The art of graveing and etching wherein is exprest the true way of graueing in copper : allso [sic] the manner & method of that famous Callot & Mr. Bosse in their seuerall ways of etching.

The Art of Graving▪ with Aqua fortis.

Sect. 1. How to make the hard Varnish for en∣graving with Aqua fortis.

TAke five ounces of Greek pitch, or (for want of that) Burgundy pitch, five ounces of Rozin of Tyre, or Colofonium, or for want of that) or∣dinary Rosine: Melt them together upon a gentle fire in a new earthen pot, well varnished, or leaded, and being very clean: These two things being first melted, and well mixt together, put into them four ounces of the best Nut Oyl; mix them well together upon the same fire the space of a full half hour, and let them boyl well; Then let this mixture cool a lit∣tle upon a softer fire; and afterwards, touching it with the end of your finger, it will rope (if it be boyled enough) like a glewy Syrup. Then take the pot from the fire, and (the varnish being a little more cooled) strein it through a fine Linnen cloth, or Taffata, into a well varnished earthen pot; or else put it into any thick glasse bottle, or any other thing that will not drink it up, and stop it well. Var∣nish thus made will last twenty years, and it will be the better the longer it is kept.

It is reported of Monsieur Callot, that he had his varnish sent him ready made from Italy, which was made there by the Joyners, who used it to var∣nish

their work: They called it Vernice grosso de Lig∣naioly: He gave some to the Author, which he used a long time; but since made use of the varnish where∣of you have a description before.

Sect. 2. How to make the composition or mixture of grease and oyl, to cover those places in your plate, where you would not have the Aqua fortis to eat in.

TAke an earthen porrenger well leaded; put into it a quantity of Sallad oyl, and set it on the f••re, and when the oyl is hot, put into it a quan∣tity of Candles-grease; when that is melted, take a pencil and dip it in, and let a drop or two fall on a plate, or any cold hard thing; and if the drops be a little hardened and firm, it sheweth that the mixture is well made. For you may judge, that if it is too liquid, it is because there is too much oyl; and if so, then you must put in more grease; and by the same reason, if it be too hard, you must put in more oyl: having made it in this manner, boyl it well the space of an hour, that the oyl and the grease may be well mixed together, and that you may perceive them of a reddish colour, otherwise they will be apt to separate, when you should use them.

The reason why you melt the oyl, and the grease together, is to make the grease more liquid, and not cool too fast: for should you melt the grease alone, you shall no sooner take it up with the point of your pencil to carry it to the place where you would use it, but it will grow cold.

Put in a greater quantity of oyl in Winter, then in Summer.

Sect. 3. How to prepare the Ingredients for making the Aqua fortis for the hard varnish.

THe Aqua fortis is made of Vinegar, Salt Armo∣niack, Bay-salt, and Vert de griz.

The Vinegar must be of the best sort of white-wine Vinegar; but if it be distilled, it is the bet∣ter, and not so subject to break up the varnish.

The Salt Armoniack must be clear, transparent, white, pure, and clean.

The Bay-salt must be also pure and clean.

The Vert de griz must be clean, and free from any scrapings of brasse.

The Salt Armoniack and Vert de griz are com∣monly sold at the Druggists.

Sect. 4. How to make this Aqua fortis.

TAke three pints of Vinegar, six ounces of Salt Armoniack, six ounces of Bay salt, and four ounces of Vert de griz; or of each according to this proportion, as you will make your quantity more or lesse: put them all together in an earthen pot well varnished, large enough, that it may not boyl over: Cover the pot, and put it on a quick fire, and let it speedily boyl two or three great walmes and no more: When you perceive it ready to boyl, and not before, uncover the pot, and stirre it with a little stick sometimes, and take heed that it do not boil over: Having thus boyled it two or three great walmes, take off the pot from the fire, and let it cool; but keep the pot covered, and

when it is cold poure it into a glasse bottle, and let it stand stopped a day or two before you use it: and if you shall find it too strong in the etching, poure into it a glasse or two of the same Vinegar you made it of.

Sect. 5. How to know good Copper from bad.

