GLAZING. 



colour ; and its Intent is, to give a greater degree t)f clear- 

 nefs and brilliancy to the colour produced by tliis procefs, 

 tkiin can be obtaiiicd by mixing togetlier in fubllance the 

 two colours thus employed. lu this mode their hues are 

 blended, without dilparagement of each other; whereas, in 

 mixing them in tlie ordinary way, a certain diminution ol 

 their brilliancy talces place, produced l)y the difTunilar nature 

 of their qualities. 



Gla/.in'j; appears to h;'.ve been praftifed very early in oil- 

 painting ;'^and probably the ufe of varnilhes over pictures 

 painted with water-colours may have hr(l ihewn its utdity. 

 Indeed it could not fail to be the cafe, if the varnilh em- 

 ployed happened to be tinged with any colour; for the 

 luilre pictures acquiredby that circumllance mull be llriking- 

 iv engaging : a harmony and fweetnefs are tliereby gained, 

 ■\vhich all other means are vainly employed to obtain. It is 

 therefore i'urprizing that all thofe wlio prattifed the art of 

 painting after the difcovery of the ufe of oil, fliould not have 

 given in to tlic application of it. Yet it is certain that the 

 Roman fchool is remarkably deficient in the knowledge of 

 the value of this praAice, and moll frequently negicdted to 



which lie propofes to ufe to A\e general hue of the pidlure 

 bi-fore he applies it. It is not poflibh- to give rules more ex- 

 plicit on tills matter ; tlie indelinlte fubdivlllons of hues which 

 all colours are capable of, mult for ever leave to the reeling and 

 judgment of the artilt their peculiar application. It is hardly 

 neccirary to ilale that a glaze of red, over blue, will produce 

 purple ; of blue, over yellow, green ; and of red, over yel- 

 lov.', orange ; but it may aid the Ihident in his practice, if he 

 coniiders, that all the varieties of tone the original colours 

 are capable of, will, when equally employed, produce a cor- 

 rcfpoiiding compound ; and, of courfe, if his pitture be of 

 too red a Ime, thougli of a light tone, a correfponding one 

 of blue, or of yellow, will cliange it to the one he may re- 

 quire ; and if he ule the blue and yellow together as a green, 

 it will produce a ncg.itive colour ; totally deftroying thered ; 

 but the varieties are too conipHcated and numerous to fol- 

 low. 



Glazixos/" Cloth. The procefs of glazing is ufed for 

 all the llout fabrics of cotton goods, and fometimcs for 

 thofe of linen. It is a part of the general proceffes of 

 iinilhlng goods for the market, and which is carried on by 



life it • owing probably to the employment painlnig found thofe who are generally called cloth-lappcrs, or calender 

 in frefco. The Venetian and Dutch frhools, on the other rr^i i ■ • ., 



hand, employed it in perfeftion, and it is in their works that 

 a knowledge of it may bell be acquired. 



The principal difficulty attending the ufe of glazing, is to 

 avoid the too common application of it ; as it does not fuit 



men. The glazing is done by puttnig on the cloth a fraall 

 quantity of white wax, fuch as that ufed in the manufattm-e 

 of wax candles, and the glofs isafterw?rds effefted by the 

 friction of any fmooth body on the furface of the cloth. By 

 the ordinary procels the apparatus is very hmple, confiit- 



the reprefentations of all fubilances, in its more immediate ing merely of a fmooth table, a little inclined towards the 

 fenfe ; though one general glaze over a picture, completed 

 in its forms, will at all times benefit the work ; if it hap- 

 pens not to be too low, or infipid, in its tones of colour. 



