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ENGRAVING. aqua fortis, of those made by the interven- the copper-plate printers' rolling press, who tion of that liquid the principal is Etching, will accomplish it by laying the plate carehe that would excel in this branch of the fully on the board of his press, the pencilled arts must be thoroughly acquainted with paper slightly damped on it, and turning drawing, otherwise his works will appear the press the lead will be conveyed firmly tasteless indeed. The ground used in etch- to the ground, which will appear in perfect ing is a combination of asphaltum, gum- outlines on removing the paper. Another mastick, and virgin wax, mixed in such pro- method is to draw the design reversed from portions as will prevent the asphaltum from the original; rub the back with powdered breaking the composition when under the white chalk, and laying it on the ground aqua fortis, or the wax from making it so trace the lines through with a blunt point; soft as to close the lines when cut through this operation requires much precaution or it by the needle. As every thing depends the point will cut the ground; besides, if upon the stability of the ground, it should the paper is not securely fastened with wax be purchased of those persons who are most at the corners it may slip, and either intercelebrated for making it; or if the person rupt the true continuation of lines, or wishing to use it prefers doing it himself, scratch the ground. let him remember that he must keep every In working with the etching needle particle of grease or oil far from him and nothing more is required than to keep his materials, and that without the greatest it npright, that the lines made by it care the inflammability of the asphaltum through the ground may not slope, and thus will ruin his operations in melting them. make the aqua fortis corrode improperly; The proportions of the ingredients should be but it should be particularly observed, that obtained by experimer:t.

the point, thouglı taper, must be so rounded After being prepared in the above man- as to be free from a possibility of its tearing ner the ground is tied in a piece of lustring the surface of the copper, which would pre. for use, and another piece of the same kind vent the progress of the point, and ruin the of silk must be made into a dabber by plate when bitten; the necessary polish of tying a quantity of cotton in it. The cop- the point may be accomplished by rubbing per-plate, hammered to a considerable de- it on the sole of a shoe. The young artist gree of hardness, polished as if intended for must now be left to bis own exertions, as the graver, and perfectly cleansed with directions for etching beyond those already whiting, is then secured at one corner by given are useless, and he will acquire more a hand vice, heated over a charcoal tire, knowledge and freedom from copying good and the silk containing the ground rubbed prints in one week than a quarto volume over it till every part is covered by the of observations would afford. melted composition; but before it cools the almost needless to add, that every line must silk dabber must be applied in all direc- be kept distinct, at all events, throughont tions, till the surface of the plate is thinly the plate, and that the most distant should and equally varnished. After this part of be closer and more regular than those in the process is completed, several lengths of the fore ground, as the greater the depth of wax taper, twisted together, are to be shade the broader and deeper must the lines lighted, the plate raised by the vice in the be made. left hand, and the right holding the burning When the etching of the plate is comtaper is to be moved gently backwards and pletely finished, the edges of it must be surforwards under the ground, carefully avoid rounded by a high border of wax, so well ing touching it with the wick, yet causing secured that water will not penetrate bethe flame to spread over the surface, which tween the plate and it. The best spirits will render it perfectly black, smooth, and of nitre fortis must then be diluted with shining, in a short time; this is to be ascer- water, in the proportion of one part of tained by turning the plate : if the copper the former to four of the latter, which will appears through the ground, the taper must be found to answer the first operations, it be applied again immediately; but if it is the weather is fine and the atmosphere held too long beneath the plate, the ground free from moisture; but, if the contrary is will become opaque, and break when the the case, the spirits of nitre must be inaqua fortis is used.

creased in proportion to the humidity of The next object is to transfer the design the air; this, when poured on the plate, to the ground, which may be done by cannot be too attentively observed in order drawing it on thin white paper with a black to remove the bubbles of fixed air with lead pencil, and having it passed through a feather, and to ascertain the tinie for