COpper is best for graving with a Graver, or Aqua fortis; Brasse is too brittle. That Copper is best which is free from flaws, and not too hard, which you may perceive by its yellowish colour, al∣most like brasse: & if it be too soft, you may some∣what perceiv it by its too much pliableness in bend∣ing. When you are to make use of it, you shall per∣ceive (in that which is good) a firm, yet easie force in the entring of your graver: and that Copper which is best for graving, is also best for etching.

Sect. 6. How to planish and polish your Plate.

HEre in England you must buy your Copper rea∣dy forged from the Brasiers.

It is not necessary, that they which desire to en∣grave should forge and polish their Copper them∣selves; but because in divers places there is not conveniency of having it ready polished, I have thought fit to set down the manner how it may be done.

Those Plates which you intend to forge and pla∣nish,

must be fully as thick as an half-crown, be∣cause in their forgeing and planishing they will be∣come somewhat thinner. You must planish your Copper cold, as the Silver-Smiths do their Plate: And the more it is beaten or planished with an hammer, the firmer it is, and lesse subject to holes or flaws.

Your Plate being well planished, make choice of the smoothest side for polishing: Before you begin to polish it, fix it upon a board; and when you po∣lish it, let your board (to which the plate is fixed) stand a little declining or sloping.

To polish your Plate, take a piece of a Grind∣ing-stone about the bignesse of your fist, and fair water, and rub it firmly, and evenly all over; and in your rubbing throw water often on it, and con∣tinue so doing, till you cannot perceive any dints, or flaws, or marks of the hammer: Then wash it clean with water▪ Afterward take a good Pumice-stone, and rub the same Plate with it and water, till there appear none of the rough stroaks, or marks of the stone: Then wash it clean with water, as you did before.

Again, do the same thing with a fine smooth Hoan and water, till all the marks of the Pumice-stone are quite rubbed out: This done, wash it clean with fair water.

Then choose out a Chark-cole smooth, without any knots, or rough grain, and put it in a well-kindled fire: let it be there, till you may perceive it red hot; Then take it out of the fire, and immediately quench it in cold water; Then take it out, and pair off the uttermost rind, and

rub your Plate with it, and water, till all the small strokes of the Hone be rubbed out: If the cole be naught, it will only slide upon the Plate, and not rub out the strokes.

After you have thus polished it with a Chark-cole, if you perceive any small stroaks, or scratches on your Plate, then take a well-hardened piece of steel, made somewhat roundish at the end, which is commonly called a burnisher; and with it rub those places firmly and evenly, where you perceive any strokes, or scratches. When you have done this, wash it clean, and dry it by the fire: and if by a∣ny accident your Plate be foul or greasie, take the crummes of stale bread, or fine-powdered Chalk, and rub your Plate over with it: The Plate being thus polished and cleansed, is fitly prepared to lay on your Varnish.

[illustration]

Sect. 7. How to apply your hard Varnish on the Plate, and make it black.

TAke your Plate thus cleansed, and lay it on a chafing-dish with a little fire in it, and when it is indifferently hot, take it away, and take up some of the Varnish with a little stick, and put a drop of it on the top of one of your fingers; then lightly touch the plate with the top of your finger in severall places at equall distances; as the upper∣most figure in the plate sheweth you, the same be∣ing marked with the letter O: and lay no more on one place then on another. And if your plate grow cold, heat it again as before, being very care∣full to keep it from dust or filth. This done (ha∣ving well-wiped the fleshy part of the palm of your hand) tap it upon the Plate, till all the little spots of varnish are equally spread upon the Plate.

After this tapping, wipe or slide your hand up∣on the Varnish, to make it more smooth, and equal: Take great care, that there be not too much Varnish upon the plate, and that your hand be not sweaty; because the sweat mixing with the Varnish, wil cause little bubbles, when it is applied to the fire, which will become little holes in the Varnish.

Your Varnish being thus smoothed upon the Plate, the way to black it is thus. Take a great tal∣low-candle lighted, which burneth clear; let it have but a short snuff; then place the corner of your plate against the wall, with the varnished side downward, as the lower figure in the Plate represents it to you.

