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communicates with F, but acts through G the horse's falling when the ram is disupon the lower part of the piston. H, and charged; C, the drum on which the great raises it; while the contents of the great rope is wound; D, the follower (with a rolcylinder above that piston are driven out ler at one corner) in which are contained through F, and pass through the opening at the tongs, to take hold of the ram, and are D into R. It may be observed, that the fastened to the other end of the great rope, column which acts against the piston is as- which passes over the pulley, near the upsisted by the pressure of the atmosphere, per end of the guides between which the rendered active by the column of water ram falls; E, the inclined planes, which hanging in R, to which that assisting pres- serve to open the tongs, and discharge the sure is equivalent, as has already been no- ram;F, the spiral barrel that is fixed to the ticed. When the piston has ascended drum, on which is wound a rope with a through a certain length, another slide or counterpoise, to hinder the follower from block upon the pit-rod (not seen) applies accelerating, when it falls down to take up against the tail, K, of the tumbler, which it the ram; G, the great bolt which locks the raises and again oversets, producing once drum to the great wheel ; H, the small lemore the position of the plugs, DE, liere ver, which has a weight fixed at one end, delineated, and the consequent descent of passes through the great shaft below the the great piston, H, as before described. great wheel, and always tends to push the The descent produced the former effect on great bolt upwards, and lock the drum to the tumbler and plugs, and in this manner the great wheel; I, the forcing bar, which it is evident that the alternations will go on passes through the hollow axis of the great without limit, or until the manager shall shast, bears upon the small lever, and has think fit to place the tumbler and plugs, near the upper end a catch by which the D E, in the positions of rest, namely, so as crooked lever keeps it down; K, the great to stop the passages, F and G. The length lever, which presses down the forcing bar, of the stroke may he varied by altering the and discharges the great bolt at the time positions of the pieces, I, and the other the long end is lifted up by the follower; lower down, which will shorten the stroke, L, the crooked lever, one end of which has a the nearer they are together; as in that roller, that is pressed upon by the great case they will sooner alternate upon the rope, the other end bears upon the catch of tail, K. As the sudden stoppage of the the forcing bar during the time the follower descent of the column, A B, at the instant is descending; M, the spring that presses when the two plugs were both in the water- against the crooked lever, and discharges it way might jar and shake the apparatus, those from the catch of the forcing bar as soon as plugs are made half an inch shorter than the great rope slackens and gives liberty to the depth of the side holes, so that in that the small lever to push up the bolt. ease the water can escape directly through By the horse's going round, the great both the small cylinders to R. This gives rope is wound about the drum, and the a moment of time for the generation of the ram is drawn up, till the tongs come becontrary motion in the piston, and the water tween the inclined planes, where they are in G GG, and greatly deadens the concus- opened, and the ram is discharged. sion which might else be produced. See Immediately after the ram is discharged, STEAM ENGINE.