AU kinds of gems and poliflied fubilances, fuch as metals, 

 fdks, velvets, &c. arc iniperfettly wrought to effeft, when 

 it is not employed ; and ilefli, which is in nature compounded 

 of a great variety of colours, is feldom quite perfeA in its 

 hue, when glazing is not employed to fmidi with. It is a 



fpeciesof it, produced by the yellow varnifh being but par- 

 tially removed from old pictures, which gives them their pe- 

 culiar and brilliant luilre. It is quite impoflible to make any 



etfecl exadliy like it with frelh colours, unlefs fome artifice 



be ufed to forerun the eficfts of time ; fuch as rubbing in 



dirt, aud then partially removing it, &c. tricks which picture 



dealers are pcrfedly converfant with; and by which many 



an ingenious copy is paffed oif upon tlie unlearned amateur, 



to the enrichment of the dealer, and the future annoyance of the 



buyer, when lime and improved information let him into the 



fecret. 



Glazing is the moft valir.-.b'.e part 



painting, when judicioufly employed ; 



broken tones of colour, whicli leave 



the pallette, but deceive the cy 



hues, and dazzling efFcft 



of liglit, 



of the practice of 

 as it produces clear 

 no ren.c:i.brancc of 

 by the variety of 

 produced by one 

 colour ihining through another hi difierent degrees of illu- 

 mination ; much more like the effefts of natural objects, 

 than the ufe of O] aque colours can poiTibly produce. But 

 then great dexterity and judgment are reqiiirtd to ufe it pro- 

 pr-rlv in fo general a manner. A well-informed and fcienti- 

 fic artill knows the tone which one colour glazed over an- 

 other wiU produce ; aud without that knowledge, a dirty 

 dulnefs may be the eRVft, inilead of the clearnefs required : 

 and if not fucccfsful, it is always injurious ; tiure is no me- 

 dium in the application of it. If the under colour is not 

 improved, it is fure to be deteriorated ; and it will require 

 repainting, to reilore its original fiernneis. So that when 

 a painter has prepared a work for glazing, {which fliould 

 always be done with great clearnels and precifion,) the moll 

 extreme caution is requiiite in adapting the tone oi the glaie 



operator, like a common writing deilc, ii])on which the cloth 

 to be glazed is fpread inioothly, and drawn over, as occa- 

 fion requires, from one end of the piece to the other. Above 

 this is a lever, fufpended from any convenient fixture to the 

 roof, the lower end hanging in contaft with the cloth, 

 and by movhig this backward and forward, the ne- 

 ceflary friftion is produced. The end of the lever next 

 to, and in contatl with the cloth, is faced with a fmooth 

 piece of flint or pebble, finely pohfhcd, and of a cylindrical 

 form, the under furface of wlilch is in contaft with the 

 cloth. This lever being drawn backward and forward by 

 the operator's hands, the whole clotli is polillied or glazed in 

 fuecelfion, the joint at the top of tlie lever being fitted into 

 a horizontal fiider, which allows the poliflier or liint to be 

 mov.-d from one fide of the cloth to the other. In this way 

 of glazing, the whole is performed by the ]iower of a ir.an's 

 arms and hands ; and, from the pofition of his body being- 

 conilantiy inclined over the table, is found to be a very hibo- 

 rious and fatiguing operation. The great number of people 

 neceffarily employed by this operation, and the difficulty of 

 getting large quantities of goods rapidly glazed to anfv.cr 

 the demands of hurried (hipments for exportation, fuggellcd 

 lately the idea of a more fpeedy and efficacious manner of 

 perferming the operation of glazing by an improveir.ent and 

 alteration in the conftrudtion of the common five-howl caleu- 

 dcr. This improvement was planned and execu'ed at the cx- 

 tenlive works of the late Mr. John Mil'er of Glafgow, who 

 furnifiied the inventor with the means of carrying his plan 

 into effltl, and upon a proof of its efRcacy on trial, his ma- 

 jelly's royal letters patent for itsexcliifive ufe to the invi ntor 

 or his aliignees witliin Scotland were obtained in the ufual 

 form. Two or three machines were t'aen conilrutted for his 

 own works, to which, as far as we know, they are flill con- 

 fined ; and thefe machines have given the moll univerf?! fatis- 

 faftion to all who have had their goods glazed by lh<m, 

 while at the fame time an im.imnfe reduction of labour has 

 , been effedied by their ufe. 



The patent glazing machine, like the common calender, 

 confifts of five bowls, or cyh'nders, four of which are of 



call 



