cold end, till the heated end be beat, or up-set, into the Body of your Work. But if it be a long piece of Work, and you fear its length may wrong the middle, you must hold it in your left hand, and lay it flat on the Anvil; but so as the heated end intended to be up-set, may lie a lit|tle over the further side of the Anvil, and then with your Hand-hammer in your right hand, beat upon the heated end of your work, minding that every stroak you take, you hold your work

stiff against the Face of the Hammer. Afterwards smooth it again with a Blood-red Heat.

If you are to Forge a Shoulder on one, or each side of your work, lay the Shank of your Iron at the place where your Shoulder must be on the edge of your Anvil▪ that edge which is most con|venient to your hand) that if more Shoulders be to be made, turn them all successively, and ham|mer your Iron so, as that the Shank of the Iron that lies on the flat of the Anvil, feel as well the weight of your Blows, as the Shoulder at the edge of the Anvil▪ for should you lay your blows on the edge of the Anvil only, it would instead of flatting the Shank to make the Shoul|der, cut your work through.

Your Work will sometimes require to have holes punched in it at the Forge, you must then make a Steel Punch to the size and shape of the hole you are to strike, and harden the point of it without tempering, because the heat of the Iron will soften it fast enough, and sometimes too fast, but then you must re-harden it; then taking a Blood-heat of your Iron, or if it be very large, almost a Flame-heat; lay it upon your Anvil, and with your left hand, place the point of the Punch where the hole must be, and with the Hand-hammer in your right hand punch the hole; or if your work be heavy, you may hold it in your left hand, and with your Punch fixed at the end of a Hoop-stick, or some such Wood, hold the stick in your right hand, and place the point of your Punch on the work where the hole must be, and let another Man strike, till your Punch come pretty near the bottom of your work; which when it does, the sides of your work round about the hole, will rise from the Face of the Anvil, and your Punch will print a bunching mark upon the hole of a Bolster, that is,

a thick Iron with a hole in it, and placing your Punch, as before, strike it through. But you must note, that as oft as you see your Punch heat, or change Colour, you take it out of the hole, and pop it into Water to re-harden it, or else it will batter in the hole you intend to strike, and not only spoil it self, but the Work too, by running aside in the Work. Having punched it through on the one side, turn the other side of your work, and with your Hammer set it flat and straight, and with a Blood-heat punch it through on the other side also; so shall that hole be fit for the File, or square bore, if the curiosity of your purposed Work cannot allow it to pass without filing. When your Work is Forged, do not quench it in water to cool it, but throw it down upon the Floor, or Hearth, to cool of it self; for the quenching it in water will harden it; as I shall shortly shew you, when I come to the Tempering of Steel.

Of Brazing and Soldering.

YOU may have occasion sometimes to Braze or Solder a piece of work; but it is used by Smiths only, when their work is so thin, or small, that it will not endure Welding. To do this, take small pieces of Brass, and lay them on the place that must be brazed, and strew a little Glass beaten to powder on it to make it run the sooner, and give it a Heat in the Forge, till (by sometimes drawing it a little way out of the Fire) you see the Brass run. But if your work be so small, or thin, that you may fear the Iron will run as soon as the Brass, and so you lose your work in the Fire, then you must make a Loam of three parts Clay, and one part Horse-dung, and after they are wrought and mingled very well together in your hands, wrap your work with the Brass, and a little beaten Glass upon

the place to be brazed close in the Loam, and laying it a while upon the Hearth of the Forge to dry, put the lump into the Fire, and blow the Bellows to it, till you perceive it have a full Heat, that is, till the Lump look like a well burnt Coal of Fire; then take it out of the Fire, and let it cool: Afterwards break it up, and take out your Work.

Thus much of Forging in general. It remains now, that you know what sorts of Iron are fittest for the several Uses, you may have occasion to ap|ply them.

Of several Sorts of Iron, and their proper Uses.

IT is not my purpose, in this place, to tell you how Iron is made, I shall defer that till I come to treat of Mettals, and their Refinings. Let it at present satisfie those that know it not, that Iron is, by a violent Fire, melted out of hard Stones, called Iron-Stones; of these Iron-Stones, many Countries have great plenty. But because it wastes such great quantities of Wood to draw the Iron from them, it will not, in many Places, quit cost to use them. In most parts of England, we have abundance of these Iron-Stones; but our English Iron, is generally a course sort of Iron, hard and brittle, fit for Fire-bars, and other such course Uses; unless it be about the Forrest of Dean, and some few places more, where the I|ron proves very good.

Swedish Iron is of all Sorts, the best we use in England. It is a fine tough sort of Iron, will best en|dure the Hammer, and is softest to file; and there|fore most coveted by Workmen, to work upon.

Spanish Iron, would be as good as Swedish Iron, were it not subject to Red-sear, (as Workmen phrase it) that is to crack betwixt hot and cold. Therefore when it falls under your hands, you

must tend it more earnestly at the Forge. But tho' it be good, tough, soft Iron, yet for many Uses, Workmen will refuse it, because it is so ill, and un-evenly wrought in the Bars, that it costs them a great deal of labour to smooth it; but it is good for all great works that require welding, as the bodies of Anvils, Sledges, large Bell-clappers, large Pestles for Mortars, & all thick strong Bars, &c. But it is particularly chosen by Anchor-Smiths, because it abides the Heat better than other Iron, and when it is well wrought, is toughest.

There is some Iron comes from Holland (tho' in no great quantity) but is made in Germany. This Iron is called Dort Squares, only because it comes to us from thence, and is wrought into square Bars three quarters of an Inch square. It is a bad, course Iron, and only fit for slight Uses, as Window-Bars, Brewers-Bars, Fire-Bars, &c.