the roller, which is at one end of the folSome former attempts to make pressure lower, takes hold of the rope that is fastengines upon the principle of the steam-en- ened to the long end of the great lever, and gine have failed; because water not being lifts it up; the other end presses down the elastic, could not be made to carry the pis- forcing bar, unlocks the drum, and the fol. ton onwards a little, so as completely to lower comes down by its own weight. shut one set of valves and open another; As soon as the follower touches the ram, in the present judicious construction the the great rope slackens, and the spring, M, tumbler performs the office of the expansive discharges the crooked lever from the catch force of steam at the end of the stroke. of the forcing bar, and gives liberty to the
Engine for driving piles, used at build- small lever to push up the great bolt, and ing Westminster bridge, is constructed as to lock the drum to the great wheel, and follows: A, (Plate V. Miscel. fig. 3.) is the the ram is drawn up again as before. great shaft, on which are the great wheel and ENGINEER, in the military art, an drum: B, the great wheel with cogs, that able, expert man, who by a perfect knowturns a trundle head with a fly, to prevent ledge in mathematics, delineates upon paper, or marks upon the ground, all sorts of closely, it might be proved, that ontlines forts, and other works proper for offence have been cut in metals, representing and defence. He should understand the figures, &c. from the most remote periods art of fortification, so as to be able, not of antiquity, but being subject to decay, only to discover the defects of a place, but they have not reached our time as the to find a remedy proper for them, as also more durable granites have done, embelhow to make an attack upon, as well as to lished with hieroglyphics cut in them in a defend the place. Engineers are extremely manner which might be printed on paper. necessary for these purposes : wherefore it Arguing from these premises, it may be inis requisite that, besides being ingenious, ferred, that the antients understood the art they should be brave in proportion. When of engraving in metal, though without conat a siege the engineers have narrowly sur- ceiving that the copies of their productions veyed the place, they are to make their re- might be multiplied by means of ink on port to the general, by acquainting him soft white cloth, or similar materials. Alwhich part they judge the weakest, and bert Durer, born in 1470, and who died at where approaches may be made with most Nuremberg 1528, is said to have been the success. Their business is also to delineate first person on record claiming the name of the lines of circuinvallation and contraval- an engraver in the long list of celebrated lation, taking all the advantages of the artists ; but certainly very excellent enground; to mark out the trenches, places graved brass figures, the lines filled with of arms, batteries, and lodgments, taking substances to show them more clearly, are care that none of their works be flanked or now extant on tombs in some hundreds of discovered from the place. After making a churches in England, the dates of many faithful report to the general of what is a of which are prior to the time of his birth. doing, the engineers are to demand a suffi. This fact will serve to prove that the printcient number of workmen and utensils, and ing of engraved plates was discovered be. whatever else is necessary.
tween 1470 and 1528; indeed the perfecENGRAFTING, or GRAFTING, in gar- tion that engraving had reached in the latdening. See the article GRAFTING. ter century, plainly demonstrates that the
ENGRAILED, or INGRAILED, in he- use of the graver was by no means a moraldry, a term derived from the French, dern discovery. The encouragement of the hail; and signifying a thing the hail las fine arts has ever been a distinguishing trait fallen upon and broke off the edges, leaving of the inhabitants of the continent of Euthem ragged, or with half rounds, or semi- rope ; it is not wonderful, therefore, that circles, struck ont of their edges.
engraving closely followed the footsteps of ENGRAVING. This term is at pre
the parent arts, and flourished there in sent confined to the art of excavating cop- greater perfection than in England, where per and wood, in lines, in so judicious a man. they have been in a state of miserable ner as to produce imitations of paintings depression till within the last century, when and drawings when printed on paper. It is literature was supposed to receive some aid certain that engraving for the production of from the graver, the booksellers taking the prints was unknown long after the practice hint, have encouraged the predilection of of painting in oil had arrived to great per- the public, which has operated as a stimulus fection, but good prints are common from to the artist, and the consequence is, that plates engraved in the fifteenth century, the graphic embellishments of British topomany of which are landscapes most labori- graphical and poetical works are equal, if ously, and even excellently performed by not superior, to any in Europe. the graver, although it is well known that Historical engravings for the port folio the instrument just' mentioned cannot freely and furniture seemed at one period to express those serrated and serpentine lines advance rapidly towards perfection, to necessary for foliage and short grass inter- which the late Alderman Boydell greatly mixed with plants, since so admirably deli- contributed; but the death of Strange, neated in etchings. A goldsmith of Flo- Hall, and Woollet, have been almost fatal to rence, named Maso Finiguerra, is said to the hopes of the amatenr, which rest, in a have discovered the art; but this assertion great measure, upon Heath, Sharp, Brommust undoubtedly merely apply to his ob- ley, and a few others, as in this particular taining impressions from lines engraved ori- instance we do not include those eminent ginally without the least idea of such a foreigners who have, or do at present reside result: were we to examine the subject in England. Whatever deficiencies we may discover in the prosecution of the arts in form, being sharpened on the oil-stone, are this country, is fortunately not to be attri- used for scraping off the roughness occabuted to want of genius, or relaxation from sioned by the graver, and erasing erronestudy in the artist; the chill of apathy in ous lines, the rich, who view a wretched coloured aqua- The burnisher is a third instrument of tint with the same or more pleasure than steel, hard, round, and highly polished, for the most laboured production of the graver, rubbing out punctures or scratches in the is the baleful cause of the languishing state copper, 'The oil-stone has been already of historical engraving. When persons mentioned, to those may be added the neecapable of affording patronage are taught dle or dry point for etching, and making discrimination, future Woollets will fasci. those extremely fine lines which cannot be nate the best judges of engraving.