Take heed that your fingers do not touch the Var∣nish: then take your candle, and apply the flame to the Varnish, as close as you can without touching the Varnish with the snuffe of the candle: guide the flame all over, till you see it perfectly black; keep it then from dust or filth untill it be dried.

Plate 1, 2.

[illustration]

Sect. 8. How to dry, or harden the Varnish upon the Plate.

KIndle a fire in a chimney of such chark-coles as are not subject to sparkling, and when they are well kindled, range them in a square somewhat lar∣ger than the Plate, as the letter P sheweth you. Be∣fore you place your plate to be dried, hang up a cloth in the chimney to hinder and keep off any soot or filth from falling down upon it, as you may see by the letters B C D. Then take your plate and place it in the middle of the range upon two low Andirons, as the letter O directs: this done, you will soon perceive the Varnish to smoke; and when you perceive the smoke begins to abate, then take off the plate from the Andirons, and with a stick pointed scratch near the side of your plate; and if it easily take off the Varnish, then you must lay it again upon the Andirons for a little space: Then take it off, and touch it again with your pointed stick, and if it take off the Varnish not too easily, then immediately take it from the fire and let it cool.

If the Varnish do much resist the point of the stick, then presently throw on some cold water on the back-side of the plate to cool it, so that the heat of the plate may not cause the Varnish to be too hard and brittle.

Sect. 9. How to choose your needles wherewith to make your tools to etch with. Pl. 3.

CHoose some broken needles of severall sizes and bignesse, such as break neat without bending, and of a fine grain. Then take round sticks of a good firm wood, not apt to split, of the length of half a foot or somewhat lesse, of the thicknessse of a good large quill: at the ends of which sticks fix in your needles, so that they stand out of the sticks a∣bout as much as you see in the figure following.

Sect. 10. How to whet the points of your needles.

THere are two wayes of whetting your needles, the one round, the other sloping.

You must have an oyl stone with a fine grain to whet your needles upon. For those you would have to be round, you must upon the oyl-stone whet their points short, not as your sowing needles are, but as the Figure shews you. For the other which you intend to make sloping, first upon the oyl-stone make it blunt, then holding it firm and steddily, whet it sloping upon one side only, till it come to a short roundish Oval, for the long Oval is not so good to work with.

You will need a soft brush-pencill, to brush off the varnish, which you work off with the strokes of your needle, as is represented by the Letter A.

[illustration]

Sect. 11. To preserve your Varnish upon the plate.

YOur plate being varnished, place it upon a low desk or such like thing, and cover that part which you do not work one with a sheet of fine white paper, and over that a sheet of brown paper, where∣on you rest your hand to keep it from the varnish when you work.

When you have occasion to use your Ruler to draw streight lines, lay some part of it upon the pa∣per, that it may not rub off the varnish. But above all things have an especiall care that no filth or dust gets in between the paper and the varnish, for that will cause some holes and scratches in the varnish.

Sect. 12. How to etch.

IN etching you will have occasion to make divers sorts of lines or hatches, some bigger, some smal∣ler, some streight, some crooked. To make these you must use severall sorts of needles, bigger or smaller as the work requires. The great lines are made these three severall wayes,

1. By leaning harder on the needle, and the point being short and thick makes a larger passage; but the point being round it will not cut the varnish clear.

2. By making divers lines or hatches, very close one to another, and then by passing them over again with a thicker needle; but this way is both too te∣dious and withall very difficult.

3. By making the lines with an indifferent bigg

needle, and letting the Aqua fortis lie the longer on it. Those needles which you whet sloping with an Oval, are the best to make the large lines withall, be∣cause with their sides they cut that which the round points cannot.

Pl. 4.

Sect. 13. How to guide your needles upon the plate.

YOu may perceive from what is said, that those points which you intend to make use of, in graving with Aqua fortis, ought to be whet exactly round, that they may turn more freely upon the plate. Some of those round points must be whet very sharp, that they may cut the varnish and cop∣per more easily. If you find that your point cuts not freely and smoothly, 'tis because it is not whet ex∣actly round.

If you have occasion to make your lines or hatch∣es of an equall bignesse from one end to the other, whether they be streight or crooked, as those two lines in the letters A B represents, you must, as rea∣son will tell you, lean on your point with an equall force from one end to the other.