There is another sort of Iron used for making of Wyer, which of all Sorts is the softest and toughest: But this Sort is not peculiar to any Country, but is indifferently made where any Iron is made, though of the worst sort; for it is the first Iron that runs from the Stone when it is melting, and is only preserved or the ma|king of Wyer.

By what hath been said, you may see that the softest and toughest Iron is the best: Therefore when you chuse Iron, chuse such as bows oftenest before it break, which is an Argument of tough|ness; and see it break sound within, be grey of Colour like broken Lead, and free from such glistering Specks you see in broken Antimony, no flaws or divisions in it; for these are Argu|ments that it is ••ound, and well wrought at the Mill.

Of Filing in General.

THE several sorts of Files that are in com|mon use are the Square, the Flat, the three Square, the half Round, the Round, the Thin File, &c. All these shapes you must have of several Si|zes, and of several Cuts. You must have them of several sizes, as well because you may have seve|ral sizes of work, as for that it sometimes falls out that one piece of work may have many parts in it joined and fitted to one another, some of them great, and others small; And you must have them of several Cuts, because the Rough-tooth'd File cuts faster than the Bastard-tooth'd File, the Fine-tooth'd File faster than the Smooth-tooth'd File.

The Rough or Course-tooth'd File (which if it be large, is called a Rubber) is to take off the un|evenness of your work which the Hammer made in the Forging; the Bastard-tooth'd file is to take out of your work, the deep cuts, or file-strokes, the Rough-file made; the Fine-tooth'd file is to take out the cuts, or file-strokes, the Bastard-file made; and the Smooth-file is to take out those cuts, or file-strokes, that the Fine file made.

Thus you see how the Files of several Cuts suc|ceed one another, till your Work is so smooth as it can be filed. You may make it yet smoother with Emerick, Tripoli, &c. But of that in its pro|per place, because it suits not with this Section of Filing.

You must take care when you use the Rough File, that you go very lightly over those dents the Hammer made in your work, unless your work be forged somewhat of the strongest, for the dents being irregularities in your work, if you should file away as much in them, as you do off the Eminencies or Risings, your work (whether it be straight or circular) would be as irregular, as it was before you filed it: And

when you file upon the Prominent, or rising Parts of your Work, with your course cut File, you must also take care that you file them not more away than you need, for you may easily be deceived; because the course File cuts deep, and makes deep scratches in the Work; and be|fore you can take out those deep scratches with your finer cut Files, those places where the Ri|sings were when your work was forged, may become dents to your Hammer dents; therefore file not those Risings quite so low, as the dents the Hammer made, but only so low as that the scratches the Rough-file makes may lie as low, or deep in your work, as your Hammer dents do; for then, when you come with your smoother Cut Files, after your Rough-file, the scratches of your Rough-file, and your Hammer-strokes, or dents, may both come out together. But to do this with greater certainty, hold your File so, that you may keep so much of the length of your File as you can to rub, range, (or, as near range as you can) upon the length of your work; for so shall the File enter upon the se|cond Rising on your work, before it goes off the first, and will slip over, and not touch the dent or hollow between the two Risings, till your Risings are brought into a straight line with your hollow dent. But of this more shall be said when I come to the Practice of Filing▪ upon several particular sorts of work.

If it be a square Bar, (or such like) you are to file upon, all its Angles, or Edges, must be left very sharp and straight. Therefore your Vice being well set up, according to foregoing Di|rections, you must in your filing athwart over the Chaps of the Vice, be sure to carry both your hands you hold the file in, truly Horizontal, or flat over the Work; for should you let either of

your hands mount, the other would dip, and the edge of that Square it dips upon would be taken off; and should you let your hand move never so little circularly, both the Edges you file upon would be taken off, and the Middle of your intended Flat would be left with a Rising on it. But this Hand-craft, you must attain to by Practice; for it is the great Curio|sity in Filing.

If it be a round Piece, or Rod of Iron, you are to file upon, what you were forbid upon Square Work, you must perform on the Round for you must dip your Handle-hand, and mount your end-hand a little, and laying pritting near the end of your File to the Work, file circu|larly upon the Work, by mounting your Handle-hand by degrees, and dipping your End-hand, in such manner, as when the Middle of your File comes about the top of your Work, your File may be flat upon it, and as you continue your stroaks forwards, still keep your hands moving circularly till you have finished your full Stroak, that is, a Stroak the whole length of the File. By this manner of Circular filing, you keep your Piece, or Rod round; but should you file flat upon the top of your work, so many times as you shall remove, or turn your work in the Vice, so many Flats, or Squares, you would have in your work; which is contrary to your purpose.

When you thrust your File forwards, lean hea|vy upon it, because the Teeth of the File are made to cut forwards; but when you draw your File back, to recover another thrust, lift, or bear the File lightly just above the work; for it cuts not coming back.

Thus much of FILING in General.

Of the making of Hinges, Locks, Keys, Screws, and Nuts, Small and Great.

Of Hinges.

IN Fig. 1. A the Tail, B the Cross, CDDDDE the Joint, DDDD the Pin-hole. When the Joint at C on the Tail, is pind in the Joint at E in the Cross, the whole Hinge is called a Cross-Garnet.

