ENCYCLOPÆDIA PERTHENSIS. FOU FOUNDERY. At the conclufion of our laft Volume, (fee page 718,) we inferted this word in its proper order, with its diferent definitions, but had not fuffi. cient room remaining in that volume to infert the various branches of this art, in the complete manner, which an article of fuch importance required. 1.FOUNDERY OF BELLS. The metal, it is to be obferved, is different for bells from what for ftatues; there being no tin in the latter; but there is a eth, and fometimes more, in the bell-metal. The dimenfions of the core and the wax for beit, if a ring of bells efpecially, are not left to Chance, but must be measured on a scale, or diapafa, which gives the height, aperture, and thicknel, neceffary for the feveral tones required. It is Go the wax that the feveral mouldings and other oraments and infcriptions, to be reprefented in relevo on the outfide of the bell, are formed. The Capper or tongue is not properly a part of the be, but is furnished from other hands. In Eu. tope, it is ufually of iron, with a large knob at the extremity; and is fufpended in the middle of the bell. In China, it is only a huge wooden maliet, ftruck by force of arm againit the bell; wince they can have but little of that confonanty to much admired in fome of our rings of bells. The Chinese have an extraordinary way of increa fing the found of their bells, viz. by leaving a hole under the cannon; which our bell founders would reckon a defect. The proportions of our bells der very much from thofe of the Chinese, as we as their fizes. See BELL, N° I, 5. In ours, the modern proportions are, to make the diameter 15 times the thickness of the brim, and the beight 12 times. The parts of a bell are, 1. The founding bow, terminated by an inferior circle, which grows thinner and thinner. 2. The brim or that part of a bell whereon the clapper frikes, and which is thicker than the reit. 3. The outward finking of the middle of the bell, or the point under which it grows wider to the orim. 4. The waist or furniture, and the part that grows Wider and thicker quite to the brim. 5. The upper vale, or that part which is above the wait. 6. The pallet which fupports the ftaple of the clarper within. 7. The bent and hollow branches VOL. X. PART I. FOU of metal uniting with the cannons, to receive the which is its fupport and counterpoife, when rung iron keys, whereby the bell is hung up to the beam, out. The bufinefs of bell-foundery is reducible to three particulars. 1. The proportion of a beil, ting of the metal. There are two kinds of pro2. The forming of the mould. And, 3, The melportions, viz. the fimple and the relative; the former are thofe proportions only that are between the feveral parts of a bell to render it fond. rous: the relative proportions establish a requifite harmony between feveral beils. The me thod of forming the profile of a bell, previous to its being caft, in which the proportion of the fe veral parts may be feen, is as follows: the thicknefs of the brim, C1, Flute CLV. fig. 12. is the foundation of every other meafure, and is divided into three equal parts. First, draw the line HD, which reprefents the diameter of the bell; bifect it in F, and erect the perpendicular Ff; let DF and HF be alfo bifected in E and G, and two other perpendiculars E e, G a, be erected at F and G; GE will be the diameter of the top or upper vafe, i. e. the diameter of the top will be hair that of the bell; and it will, therefore, be the diameter of a bell which will found an octave to the other. Divide the diameter of the bell, or the line HD, into 15 equal parts, and one of thefe will give Cr the thicknets of the brim: divide again each of thefe 15 equal parts into three other equal parts, and then form a icale. From this fcale take 12 of the larger divifions or two 15ths of the whole scale in the compafs, and fetting one leg in D describe an arc to cut the line Ee in N; draw ND, and divide this line into 12 equal parts; at the point 1 erect the perpendicular 1C = 10, and C1 will be the thicknefs of the brim one 15th of the diameter; draw the line CD: bifect DN; and at the point of the bifection 6 erect the perpendi cular 6 K = 1 of the larger divifions on the fcale. With an opening of the compafs equal to twice the length of the fcale or 30 brims, fetting one leg in N, defcribe an arc of a circle, and with the fame leg in K and the fame opening, defcribe another are to interfect the former: on this point of interfection as a centre, and with a radius equal to 30 brims, defcribe the arc NK; in 6 K produced take KB of the larger meature of the fcale or of the brian, and on the fame centre with the radius 36 brims defcribe an arc AB parallel to NK. For the arc BC, take 12 divifions of the fcale or 12 brims in the compafs; find a centre, and from that centre, with this opening, deferibe the arc BC, in the fame manner as NK or AB were defcribed. There are various ways of defcribing the arc Kp; fome describe it on a centre at the distance of nine brims from the points p and K; others, as it is done in the figure, on a centre at the diftance only of feven brims from thofe points. But it is neceflary firft to find the point p, and to determine the rounding of the, bell p. For this purpofe, on the point C