done with the graver. We shall now proceed to explain the me- Cushions made of soft leather, and filled thods of executing different descriptions of with fine sand, hence called sand-bags, are engraving. The graver, an instrument of required for the support of the plate in steel, is the primary object for engraving engraving, which, from their circular suron copper; it is square for cutting of broad face, permits the copper to turn with ease, lines, and lozenge for the finest, and, must and facilitates the cutting of those true be tempered to that exact state which will carves composing the shading of most subprevent the point from breaking or wearing jects. The oil rubber and charcoal are ne. by its action on the metal ; to obtain this cessary for polishing the plate. state, it is customary to heat it when too Every thing depends upon the free use of hard on the end of a red hot poker, till it the graver, therefore the utmost care must assumes a straw colour, and then cool it in be taken to hold it properly, by preventoil; if held too long, it will become blue, ing the interposition of the fingers between soft, and useless, till the process of tem- the graver and the plate, with the fore fin. pering the steel is renewed. As it is possi- ger on the upper angle, which enables the ble a graver may be of the proper degree artist to couduct it parallel with the subof solidity, except in some inconsiderable stauce engraved, thus preventing the point part, it would be well to rub it on the oil from entering deeply, and impeding the stone till that is ascertained. The graver is progress of the tool, inserted in a handle of hard wood, resem- To engrave well requires good materials, bling a pear with a longitudinal slice cut off
, though those are nearly confined to two, which is to enable the artist to use it as flat the graver, and the best copper, the latter on the plate as his fingers and thumb will should be free from flaws, small punctures, permit. In order to prepare this instruç well hammered to close the pores, and poment for cutting a clear smooth line, great lished to such a degree as to be free from care must be taken in sharpening it, that the slightest scratches. the original general form should be pre- To trace the design in'ended for engrav· served, by laying the sides flat upon the oil. ing accurately on the plate, it is usual ta stone, and rubbing them so as not to round heat the latter sufficiently to melt white them in the least, after which the graver is wax, with which it must be covered equally to be held sloping towards the person, and and thin, and suffered to cool; the drawing rubbed thus till the point is extremely is then copied in outlines with a black-lead sharp; besides these precautions, it will pencil on paper, which is laid with the penbe necessary that the point should not be cilled side upon the wax, and the back rubexactly in a right line with the lower part bed gently with the burnisher, which will of the graver, but a little higher, that it transfer the lead to the wax. The design may not press too deep into the copper, must next be traced with an etching necIn rubbing the sides of the graver, the dle through the wax on the copper, when, usual manner has been to confine the right on wiping it clean, it will exhibit all the arm close to the side, placing the fore fin. outlines ready for the graver. ger of the left hand on the upper side of The table intended for engraving on the tool when on the stone. This instru- should be perfectly steady, and the sand. ment is used for finishing the imperfections bags placed equally firm; in cutting of discoverable in etchings, and exclusively in curved or undulating lines, the graver must engraving writing.