Hinges, if they be small (as for Cup-board doors; Boxes, &c.) are cut out of cold Plate I|ron with the * 1.1 Cold-Chissel, but you mark the out-lines of your intended Hinge, as Fig. 1. the Cross-Garnet, either with Chalk, or else rase upon the Plate with the corner of the Cold-Chissel, or any other hardned Steel that will scratch a bright stroke upon the Plate; and then laying the Plate flat upon the Anvil, if the Plate be large, or upon the * 1.2 Stake, if the Plate be small, take the Cold-Chissel in your left hand, and set the edge of it upon that Mark, or Rase, and with the Hand-hammer in your right hand, strike upon the head of the Cold-Chissel, till you cut, or rather punch the edge of the Cold-Chis|sel, almost thro' the Plate in that Place, I say, almost through, because, should you strike it quite through, the edge of the Cold-Chissel would be in danger of battering, or else breaking; for the Face of the Anvil is hardned Steel, and a light blow upon its Face would wrong the edge of the Cold-Chissel; besides, it sometimes hap|pens, that the Anvil, or Stake, is not all over so hard as it should be, and then the Cold-Chis|sel would cut the Face of the Anvil, or Stake, and consequently spoil it: Therefore when the edge of the Cold-Chissel comes pretty near the

[figure]

bottom of the Plate, you must lay but light blows upon the Cold-Chissel; and yet you must strike the edge of the Cold-Chissel so near through the bottom of the Plate, that you may break the remaining substance asunder with your Fin|gers, or with a pair of Plyers, or sometimes by pinching the Plate in the Vice, with the Cut place close to the Superficies of the Chaps of the Vice; and then with your Fingers and Thumb, or your whole hand, wriggle it quite asunder. But having cut one breadth of the Cold-Chissel, remove the edge of it forward in the Rase, and cut another breadth, and so move it successively, till your whole intended shape be cut out of the Plate.

When you cut out an Hinge, you must leave on the length of the Plate AB in this Figure, Plate enough to lap over for the Joints, I mean, to Turn, or Double about a round Pin, so big as you intend the Pin of your Hinge shall be, and also Plate enough to Weld upon the inside of the Hinge below the Pin-hole of the Joint, that the Joint may be strong.

The size, or diameter of the Pin-hole, ought to be about twice the thickness of the Plate you make the Hinge of, therefore lay a wyre of such a diameter towards the end B, in this Figure on

[figure]

the Tail piece, a-thwart the Plate as CD, and Double the end of the Plate B, over the wyre to lap over it, and reach as far as it can upon the end A; then hammer the Plate that is lap'd o|ver the wyre close to the wyre, to make the Pin-hole round; but if your Plate be thick, it will require the taking of an Heat to make the

hammer the closer to the wyre, and consequent|ly make the Pin-hole the rounder: Your work may also sometimes require to be Screwed into the Vice, with the doubled end upwards, and the bottom side of the wyre close against the Chaps of the Vice, and then to hammer upon the very top of the Pin-hole to round it at the end also. When you have made the Pin-hole round in the inside, take the Pin CD out of the Pin-hole, and put the Joint-end of the Hinge into the Fire to make a Welding-heat; which when it hath, snatch it quickly out of the Fire, and hammer, or weld, the end B upon the Tail-piece A till they be in|corporate together. But you must have a care that you hammer not upon the Plate of the Pin-hole, lest you stop it up, or batter it; when it is well Welded, you must again put in the Pin CD, and if it will not well go into the Pin-hole, (because you may perhaps have hammer'd either upon it, or too near it, and so have some|what closed it) you must force it in with your hammer; and if it require, take a Blood-heat, or a Flame-heat, of the Joint end) and then force the Pin into the Pin-hole, till you find the Pin-hole is again round within, and that the Pin, or Wyre, turn evenly about within it.

Afterwards with a Punch of hardned Steel (as you were taught Page 11.12.) Punch the Nail-holes in the Plate; or if your Plate be very thin, you may punch them with a * 1.3 cold Punch. After all, smooth it as well as you can with your Hand-hammer; take a Blood-red-heat, if your work require it, if not, smooth it cold; so will the Tail-piece be fit for the File. Double, and Weld the Cross-piece, as you did the Tail-piece.

Having forg'd your Hinge fit for the File, you must proceed to make the Joint, by cutting a Notch in the Middle of the Pin-hole between DD in Plate 2. on the Cross, as at E, and you must cut down the Ends of the Pin-hole on the

Tail-piece, as at DD, till the Joint at C fit ex|actly into the Notch in the Cross, and that when the Pin is put into the Pin-hole DD on the Cross, the Pin-hole in the Tail-piece may also receive the Pin; then by holding the Tail-piece in one Hand, and the Cross in the other, double the Tail and Cross towards one another, to try if they move evenly and smoothly without shaking on the Pin; which if they do, the Joint is made; if they do not, you must examine where the Fault is, and taking the Pin out, mend the Fault in the Joint.

Then File down all the Irregularities the Cold-Chissel made on the Edges of your Work, and (if the Curiosity of Work require it) file also the outer Flat of your Work. But tho' Smiths that make Quantities of Hinges, do brighten them, (as they call it) yet they seldom file them, but Grinde them on a Grindstone till they become bright, &c.

Having finished the Joint, put the Pin in again; but take care it be a little longer than the Depth of the Joint, because you must batter the Ends of the Pin over the outer Edges of the Pin-hole, that the Pin may not drop out when either Edge of the Cross is turned upwards.

The chiefest Curiosity in the making these, and, indeed, all other Hinges is, 1. That the Pin-hole be exactly round, and not too wide for the Pin. 2. That the Joints are let exactly into one another, that they have no play between them, lest they shake upwards or downwards, nor yet are forced too hard into one another, lest when they are nailed on the Door, the Joint be in Danger of Breaking. 3. That the Cross, and the Tail lie on the Under-side exactly flat, for should they warp out of flat when they are nail|ed on, the Nails would draw the Joint a-wry, and not only make it move hard, and unevenly, but by oft Opening and Shutting break the Joint. 4. If your Work be intended to be curious, the

true Square-filing the Upper-side, as you were taught Page 15, 16, 17. is a great Ornament.