It seems

stopping out the lightest parts ; for it must with figures, when printed in colours have a be remembered the whole secret of biting pleasing effect; and small portraits stipled or corroding any subject consists in the will bear examination; but historical subjudicions manner in which the depth and jects, which have great breadth of shade, breadth of the lines are varied, as by pro- appear to no advantage engraved in this per management they may be left scarcely manner. Stipling is performed by etching perceptible, or increased very considerably. the plate with dots and biting it, laying the The composition used for the above pur shades with a tool for the purpose, using pose is, turpentine varnish mixed with the graver and the dry point, and scraping lamp-black, and diluted so as to be used off the roughness thus occasioned. freely with a camel's hair pencil; this ap- Engruving in Aquatinta. The print from plied to the parts of the plate sufficiently an aqua-tinted plate resembles a neatly corroded, will effectually prevent the aqua finished drawing in Indian ink ; this effect is fortis from touching it again, and the re- produced by corroding the plate between mainder proceeds as if no such application the particles of a material entirely differhad taken place: it will be necessary to ent from the etching ground. The first step strengthen the water as the work becomes in this process is to prepare a plate exactly nearer completion, but cautionsly, lest the in the way already described, and etch the ground should be broken; and every time outlines of the subject to be aqua-tinted, the aqua fortis is removed the plate must whịch are to be slightly bitten, and the plate be washed with clean water and gradually thoroughly cleansed. The substance used dried, otherwise the varnish cannot be nsed, to form the grains of the subject (which may and the lines would be clogged with the de. be common resin, burgundy-pitch, asphal. composed metal. For taking the ground from tum, gum-mastich, or gum-copal, either the plate it is usual to cover the surface with separate or mixed) should be reduced to a olive oil, and heating it, wipe the plate with fine powder and sifted, put into a piece of a soft piece of old linen and spirits of tur- muslin, and holding it high above the plate pentine, will effectually remove all remain- it must be struck against any substance ing dirt.

held in the left band till the shower of dust Re-biting, is the art of strengthening those thus produced has covered the plate equally lines of an etching in a plate from which the throughout, preserving it carefully in this original ground has been cleansed. This is situation, the plate is to be heated suffi. done by applying the ground as at first di- ciently to melt the powder, which will rected, but with great care that the melted make the grains assume a circular form, and composition does not fill, or even partially contract, leaving, when cold, a beautiful surfill the lines, to prevent which the cotton face fit for the aqua fortis. Common resin wrapt in silk, called the dabber, should be is generally preferred for this part of the used exclusively by taking a small quantity operation, but gum-copal is less liable to of melted ground on it, and gently touching be broken loose from the plate during the the parts between the lines till they are process of biting. equally and completely covered; if the The drawing to be copied must serve as plate is considerably heated, the ground the future basis of proceeding, which is to will spread with more facility over the be imitated in the following manner: the various interrupted surfaces. Carelessness perfectly white parts of the intended print or inattention will instantly ruin this pro- are to be covered on the plate, with the cess, and the whole of the plate: a border varnish mentioned in etching, by the use of of wax must surround the parts to be re- a camel's-hair pencil; a border of wax must bitten, and a channel made to carry off the then be raised, and the aqua fortis diluted aqua fortis without injuring those already poured on; the same method is afterwards completed. Supposing the operations of practised in the stopping out before recometching and biting the plate entirely finish- mended, except that the depth of the cored, nothing more remains than to examine roding cannot be so great as in the line it attentively, and improve it with the manner. graver and dry point.

In order to obviate any difficulties which Stipling, or engraving in the dotted man- occur in procuring sufficient depths of mer, was in a great measure introduced by shade, a method has been invented that en. Bartolozzi, whose works in this way are ables the artist to produce an effect almost astonishingly numerous, éxclusive of those equal to the decisive touches of a brush to which his name is affixed and not the filled with colour in drawing, which is the products of bimself. Some pastoral scenes, use of a liquid made with water, treacle, ENG