be held still, or moved, to suit the turning The scraper is a long triangular piece of of the plate with the left hand, but when steel, tapering gradually from the handle to straight lines are intended, the plate is to the point; the three edges produced by this be held stationary, and the graver urged
forward with more or less pressure, accord- wards repeated from end to end, and froin ing to the thickness of the line. Great care each corner to the opposite; but it is ne. is necessary to carry the hand with such cessary to observe, that the tool must never steadiness and skill as to prevent the end be permitted to cut twice in the same of the line from being stronger and deeper place; by this means the surface is conthan the commencement; and sufficient verted into a rongh chaos of intersections, space must be left between the lines to en- which, if covered with ink and printed, able the artist to make those stronger, gra- would present a perfectly black impression dually, which require it. The roughness or upon the paper. burr occasioned by the graver must be re- To transfer the design to be scraped, it moved by the scraper, the lines filled by is usual to rub the rough side of the plate the oil-rabber, and the surface of the cop- with a rag dipped into the scrapings of per cleansed, in order that the progress of black chalk, or to smoke it with burning the work may be ascertained.
wax taper, as in the process for etching; If any accident should occur by the slip the back of the design is then covered with ping of the graver beyond the boundary re- a mixture of powdered red chalk and flake quired, or lines are found to be placed er- white, and laid on the plate through which it roneously, they are to be effaced by the 'is traced; particles of red, in the form of the burnisher, which leaving deep indentings, outlines, are thus conveyed to the black chalk those must be levelled by the scraper, rub- on the plate, which are to be secured there bed with charcoal and water, and finally by the marks of a blunted point; the process polislied lightly with the burnisher. must then be carried on with the scraper, by
As the uninterrupted light of the day restoring the plate in the perfectly light causes a glare upon the surface of the cop- parts of the intender print to a smooth surper, hurtful and dazzling to the eyes, it is face, from which the gradations are precustomary to engrave beneath the shade of served by scraping off more or less of the silk paper, stretched on a square frame, rough ground; but the burnisher is neceswhich is placed reclining towards the room sary to polish the extreme edges of dranear the sill of a window.
pery, &c., where the free touch of the brush Snch are the directions and means to be in painting represents a brilliant spot of employed in engraving historical subjects; light. The deepest shades are sometimes indeed the graver is equally necessary for etched and corroded by aqua fortis, and so the completion of imperfections iu etching, blended with the mezzotinto ground added to which must be added the use of the dry afterwards, that there is nothing offensive to point in both, for making the faintest shades the eye in the combination. in the sky, architecture, drapery, water, Many proofs are required to ascertain &c. &c.
whether the scraping approaches the deEngraving of Mezzotintos differs entirely sired effect, which is done by touching the from the manner above described; this me- deficient parts with white or black chalk, thod of producing prints, which resemble on one of the proofs from the original draw. drawings in Indian ink, is said by Evelyn, ing, and then endeavouring to make the in his history of chalcography, to have been plate similar by further scraping, or re-laydiscovered by Prince Rupert, and was ing the ground with a small tool made for some years past a very favourite way of en- this particular purpose, where too much of graving portraits and historical subjects; of the roughness has been effaced. the former, the large heads by Fry are of Engraving on Steel is confined to the cutsuperior excellence.
ting of punches, for the conveyance of any The tools required for this easy and rapid form a certain depth into that or any other mode of proceeding, are the gronnding-tool, metal, seals, and dyes, for impressing the the scraper, and the burnisher; the copper. designs of coins, medals, &c. on gold, silver, plate should be prepared as if intended for or copper, &c. The punches are engraved the graver, and laid flat upon a table, with from models in wax made in relievo, and a piece of flannel spread under it to prevent when completed, are tempered to that dethe plate from slipping; the grounding-tool gree of solidity which will bear the violent is then held perpendicularly on it, and blows without blunting the finest parts or rocked with moderate pressure backwards breaking them, necessary to produce the and forwards, till the teeth of the tool have matrix in the steel intended for striking of equally and regularly marked the copper medals or coins, which must be heated to from side to side, the operation is after prevent such a disaster, and tempered kgain, for a similar reason to the preceding, lar position, that may be closed, or otherafter it is finished.