(a) Smiths call all Chissels they use upon cold Iron, Cold-Chissels.

(b) The Stake is a small Anvil, which either stands upon a broad Iron Foot, or Basis, on the Work-Bench, to remove as Occasion offers; or else it hath a strong Iron Spike at the Bot|tom, which Iron Spike is let into some certain Place of the Work-Bench not to be removed. Its Office is to set small cold Work straight upon, or to Cut or Punch upon with the Cold-Chissel, or Cold-Punch.

(c) Smiths call all Punches they use upon cold Iron, Cold-Punches.

If the Hinge you are to make be large, and Plate-Iron is not strong enough for it, you must Forge it out of Flat Bar-Iron, as you were taught from Page 7 to Page 12.

The manner of working Duftails, Fig. 5. and Side-hinges, Fig. 6. &c. is (the shape considered) in all respects the same I have here shewed you in Cross-Garnets; but in these (or others) you may (if your Work require Curiosity) instead of Doubling for the Joint, Forge the Round for the Joint of full Iron, and afterwards Drill a Hole through it, for the Pin-hole; and by curious Fi|ling, work them so true into one another, that both sides of the Hinge shall seem but one Piece; as I shall shew more at large, when I come to the making of Compasses, and other Joints for Mathematical Instruments.

Of Locks and Keys.

AS there are Locks for several Purposes, as Street-door Locks, called Stock-Locks; Cham|ber-door Locks, called Spring-Locks; Cupboard-Locks, Chest-Locks, Trunk-Locks, Pad-Locks, &c. So are there several Inventions in Locks, I mean, in

the Making and Contriving their Wards, or Guards. But the Contrivances being almost in|numerable, according to the various Fancies of Men, shall be referred to another Time to dis|course; and I shall now shew you the Working of a Spring-Lock, which when you know how to do, your Fancy may play with Inventions, as you best like.

In Fig. 2. AAAA the Main-plate, BC the Key-hole. EDE the Top-hook, EE Cross-wards, F the Bolt, G the Bolt-Toe, or Bolt-Nab. H the Draw-back Spring, I the Tumbler, K the Pin of the Tumbler, LL the Staples.

In Fig. 3. AAAA the Cover-Plate, B the Pin, BCD the Main-ward, DD Cross-wards, E the Step-ward or Dap-ward.

In Fig. 4. A the Pin-hole, B the Step, or Dap-ward, C the Hook-ward, D the Middle, or Main Cross-ward, EE the Cross-ward, F the Main-ward, GG Cross-ward, H the Shank, I the Pot, or Bread, K the Bow-ward, L the Bow, BCDEEFGG the Bit.

First, Cut out of an Iron Plate with a Cold-Chissel, the Size and Shape of the Main-Plate, as you were taught to cut the Cross and Tail-piece of the Cross-Garnet; then consider what Depth you intend the Bit of the Key shall have, and set that Depth off on the Main-Plate, by leaving about half an Inch of Plate between the Bottom of the Key-hole, and the Lower Edge of the Main-Plate, as at C (or more or less, according to the Size of the Lock.) Then measure with a Pair of Composses between the Bottom of the Bit, and the Centre of your Key (or your intended Key) and set that di|stance off from C to B, near the Middle between the two Ends of the Main-Plate, and with the * 1.4 Prick-punch, make there a Mark to set one Foot of your Compasses in, then opening your Compasses to the Middle of the Bit of your intended Key, as

to D, describe the Arch EDE for the true Place the Top-hoop must stand on.

Then cut one other Piece of Plate as AAAA in Fig. 3. for a Cover-plate, with two Pieces one on each side, long enough to make Studs of to turn downwards, and then outward again as FF, GG, that the Cover-plate may stand off the Main-plate, the Breadth of the Bit of the Key; and at the two End of these Studs Punch holes, as GG, to Rivet the Cover-plate into the Main-plate. In the Middle of this Plate make the Centre, as at B, then open your Compasses to three Quarters the Length of the Bit, and half the Diameter of the Shank of the Key, and placing one Foot in the Point B, describe with the other Foot the Arch DCD for the true Place of the Main-ward, then set your Compasses to a little more than half the Diameter of the Shank, and place one Foot (as before) in the Centre B, and with the other Foot describe the small Arch E, for the true Place the Step-ward, or (as some call it) the Dap-ward must stand: So have you the true Places of the Wards, for an ordinary Spring-Lock; you may (if the Depth of your Bit will bear it) put more Wards in your Plates. But you must note, that the more Wards you put in, the weaker you make your Key; because that to every Ward on the Plates, you must make a Slit, or Ward in the Bit of the Key; and the more Wards you make, the weaker the Iron of the Bit will be; and then if the Bolt shoot not easily backwards, or forwards, the Bit may be in Danger of Breaking.

Having marked on your Plates the Places of all your Wards, you must take thin Plate, and with Hammering and Filing make them both * 1.5 Hammer-hard, and of equal Thickness all the way. Then file one Edge very straight, by laying a straight Ruler just within the Edge of it, and draw|ing, or racing with a Point of hardned Steel, a bright Line by the side of the Ruler; File away

the Edge of the Plate to that Line, then draw (as before) another straight Line Parallel to the first straight Line, or which is all one, Parallel to the filed Edge, just of the Breadth you intend the Wards shall be, and file as before, only, you must leave two, or sometimes three Studs upon this Plate, one near each End, and the other in the Middle, to Rivet into the Main-plate, to keep the Ward fixt in its Place. Therefore you must take care when you elect this thin Piece of Plate, that it be broad enough for the Ward, and these Studs too. Then laying the Plate a-thwart the Pike of the Bickern, hold your Hand even with the Face of the Bickern, and hammer this Plate down somewhat by the side of the Pike, and by Degrees you may (with care taken) bring it unto a circular Form, just of the Size of that Circle you described on the Main-plate; which when you have done, you must apply this Ward to the Circle you described on the Main-plate; setting it in the Position you intend it shall be fixed, and marking with a Steel Point where the Studs stand upon that Circle, in those marks Punch holes to Rivet the Studs to. Work so by all the other Wards.

