1847.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



355 



alterable colours. G. The application of the above-described colours 

 to the process cf painting and printing on paper-hangings. 7. The 

 application of the above-described colours and dryer to the process of 

 polished painting. 8. The mixture of the above colours with other 

 unalterable colours, with or without the dryer, for the purpose of ob- 

 taining anj' desired shade of colour. 



JAPANNING METALS. 



FnEDEr.iCK Walton, of Wolverhampton, Staffordshire, japanner 

 and tin-plate worker, for "an Improved mode of coaling or conring, 

 or of coating, covering, and ornamenting the surfaces of articles mliicfi 

 are or may be made of wrought iron, or of other metal or metals ; which 

 improved mode may be used in substitution of japanning, tinning,or other 

 modes, now in common use, of coating, covering, or of coating, covering. 

 Olid ornamenting such articles." — (iranted February 24 ; Enrolled 

 Aug. 24, 1S47. — [Reported in Newton's London Journal."^ 



This invention relates to coating the surfaces of wrought iron, or 

 other malleable metal that will bear a strong red heat without injury 

 (such as brass or copper), so as to furm a glazed enamelled surface 

 either plain or ornamented. 



The first preparation is to clean the surfaces of the articles, by first 

 subjecting tliem to a red heat in an annealing oven, or in a muffle, ac- 

 cording to their size, for about half an hour, to dissipate all liquid 

 or greasy matter, and oxidate the surfaces. The oxide is removed 

 by rubbing with sand-stone, or scrapers. When cleaned, the articles 

 are to receive a first coat of partially vitrifiable materials, which is 

 poured in a semi-liquid state over the surface of the article, and dis- 

 tributed evenly; the article is then placed in an ordinary japanner's 

 stove, heated to 180°, and left therein until all moisture is gradually 

 dried away, leaving the same in a state of dry whitish composition, 

 which will adhere to the article, without it is roughly touched with 

 the fingers. 



The composition for the first coating is prepared as follows: — G 

 parts, by weight, of flint-glass, broken into small fragments, 3 parts of 

 borax, 1 part of red lead, and 1 part of oxide of tin, are to be well 

 mixed, by pounding in an iron mortar, and "fritted" in the same man- 

 ner as is usually done with the materials for making glass. 1 part, by 

 weight, of the " fritt," so made, is to be mixed vvitti two parts of cal- 

 cined bone, ground to powder; and the mixture of fritt and bone is 

 then to be ground with water in a "porcelain mill," until a semi- 

 liquid, of the same consistence and appearance as thick cream, is 

 produced, which, after being passed through sieves of fine lawn, is 

 ready to be applied to the articles, as above mentioned. 



