CHAPTER I. ON THE ART OF NIELLO.
Take an ounce of the finest silver, two ounces of copper well purified, and three ounces of lead as pure as you can possibly get it. Then take a little goldsmiths’ crucible sufficiently big to melt the three in together. You must first take the one ounce of silver & the two ounces of copper and put the two together in the crucible, and the crucible in a goldsmiths’ blast-furnace, and when the silver and the copper are molten & well mixed together, add the lead to them. Then quickly draw the crucible out, and with a bit of charcoal held in your tongs, stir it round till it is well mixed. The lead, according to its wont, will make a little scum, so with your charcoal try and take this off as much as possible, until the three metals are fully & cleanly blended. At the same time have ready a little earthenware flask about as big as your fist, the neck of which should, however, not be wider than might hold one of your fingers. Fill this flask about half full with very finely ground sulphur, & empty into this your molten mass, while quite fluid & hot. Then quickly stuff it up with moist earth, and holding it in your hand wrapped up in a stout bit of canvas, say for instance an old sack, shake it to & fro while it is cooling. As soon as it is cold, break the flask and take out the stuff, and you will see that by virtue of the sulphur it will have got the black colour you want. But mind you take care that the sulphur is the blackest you can get.[14]As for the flask, you may take one of those which are generally used for separating gold from silver. Take then your niello, which will now be in a number of little grains,—for you must know that the object of all this shaking up and down whilst cooling in the sulphur is to make it combine,—& put it anew into a crucible, then melt it in a moderate fire, adding to it a grain of borax. When you have recast it two or three times, and after each casting broken up your niello, take it out, for you will see it will now be splendidly broken up,[15]and that is as it ought to be,—and that will do.
Now I’ll show you how to apply and make up your niello; but first a word or two about the plate on which your intaglio is to be engraved, whether in silver or in gold, for niello is used only on these metals. If you want to get the plate on which you have cut your work nice and smooth & without holes,[16]you must boil it in a solution of clean watermixed with a deal of very clean charcoal, the best for this purpose being charred oak. When your work has cooked in the pot for about a quarter of an hour or so, transfer it to a beaker of clean fresh water, and scrub it for a long time with a clean brush till every particle of dirt be rubbed off it. Then see that you have ready a bit of iron long enough to hold the work to the fire: its length should be about three or four palms, more or less in accordance with what the nature of your work may seem to you to need. But mind you look out that the iron to which your work is fixed be neither too thick nor too thin; for it should be of such sort that when you put both to the fire they should heat equally; for if either the iron or the plate become heated first, you’ll make a mess of it, so pay great attention to this. Next take your niello, & crush it on an anvil, or on a porphyry stone, & do this with a pair of pliers or a copper rod, and so that it does not spring aside. Take care, too, that it is crushed to grains and not to a powder, & these grains should be as equal as possible, and about the size of a grain of millet or sago, if not less. After this put the niello grains into some sort of vase or glass bottle, and with fresh clean water wash it out well till it be quite purified from any dust or dirt that may have got into it during the pounding. This done, take a spatula of brass or copper, and spread the niello evenly over your engraved plate to about the thickness of the back of a table-knife. Then powder over it a little well-ground borax, but mind it be not too much. Put a few pieces of wood or charcoal so that you can blow them into flame with your bellows, and this done, put your work very slowly to the wood fire & subject it to the heat very dexterously till you see the niello beginning to melt. But look out that, when it does begin to melt, you don’t get it too hot, or into a red heat, for if it gets too hot, it will lose its natural character and become soft, because, the principal component of niello being lead, this lead will begin to corrode the silver, or even the gold of which your work is made; in this way you might have all your pains for nothing. Have great heed to this, therefore, which is as important as your good engraving to begin with.
Now before we follow the work through to the end, we will pause and consider things a bit. I advise you when you are holding your work over the fire and see the niello begin to disintegrate, to have at hand a fairly stout iron rod, with a flatted end: this end hold in the fire, and when the niello begins to run, rapidly put your hot iron over it, and, treating it as if it were wax, spread it well, until it has quite filled all the graven part of your intaglio. After this, when your work has got cold, take a delicate file, and file off your niello, & after you have removed a certain quantity, not so as to graze your intaglio, but sufficient to lay it bare, take your work and put it on the hot ashes or the live charcoal.
When it is a little hotter than the hand can bear, or even a bit hotter still, but before it gets too hot, take your steel burnisher, well-tempered, & with a little oil burnish your niello as firmly as the work would seem to admit of, and with due discretion in every case. The only object of this burnishing, is to stop up certain bubble holes[17]that sometimes come during the process. You’ve only got to have patience enough, and with a little practice you’ll find this burnishing stops all the holes up beautifully.
After this, take your knife & touch up the intaglio. Then to finish with take some Tripoli powder and pounded charcoal, & with a reed peeled down to the pith, scrub your work till it is smooth and beautiful.
Oh thou discreetest of readers, marvel not that I have given so much time in writing about all this, but know that I have not even said half of what is needed in this same art, the which in very truth would engage a man’s whole energies, and make him practise no other art at all. In my youth from my 15th to my 18th year I wrought a good deal at this art of niello, always from my own designs, and was much praised for my work.
FOOTNOTES:[14]This is obscure, as the purest yellow sulphur would answer.[15]Perhaps: ‘have a fine fracture.’[16]Bucolini. Perhaps: ‘specks.’[17]Spugnuzze.
[14]This is obscure, as the purest yellow sulphur would answer.
[14]This is obscure, as the purest yellow sulphur would answer.
[15]Perhaps: ‘have a fine fracture.’
[15]Perhaps: ‘have a fine fracture.’
[16]Bucolini. Perhaps: ‘specks.’
[16]Bucolini. Perhaps: ‘specks.’
[17]Spugnuzze.
[17]Spugnuzze.