If you have a Pin to the Lock, Punch a Hole through the Centre on the Cover-plate, somewhat smaller than the Wyre you are to make your Pin of, because you may then file one End of the Pin away to a Shank, which must fit the smaller Hole on the Plate, and the whole Thickness of the Pin will be a Sholder, which will keep the Pin steddy in the Centre-hole of the Plate, when the Pin is rivetted into the Plate. But because there is some Skill to be used in Rivetting, I shall, before I proceed any farther, teach you

The manner of Rivetting.

RIvetting is to batter the Edges of a Shank o|ver a Plate, or other Iron, the Shank is let into, so as the Plate, or other Iron, may be clinched close, and fixed between the Battering at the End of the Shank and the Sholder. So that

When you Rivet a Pin into a Hole, your Pin must have a Sholder to it thicker than the Hole is wide, that the Sholder slip not through the Hole, as well as the Shank; but the Shank of the Pin must be exactly of the Size of the Hole the Shank must be Rivetted into, and somewhat longer than the Plate is thick; file the End of the Shank flat, so shall the Edges of the End, the ea|silier batter over the Plate; then put your Shank into the Hole, wherein it is to be Rivetted, but be sure you force the Shank close up to the Sholder; then turn the Top of this Sholder down|wards (Plate and all) upon your Stake, but lay it so, as that the Sholder lie solid, and the Shank, at the same time, stand directly upright, and with your left Hand, keep your Work bearing hard upon the Flat, or Face of the Stake. Then holding your Hammer in your Right-hand, hold the Edge of the Face of it Dripping a-slope from the Right-hand outwards, and lay pretty light Blows upon the Edge of the End of the Shank, turning with your Left-hand your Work round to the Face of the Hammer, till you have battered the Edges of the Shank quite round about; but this is seldom done, with once turning your Work about; therefore you may thus work it round again and again, till you find it is pretty well Rivetted; then lay heavier Blows upon it, sometimes with the Face, sometimes with the Pen of the Hammer, till the End of the Shank is bat|tered effectually over the Plate.

One main Consideration in Rivetting is, that the Pin you rivet in, stand upright to the Plate,

or other Iron you rivet it upon; for if it do not stand upright, you will be forced to set it up|right, after it is rivetted, either in the Vice, or with your Plyers, or with your Hammer, and that may, if your Plate be thin, bow it, or if it be thick, break the Shank, or else the Sholder of your Rivet, and so you lose your Labour, and some|times spoil your Work.

Another Consideration is, that when you rivet a Pin to any Plate, and you fear it may after|wards twist about by some force that may be offered it, you must, to provide against this Danger, file the Shank you intend to Rivet, ei|ther Square, or Triangular, and make the Hole in the Plate you rivet it into, of the same Size and Form, and then rivet in the Shank, as be|fore. There are two ways to make your Hole, Square or Triangular, one is by filing it into these Forms, when it is first Punched round; the other by making a Punch of Steel, of the Size and Shape of the Shank you are to rivet, and punching that Punch into the Plate, make the same Form.

Now to return where I left off. The Pins and Shanks of these Wards must be made of a long Square Form, because, (the Plates of the Wards being thin) should you make them no broader than the Plate is thick, the Studs, or Shanks would be too weak to hold the Wards, therefore you must make the Rivetting-shank three or four times, or sometimes more, as broad as the Plate is thick, and then rivet them in, as you were taught just now.

Then place the Cover-plate upon the Main-plate, so as the Centre of the Cover-plate, may stand directly over and against the Centre of the Main-plate, and make marks through the Hole GG, of the Studs of the Cover-Plate upon the Main-plate, and on those Marks Punch holes, and fit two Pins into them, to fasten the Cover-plate on to

the Main-plate, but you must not yet rivet them down, till the Key-hole be made, because this Cover-plate would then stop the Progress of the File through the Main-plate, when you file the Key-hole. When you have placed the Cover-plate upon the Main-plate, and fitted it on with Pins, so, as you may take it off, and put it on again, as your Work may require, you must Punch the Key-hole, or rather drill two Holes close by one another, if the Key-hole falls near the Wards, be|cause Punching may be apt to set the Wards out of Form, and with small Files, file the two Holes into one another, to make the Hole big enough to come at it with bigger Files, and then file your Key-hole to your intended Size and Shape.

The Key-hole being finished, forge your Key, as you were taught, Page 7. and if your Key is to have a Pin-hole, drill the Hole in the Middle of the End of the Shank, then file the Wards, or Slits in the Bit with thin Files; yet sometimes Smiths Punch, or cut them with a Cold-Chissel, at the same Distances from the Middle of the Pin-hole in the End of the Shank (which is the same Centre, which was made before, in the Main-plate on the Cover-plate) which you placed the Wards at, from the Centre of the Main and Cover-plate. But before you file these Wards too deep into the Bit of the Key, make Trials, by putting the Bit into the Key-hole, whether the Wards in the Bit, will agree with the Wards on the Plates, which if they do, you may boldly cut them to the Depth of the Wards on the Plate; if not, you must alter your Course till they do; but you must take great Care in Cutting the Wards down straight, and square to the Sides of the Bit; for if they be not cut down straight, the Wards on the Plates, will not fall in with the Wards in the Bit of the Key; and if they be not Square to the Sides of the Bit, the Bit will not only be weaker than it need be, but it will

shew unhandsomely, and like a Botch to the Eye.

