Abbildungen der Seite
PDF
EPUB

AE

E56

10.

ENCYCLOPÆDIA PERTHENSIS.

out.

1.

F OU

É O U
FOUNDERY.

of metal uniting with the cannons, to receive the As the conclusion of our last Volume, (see page which is its support and counterpoife, when rug

iron keys, whereby the bell is hung up to the beam, 918,) we inserted this word in its proper order, with its different definitions, but had not suffi

The business of beil-foundery is reducible cient room remaining in that volume to insert the to three particulars. 1. The proportion of a bell, various branches of this art, in the complete ting of the metal. There are two kinds of pro

2. The forming of the mould And, 3, The mel. manner, which an article of such importance portions, viz. the fimple and the relative; the required.

former are those proportions only that are beF , :

FOUNDERY OF BELLS. The metal, it is to tween the several parts of a bell to render it fonois for ftatues; there being no tin in the latter ; but quifite harmony between several bells. The methere is a sth, and sometimes more, in the bell-me. thod of forming the profile of a belt, previous to tal. The dimenfions of the core and the wax for its being cast, in which the proportion of the lebells, if a ring of bells especially, are not left to veral parts may be seen, is as follows: the thickchance, but must be measured on a scale, or diapa- ness of the brim, Ci, Plate CLV. fig. 12. is the fon, which gives the height, aperture, and thick- foundation of every other meafure, and is divided ness, necelary for the several tones required. It is into three equal parts. First, draw the line HD, on the wax that the several mouldings and other or which represents the diameter of the bell; bifect naments and infcriptions, to be represented in re it in F, and erect the perpendicular Pf; let DF and lievo on the outside of the bell, are formed. The HF be also bifected in E and G, and two other clapper or tongue is not properly a, part of the perpendiculars E é, G a, be erected at F and G; bell, but is furnished from other hands. In Eu- GE will be the diameter of the top of upper vale, rope, it is usually of iron, with a large knob at i.e. the diameter of the top will be half that of the extremity; and is fufpended in the middle of the bell; and it will, therefore, be the diameter the bell. In China, it is only a huge wooden of a bell which will sound an octave to the other. mallet, ftruck by force of arm againit the bell; Divide the diameter of the bell, or the line HD, inwhence they can have but little of that consonan- to is equal parts, and one of these will give Cs oy so much admired in some of our rings of beils. the thickness of the brim : divide again each of The Chinese have an extraordinary way of increa- these 15 equal parts into three other equal parts, fing the found of their bells, viz. by leaving a hole and then form a fcale. From this scale take 12 of under the cannon ;'which our bell founders would the larger divisions or two 15ths of the whole fcale reckon a defe&. The proportions of our bells in the compass, and setting one leg in D describe differ very much from those of the Chinese, as an arc to cut the line E e in N; draw ND, and well as their fizes. See Bell, No 1, § 5. In ours, divide this line into's 2 equal parts; at the point the modern proportions are, to make the diame. I erect the perpendicnlar C= 10, and Ci will ter 15 times the thickness of the brim, and the be the thickness of the brim =one 15th of the height 12 times. The parts of a bell are, 1. diameter; draw the line CD: bisect DN; and The founding bow, terminated by an inferior cir. at the point of the bifection 6 erect the perpendia cle, which grows thinner and thinner. 2. The cular 6 K=vf the larger divisions on the scale. brim or that part of a tell whereon the clapper with an opening of the compass equal tp twice frikes, and which is thicker than the reit. the length of the scale or 30 brims, setting one lez The outward finking of the middle of the bell, or in N, describe an arc of a circle, and with the fime the point under which it grows wider to the brim. leg in K and the same opening, describe another 4. The waist or furniture, and the part that grows arc to interfect the former: on this point of inte wider and thicker quite to the brim. 5. The up- tersection as a centre, and with a radiis equal to per vase, or that part which is above the waist. 30 brims, describe the arc NK; in 6 K produced 6. The pallet which supports the staple of the fake KB= { of the larger measure of the scale or clapper witbin. 7. The bent and hollow branches '* of the brim, and on the same centre with the VOL. X. PART I,