If you would make your strokes thicker at one end then at the other; as the second letters A B shews you, then you must lean on your point with your hand harder at the beginning, and by degrees lighter and lighter towards the end.

If you would have your strokes to be such as are re∣presented in the third figure marked also a b, that is to say, larger in the middle then at either end, you must lean gently at the beginning, & then by degrees harder and harder till you come to the middle, and

[illustration]

then by degrees lighter and lighter till you come to the end.

These three sorts of lines or hatches may indif∣ferently serve for all manner of hatching your sha∣dows in any design what soever, as appears in the fi∣gures, M N. O P. Q G R. T E V. wherein is ma∣nifest, that the shadowing is but a reiteration of the same strokes close one to another.

If you desire that your etching with Aqua fortis should look as like graving as may be, you must lean hard upon your needle in those places where you would have the lines appear deep and large, that is, so hard that the needle may make some impression in the copper. And by the same reason you are to lean very light on those places which you would have appear faint and small.

If it happen that you have made some lines or hatches too small, and are desirous to enlarge your stroke, you must passe it over again with a round short point, of such a thicknesse as you desire your line should be of, and lean strong and firmly on those parts of the line which you would have large and deep.

If at any time, by reason of the large lines or hatches, which you were to make, you have used an Oval point (which is the best to cut the varnish) you must afterwards, with one of your large needles whetted short and round, passe in the midst of the said stroke firm and strongly, but especially in those places which you would have large and deep.

Sect. 14. How to use the Oval points to make large strokes in etching or graving with Aqua fortis. Pl. 5.

YOu may see in the figure A B C D the form of those Oval points, and that part next to C de∣scribes the end of it, and B D the sides. The man∣ner of holding it is much after the manner of hold∣ing a pen, only the flat side whetted is usually held towards the thumb, as is represented in figure iii. Not but that it may be used otherwise, with the face of the Oval turned towards the midle-finger as it is shewn in Fig. iv. but I have found the other manner to be much better, because that way you may more firmly and with more strength inforce your strokes.

Now to shew you how to make your strokes large and deep, and that these Oval points are the most proper for it, take notice of the two upper first and second figures, which are made the larger purposely, that you may the better apprehend what shall be hereafter spoken of it. Your own reason will tell you, that if you lean lightly in making your strokes, those strokes will accordingly be lesse deep, smaller, and more faint; for the harder you lean, the deeper and larger your strokes will be. Of this you have an example in the third figure marked r n s; where lean∣ing lightly at the beginning, viz. r. and then harder by degrees to n. and afterwards lighter by degrees to s. you make your stroke bigger or smaller accord∣ing to your leaning on it, as you find represented in the said third Figure.

But if you would have your strokes come very small and delicate at the end, then with the point of

[illustration]

your small needle lengthen out your stroke, as you find it represented in the two strokes of the fifth Fi∣gure.

Some will first make their stroke with a round needle, and then paste it over again with an Oval point to inlarge it in those places which they would have deeper and bigger; but the other is the better way.

They that know how to grave after they have done etching their lines with Aqua fortis, may with the assistance of their graver make them more neat and deeper.

I shall only think it not amisse to advise you by the way, that in making your strokes with your O∣val points, you must hold them as upright and streight in your hand as you can, and accustome your self to strike your strokes firm and bold, for that will contribute very much to their neatnesse and clearnesse. To do this the better, you must be very carefull to have your points alwayes well whetted.

In those places which you would have appear in your piece by way of Landskip, that is at the fur∣thest distance from the sight, as also in those places which approach nearest the light, you must use a ve∣ry slender point, leaning so lightly with your hand, as to make a small faint stroke. But when you come to those places which you would have more shadowed, lean so much the harder, as that when you come to eat it in with your Aqua fortis, you may cover most of your faint places at one and the same time, for you must know that those strokes, which you lean lightest on, do little more then raise up the varnish. So that

when you shall apply your Aqua fortis to etch it, it will appear much fainter then in those places where you have leaned with greater force, though the strokes are done with one and the same needle. In∣somuch, that when you shall have cover'd the great∣est part of your faint places with your mixture, those places, whereon you lean'd more strongly, will appear deepest, though they were all covered at the same time. In your working be carefull to brush off all the dust which you work off with your needles.