as a' centre, and with the radius C 1, defcribe the arc I pn; bif & the part 1, 2, of the line D n, and erecting the perpendicular p m, this perpendicular will cut the arc I pn in m, which terminates the rounding 1 p. Some founders make the bendings K a third of a brim lower than the middle of the line DN; others make the part CID more acute, and instead of making C 1 perpendicular to DN at 1, draw it one 6th of a brim higher, making it fill equal to one brim; fo that the line ID is longer than the brim C. In order to trace out the top part Na, take in the compafs eight divifions of the fcale or 8 brims, and on the points N and D as centres, defcribe arcs to interfect each other in 8: on this point 8, with a radius of eight brims, defcribe the ark Nb; this arc will be the exterior curve of the top or crown; on the fime point 8 as a centre, and with a radius equal to 7 brims, defcribe the arc A e, and this will be the interior curve of the crown, and its whole thickness will he one third of the brim. As the point & does not fall in the axis of the bell, a centre M may be found in the axis by defcribing, with the interval of 8 brims on the centres D and II. arcs which will interfect in M; and this point may be made the centre of the inner and outer curves of the crown as before. The thickness of the cap, which strengthens the crown at Q, is about one third of the thickness of the brim; and the hollow branches or ears about one fixth of the diameter of the bell. The height of the bell is in proportion to its diameter as 12 to 15, or in the proportion of the fundamental found to its third major: whence it follows that the found of a bell is principally compofed of the found of its extremity or brim, as a fundamental of the found of the crown which is an octave to it, and of that of the height which is a third. The particulars neceffary for making the mould of a bell are, 1. The earth: the most cohetive is the best; it muft be well ground and fifted, to prevent any chinks. 2. Brick ftone; which must be used for the mine, mould, or core, and for the furnace. 3. Horfe-dung, hair, and hemp, mixed with the earth, to render the cement more binding. 4. The wax for infcriptions, coats of arms, &c. 5. The tallow equally mixed with the wax, in order to put a flight lay of it upon the outer mould, before any letters are applied to it. 6. The coils to dry the mould. For making the mould they have a fcaffold contuting of four boards, ranged upon treffels. Upon tha they carry the earth, grofs y diluted, to mix with horfe-dung, beating the whole with a large Patuh. The compiles of construction are the eef inftrument for making the mould: They confift of two different legs, joined by a third this this layer is thoroughly dried, they cover it with a fecord of the fame matter, but fomewhat thicker; when this fecond layer becomes of fome confifterce, they apply the compafles again, and light a fire in the core, fo as to melt off the wax of the iricuptions, &c. After this, they go on with the other layers of the fhell, by means of the com-, pacs. Here they add to the cow's hair a quan try of hemp, fpread upon the layers, and afterweds Imoothed by the board of the compaffes. The thickness of the shell comes to 4 or 5 inches lower than the mill ftone before obferved, and furrounds it quite clofe, which prevents the extravalation of the metal. The wax fhould be taken out betore the melting of the metal. The ear of the bell requires a feparate work, which is done during the drying of the feveral incruftations of coscut. It has 9 rings: the 7th is called the Budge, and unites the others, being a perpendicular support to ftrengthen the curves. It has an aperture at the top, to admit a large iron peg, bent at the bottom; and this is introduced into two boles in the beam, fastened with two ftrong iron keys. There are models made of the rings, with mailes of beaten earth, that are dried in the fre. in order to have the hollow of them. These ngs are gently preffed upon a layer of earth and cow's hair, one half of its depth; and then taken cut, without breaking the mould. This operaton is repeated 12 times for 12 half moulds, that two and two united may make the hollows of the fx mngs; the fame they do for the hollow of the br ge, and bake them all, to unite them together. Upon the open place left for the coals to be put in, are placed the rings that conftitute the ear. They firft put into this open place the iron ring to fupport the clapp r of the bell; then they make a round cake of clay, to fill up the diameter of the thickness of the core. This cake, after baking, is clapped upon the opening, and foldered with a thin mortar spread over it, which binds the cover close to the core. The hollow of the model is filled with an earth, fufficiently moift to fix on the place, which is ftrewed at feveral times upon the cover of the core; and they beat it gent ly with a peftle, to a proper height; and a workman fimooths the earth at top with a wooden trowel dipped in water. Upon this cover, to be taken off afterwards, they aflemble the hollows of the rings. When every thing is in its proper pace, they frengthen the outfide of the hollows with mortar, in order to bind them with the brace, and keep them fteady at the bottom, by