A

radius

3

radius 301 brims describe an arc AB parallel to contist of two diferent legs, joined by a third NK. For the arc BC, take 12 divifions of the piece. And last of all, the founders shelvee, oo scale or 12 brims in the compass; find a centre, which are the engravings of the letters, cartridges, ard from that centre, with this opening, describe coats of arms, &c. They first dig a hole of a the arc pc, in the same manner as NK or AB sufficient depth to contain the mould of the bell, were defcribed. There are various ways of de. together with the case or cannog, under ground; fcribing the arc Kp; fome describe it on a centre and about fix inches lower than the terreplain, at the distance of nine brims from the points.p where the work is performed. The hole must be and K; others, as it is done in the figure, on a wide enough for a free passage between the mould centre at the diftance only of leven brins from and walls of the hole, or between one mould those points. But it is neceffary first to find the and another, when several bells are to be cast. point p, and to determine the rounding of the At the centre of the hole is a stake erected, that is bell p 1. For this purpose, on the point C as a strongly fastened in the ground. This supports centre, and with the radius C i, describe the are an iron peg, on which the pivot of the second ipn; bifcet the part 1, 2, of the line D n, and branch of the compattes turns. The flake is en. erecting the perpendicular p m, this perpendicu- compassed with a solid brick work, perfectly round, lar will cut the arc i pnin m, which terminates about half a foot high, and of the proposed beli's the rounding i p. Some founders niake the bend. diameter. This they call a mill fione. The parts irgs K a third of a brim lower than the middle of of the mould are, the core, the model of the be!! the line DN; others make the part C i D more and the shell. When the outer surface of the core acute, and inftead of making C i perpendicular is formed, they begin to raise the corr, which is to DN at 1, draw it one 6th of a brim higher, made of bricks that are laid in courses of equal making it fill egnal to one brim; so that the line height upon a lay of pain earth. At the laying 1 D is longer than the brim C!. In order to race of each brick, they bring near it the branches of out the top part Na, take in the compass eight the conipaíses, on which the curve of the core is divisions of the scale or 8 brims, and on the points shaped, so as that there may remain bet ween it .N and D as centres, describe arcs to interfect and the curve the distance of a line, to be, aftereach other in 8 : on this point 8, with a radius of wards filled up with layers of cement. The work eight brims, describe the ark Nb; this arc will be is continued to the top, only leaving an opening the exterior curve of the top or crown ; on the for the coals to bake the core. This work is cofame point 8 as a centre, and with a radius equal vered with a layer of cenient, made of earth and tor} brims, defcribe the arc A e, and this will horse-dung; on which they move the compasses be the interior curve of the crown, and its whole of construction, to make it of an even smootbacks thickness will he one third of the brim. As the every where. The firít layer being finished, they point 8 does not fall in the axis of the Bell, a put the fire to the core, by filling it half with coals, centre M may be found in the axis by describing, through an opening that is kept shut during the with the interval of 8 brims on the centres D and baking, with a cake of earth that bas been fepa. 11, arcs which will intersect in M; and this point rately baked. The first fire consumes the fate, may be made the centre of the inner and outer and the fire is left in the core half or sometimes a curves of the crown as before. The thicknefs of whole day: the first layer being thoroughly dry, the cap, which strengthens the crown at I, is about they cover it with a second, third, and fourth one thirel of the thickness of the brim; and the each being smoothed by the board of the compal