The Cross and Hock-wards is made, or, at least, entred at the Forge, when the Iron hath a Blood, or almost a Flame Heat, yet sometimes Smiths do it on cold Iron, with a thin Chissel, as you was taught Page 11.12. But you must take care that your Chissel be neither too thick, or too broad, for this Punching of Wards is only to give the thin Files Entrance to the Work; which Entrance when you have, you may easily file your Cross, or Hook-wards, wider or deeper, as your Work may require; but if your Chissel be too broad, or too thick, it will make the Wards in the Bit too long, or too wide, and then (as I said before) the Bit of your Key will prove weaker than it needs to be.

Having made the Wards on the Plate, and in the Bit of the Key, you must Forge the Bolt of a considerable Substance, Thick and Square at the End that shoots into the Staple in the Frame of the Door, that it may be strong enough to guard the whole Door; but the rest of the Bolt that lies between the two Staples on the Main-plate, may be made very thin inwards, that is, the Side that lies towards the Main-plate, which because it can|not be seen when the Bolt is fixed upon the Plate, I have made a Figure of it, and turned the Inside to View, as in Fig. 4. where you may see, that the End A, hath a considerable Substance of Iron to guard the whole Door, as aforesaid, and B is a Square Stud, which doth as well keep the Outside flat of the Bolt on the Range, as serve for a Stud for the Spring H in Fig. 2. to press hard against, and shoot the Bolt forwards: This Bolt must be wrought straight on all its Sides, except the Topside, which must be wrought straight only as far as the Sholder G, called the Toe, or Nab of the Bolt, which rises, as you see in the Figure, considerably high, above the Straight on the Top of the Bolt; The Office of this Nab,

is to receive the Bottom of the Bit of the Key, when in turning it about, it shoots the Bolt back|wards or forwards.

Having forged and filed the Bolt, you must fit the Hollow-side of it towards the Main-plate, at that Distance from the Key-hole, that when the Key is put into the Key-hole, and turned towards the Bolt, the Bottom of the Bit may fall almost to the Bottom of the Nab, and shoot the Bolt back so much, as it needs to enter the Staple in the Door-frame. And having found this true Place for the Bolt, you must with square Staples, just fit to contain the Bolt with an easie Play, fasten these Staples, by Rivetting them with the Bolt within them, one near the Bolt end, the other near the Nab end, as at LL to the Main-plate.

Then Punch a pretty wide Hole in the Main-plate, as at K, to receive a strong Pin, and file a Sholder to the Shank of the Pin that goes into the Plate. This Pin is called the Pin of the Tumbler; the Tumbler is marked I, which is a long Piece of Iron, with a round Hole at the Top to fit the Pin of the Tumbler into, that it may move upon it, as on a Joint, and it hath an Hook returning at the Lower End of it, to fall into the Breech of the Bolt, and by the Spring H forces the Bolt forwards, when it is shot back with the Key. This Spring is made of Steel, and afterwards temper'd (as I shall shew you in proper Place.) It is fixed at the Bottom of the Main-plate, by two small Shanks proceeding from that Edge of the Spring that lies against the Main-plate, as at OO: These Shanks are to be rivetted (as you were taught even now) on the other Side of the Main-plate.

All things being thus fitted, punch an Hole on each Corner of the Main-plate for Nails to enter, that must nail the Lock to the Door. Or if you intend to screw your Lock on the Door, you must make wide Holes, big enough to receive the

Shank of the Screw. Last of all, rivet down your Cover-plate to the Main-plate, and file your Key, and polish it too, if you will; so shall the Lock and Key be finished.

(a) A Prick-punch, is a Piece of temper'd Steel, with a round Point at one End, to prick a round Mark in cold Iron.

(b) Hammer-hard, is when you harden Iron, or Steel, with much hammering on it.

The making of Screws and Nuts.

THe Shank of the Screw for Doors, and many other Purposes, must be forged square near the Head, because it must be let into a Square-hole, that it may not twist about when the Nut is turned about hard upon the Screw-pin. Therefore take a Square-bar, or Rod of Iron, as near the Size of the Head of the Screw-pin as you can, and taking a Flame-heat of it, lay so much of this Bar as you intend for the Length of the Shank, with one Square-side flat, upon the Hither-side of the Anvil, and hammer it down to your intended Thickness: But have a care you do not strike your Iron on this Side the Edge of the Anvil, lest you cut the Iron, as I told you Page 11. Thus, at once, you will have two Sides of your Shank forged; the Under-side made by the Anvil, and the Upper-side beaten flat with the Hammer: The Head will be in the main Rod of Iron; then if your Iron grows cold, give it another Heat, and lay one of the unwrought Sides upon the Hither-side of the Anvil, just to the Head, and hammer that down, as before, so shall the two other Square-sides be made; then hammer down the Corners of so much of this Shank, as you in|tend for the Screw-pin, and round it, as near as you can, with the Hammer; set then the Chissel to the Thickness you intend the Head shall have, and strike it about half through, then turn the Sides successively, and cut each Side also half through, till it be quite cut off. If the Sholder be not square enough, hold it in your Square-nos'd

Tongs, and take another Heat, and with speed (lest your Work cool) screw the Shank into the Vice, so as the Sholder may fall flat upon the Chaps of the Vice; then hammer upon the Head, and square the Sholder on two Sides, do the like for squaring the other two Sides. This was, in part, taught you before, in Page 11. but because the cutting this Iron Rod, or Bar, just above the Sholder makes the Head, and for that I did not mention it there, I thought fit (since the Purpose required it) to do it here: The Forging of the Nuts are taught before, Page 11.12.

