CHAPTER I 
MATERIALS AND TOOLS 
Gold and silver—Care of material—Assay—Copper and brass—Other metals and alloys—The workshop—Various tools. 
Gold and silver may be purchased from many dealers in jewellers' materials, either in the pure or in the alloyed state, in sheet, wire and granular form. The sheet metal is generally kept in a coiled strip, perhaps 6 or 12 inches wide and of considerable length. But sheets can be rolled to any size or thickness. The surface is generally free from scratches and blisters. Wire can be obtained of almost any size and section. Gold and silver are sold in the granular form for casting or alloying. They may also be had in the form of tube or " chenier." This can be obtained with a soldered join up the side, or seamless; the latter variety being very useful for joints and hinges. Solid or hollow mouldings, hollow beads, chains, snaps, swivels, mounts, settings for stones, blanks for rings and other similar things are kept in many different designs, and in several qualities. 

Owing to the cost of the material a number of precautions are taken in the workshop against the loss of any portion of it, however small. The bench is swept several times a day with a hare's foot, which forms a convenient little brush to which the gold will not adhere. All filings—lemel is the technical name for them—are carefully preserved. The residue from the polishings, the dust from the floor, and even the sediment from the water in which the men wash their hands, are carefully dealt with. The mud and dust are taken to a refiner's, and he recovers the precious metal from them. 

Sometimes dirt or some other foreign matter gets mixed with gold, and makes it difficult to work. To clean the gold—melt it in a crucible and add to it corrosive subli mate (bichloride of mercury, HgCl2). Avoid the fumes. To clean silver—say you are melting down lemel (filings),—add saltpetre to the molten metal, and when it boils up, throw a little common salt into the skittle-pot or crucible in which it is. This will cause it to subside. The dirt will come away with the flux. 

There are two methods by which it is possible to ascertain the quality of gold in any article. The first is by the " touch " or black stone. This is a hard black stone. The gold to be tested is rubbed along it, leaving a streak. The colour of this streak, or touch, is compared with that made by a small bar of known quality, known as a touch needle. Touch needles are made for each carat. The streaks on the blackstone are, after examination, washed over with nitric acid, and again compared. The quality of the gold may in this manner be roughly ascertained. 

But a much more accurate method is generally adopted. A description of this process, taken from Mr. Cripps' valuable book on Old English Plate, is as follows :— 
" For gold, to a portion of metal scraped off the article to be examined, say about eight grains, after being accurately weighed, is added three times its weight of silver, and a proper proportion of lead, the latter by wrapping the gold and silver in a piece of sheet-lead. The whole is placed in a small shallow porous crucible made of bone ashes, called a cupel, and exposed to a bright-red heat; the metals melt, and whilst the silver and gold combine, the lead and alloying metals become oxidised, and the oxides are absorbed by the cupel, leaving a button of pure gold and silver. This button is then flattened, rolled out into a strip, which is then coiled into a sort of screw, called a ' cornet '; this is placed in hot diluted nitric acid, by which the silver is dissolved and the gold alone remains, the cornet is then treated with stronger nitric acid, washed, and lastly made red-hot; when cold it is weighed again, and the dift'erence between its present weight and the original weight of the scrapings carefully determined. For silver the process is much the same : a certain portion,usually about ten or twenty grains,is scraped off the article, some being taken from each separate part: 
thisis wrapped inleadofproportionateweight, and the whole heated in the cupel. The result is the same as in the case of gold, except that the button remaining is of pure silver only; the difference between the weight of this button and the original weight of the portion operated upon, shows the 
amount of alloy. The portion of metal taken off for examination is called the ' diet.' " 

Copper, brass, etc., are supplied in rolls, many yards long, of anywidth upto 12 inches or more. They are also keptin sheets measuring 48 x 24 inches. Their surface varies much in quality, some sheets being badly scratched and blistered. Perfectly smooth metal may, however, be procured. The sheets may be had in soft annealed finish, hard-rolled, or burnished. For raising or repousse work the first should be chosen. Copper and brass are also supplied in the form of strip, wire and rod. There is hardly any limit to the size or variety of shape in which these are made. Seamless copper tubes up to six inches or greater diameter are to be met with. They are useful for a number of purposes where a join up the side of a vessel would be objectionable. A length of the tube can, of course, be hammered and shaped in the manner described in Chapter XL A considerable saving in time may be thus effected. Mouldings and hollow beads of various shapes are also kept ready made. Gilding metal and the various bronzes and brasses can also be had in a variety of forms. Among the other metals or alloys employed are— 

German silver. Good white colour. It is a hard, springy material to work in.—Nickel. Greyish-white colour. It spins well. Has a strong magnetic property.—Cobalt is very similar in colour, but is too hard to work comfortably. —Aluminium. Goodfor raising and spinning. Joints should be riveted, as no aluminium solder seems to make a quite permanent joint.—Pewter. Very soft and easy to work. •—Tin. Very similar to pewter, and often employed in its place. 

The arrangement of the workshop varies considerably according to the kind of work to be undertaken. For large work the bench should be about 2 feet 10 inches high ; the top being of hard wood, and at least 2 inches thick. It should be firmly fixed to the wall. The vice should not weigh less than 65 ft. If lighter, it will vibrate too much when raising is being done. The soldering hearth is de scribed in Chapter III. The gas supply pipe should measure not less than half an inch clear bore. A pipe with three quarters of an inch bore is better, for unless you get a good supply of gas you may have difficulties in getting the work hot enough. Get a good-sized blowpipe also. Fletcher's No. 5 Bellows are large enough for most purposes. The lathe is mentioned in Chapter XII. It need not be back-geared. A slide rest, a drill chuck, and a face-plate with dogs make it an extremelyhandy tool for themanyodd jobs which turn up in the course of the work. A number of wooden chucks should also be provided. A surface plate is a 'rather expensive tool, but it is useful in trueing up work which has to stand or fit accurately. A good piece of plate glass will make an excellent substitute, however. The grindstone should be mounted with treadle and drip can. A large, smooth slab of stone is useful for"grinding smooth the rims of bowls and other vessels after they have been filed as truly as possible. The kind of stone does not seem to matter much. A smooth York paving stone answers verywell. ThedrawbenchisdescribedinChapterXV. The polishing lathe, Fig. 1, has a horizontal mandrel, perhaps a foot long, driven by a cord or strap from the fly-wheel. At each end of the mandrel a tapering screw thread is cut, upon which various brushes and mops can be screwed. The polishing materials are applied to them with a stick or brush. 

The jeweller's bench is described in Chapter VI. A list of the special tools required for each branch of the work will be found in the chapters devoted to it.