276 ENAMELS 



Tlio oiwmclliug workshop ought to admit little or no daylight, otherwise the artist, 

 not perceiving the flame distinctly, would be apt to commit mistakes. 



It is impossible to describe all the manipulations of this ingenious art, over which 

 taste and dexterity so entirely preside. Ihit wo may give an example. Suppose the 

 cnamoller wishes to make a swan. Ho takes a tube of white enamel, seals one of its 

 ends hermetically at his lamp, and while the matter is sufficiently hot, ho blows on 

 it a minikin flask, resembling the body of the bird : he draws out and gracefully 

 bonds the neck ; he shapes the head, the beak, and the tail; then with slender enamel 

 rods of a proper colour, ho makes the eyes ; he next opens up the beak with pointed 

 scissors ; he forms tho wings and the legs ; finally attaching the toes, the bird stands 

 complete. 



The enamellcr also makes artificial eyes for human beings, imitating so perfectly 

 the colours of tho sound eye of any individual as to render it difficult to discover that 

 he has a blind and a seeing one. 



It is difficult to make large articles at the blowpipe; those which surpass 5 or 6 inches 

 become nearly unmanageable by the most expert workman. 



K.N ; CELLING OF CAST IRON AND OTHER HOLLOW WARE FOR SAUCEPANS, &c. In 

 December 1799, a patent was obtained for this process by Dr. Samuel Sandy Hi ckling. 

 His Specification is subdivided into two parts : 



The coating or lining of iron vessels, &c., by fusion with a verifiable mixture, 

 composed of 6 parts of calcined flints, 2 parts of composition or Cornish stone, 9 parts 

 of litharge, 6 parts of borax, 1 part of argillaceous earth, 1 part of nitre, 6 parts of 

 calx of tin, and 1 part of purified potash. Or, 2nd, 



8 parts of calcined flints, 8 rod lead, 6 borax, 5 calx of tin, arid 1 of nitre. Or, 3rd, 



12 of potter's composition, 8 borax, 10 white lead, 2 nitre, 1 white marble calcined, 

 1 argillaceous earth, 2 purified potash, and 5 of calx of tin. Or, 4th, 



4 parts calcined flint, 1 potter's composition, 2 nitre, 8 borax, 1 white marble cal- 

 cined, ^ argillaceous earth, and 2 calx of tin. 



Whichever of the above compositions is taken, must be finely powdered, mixed, and 

 fused ; and the vitreous mass is to be ground when cold, sifted, and levigated with 

 water. It is then made into a pap with water or gum-water. This pap is smeared or 

 brushed over the interior of the vessel, dried and fused with a proper heat in a muffle. 



Calcined bones are also proposed as an ingredient of the flux. 



The fusibility of the vitreoiis compounds is to vary according to the heat to bo 

 applied to the vessel, by using various proportions of the siliceous and fluxing 

 materials. Colours may be given, and also gilding. 



The second part or process in his Specification describes certain alloys of iron and 

 nickel, which he casts into vessels, and lines or coats them with copper precipitated 

 from its saline solutions. It also describes a mode of giving the precipitated copper 

 an enamel surface by acting upon it with bone-ashes and zinc with the aid of heat. 



A factory of such enamelled hollow wares was carried on for some time, but it was 

 given up for want of due encouragement. 



A patent was granted to Thomas and Charles Clarke, on the 25th of May 1839, for 

 a method of enamelling or coating the internal surfaces of iron pots and saucepans, in 

 such a way as shall prevent the enamel from cracking or splitting off from the effects 

 of fire. This Specification prescribes the vessel to be first cleaned by exposing it to tho 

 action of dilute sulphuric acid (sensibly sour to tho taste) for three or four hours, 

 then boiling the vessel in pure water for a short time, and next applying the composi- 

 tion. This consists of 100 Ibs. of calcined ground flints ; 50 Ibs. of borax, calcined, 

 and finely ground with the above. That mixture is to be fused and gradually cooled. 



40 Ibs. weight of tho above product is to be taken -with 5 Ibs. weight of potter's clay ; 

 to br ground together in water until tho mixture forms a pasty consistent mass, 

 which will leave or form a coat on the inner surface of the vessel about one-sixth of an 

 inch thick. When this coat is set, by placing tho vessel in a warm room, the second 

 composition is to be applied. This consists of 125 Ibs. of white glass (without lead), 

 25 Ibs. of borax, 20 Ibs. of soda (crystals), all pulverised together and vitrified by 

 fusion, then ground, cooled in water, and dried. To 45 Ibs. of that mixture, 1 Ib. of 

 soda is to be added, tho whole mixed together in hot water, and when dry pounded; 

 then sifted finely and evenly over tho internal surface of tho vessel previously covered 

 with tho first coating or composition whilst this is still moist. This is tho glazing. 

 The vessel thus prepared is to bo pur. i'lto a stove, and dried at tho temperature of 

 212 Fahr. It is then heated in a kiln or inuflle like that used for glazing china. Tin 

 kiln being brought to its full heat, the ves<--l is placed first at its mouth to heat it. 

 gradually, and then put into the interior for fusion of the glaze. In practice it has 

 been found advantageous also to dust, the glaze powder over the fused glaze, and apply 

 a second fluxing heat in the oven. The enamel, by this double application, becomes 

 much smoother and sounder. 



Messrs. Kenrick, of West 13romwich, produced in their factory some excellent 