ENN or sugar, and fine washed whiting, exactly landscape than if the granulations had been of the consistence of Indian-ink, and laid equally fine; in large subjects the grain is on the granulated surface with a pencil, in sometimes laid coarse purposely in the parts the same free manner adopted on paper; requiring it. after the above composition is thoroughly Although a fine grain has a very pleasing dry, the whole plate must be covered with effect, and will bear close examination, it a thin, weak, varnish of mastich, turpentine, has several disadvantages; for this reason a or asphaltum, and when dried a second time, medium description of granulation is prethe aqua fortis is to be applied, which im- ferable, which admitting the aqua fortis mediately breaking the varnish and whiting, freely to the copper, it bites dceper, and is will corrode the plate precisely in the marks less apt by acting laterally to force off the of the pencil. The border of wax may be resin, besides, the plate will of course afford removed by heating the plate gently, and a greater number of impressions. the ground varnish, &c. by oil of turpentine ; Some hints have been given already for a little fine whiting and a clean rag will then biting the plate; but however useful those render the plate fit for the printer. may be found in particular instances, there

As the manner of procuring the grain by are others which can only be extracted from beating the powdered substance scattered close application and experiment, and those over the plate is liable to objections, on ac- are often varied in their results : as an illuscount of the difficulty of making the par. tration, we may suppose an artist provided ticles assume the desired coarseness, or the with several pieces of copper granulated, reverse, and the engraving so produced ra- and trying each successively by his watch pidly wearing out in the printing, another with spirits of nitre diluted to the state of has been contrived far more certain and the air at the commencement of his operasatisfactory. In this mode, common resin, tions, how many minutes is necessary to mastich, or Burgundy pitch, is dissolved in produce one tint, how many for a second, highly rectified spirits of wine of the best &c. granting him two hours for his experi. quality, each of which produce different ment; during this interval a violent shower descriptions of grains; but these substances of rain may occur, which will immediately may be mixed in such proportions as the affect the acid by weakening its properties artist prefers, and he must recollect that the in the same proportion as salt is observed to resin makes the coarsest: to satisfy him- be dissolved by a humid atmosphere: thus self in this particular, the grain of every it appears, a result obtained on a clear dry proportion should be tried on useless pieces day will not suit a rainy one, and vice versa. of copper. Having a solution to his mind, In opposition to this discouraging uncerit must remain undisturbed till every im- tainty, and in opposition to the judgment and pure particle has subsided. The plate, po- preference of all true connoisseurs, aqualished and cleansed with whiting, is then tinted prints seem to increase in value in placed to receive the liquid, which being the estimation of many persons, who forget poured on it, is held slanting till the most that national taste should be improved by Anid parts has run off; it is afterwards laid works of superior execution, and not vitiatto dry, in the progress of which the resin ed by being constantly familiarized to those granulates, and adheres firmly to the sur produced by means which set genius at deface. The greatest precaution must be fiance. used in going through this process, as the ENNEAGON, in geometry, a polygon interposition of dust, grease, hairs, or fibres with nine sides. If each side be 1, the area of linen, will cause total derangement, and will be 6, 18, &c. even then it is subject to most vexatious ENNEANDRIA, the name of the ninth uncertainty, often compelling the experi- class in Linnæus's sexual system, consistensed artist to renew it to obtain a good ing of plants which have hermaphrodite grain; in short, the weather and untoward flowers, with nine stamina or male organs. accidents frequently ruin his labours, though The orders, or secondary divisions, in this guarded against by every method his inven- class are three, being founded on the namtion suggests. There is one advantage at- ber of the styles, seed buds, or female or tending the pouring the liquid off, which is, gans. Laurus, tinus, and cassytha, have that the heaviest particles of the resin will one style; rhubarb (rheum), has a triple float to the lower side, and consequently stigma or summit, but scarce any style; leave a coarser grain there than above, flowering rush has six styles. The genera sanch better suited to the deep shades of a just enumerated are all that belong to the

class Enneandria. The first genus, laurus, tude, yet they surpass, in variety of strucis very extensive ; comprehending the bay- ture and singularity of appearance, all the tree, cinnamon tie, camphor tree, benja- larger branches of the animal vorld. No min tree, sassafras tree, and the avocado or one can examine with an attentive eye the avogato pear.