Sect. 15. How to prepare your plate to receive the Aqua fortis.

YOur plate being finished and ready for the A∣qua fortis, brush off all the rubbidge and dust that is in the strokes. And if there happen to be any strokes which you would not have the Aqua fortis eat into, or any places where the varnish is rubb'd off, then melt your mixture of oil and grease which you have made, and with a pencill, bigger or smaller, according to the proportion of those places which you would mend, cover those places indifferently thick, and the Aqua fortis will not eat in.

This done, take a brush or pencill, or ragg, and dip it into the said mixture of oil and grease, and rub the back-side of your plate all over, to prevent the Aqua fortis from eating any part of it; but take heed that your mixture be not too thin or liquid, for if it be, when you cast your Aqua fortis on the plate, it will force it from those places whereto you had applied it.

When I find my mixture begin to grow cold, I

commonly use to put some small quantity of it on my left hand, thereby to keep it warm, to be used as occasion shall require.

In the winter time, especially when the weather is cold and moist, before you apply your Aqua fortis to the plate, it will not be amisse to warm it gently by the fire, to dry up the moisture, which the plate is subject to by reason of the distemperature of the weather. Nay if it be not warmed, it may haply endanger the breaking up of the varnish, upon the first pouring of the Aqua fortis upon the plate.

Sect. 16. How to make your trough and frame to hold your plate when you would poure the Aqua fortis on it.

THe Figure opposite hereto represents both trough and frame. The letter A is one intire piece of Elm or Oak, of about four inches thick and six inches broad, and may be of such a length as you shall think fittest for your use. You must cut this piece of wood into the fashion of a trough, as the figure sheweh you, making it a little deeper in the middle, that the water running thither may fall through a hole there made for that purpose. Set this upon a Tressel with four leggs as the figure shews you.

Under the hole in the trough, place an earthen pan well leaded on the inside, as you see in the figure B; and therein put your Aqua fortis, let it not stand too much below the trough.

The figure M N O P is one intire board of an in∣different largenesse as you may judge by the figure. About the two sides and top of which board you must fasten a ledge about two inches broad, to keep the Aqua fortis from running off from the sides, when you poure it on. The inside of this board and trough must be covered or primed over with a thick oil-colour, to hinder the Aqua fortis from eating or rotting the board. Place the lower end of this board in the trough leaning sloping against a wall or any other thing. In the board you must fix severall peggs of wood or nails whereon to rest your plate.

[illustration]

How to poure y^e: Aqua Fortis upon y^e: Plate.

[illustration]

The figure Q describes a little earthen pot well leaded on both sides, which you must have to take up your Aqua fortis out of the panne, and to pour it on the plate.

Sect. 17. The manner of casting the Aqua fortis upon the plate; as also how to cover the places, that are faintest and most remote from the eye, with the fore∣mentioned mixture, as occasion shall require.

HAving observ'd the way of placing the plate for the receiving of the Aqua fortis, there re∣mains only to consider the method you are to fol∣low in casting it on as occasion shall require; for in some works it will be necessary to cast it on severall times, for the reasons hereafter to be mentioned. Having a sufficient quantity of Aqua fortis in your pan, fill your earthen pot, and poure it upon your plate, beginning at the top, and moving your hand equally so that it may run all over the plate, taking great heed that the pot touch not the plate. Having so pour'd 8. or 10. times, the plate being as in the po∣sture express'd in the precedent figure, you must turn it crosse-wayes, as is represented in the upper part of the following figure marked C, and poure on it as it lies that way ten or twelve times as before: That done, turn your plate suitably to the posture ex∣press'd by the lower part of the following figure a∣foresaid, that is to say, corner-wise, and as it lies so, poure thereon eight or ten times; pouring the Aqua fortis thus at severall times, for the space of half a quarter of an hour, more or lesse, according to the strength or the water, and nature of the copper.

