ENAMELLING. 



however, to enamel on finer gold than 

 22 carats; and the operation would be 

 very defective, if a coarser kind than that 

 of Ib carats were used. For in this case 

 more alkali must be added to the enamel, 

 to renuer it more fusible, and this addi- 

 tion would, at the same time, render it 

 softer and less brilliant. 



Rejecting ail these exceptions, the fol- 

 lowing description may be taken, by way 

 of example, of fixing a transparent blue 

 enamel upon gold ot 22 carats. 



The artist begins his operation by 

 breaking his enamel into small .pieces in 

 a steel mortar, and afterwards pulverizing 

 it in a mortar of agate. He is careful to 

 add water in this part of the process, 

 wliidi prevents the splinters of glass from 

 flying about. There are no means of ex- 

 plaining the point at which the tntura- 

 tion ought to be given up, as this can be 

 learned only by experience. Some ena- 

 meis require to be very finely triturated; 

 but others may be used in the form of 

 a coarse powder. As soon as he ap- 

 prehends that his enamel is sufficiently 

 pounded, he washes it by agitation in very 

 clear water, and pouring off the fluid as 

 it becomes turbid. 1 his process, which 

 is made for carrying off dust and every 

 other impurity from the enamel, is con- 

 tinued until the water comes oft as clear 

 as it was poured on. 



The workman puts his enamel thus 

 prepared into a white earthern or china 

 saucer, with water poured on it to the 

 depth of about one tenth of an inch. 

 He afterwards takes up the enamel with 

 an iron spatula as equally as posible. 

 As the enamel here spoken of is trans- 

 parent, it is usual to ornament the gold 

 with rose work, or other kinds of work, 

 calculated to produce a good effect 

 through the enamel. 



The thickness of this first layer de- 

 pends entirely upon its colour : delicate 

 colours n general require that it should 

 have no great thickness. 



The moist enamel, being thus placed, 

 is dried, by applying a very clean half- 

 worn linen cloth to it, which must be very 

 carefully done, to avoid removing the 

 enamel by the action of wip>ng. 



In this state the piece is ready for the 

 fire. If it be enamelled on both sides, it 

 is placed upon a tile, or iron plate, hol- 

 lowed out in such a manner, that the un- 

 covered edges of the piece alone are in 

 contact with the support But if it be 

 enamelled on one side only, it is simply 

 laid upon the plate, or upon a tile. Two 

 things, however, require to be attended 



to. 1. If the work be very small, or not 

 capable of being enamelled on the oppo- 

 site side, the iron plate must be perfect- 

 ly flat, in order that the work may not 

 bend when softened by heat. 2. If the 

 work be of considerable size, it is always 

 counter-enamelled, if possible ; that is to 

 say, an enamel is applied on the back 

 surface, in order to counteract the ef- 

 fect which the other coating of glass 

 might produce on the soft metal, when 

 it came to contract by cooling. 



The enameller's furnace is square, and 

 built of bricks, bedded in an earth pro- 

 per for the purpose. It may be consi- 

 dered as consisting of two parts, the 

 lower part which receives a muffle rest- 

 ing on the floor of the furnace, and open 

 on both sides. 



The upper part of the furnace consists 

 of a fire-place, rather larger and longer 

 than the dimensions of the muffle. The 

 fire-place contains the muffle, and must 

 surround it on all sides, except at the 

 bottom. The charcoal is put in at a 

 door above the muffle, which is closed 

 as soon as the fire is lighted. A chim- 

 ney proceeds from the summit of the 

 furnace, with a moderate aperture, which 

 may be closed at the pleasure of the ar- 

 tist, by applying a cast iron plate to it. 

 This furnace differs from that of the as- 

 sayer, in the circumstance that it is sup- 

 plied with air through the muffle itself: 

 for if the draught were beneath the 

 muffle, the heat would be too strong, 

 and could not be stopped when requisite. 



As soon as the fire is lighted, and the 

 muffle has acquired the requisite degree 

 of ignition, tiie charcoal is disposed to- 

 wards the lower part of the muffle, in 

 such a manner as that it shall not fall 

 upon the work, which is then conveyed 

 into the muffle, with the greatest care, 

 upon the plate of iron or earthen-ware, 

 which is taken out by long spring pin- 

 cers. The work is placed as near as 

 possible at the farther extremity of the 

 muffle ; and as soon as the artist per- 

 ceives a commencement of fusion, he 

 turns it round with great delicacy, in or- 

 der that the fusion may be very uniform. 

 And as soon as he perceives that the fu- 

 sion has entirely taken place, he instant- 

 ly removes it out of the furnace : for 

 the fusion of gold happens so very near 

 to that of the enamel, that the neglect 

 of a few seconds might be attended with 

 considerable loss. 



When the work is cooled, a seond coat 

 of enamel is applied in the same manner 

 as the first, if necessary. This, and the 