Having forged and filed your Shank square, and the Head either Square or Round, as you intend it shall be, file also the Screw-pin, from the Ri|sings and dents left at the Forge; and file it a little Tapering towards the End, that it may enter the Screw-plate; the Rule how much it must be Ta|pering is this, consider how deep the Inner Groo|ves of the Screw-plate lie in the outer Threds, and file the End of the Screw-pin so much smaller than the rest of the Screw-pin, for the outer Threds of the Screw-plate must make the Grooves on the Screw-pin, and the Grooves in the Screw-plate, will make the Threds on the Screw-pin. Having fitted your self with a Hole in your Screw-plate (that is, such a Hole whose Diameter of the hollow Groo|ves, shall be equal to the Diameter of the Screw-pin, but not such a Hole, whose Diameter of the outer Threds, shall be equal to the Diameter of the Screw-pin, for then the Screw-plate will indeed turn about the Screw-pin, but not cut any Grooves, or Threds in it) screw the Shank with the Head downwards in the Vice, so as that the Screw-pin may stand directly upright, and take the Handle of the Screw-plate in your Right-hand, and lay that Hole flat upon the Screw-pin, and press it very hard down over it, and turn the Screw-plate evenly about with its Handle towards you, from the Right towards the Left-hand, so shall the outer

Threds of the Screw-plate cut Grooves into the Screw-pin, and the substance of the Iron on the Screw-pin, will fill up the Grooves of the Screw-plate, and be a Thred upon the Screw-pin. But take this for Caution, that, as I told you, you must not make your Screw-pin too small, because the Screw-plate will not cut it, so if you make it too big (if it do en|ter the Screw-plate where it is Taper) it will en|danger the breaking it, or, if it do not break it, yet the Screw-plate will, after it gets a little below the Tapering, go no farther, but work and wear off the Thred it made about the Tapering.

To fit the Pin therefore to a true size, I, in my Practise, use to try into what hole of the Screw-plate, the Tap or place of the Tap, (if it be a ta|pering Tap,) I make the Nut with, will just slide through; (Threads and all;) (which generally in most Screw-plates is the hole next above that to be used) for then turning my Pin about in that hole, if the Pin be irregularly filed, or but a little too big on any part of it, the Threds of that Hole will cut small marks upon the Pin, on the irregular places, or where it is too big; so that afterwards filing those Marks just off, I do at once file my Pin truly round, and small enough to fit the H••le I make my Screw-pin with.

As the Hole of the Screw-plate must be fitted to the Screw-pin, so must the Screw-tap that makes the Screw in the Nut, be fitted to to the round hole of the Nut; but that Tap must be of the same size of your Screw-pin too, which you may try by the same hole of the Screw-plate you made the Scr••w-pin with. Screw the Nut in the Vice directly flat, that the hole may stand upright, and put the Screw-tap upright in the hole; then if your Screw-tap have an handle, turn it by the handle hard round in the Hole, so will the Screw-tap work it self into the Hole, and make Grooves in it to fit the Threds of

the Screw-pin. But if the Screw-tap have no han|dle, then it hath its upper end filed to a long square, to fit into an hollow square, made near the handle of the Screw-plate; but that long square hole, o|ver the long square on the top of the Tap, and then by turning about the Screw-plate, you will al|so turn about the Tap in the hole▪ and make Grooves and Threds in the Nut.

But though small Screws are made with Screw-plates, yet great Screws, s••ch as are for Vices, Hot-Pr••sses, Printing-Presse, &c. are not made with Screw-plates, 〈◊〉〈◊〉 must 〈◊〉〈◊〉 out of the main Iron, with heavy blow•• 〈◊〉〈◊〉 a Cold-Chissel. The man|ner of making them, is as follows.

The Rules and manner of Cutting Worms upon great Screws.

THE Threds of Screws, when they are bigger than can be made in Screw-plates, are call'd Worms. They consist in length, breadth and depth; the length of a Worm begins at the one end of the Spindle, and ends at the other; the breadth of the Worm, is contain'd between any two Grooves on the Spindle, viz. The upper and un|der Groove of the Worm, in every part of the Spindle; the depth of the Worm, is cut into the Diameter of the Spindle, viz. The depth, between the outside of the Worm, and the bottom of the Groove.

The depth ought to be about the one seventh part of the Diameter, on each side the Spindle:

You ought to make the Groove wider than the Worm is broad, because the Worm being cut out of the same intire piece with the Spindle, will be as strong as the Worm in the Nut, tho' the Worm 〈…〉〈…〉 be smaller; for you cannot come 〈…〉〈…〉 the Nut, to cut it with Fl••es, as you 〈…〉〈…〉, and therefore you must either

Turn up a Rod of Iron, to twist round about the Grooves on the Spindle, and then take it off, and Braze it into the Nut, or else you must Cast a Nut of Brass upon the Spindle, which will neither way be so strong as the Worm cut out of the whole Iron, by so much as Brass is a weaker Mettal than Iron, and therefore it is that you ought to allow the Worm in the Nut, a greater breadth than the Worm on the Spindle, that the strength of both may, as near as you can, be equaliz'd; for both being put to equal force, ought to have equal strength. The Worm may very well be the one seventh part smaller than the Groove is wide, as aforesaid.