. hollow brauches or ears about one fixth of the ses, așd thoroughly dried before they proceed to diameter of the bell. The height of the bell is in another. The core being completed, they take proportion to its diameter as 12 to 15; 'or in the compases to pieces, with intent to cut off the the proportion of the fundamental sound to its thickness of the model, and the companies are third major: whence it follows that the sound of immediately put in their place to begin a fecon! a bell is principally composed of the found of its piece of the mould. It consists of a mixture of extremity or brim, as a fundamental of the found earth and hair, applied with the hand on the of the crown which is an octave to it, and of that core, in several cakes that close together. This of the height which is a third. The particulars work is finished by several 'layers of a thinner cenecessary for making the mould of a bell are, I. ment of the same matter, smoothed by the comThe earth : the most cohesive is the best ; it must paffes, and thoroughly dried before another is be well ground and fifted, to prevent any chinks. laid on." The first layer of the model is a mixture 2. Brick stone; which must be used for the mine, of wax and grease spread over the whole. After mould, or.core, and for the furnace. 3. Horse-dung, which are applied the infcriptions, coats of arm, hair, and hemp, mixed with the earth, to render &c. besmeared with a pencil dipped in a vetiel of the cement more binding. 4. The wax for inferip- wax in a chafing dish : this is done for every leue. Lions, coats of arins, &c. s. The tallow equally Before the shell is begun, the compafles are fåken mixed with the wax, in order to put a light lay to pieces, to cut off all the wood that fills the of it upon the outer mould, before any letters are place of the thickness to be given to the helt. applied to it. 6. The coals to dry the mould The first layer is the same earth with the re, For making the mould they have a scaffold con- fifte: very fine ; whilft it is tempering in water, Gisting of four boards, ranged upon treffels. Upon it is mixed with cow's hair to make it cobert, this they carry the earth, grossiy diluted, to inix The whole being a thin cullis, is gently peureu i: with horse-dung, beating the whole with a large on the model, that fills exactly all the finuofitius fpacula. The compasses of construction are the of the figures, &c. and this is repeated till the chiet instrument for making the mould: They whole is iwo lines thick over the model. When

this layer is thoroughly dried, they cover it with à earth, throu: h which the metal met run, frem fecond of the same matter, but somewhat thicker; the hollow of the rings, beiween the sheil ard the when this second layer becomes of some conhf. core. They finoke ine inlide of the thell, by tence, they apply the compafles again, and light burning fraw under it, that helps to smooth the a fin in the core, so as to melt off the wax of the surface of the bell. Then they put the thell in the inscriptions, &c. After this, they go on with the place, so as to leave the same interval between ollier lays of the thell, by means of the com- that and the core; and before the hollows of the paties. Here they add to the cow's hair a quan. rings or the cap are put on again, they idú into ity of hemp, spread upon the layers, and after- vents, that are united to the rings, and to cach wards imoothed by the board of the compatles. Other, by a mats of baked cement. After which The thickness of the shell comes to 4 or 5 inches theç put on this mass of the cap, the rinys, and lower than the mill stone before obferver, and fur- the vent, over the theli, and folder it wich thin rounds it quite clofe, which prevents the extra. cement, which is cried gradually by covering it vafation of the metal. The wax thould be taken with burning coals. Then they fill up the pit out before the melting of the metal. The ear of with earth, beating it strongly all the time round the bell requires a separate work, which is done the mould. The surface has a ;lace for ii fie during the drying of the several incrustations of and another for the metal. The fire place has a cement. It has 9 rings: the 7th is called the large chimney with a spacious ath-hole. The furbridge, and unites the others, being a perpendi- nace which contains the metal is vaulted, whose cular support to strengthen the curves. It has an bottom is made of earth, rammed down; the rest aperture at the top, to admit a large iron peg, is built with lyrick. it has four