For if the copper be brittle and hard, there must be the lesse time allow'd for the pouring on of the water; but if soft, the more.

And whereas you may not haply at the first be so well assured of the strength of your water, and the precise quality of your copper, it will not be a∣misse to give you some directions how to know both, that you may proceed according to the strength of neatnesse which you expect to find in your work. For there are some pieces require more force, and some more tendernesse then others. To know there∣fore the nature of your copper, and the strength of your water, that they be such as the work you in∣tend doth require, pour of it on your plate, for the first time, as is before mention'd, for the space of the fourth part of a quarter of an hour. Then take a∣way the plate, and cast on it a quantity of fair wa∣ter, holding the pot at a good height from the plate, to wash off the Aqua fortis; for if it be not clean wash'd, the work will appear green, and con∣sequently, you cannot so well perceive the operati∣on of your Aqua fortis.

That done, hold your plate before the fire, at such a distance, as that, without melting the mix∣ture which may be upon it, the fair water may be dried up. Then take a little piece of charcole, and therewith rub off the varnish in some place where the strokes are faint: and if you find that the Aqua fortis hath eaten deep enough in those faint places, melt your mixture, and having plac'd your plate upon a desk or easell, take of the said mixture with a pencill fit for your work, and cover therewith all those places which you desire should be tender, and

free from any further operation of the Aqua fortis, taking great care that you bestow mixture thick e∣nough on the places which you would have covered, that is, that the mixture may fill up the strokes. And it is at this first operation, that you are to cover all the faintest and sweetest places.

Having held your plate so long to the fire that the moisture is quite-taken off (a thing only necessary in the winter time) put it again upon your board, and pour on your water as before, for the space of a∣bout half an hour, turning your plate from time to time according to the severall postures, as is before expressed. That done, wash off the Aqua fortis with fair water as before, and dry your plate by the fire, taking especiall care that you melt not the mixture which you had before put upon it.

Your plate being dri'd put it upon the desk or ea∣sell, as before, and having melted your mixture, co∣ver therewith those faint places and hatches that are next in point of faintnesse to those that you had covered before. The severall degrees of faint¦nesse in the hatches you have severall examples of in the following figure.

You have been directed before how to guide your needles and Ovall points, and I have told you how you were to lean strong and firmly on the places where you would have the strokes to be black and deep, and slack and lighten your hand where you would have them faint and tender, a thing which very much facilitates the operation of the Aqua fortis. For instance, when you have at the first time with your mixture cover'd that part which is en∣clos'd by the line A B C D. which makes a kind of

an Oval: you come at the second time to cover that space which is between the line A B C: and the line E O F. conceiving well, that having suffered the Aqua fortis to eat in for the time requisite, it will have an effect somewhat near that which you ex∣pected.

At the upper end of the plate you have the form of a woman's arm, wherein you may perceive, by the line marked a b c d; as also by the other which lies yet nearer the shadow, how the small hatches and fainter places are ordinarily covered at two se∣verall operations, as occasion shall require; though in the forementioned example of the arm, one time covering might haply serve.

I have also thought fit at the bottome of the plate, to set down four severall pieces of ground in land∣skip, the first marked m m m, is the first covered, as being the farthest of all from the eye, then at a∣nother operation that marked n n n; then that marked o o o: there being only that marked p, wherein the Aqua fortis eats in full and deep.

It may be objected, that the light or hard lean∣ing on the points in their proper places in working, may make the strokes and hatchings so, as that the Aqua fortis may eat in answerably to your expecta∣tion, without the trouble of covering any places with your mixture: To this I answer, that the work will not altogether have that effect, but will be like the second plate, which I have purposely made after that manner: for though you can lean harder on some places, and lighter on others; yet the Aqua fortis being pour'd equally all over the plate, during the whole time, it must follow that some

[illustration]

places will not be so sweet and tender as they ought, and shall come farre short of that beautifull and lively continuity which you may perceive in those lines and strokes where you use the mix∣ture.