subjects of this branch of science without ENS martis, an old name given by che surprise ; the great variety of forms, the mists to sal ammoniac sublimed with iron nice adaptation of their parts to the situafilings, and therefore consisting of muriate tion in which each happens to be placed, of ammonia mixed with a little muriate of may excite the amazement of the curious iron.

and intelligent mind. The same power and Ens reneris, a similar preparation, in wisdom which are manifested in the order, which copper filings are substituted for those harmony, and beauty of the heavenly boof iron.

dies, are equally shewn in the formation of ENSATÆ, (from enses, a sword), the the minutest insect; each has received that name of the sixth order in Linnæus's Frag. mechanism of body, those peculiar instincts, ments of a Natural Method, consisting of and is made to undergo those different plants with sword-shaped leaves.

changes, which fit it for its destined situaENSIFORM, in general, something re- tion, and enable it to perform its proper sembling a sword, ensis : thus we find men- functions. The utility of many insects, eition of ensiform leaves, ensiform cartilage, ther in their living or dead state, as the bee, &c.

the crab, the silk-worm, cochineal insect, ENSIGN, in the military art, a banner (see Apis, Coccus, &c.) renders them inunder which the soldiers are ranged accord- teresting and important; besides, though ing to the different companies or parties diminutive in point of size, they are, in rethey belong to. The European ensigns are gard to numbers, unquestionably the most pieces of taffety with various figures, arms, distinguished of the works of nature; they and devices painted on them in different are to be found in every situation, in water, colours: the Turkish ensigns are horses' tails. in air, and in the bowels of the earth ; they

Ensign is also the officer that carries the live in wood, upon animals, decayed vegecolours, being the lowest commissioned of. tables, and all kinds of flesh, and in every ficer in a company of foot, subordinate to state of its existence down to the most puthe captain and lieutenant. It is a very ho trid. nourable and proper post for a young gen- The general characters by which insects tleman at his first coming into the army; he are distinguished are the following: they is to carry the colours both in assault, day are furnished with several, six or more, of battle, &c., and should not quit them feet; the muscles are affixed to the interbut with his life; he is always to carry them nal surface of the skin, which is a substance himself on his left shoulder, only on a march more or less strong, and sometimes very he may have them carried by a soldier. If bard and horny; they do not breathe like the ensign is killed, then the captain is to larger animals, by lungs or gills situated in carry the colours in his stead.

the upper part of the body; but by a sort ENTABLATURE, in architecture, is of spiracles, distributed in a series or row that part of an order of a column, which is on each side the whole length of the abdoover the capital, and comprehends the men; these are supposed to communicate architrave, frieze, and cornice.

with a continued chain, as it were, of lungs, ENTAIL, in law, signifies fee-tail, or or something analogous to them, distributed fee-intailed. See EsTATE.

throughout the whole length of the body; ENTIERTIE denotes the whole, in con- the head is furnished with a pair of what tradistinction to moiety, which denotes the are termed antennæ, or horns, which are half; and a bond, damages, &c. are said to extremely different in different tribes, and be entire when they cannot be apportioned. which, by their structure, &c., form a lead

ENTIRE tenancy, signifies a sole posses- ing character in the institution of the gesiop in one man.

nera into which insects are divided. ENTOMOLOGY is that branch of na

Writers op natural history formerly intural history that treats of insects. The cluded snails, worms, and the smaller ani. study of insects has sometimes been ridi- mals, or animalcules, in general, among in. culed as unworthy the attention of men of sects: these are now more properly placed science ; for this, however, there is no just among the tribe vermes, or worm-like anireason ; though inferior in point of magni- mals. Insects have also been denominated

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ENTOMOLOGY.
Bloodless animals, which modern disco- in this state likewise, the insects of dif-
veries have shewn to be contrary to fact: ferent genera differ alınost as much as the
some of them, as the cimex lectularius, larva. "In most of the beetle tribe it is fur-
have been frequently used with the micro- nished with short legs, capable of some de.
scope, to exhibit in a striking manner the gree of motion, though very rarely exerted.
circulation of the blood. In this insect, In the butterfly tribe it is destitute of legs ;
with a good glass, the vibrations and con- but in the locust tribe it differs

very

little
tractions of the arteries may be distinctly from the perfect insect, except in not hav-
observed.