When the first coating is dry, the articles are ready for firing, in 

 order so far to vitrify the materials, as to harden the coating, and 

 fasten it on the surfaces of the articles. The firing is performed in a 

 furnace of the kind used by painters in enamel. The muffle having 

 been brought to a full red heat, the articles are introduced, and are 

 left therein until the earthy composition has undergone so much of 

 the commencement of fusion, or partial semi-vitrification, as to render 

 the earthy particles of the coating firmly adherent to one another, and 

 to the surface of the articles, which are then to be withdrawn from 

 the muffle, and laid on a flat iron bench to cool ; when cold, those 

 parts of the surface which have been coated, present a dead whitish 

 appearance, resembling earthenware in the state of " biscuit :" the 

 time that the articles must remain in the muffl", varies from a few 

 minutes to half an hour, according to the heat of the muffle, the size 

 of the articles, and the number of articles in the muffle at the same 

 time. After the articles have become cool, the coating is wetted 

 with water, and a second coat is then applied over the first coat, and 

 dried thereon in the japanner's stove; it is then fired in the muffle in 

 the same manner as the first coat. The composition for the second 

 coat is prepared as follows : — A thick paste is made, by mixing 32 

 parts, by weight, of calcined bone, ground to fine powder, 16 parts of 

 china-clay, 14 parts of Cornwall stone, in fine powder, and 8 parts of 

 carbonate of potash, the latter being dissolved in water; the mixture 

 is fritted for two or three hours in a reverberatory furnace, until it 

 assumes the appearance of biscuit-china ; and then it is to be reduced 

 to powder. 5i parts, by weight, of this powder, are mixed with 16 

 parts of flint glass, broken small, 5^ parts of ground calcined bone, 

 and 3 parts of ground calcined flint ; and the mixture is reduced to 

 the consistence of cream, by grinding in a porcelain mill, in the man- 

 ner described for the first composition. In firing the second coating, 

 care must be taken that the heat of the muffle is sufiicient, and that 

 the articles are kept in long enough to effect the thorough incorpora- 

 tion of the second coat with the first, and to harden both coats. Alter 

 the second coating, the articles will have a stronger and whiter colour, 

 tind bear a mure decided resemblance to articles if liied earthenware 



in a state of biscuit; but in case it is desired to give a very white 

 colour to the second coating, in order that it may resemble the finest 

 earthenware in the state of biscuit, then, in place of the IG parts of 

 flint-glass, last mentioned, the patentee substitutes a like quantity of 

 a composition, formed by mixing 4 parts, by weight, of pulverized 

 felspar, 4 parts of white saud, 4 parts of carbiniate of potash, 1 part 

 of arsenic, parts of borax, 1 part of oxiile of tin, 1 part of nitre, and 



1 part of whiting, fritting the mixture, and then reducing it to pow- 

 der. 



When the articles have become cool, after receiving the second 

 coat, this coat is wetted with water, and a third coat is applied, and 

 fired in a similar manner ; and, when cool, the article will present the 

 appearance of glazed earthenware of good quality, or of the best 

 quality, in case the composition, last mentioned, has been substituted 

 for the flint-glass amongst the materials for the second coat. The 

 materials used for forming the third coat or glaze are, 12 parts, by 

 weight, of pulverized felspar, 4J parts of china-clay, 18 parts of 

 borax, 3 parts of nitre, IJ parts of carbonate of potash, and 14 parts of 

 oxide of tin: these ingredients are treated in the same manner as 

 those for making the second coat. Instead of the materials and pro- 

 portions just mentioned, the following may be used: — 9 parts, by 

 weight, of pulverized felspar, 2 parts of china-clay, 9 parts of borax, 



2 parts of nitre, 3 parts of carbonate of soda, and i part of arsenic. 

 In case there are any imperfections in the glaze, after it has been 

 fired, then, when the articles are cold, another coat of the glaze may 

 be applied, in a semi-liquid state, and dried in the japanner's stove, 

 and fired in the muffle in the same manner as the first glaze : in like 

 manner, a third coating of the glaze may be applied, if requisite. 



The articles that have been coated on one side, may have the 

 opposite side coated with black glaze, applied with a sponge when 

 in a semi-liquid state, dried on in the japanner's stove, and then 

 fired in the muffle. The black glaze may be composed of the name 

 materials as either of the compositions, before described, for thsSIiird 

 coat or glaze, with the addition of 2 parts, by weight, of oxide of 

 manganese, and 1 part of cobalt ; which materials are to be added to 

 the other ingredients, previous lo the mixture being fritted. If ix 

 deep blue glaze is preferred to black, then the oxide of manganese 

 may be diminished or omitted ; and so much as is omitted may be re- 

 placed, weight for weight, by cobalt, in addition to the quantity of 

 cobalt above mentioned. Or, instead of the back or under side of the 

 article being coated with black or blue glaze, it may be finished by 

 japanning, according to the method usuahy adopted by japanner*. 



ELECTRIC LIGHT. 



Thomas Wright, of Cooper's-hill, Thames Ditton, Surrey, Esq., 

 for " Improvements in apparatus for the production and diffusion of 

 WgA^"— GrMted Ma.ch 9; Enrolled Sept. 9, 1845. 



This invention consists in producing a permanent light, by present- 

 ing one or more fresh points or surfices of carbon, or other suitable 

 material, continually to the path of an electric current, by an appara- 

 tus similar to the annexed engraving, a, is a double annular frame 



of wood, or other non-conductor of electricity, with five (or more) 

 discs b, c, d, e,f, turning on axes with bearings attached to the frame 

 a. The discs consist of two circular plates of brass, or other metal, 

 with a disc of plumbago or carbon (the latter being preferred), be- 

 tween them, somewhat larger in diameter than the brass plates, about 

 one-fourth of an inch thick, and having an angular or V-sh.iped 

 edge. The ''axes of 'wo of the discs c, e, are mounted in sliding 



46* 



