ENGRAVING, 



The tools required for this easy and 

 rapid mode of proceeding- are, the ground- 

 ing-tool, the scraper, and the burnisher ; 

 the copperplate should be prepared as if 

 intended for the graver, and laid flat upon 

 a table, with a piece of flannel spread 

 under it, to prevent the plate from slip- 

 ping- ; the grounding-tool is then held 

 perpendicularly on it, and rocked with 

 moderate pressure backwards and tor- 

 wards, till the teeth of the tool have 

 equally and regularly marked the copper 

 from side to side; the operation is after- 

 wards repeated from end to end, and from 

 each corner to the opposite ; but it is ne- 

 cessary to observe, that the tool must 

 never be permitted to cut twice in the 

 same place ; by this means the surface is 

 converted into a rough chaos of intersec- 

 tions, which, if covered with ink and 

 printed, would present a perfectly black 

 impression upon the paper. 



To transfer the design to be scraped, 

 it is usual to rub the rough side of the 

 plate with a rag dipped into the scra- 

 pings of black chalk, or to smoke it with 

 burning wax taper, as in the process for 

 etching ; the back of the design is then 

 covered with a mixture of powdered red 

 chalk and flake white, and laid on the 

 plate through which it is traced ; parti- 

 cles of red, in the form of the outlines, 

 are thus conveyed to ilie black chalk on 

 the plate, which are to be secured there 

 by the marks of a blunted point ; the 

 process must then be carried on with the 

 scraper, by restoring the .plate in the 

 perfectly light parts of the intended print 

 to a smooth surface, from which' the gra- 

 dations are preserved by scraping off 

 more or less of the rough ground ; but 

 the burnisher is necessary to polish the 

 extreme edges of drapery, -.c., where the 

 free touch of the brush in painting repre- 

 sents a brilliant spot of light. The deep- 

 est shades are sometimes etched and cor- 

 roded by aquafortis, and so blended with 

 the mezzotinto ground added afterwards, 

 that there is nothing offensive to the eye 

 in the combination. 



Many proofs are required to ascertain 

 whether the scraping approaches the de- 

 sired effect, which is done by touching 

 the deficient parts with white or black 

 chalk, on one of the proofs from the 

 original drawing, and then endeavouring 

 to make the plate similar by further 

 scraping, or relaying the ground with 

 a small tool made for this particular pur- 

 pose, where too much of the roughness 

 has be en effaced. 



Engraving on Steel is confined to the 

 cutting of puncht-s, for the conveyance 

 of any form a certain depth into that or 

 any other metal, seals, and dyes, for im- 

 pressing the designs of coins, medals, &,c . 

 on gold, silver, or copper, &c. The 

 punches are engraved from models in 

 wax made in relievo, and, when com- 

 pleted, are tempered to that degree of 

 solidity, which will bear the violent blows, 

 without blunting the finest parts or break- 

 ing them, necessary to produce the ma- 

 trix in the steel intended for striking of 

 medals or coins, which must be heated 

 to prevent such a disaster, and tempered 

 again, for a similar reason to the preced- 

 ing, after it is finished. 



There are several tools used in finish- 

 ing of dyes, which are, gravers, chissels, 

 and flatters ; and many little punches for 

 making ornamental borders and mould- 

 ings to coins and medals ; the latter are 

 always in greater relief than the former, 

 and consequently more difficult to exe- 

 cute in perfection. 



Engraving on precious Stones is accom- 

 plished with the diamond or emery. The 

 diamond possesses the peculiar property 

 of resisting every body in nature, and, 

 though the hardest of all stones, it may 

 be cut by a part of itself, and polished by 

 its own particles. In order to render this 

 splendid substance fit to perform the 

 operations of the tool, two rough dia- 

 monds are cemented fast to the ends of 

 the same number of sticks, and rubbed 

 together till the form is obtained for 

 which they are intended ; the powder 

 thus produced is preserved, and used 

 for polishing them in a kind of mill fur- 

 nished with a wheel of iron ; the diamond 

 is then secured in a brazen dish, and the 

 dust mixed with olive oil applied, the 

 wheel is set in motion, and the friction 

 occasions the polished surface so neces- 

 sary to give their lustre due effect. Other 

 stones, as rubies, topazes, and sapphires, 

 are cut into various angles on a wheel of 

 copper, and the material for polishing 

 those is tripoli diluted with water. 



A leaden wheel, covered with emery 

 mixed with water, is preferred for the 

 cutting of emeralds, amethysts, hya- 

 cinths, agates, granites, &.c. 8cc. and they 

 are polished on a pewter wheel with 

 tripoli ; opal, lapis lazuli, &c.are polished 

 on a wheel made of wood. 



Contrary to the method used by per- 

 sons who turn metals, in which the sub- 

 stance to be wrought is fixed in the lathe, 

 turned by it, and the tool held to the sub- 