apertures; the bent at the bottom; and this is introduced into firit, through wich the faune reverbirates; the sea two holes in the beam, fastened with two strong cond is cleted with a stopple that is opened for iron keys. There are models made of the rings, the metal to run; the others are to separate the with mafies of beaten earth, that are dried in the dross or iceriæ of the metal by wooden rakes: fir, in order to have the hollow of them. Thele through these laft apertures palie's the thick firioke, rings are gently pressed upon a layer of earth and The ground of the furnace is buit floping, for cow's hair, one half of its depthi and then taken the metal to run down. out, without breaking the mould. This opera. 2. FOUNDERY OF GREAT GUNS AND MORTAR tron is repeated 12 times for 12 half moulds, that PIECES. The method of catting these pieces is **ad two united may make the hollows of the different from that of bells: they are run maliy, ha riegs; the fame they do for the hollow of the without any core, being determined by the holLiege, and bake them all, to unite them together. low of the thell; and they are afterwards bord Upon the open place left for the coais to be put with a steel trepan, that is worked either by hortis in, are placed the rings that constitute the ear. or a water mill. For the metal, parts, propor. They first put into this open place the iron ring tions, &c. of these pieces, lue GunnerY. to support the clapper of the bell; then they make 3. FOUNDERY OF LEITEPS, or CASTING OF a round cake of clay, to fill up the diameter of TYPES FOR PRINTING. In the business of cutthe thickness of the core.' This cake, after ba- ting, cafting, &c. letters for printing, the letter-cutting, is clapped upon the opening, and soldered ter muit be provided with a vice, hand-vice, hamwith a thin mortar spread over it, which binds mers, and files of all sorts such as watch-makers the cover close to the core. The hollow of the use; also gravers and sculpters of all forts, aud model is filled with an earth, fufficiently mois to an oil-fione, &c. fuitable and sizeable to the serem fix on the place, which is strewed at several times ral letters to be cut; a fiat gauge made of box to upon the cover of the core; and they beat it gent. hold a rod of steel, or the body of a mould, &c. ly with a pestie, to a proper height; and a work- exactly perpendicular to the Nat of the uting file; man smooths the earth at top with a wooden a Niding gauge u hose use is to measure and tei cfi trowel dipped in water. lipon this cover, to be distances between the fhoulder and the tooth, and taken off afterwards, they assemble the hollows to mark off from the end, or from the edge of of the rings. When every thing is in its proper the work; a face gauge, which is a square notch place, they itrengthen the outside of the hollows cut with a file into the edge of a thin plate of with mortar, in order to bind them with the steel, iron or brass, of the thicknets of a piece of briige, and keep them steady at the bottom, by common tin, whose use is to proportion the face of Theans of a cate of the same mortar, which fills each sort of letter, viz. long letters, afcending Ep the whole aperture of the shell. This they let letters, and Mort letters So there must be 3 gauges, drs, that it may be removed without breaking, and the guage for the long letters is the length To make room for the metal, they pull off the of the whole body supposed to be divided into hollows of the rings, through which the metal is 42 equal parts. The gauge for the afcending let. to pass, before it enters into the vacuity of the ters Roman ar d Italic are five ,ths, or 30 parts of muld. The ihell being unloaded of its ear, they, 42, and 33 paits for the English face. The gilięc range under the mill-ftone five or lix pieces of for the most letters is three 7ths, or 18 parts of wood, about two feet long, and thick enough to 42 of the whole body for the Roman and Italic, teach almost the lower part of the fell; between and 22 parts for the English face. The Italic and thafe and the mould, they drive in wooden wedges other standing gauges are to measure the scope of with à maliet, to ihake the shell of the model the Italic items, by app!ying the top and bottom whereon it reits, so as to be pulled up and got of the gauge to the top and bottom lines of the seteruit of the pit. When this and the wax are re. ters, and the other fine of the gauge tot- !!{m; Scared, they break the model and the layer of for when the letter conplies with these three fidea