meces of a cake of the fame mortar, which fills up the whole aperture of the fhell. This they let dry, that it may be removed without breaking. To make room for the metal, they pull off the Blows of the rings, through which the metal is to pass before it enters into the vacuity of the mould. The shell being unloaded of its ear, they range under the mill-ftone five or fix pieces of wood, about two feet long, and thick enough to reach almoft the lower part of the fhell; between thefe and the mould, they drive in wooden wedges with a mallet, to fhake the fhell of the model whereon it refts, so as to be pulled up and got out of the pit. When this and the wax are removed, they break the model and the layer of earth, through which the metal muft run, from the hollow of the rings, between the fheil and the core. They fmoke the infide of the thell, by burning ftraw under it, that helps to smooth the furface of the belt. Then they put the thell in the place, to as to leave the fame interval between that and the core; and before the hollows of the rings or the cap are put on again, they add two vents, that are united to the rings, and to each other, by a mafs of baked cement. After which they put on this mafs of the cap, the rings, and the vent, over the fhell, and folder it with thin cement, which is dried gradually by covering it with burning coals. Then they fill up the pit with earth, beating it ftrongly all the time round the mould. The furface has a place for the and another for the metal. The fire place has a large chimney with a spacious ath-hole. The furnace which contains the metal is vaulted, whofe bottom is made of earth, rammed down; the reft is built with brick. It has four apertures; the first, through which the flame reverbirates; the tecond is cloted with a stopple that is opened for the metal to run; the others are to separate the drofs or fcoria of the metal by wooden rakes: through these last apertures pafies the thick fmoke. The ground of the furnace is built floping, or the metal to run down. 2. FOUNDERY OF GREAT GUNS AND MORTAR PIECES. The method of cafting these pieces is different from that of bells: they are run maily, without any core, being determined by the hollow of the hell; and they are afterwards bored with a steel trepan, that is worked either by hortes or a water mill. For the metal, parts, propor tions, &c. of thefe pieces, fee GUNNERY. 3. FOUNDERY OF LETTERS, OR CASTING OF TYPES FOR PRINTING. In the business of cutting, cafting, &c. letters for printing, the letter-cutter must be provided with a vice, hand-vice, hammers, and files of all forts fuch as watch-makers ufe; alfo gravers and fculpters of all forts, aud an oil-ftone, &c. fuitable and fizeable to the feveral letters to be cut: a flat gauge made of box to hold a rod of fteel, or the body of a mould, &c. exactly perpendicular to the flat of the uting file; a fliding gauge whofe ufe is to measure and fet off distances between the fhoulder and the tooth, and to mark off from the end, or from the edge of the work: a face gauge, which is a fquare notch cut with a file into the edge of a thin plate of steel, iron or brafs, of the thickness of a piece of common tin, whofe ufe is to proportion the face of each fort of letter, viz. long letters, aicending letters, and fhort letters So there must be 3 gauges, and the guage for the long letters is the length of the whole body supposed to be divided into 42 equal parts. The gauge for the afcending letters Roman and Italic are five 7ths, or 3c parts of 42, and 33 parts for the Englifh face. The gauge for the fhort letters is three 7ths, or 18 parts of 42 of the whole body for the Roman and Italic, and 22 parts for the English face. The Italic and other ftanding gauges are to measure the fope or the Italic ftems, by applying the top and bottom of the gauge to the top and bottom lines of the letters, and the other fice of the gauge to the item; for when the letter complies with thele three fidok fible to bind them up in this manner, by difpofing them to rife or fpring from the fick by the fmalleft preffure from the fcrew. Now, when lying fo conveniently with the narrow edges uppermoft, which cannot poflibly be smoothed in the manner before mentioned by the ftones. the workman does this more effectually by fcraping the furface of the column with a thick edged but tharp razor, which at every stroke brings on a very fine fmooth fkin, like to polished filver; and thus he proceeds till in about half a minute he comes to the farther end of the stick, The other edges of the types are next turned upwards, and polished in the fame manner. It is whilft the types thus lie in the dref fing stick that the operation of bearding or barbing is performed, which is effected by running a plane, faced with feel, along the shoulder of the body next to the face, which takes more or lefs off the corner, as occafion may require. Whilft in the dreffing ftick they are alfo grooved, which is a very material operation. To underftand this, it must be remembered, that when the types are firft broken off from the jets, fome fuperfluous metal always remains, which would make them bear very unequally against the paper whilft under the printing prefs, and effectually mar the impreffion. That all thefe