If it happen, that when you dry your plate by the fire to take off the moisture, as hath been said before, that the mixture for want of care, do melt and run into those hatches and strokes where you would have the water to eat in further; wipe the place with a soft cloth, then take the crum of stale bread, and rub the place therewith till such time as you conceive you have taken off all the greasinesse. This remedy is only appliable in point of extremi∣ty; for you are to note, that it is impossible to take out the grease so clearly, but that it will somewhat hinder the operation of the Aqua fortis. And therefore there must be the more care taken to pre∣vent it.

Having thus cover'd your places as occasion re∣quires, for the second time place your plate on the board aforesaid, and pour on it your Aqua fortis for another good half hour.

That done, wash it with water, and dry it as for∣merly, and cover the places you think requires it for the third time, for you must know that the faint places are to be proportionable to, that is, more or lesse, according to the severall designes and pieces you work upon. When you have done this, pour on your Aqua fortis upon it for the last time, and it is at this operation, that you are to bestow more or lesse time above the precedent, according to the na∣ture of your work.

For instance, if there be in your plate such hatches and shadows as require much depth and fulnesse, and consequently must be very black, you are to pour on the Aqua fortis for the space of an hour or better at this last operation alone, that is proportionably to the precedent. You may well imagine that there can be no certain rule given in generall, either as to the convenient covering of the places, or the precise space of time that is to be observ'd in casting on the water: for it is not to be conceiv'd that Callot pour'd as much wa∣ter on his little pieces as he did on those that were greater.

I told you before, how that you may rub off your varnish or ground as occasion requires, with a char∣cole, to see whether the water hath eaten in deep enough: you are therefore to judge of the space of time that you are to employ in pouring on the Aqua fortis, by the works you are to do, and where I tell you that you may bestow an hour and better on the last operation, my meaning is, in pieces that require much blacknesse. All which notwithstanding, it is to be considered that all copper and all sorts of Aqua fortis not being of the same strength, na∣ture and equality, you are to proceed accord∣ingly.

Having therefore pour'd the Aqua fortis upon your plate for the space of an hour, more or lesse, as the work requires as is before said, wash it again with fair water; but you shall not need to dry it as in the precedent operations; but put it wet as it is upon the fire, till your mixture be all melted; and then wipe it very clean on both sides with a lin∣nen

cloth, till you have quite taken away all the mixture.

Sect. 18. How to take the ground or the varnish off the plate, after the Aqua fortis hath done its operation.

TAke a char-cole of willow or some such soft grain'd wood, and take off the rinde of it, and pouring fair water on the plate, rub it with the char-cole with an even hand, as if you were to polish copper, and it will take off the varnish. Be carefull that no dust or filth fall upon the plate; as also that the char-cole be free from all knots and roughness, for it might occasion small scratches in the plate which it would be difficult to get out, especially in those places which are most faint and sweet. Note that you are not to use such a burnt cole as you do to polish withall.

When the varnish is taken off, the plate is of an unpleasant colour, by reason of the operation of the fire and water upon it. To reduce it therefore to its proper colour, take some ordinary Aqua fortis, to which add two third parts of fair water, and with a little linnen ragg dipp'd therein, rub your plate all over, and you will find it come to its ordi∣nary colour and beauty.

That done, take immediately a dry linnen ragg, and wipe it all over so as to take off all the foresaid water. Then hold your plate a little to the fire, and pour on it a little sallad-oyl, and with the brims of an old beaver roll'd up, rub your plate well all over with it; then wipe it with a dry cloth.

This done, you will perceive plainly if there be any places that require to be touch'd with the gra∣ver, as it for the most part happens, especially in those places that are to be most black. For you may well judge, that when there are many strokes and hatchings one close to another, there is so lit∣tle varnish between, that the Aqua fortis commonly takes it off, because it eats under it.

But if this happens when you cast on your wa∣ter, you may presently cover those places where you perceive the varnish to break up with the mix∣ture, it being much more easie to touch it after∣wards with the graver, then when the Aqua fortis hath made a pit therein, which at the working of it off at the presse causes a great black patch; but after some number of coppies taken off, the said patch seems to be white, because there is not any thing for the ink to fasten on.

Having therefore in good time cover'd that part, you have no more to do but to perfect those strokes and hatchings to make them more firm and beautifull; which done, your plate is ready for the Rolling Presse.