of

A2

of the gauge, that letter has its true shape. The them with their heads to the feet of the other half; next care of the letter-cutter is to prepare gond and if then the heads and the feet be found ex. Ateei punches, well tempered, and quite free from actly even upon each other, and neither to drive all veins of iron; on the face of which he draws out nor get in, the two fides may be pronounced or marks the exact shape of the letter with pen parallel. He farther tries whether the two fides and ink if the letter be large, or with a smooth of the thickness of the letter be parallel, by frift blunted point of a needle if it he finall; and then setting his proofs in the compofing stick with their with fizeable and proper shaped and pointed gra- nicks upwards, and then turning one half with vers and sculpters, digs or fculps out the steel their heads to the feet of th other half; and if between the litrokes or marks he made on the face the heads and feet lie exactly upon each other, of the punch, and leaves the marks Aanding on and neither drive out nor get in, the two fides of the face. Having well shaped the infide ftrokes the thickness are parallel. The mould thus justiof his letter, be deepens the hollows with the fame fied, the next butiness is to prepare the matrices

. tools; for if a letter be not deep in proportion to

A matrice is a piece of brass or copper of about its width, it will, when used at press, print black, an inch and a half long, and of a thibkness in proand be good for nothing. This work is generally portion to the size of the letter it is to contain. regulated by the depth of the counter-punch. In this metal is sunk the face of the letter intendThen he works the outfide with proper files till ed to be caft, by striking the letter punch about it be fit for the matrice, Before we proceed to the depth of an n. After this the sides and face the finking and justifying of the matrices, we must of the matrice must be justified, and cleared with provide a mould to justify them by. See Plate files of all bunchings made by firking the punch. CLV. Fig. 13, and 14. Every'mouid is compof- Every thing thus prepared, it is brought to the ed of an upper and an under part. The under furnace; which is built of brick upright, with 4 part is delineated in fig. 13. The upper part is fquare fides, and a ftone on the top, in which marked fig. 14. and is in all respects made like the stone is a wide round hole for the pan to stand in, under part, excepting the stool behind, and the A foundeiy of any extent has several of t.efe turbow or spring also behind; and excepting a small naces in it. As to the metal of which the types ruundith wire between the body and carriage, are to be caft, this, in extenlive founderies, is uear the break, where the under part hath a fmall always prepared in large quantities; but caft into rounding groove made in the body. This wire, small bars, of about 20 pounds weight, to be deor rather belf-wire, in the upper part makes the livered out to the workmen as occation requires. nick in the shapk of the letter, when part of it is in the letter forundery, which has been long carreceived into the groove in the under pirt. These ried on with reputation under the direction of two parts are so exactly fitted and gauged into one Dr Alex. Wilson and fons at Glasgow, we are inanother (viz. the male.gauge marked c in fig. 14. formed, that a stock of metal is made up at tuo into the female marked g in fig. 1.3.) that when the different times of the year, sufficient to lerve the upper part of the mould is properly placed on, callers at the furnace for six months each time. and in the under part of the mould, both together for this purpose, a large furnace is built under a make the entire mould, and may be oid back. fhade, furniihei with a wheel vent, in order the wards for use so far, till the edge of either of the more equally to heat the sides of a ftrong pot of bodies on the middle oi either carriage comes just cast iron, which bolds when full 15 Cwt. of the to the edge of the female gauges cut in each car metal. The fire being kindled below, the bars riage; and they may be ilid forward so far, till of lead are let foftly down into the pot, and their the bodies on either carriage touch each other: fusion promoted by throwing in fome pitch and and the Riding of these two parts of the mould tallow, which foon inflame. An outer chimney, backwards makes the thank of the letter thicker, which is buit so as to project abcut a foot over because the bodies in each part stand wider alun. the farthest lip of the pot, catches hold of the der; and the siding them forwards makes the frame by a strong draught, and makes it act very Thank of the letter thinner, because the bodies on powerfully in melting lead; whilst ir serves at the each part of the mould are as follow : viz. a, fame time to convey away all the fumes, &e. from

e carriage. b, The body. c, The male gauge the workmen, to whom this laborious part of the de, The mouth-piece. fi, The register. 8, The buliness is committed. When the lead is thofemale gange. h, The bag. aa oa, The bottom roughly melted, a due proportion of the regu us plate. b 6'b, The woud on which the bottom or antimony and other ingredients are put in, and piate lies. ccc, The mouth. dd, The throat, lone more tallow is enflamed to make the whole e dd, The pallat. f, The nick. 8g, The ftool. incorporate foower. The workmen, having mis), The spring or bow. Then the mould musted the contents of the pot very thoroughly by be justified: and first the founder justifies the ftirring long with a large iron ladle next proced body, by casting about 20 proofs or samples of to draw the metal off into the small troughs of letters; which are set up in a composing stick, cast iron, wbich are ranged to the number of 80 with all their nicks towards the right hand; and upon a level platform faced with ftune, built tothen by comparing these with the pattern letters, wards the right hand. In the course of a day 15 fet up in the same manner, he finds the exact mea. Cwt. of metal can be easily prepared in this man. sure of the body to be cast. He also tries if the ner; and the operation is continued for as many two sides of the body ale parallel, fo that'the body days as are necessary to prepare a stock of metal be ro bigger at the head ihan at the foot, bylda of all the various degrees of bardress. After this, 4.Ing half the number of his proofs and turning the whole is dispuled into presles according to its

quality, to be depvered out occasionally to the

workmen

« ZurückWeiter »