CHAMBERS'S INFORMATION FOR THE PEOPLE. 



inclosure so formed aquafortis is poured, to the 

 depth of half an inch. This aquafortis decom- 

 poses or bites into the copper where the etching- 

 ground has been removed. During this process, 

 globules of air arise from the decomposition, and 

 these are carefully removed with a feather, to 

 allow free scope to the biting liquid. The length 

 of time employed in biting the plate is regulated 

 by the depth required, also by the state of the 

 atmosphere ; in ordinary cases, the operation 

 may be performed in about an hour. When it is 

 ascertained that the plate is properly acted upon, 

 the aquafortis is poured off, the wall of wax 

 removed, and the ground cleared with spirits of 

 turpentine. The plate is now said to be etched, 

 and when printed from in this state, exhibits the 

 appearance of a pen-and-ink sketch. To this 

 state of etching, but regulated by the nature of 

 the subject, professional engravers bring the plates 

 to be finished in the line manner. Different grada- 

 tions of power are given by the aquafortis, and parts 

 are rebitten to the depth required, the parts not 

 wanted to be rebitten being stopped out ; after 

 which, the light parts are put in with a sharp needle. 

 Other parts are then cut with gravers of various 

 sizes and forms, suited to the lines which will 

 best express the respective objects. The engraver, 

 in thus finishing his work, rests the plate on a 

 small cushion, so that, it may be conveniently 

 turned with the left hand, while the incisions are 

 cut with the graving-tool by the right. These 

 lines are re-entered, crossed in various directions, 

 or cut in the spaces between the diagonal cross- 

 ings, until the desired effect is produced. Land- 

 scapes and architecture are generally executed 

 with the needle and aquafortis : portraits and 

 historical subjects are chiefly cut with the graver 

 or burin, without the use of aquafortis. Where 

 a series of parallel lines are wanted, as in back- 

 grounds, &c., an ingenious machine called a ruler 

 is employed, the accuracy of whose operation is 

 exceedingly perfect. This is made to act on 

 etching-ground by a point or diamond connected 

 with the apparatus, and the tracings are bit in 

 with aquafortis in the ordinary way. 



As etching has become somewhat fashionable, 

 and is now pretty freely cultivated by amateurs, 

 either as an amusement, or with a view to illus- 

 trate discoveries in natural science, it may be well 

 to mention that the art can be learned in a few 

 lessons. Those who reside in large towns will 

 most readily acquire it under the direction of 

 some copper-plate engraver ; those who have no 

 such opportunity, may consult any practical 

 treatise on the subject. The apparatus is by 

 no means costly, and consists of a few copper- 

 plates, etching-needles, a hand-rest, a ball of 

 etching-ground, a dabber, oil-rubber, a little 

 rotten-stone, a smoking-taper, bordering-wax, 

 some varnish for stopping out false lines, tracing- 

 paper, and a phial of aquafortis. The great 

 advantage of etching to the amateur consists in 

 the opportunity it affords him of multiplying im- 

 pressions of his work. A sketch in oil or in water- 

 colours remains single, and a copy can only 

 be obtained by repeating the process ; whereas 

 a sketch once etched can yield hundreds of im- 

 pressions, all precisely the same in every line and 

 feature. Those who can draw in reverse, proceed 

 at once to delineate on the etching-ground ; but 

 in general it is safer to draw on paper, and 



774 



transfer. Etching with a dry point, as it is 

 called, is performed entirely with the point with- 

 out any ground, the burr raised by the graver 

 being taken off by the scraper a steel instrument 

 with three sharp edges. Engraving or etching in 

 soft ground is used to imitate chalk or pencil 

 drawings. For this purpose, the ground is mixed 

 with a portion of tallow or lard, according to the 

 temperature of the air. A piece of tissue-paper 

 being attached to the plate at the four corners by 

 some turners' pitch, and lying over the ground, 

 the drawing is made on the paper, and shadowed 

 with the black-lead pencil. The action of the 

 pencil thus detaches the ground which adheres 

 to the paper, according to the degree to which 

 the finishing is carried ; the paper being then 

 removed, the work is bit, as in etching with the 

 hard ground. 



Stippling is a style of engraving in which dots 

 of various sizes and depths in the copper, instead 

 of lines, express the forms and shades of the 

 subject. They are first made in the etching- 

 ground with the needle, or with a toothed-wheel 

 called a roulette, then bitten, and some parts 

 stopped out, to prevent the further action of the 

 aquafortis on them ; while other parts receive 

 additional bitings, till the subject has the power 

 required. After this the plate is cleaned, dotted 

 up with the needle, stippled with the graver, or 

 rebitten, until all the gradations of force are com- 

 municated. 



Mezzotinto is in a great measure a reversal of 

 those styles already described, being the reducing 

 of a darkened surface of copper to one that is 

 light. The operation is generally commenced by 

 grounding or puncturing the plate with a circular- 

 faced tool called a cradle, on the edge of which 

 are a number of points ; this instrument, by being 

 rocked regularly over the surface of the copper 

 in every direction, covers it so completely with 

 marks, that, if it were printed from, the impres- 

 sion would be perfectly black. On this dark 

 ground the subject is traced, directing where the 

 various gradations of light and half-tint are to be 

 scraped and burnished out, until the proper effect 

 is produced. This style of engraving is used 

 chiefly for portraits and historical subjects. It 

 has a pleasing, soft appearance, but it is under- 

 stood that the copper soon fails in producing 

 strong impressions, and it is therefore not well 

 adapted for subjects of which great numbers are 

 required. 



Aquatinto engraving is an exceedingly com- 

 plicated style of producing pictorial effect. In 

 appearance, it resembles tinting with Indian-ink, 

 and the prints are susceptible of being finished 

 with water-colours. In commencing the process 

 of aquatinto engraving, the plate must be cleaned 

 with an oil-rubber, which is a strip of woollen 

 cloth rolled up hard, to about two inches in 

 diameter ; this, with a little impalpable crocus 

 and sweet oil, will give to the copper-plate, when 

 perfectly cleaned from the oil, a proper surface to 

 receive the ground, which is made with pulverised 

 sifted rosin and spirits of wine, incorporated by a 

 gentle heat, till it appears like a varnish. This 

 composition is poured over the plate while placed 

 in a slanting position, so as to permit the super- 

 fluous liquid to run off. The operation must be 

 so managed as to preserve an equal surface. As 

 soon as the granulation, or drying of the grain, 