wise, as the operation requires ; the tools There are several tools used in finishing are fixed to one end of the axis and screwof dyes, which are gravers, chissels, and ed firm, the stone to be engraved is then flatters, and many little punches for making held to the tool, the wheel set in motion ornamental borders and mouldings to coins by the foot, and the figure gradually formand medals; the latter are always in ed. The materials of which the tools are greater relief than the former, and con- made is generally iron, and sometimes sequently more difficult to execute in per- brass, they are flat, like chissels, gouges, fection.
ferules, and others have circular heads. Engraring on precious Stones is accom- After the work is finished the polishing is plished with the diamond or emery. The done with hair brushes, fixed on wheels, and diamond possesses the peculiar property of tripoli. l'esisting every body in nature, and, though Engraving on Wood has been practised for the hardest of all stones, it may be cut by a several centuries, and originally with tolerpart of itself, and polished by its own parti- able success, it languished for great part of cles. In order to render this splendid sub- the 18th century, but revived towards the stance fit to perform the operations of the close, and is still practised in a manner tool, two rough diamonds are cemented fast which reflects credit on the ingenuity of the to the ends of the same number of sticks, age. Bewick will long be remembered by and rubbed together till the form is obtain- his works in this style of engraving, and his ed for which they are intended; the pow. imitators have been numerous and successder thus produced is preserved, and used ful. As it is entirely different from engravfor polishing them in a kind of mill furnish- ing on copper, the artist already acquainted ed with a wheel of iron; the diamond is with that mode would find himself at a loss then secured in a brazen dish, and the dust how to proceed on wood, as the lines, inmixed with olive oil applied, the wheel is stead of being cut into the substance, are set in motion, and the friction occasions the raised like the letters of printing types, and polished surface so necessary to give their printed in the same manner. lustre due effect. Other stones, as rubies, The wood used for this purpose is box, topazes, and sapphires, are cut into various which is preferred for the hardness and angles on a wheel of copper, and the mate- closeness of its texture; the surface must rial for polishing those is tripoli diluted with be planed smooth and the design drawn on water.
it with a black-lead pencil, the graver is A leaden wheel, covered with emerythen used, the finer excavations from which mixed with water, is preferred for the cut- are intended for white interstices between ting of emeralds, amethysts, hyacinths, the black lines produced by leaving the agates, granites, &c. &c. and they are box untouched, and the greatest lights are polished on a pewter wheel with tripoli; made by cutting away the wood entirely of opal, lapis lazuli, &c. are polished on a the intended form, length, and breadth; wheel made of wood.
but the deepest shades require no engravContrary to the method used by persons ing. Much of the beauty of this kind of who turn metals, in which the substance to engraving depends upon the printing, nor be wrought is fixed in the lathe, turned by is it every artist who can excel in it, as exit, and the tool held to the substance, the pedition and freedom are not to be attainengraver of chrystal, lapis lazuli, &c. fixes ed; in short, the best wooden cuts are evihis tools in the lathe and holds the precious dently the products rather of perseverance stone to them, thus forming vases, or any and ingenuity than easy confidence in other shape, by interposing diamond dust ability, observable in every line of fine, mixed with oil, or emery and water, be- etchings. There are some who succeed to tween the tool and the substance as often admiration in representing foliage and as it is dispersed by the rotary motion of plants, but unfortunately a few months the former.
practice will enable a pupil to etch them on The engraving of armorial bearings, sin- copper with greater truth : drapery and gle figures, devices, &c. on any of the above architecture may be well done in wood, stones after they are polished, is performed but the faces and limbs of figures never through the means of a small iron wheel, look well. the ends of the axis of which are received Such are the different descriptions of enwithin two pieces of iron, in a perpendicn- graving which do not require the aid of