inequalities may, therefore, be taken away, and that the bearings of every type may be regulated by the fhoulders imparted to them all alike from the mould, the workman or dreiler proceeds in the following manner. The types being ferewed up in the tick, as before mentioned, with the jet-end outermoft, and projecting beyond the wood about one 8th of an inch, the flick is put into an open prefs, fo as to present the jet end uppermoft, and then every thing is made faft by riving a long wedge, which bears upon a flip of wood, which lies clofe to the types the whole length; then a plane is applied, which is so constructed as to embrace the projec. ting part of the typ: 6 betwixt its long fides, which are made of polifhed iron. When the plane is thus applied, the fteel cutter bearing upon that part between the thoulders of the types, where the inequalities lie, the dreffer dexterously glides it along, and by this means ftrips off every irregu. lar part that comes in the way, and fo makes an uniform groove the w ole length, and leaves the two fhoulders ftanding; by which means every type becomes precifely like to another, as to the height againft paper. The types being now finifh ed, the tick is taken out of the prefs, and the whole column replaced upon the other ftick; and after the whole are fo dreffed, he proceeds to pick out the bad letters, previous to putting them up into pages and papers. In doing this he takes the ftick into his left hand, and turning the faces near to the light, he examines them carefully, and whenever an imperfect and damaged letter occurs, he nimbly plucks it out with a fharp bodkin, which he holds in the right hand for that purpofe. Thofe letters which, from their form, project over the body of the type, and which cannot on this account be rubbed on the ftones, are fcraped on the broad fides with a knife or file, and fome of the unctal next the face pared away with a penknife, in order to allow the type to come clofe to any other. This operation is called KIRNING. The excellence of printing types confifts not caly in the due performance of all the operations above defcribed, but alfo in the hardness of the metal, form, and fine proportion of the character, and in the exact bearing and ranging of the letters in relation to one another. 4. FOUNDERY OF SMALL WORKS, OF CASTING IN SAND. The fand used for cafting fmall wors is at first of a pretty foft, yellowish, and clamry nature: but it being neceffary to frew chare of duft in the mould, it at length becomes of a quie black colour. The red-hot metal, by burning part of the fand, contributes alfo to blacken it. Th fand is worked over and over, with a roller, on a board, placed across a cheft to receive it, after it is by thefe means fufficiently prepared, and freed from fmall ftones or hard lumps of fand. It's done, they take a smooth wooden board of a length and breadth proportioned to the things to be caft, and laying the first half of an o, en med, or wooden frame upon it, they place within it a pon the board, either wooden or metal mode's of what they intend to caft, and then fill it up with the prepired fand, a little moistened to make it cohere properly, preffing it upon the patterns with the roller, fo as to leave their impreffion in it. Along the middle of the mould is alfo laid half a small brafs cylinder to make an impreffion for the chief canal for the metal to run through, when melted, into the modelis or patterns; and from this c ief canal are drawn feveral others, which extend to each model or pattern placed in the frame. Then placing the other half of the mould over the one with the patterns in it, f, that the pins enter into the holes that correfpond to them in the other, they proceed to work it in the fame manner, fo as to make the two cavities of the pattern fall exactly on each other. After both frames of the mould are thus finished, and their backs scraped smooth, they take out the patterns, firft loofening them gently all round that the fand may not give way. The moulds are then carried to the melter; who, after ftrewing mill duft over them, dries them in a kind of oven for that purpote. Both parts of the mould being dry, they are agan joined together by means of the pins; and to prevent their giving way, by reafon of the melted metal paffing through the chief cylindrical ca nal, they are fcrewed or wedged up in a pair of wooden fcrews, like a kind of prefs. When the moulds are thus prepared, the metal is melted in a crucible, of a fize proportionate to the quantity of metal intended to be caft, and when brought to a proper heat, is poured into them at the mouth of the chief canal. When the moulds are cool, the frames are unfcrewed, and the caft work taken out of the fand, which is wet and worked over again for other caftings. 5. FOUNDERY OF STATUES. The cafting of ftatues depends on the due preparation of the pit, the core, the wax, the outer mould, the inferior furnace to melt off the wax, and the upper to ufe the metal. The pit is a hole dug in a dry place fomething deeper than the intended figure, and made according to the prominence of certain parts thereof. The infide of the pit is commonly lined with ftone, or brick; or, when the figure is very large, they fometimes work on the ground, and |