ing the wings complete. In most of the
Most insects are oviparous ; of course, fly tribe it is perfectly oval, without any
the first state in which insects appear is apparent motion or distinction of parts.
that of an ovum or egg. This relates to The pupa of the bee is not so shapeless as that
the generality of insects, for there are some of flies, exhibiting the faint appearance of
examples of viviparous insects, as in the ge- limbs. Those of the dragon-fly (libellula)
nera Aphis, Musca, &c. From the egg is differ most widely from the appearance of
hatched the insect in its second or cater- the complete insect; from the pupa emerges
pillar state; this second state has been the insect in its ultimate form, from which
usually known by the name of eruca, but it never changes, nor receives any farther
Linnæus has changed it to that of LARVA, increase of growth.
which see; considering it as a sort of mask- Different naturalists have attempted to
ed form or disguise of the insect in its com. arrange insects into families and genera, par-
plete state. The larvæ of insects differ ticularly the celebrated Linnæus, whose ar-
very much from each other, according to rangement may be thus explained. He has
the several tribes to which they belong; formed them into seven families or orders,
those of the butterfly and moth tribe (pha- composing his sixth class of animals, In-
læna) are generally known by the name of secta : he defines an sect, a small animal,
caterpillars; those of the beetle (scara. breathing throngh pores on its sides, fur-
bæus), except such as inhabit the water, nished with moveable antennæ and many
are of a thick, clumsy form. The larvæ of feet, covered with either a hard crust or a
the locust, or grasshopper, (gryllus), do not hairy skin. As introductory to the distin-
differ very much in appearance from the guishing marks of the orders and genera, it
complete insect, except being without will be necessary to enumerate and explain
wings. The larvæ of Aies, bees, (musca, the terms given to the different parts, and
apis,) &c. are generally known by the the most remarkable of the epithets he has
name of maggots, and are of thick short applied to them. The body is divided into
form. Those of water beetles (dytiscu s) head, trunk, abdomen, and extremities.
are of highly singular forms, and differ, per- I. Caput, the head, which is distinguish-
haps, more from that of the complete in. able in most insects, is furnished with eyes,
sect than any others, except those of the antennæ, and most frequently with a mouth;
butterfly tribe. Some insects undergo no the eyes, two, four, six, or eight in number,
change of shape, but are hatched from the destitute of eye-lids, are either small and
egg complete in all their parts, and they simple; or large, compound, and hemi-
undergo no farther alteration than that of spherical; or polyedral; they are commonly
casting their skin from time to time, till they immoveable; they are called stipitati, when
acquire the complete resemblance of the pa. placed on a stalk. The antennæ are two
rent animal. In the larvæ state most in- articulated moveable processes, placed on
sects are peculiarly voracious, as in many the head; they are either, 1. Setacea, se-
of the common caterpillars. In their per- taceous, i. e. like a bristle, when they taper
fect state some insects, as butterflies, are gradually from their base, or inserted inte
satisfied with the lightest nutriment, while the head to their point. 2. Clavatæ, cla
others devour animal and vegetable sub- vated, i. e, club-shaped, when they grov
stances with a considerable degree of gradually thicker from their base to the
avidity. When the larvæ is about to change point. 3. Filiformes, filiform, i, e. threat
into the chrysalis or pupa state, it ceases to shaped, when they are of an equal thick
feed, and having placed itself in some quiet ness throughout the whole of their lengti
situation, lies still for several hours, and 4. Moniliformes, moniliform, i. e. of the
then, by a sort of effort, it divests itself of form of a necklace, when they are of an
its external skin, and immediately appears equal thickness throughout, but formed of
in the different form of a chrysalis or pupa; a series of knobs, resembling a string of

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