Having consider'd what breadth the Worm on the Spindle shall have, take a small thin Plate of Brass, or Iron, and file a square notch at the end of it, just so wide, and so deep, as your Worm is to be broad and deep, and file the sides of the Plate that this notch stands between, just to the width of the Groove. This Plate, must be a Gage to file your Worm and Groove to equal breadth by; then draw a straight and upright Line the whole length of the Spindle; divide from this line the Circumference of the whole Spindle into eight equal Parts, and through those Divisions, draw seven Lines more parallel to the first Line; then open your Com|passes just to the breadth of one Worm, and one Groove, and set off that distance ••s oft as you can, from the one end of the Spindle to the other, (but I should first have told you, that the end of your Spindle must be square to the outside) and with a Prick-Punch, make a mark to every setting off on that line: Do the like to all the other straight upright Lines. Note, that you may chuse one of these eight upright Lines for the first, and make the next towards your left Hand, the second (but then the first must stand towards you) and the

next that, the third, and so on. And the top mark of every one of these upright straight Lines, shall be call'd the first Mark, the next un|der that the second Mark, the third, the third Mark, and so downwards in Order and Num|ber.

Having marked one of these eight Lines at the top of the Spindle, to begin the winding of the Worm at, with a Black-lead Pencil, draw a line from that Mark to the second Mark, on the next upright Line towards the left hand, from thence continue drawing on with your Pencil to the third Mark, on the third upright Line, draw on still to the fourth Mark, on the fourth upright Line, and so onwards, till you have drawn over the eight straight Lines, which when you have done, you must still continue on, drawing downwards to each lower Mark on each successive upright Line, till you have drawn your Worm from end to end: Then examine, as well as you can, by your Eye, whether the Worm you have carried on from Mark to Mark with the Black-led Pencil, do not break into Angles, which if it do any where, you must mend it in that place: Then with the edge of an half-round File, file a small Line in the Black-lead Line, and be sure that the Line you are filing, run exactly through all the Marks that the Black-lead Pencil should have run through (if it did not, for want of good gui|dance of the Hand.) This small Line is only for a guide to cut the Groove down by; for the making of a Screw is, indeed nothing else, but the cut|ting the Groove down, for then the Worm remains: But you must not file in this small line, but leave it as a guide to lie on the middle of the Worm (as I said before): Therefore to cut down the Groove, take a Cold-Chissel, somewhat thinner than you intend the Groove shall be wide, viz. about

the thickness of the breadth of the Worm, and, with heavy blows, cut out the Groove pretty near. The reason why you should not offer to cut the Grooves to their full wedth at the first, is, because your Hand may carry the Cold-Chissel somewhat awry, and should your Cold-Chissel be as thick as the Groove is wide, you could not smooth the Ir|regularities out, without making the Worm nar|rower than you intended it: Then with a Flat-file open and smooth the Groove, filing in the middle between the two next fine Lines cut by the half-round File, till you have wrought the Spindle from end to end, so shall the Worm remain. But you must not expect, that though the Groove be cut, it is therefore finished, for now you must begin to use the thin Plate-Gage, and try first, whether the Worm have equal breadth all the way. Secondly, whether the Grove have equal breadth all the way. And Thirdly, whether the Groove have equal depth all the way; and where ever you find the Worm too broad, you must file it thinner, and where the Groove is not deep enough, file it deep|er; therefore in cutting down the Groove you may observe, that if, at first, you file the Worm never so little too narrow or the Groove never so little too deep, you shall have all the rest of the Worm or Groove to file over again; because the whole Worm must be brought to the breadth of the smallest part of it, and the whole Groove to the depth of the deepest place all the way, espe|cially if the Nut be to be Cast in Brass upon the Spindle; because the Mettal running close to the Spindle will bind on that place, and not come off it; but if the Nut be not to be Cast in Brass, but only hath a Worm brazed into it, this niceness is not so absolutely necessary, because that Worm is first Turned up, and bowed into the Grooves of the Spindle, and you may try that before it is

Braz'd in the Nut, and if it go not well about, you may mend, or botch it, either by Hammering or Filing, or both.

The manner of Casting the Nut upon the Spin|dle, I shall shew when I come to the Casting of Met|tals; and the manner of Brazing hath been Taught already. Num. I. fol. 12, 13.

If your Spindle is to have three or four Worms winding about it, as Coining-Presses and Printing-Presses have, that they may not wear out too fast, you must divide the Circumference into three or four equal Parts, and having straight upright Lines, drawn as before, begin a Worm at each of those three, or four Divisions, on the Circumfe|rence, and considering the breadth of your Worm and width of your Groove, measure that width as oft as you can on all the upright Lines, and ma|king Marks on those at each Setting off, draw as before, a Line from the end of the Spindle, on the first upright Line to the Mark below it, which is the second Mark on the second upright Line, from thence to the third Mark, on the third up|right Line, and so on to the other end of the Spindle. Having drawn the first Worm, work the other Worm as this.

Thus much may at present suffice for great Screws.

[figure]

Notes

• * 1.1

  Smiths call all Chissels they use upon cold Iron, Cold-Chissels.
• * 1.2

  The Stake is a small Anvil, which either stands upon a broad Iron Foot, or Basis, on the Work-Bench, to remove as Occasion offers; or else it hath a strong Iron Spike at the Bot|tom, which Iron Spike is let into some certain Place of the Work-Bench not to be removed. Its Office is to set small cold Work straight upon, or to Cut or Punch upon with the Cold-Chissel, or Cold-Punch.
• * 1.3

  Smiths call all Punches they use upon cold Iron, Cold-Punches.
• * 1.4

  A Prick-punch, is a Piece of temper'd Steel, with a round Point at one End, to prick a round Mark in cold Iron.
• * 1.5

  Hammer-hard, is when you harden Iron, or Steel, with much hammering on it.