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II. .11 li .n.--«^. ii ijp ii i i - ii ii iii n ii n i in i n n ii m i in 1 1 m i i n m | M^ ^ ., i „ _ j» ;, „ i i n ,.,„ ,„ I,, „ ._., .. ^ * iii> i m wmmmm mmmmmmmmmmmm. mn nm , Class ~7~c\Z5 iO- Book - H C~> Copyright^ COPYRIGHT DEPOSED Digitized by the Internet Archive in 2011 with funding from The Library of Congress http://www.archive.org/details/newmetalworkerpaOOkitt THE NEW METAL WORKER PATTERN B A Complete Course of Instruction in the Modern Methods of Developing and Cutting the Patterns for Sheet Metal Work, Giving the Prin- ciples Underlying Practically every Problem that is Likely to Come up in Practice and Explaining the Selection and Use of Drawing Tools and Linear and Geometrical Drawing so Clearly that One who has had no Previous Knowledge of Arithmetic or Drawing, may Understand These Essentials and Apply Them in Using the 253 Problems in the Development of Patterns by the Parallel Line, Conical or Flaring, and Irregular orTriangula- tion Systems. BY GEO. W? KITTREDGE and ASSOCIATES New York U. P. C. BOOK COMPANY, Inc. 241-249 West 39th Street Nineteen Hundred Seventeen 5* S ° Copyrighted, 1917 By U. P. C. Book Company, Inc. Copyrighted, 1896, 1906 By David Williams Company ) 7-^£ inches to the foot). the vertical lines figured both at top and bottom) 6 inches (and last by means of the diagonal line, figured at the end of the scale, for fractions) and three-eighths. The top and bottom lines of the scale measure feet and inches only. The other horizontal lines measure feet, inches and fractions of an inch, each horizontal line having its own particular fraction, as shown. Such scales aPe frequently quite useful, as greater accuracy is obtained and, as the reader will see, may be con- structed by any one to any unit of measurement, and divided by the number of horizontal lines into any de- sired fractions. A scale in common use, and known as the tri- angular scale, is shown in Fig. 119. The shape of this scale, which is indicated by the name, and which Fig 119 — Triangular Boxwood Scale. is also shown in the cut, presents three sides for divi- sion. By dividing each of these through the center lengthways by a groove, as shown, six spaces for divisions are obtained, and by running the scales in pairs — that is, taking two scales, one of which is twice the size of the other, and commencing with the unit at opposite ends — the number of scales which may be put upon one of these instruments is increased to twelve. This article, which may be had in either boxwood, ivory or plated metal, and of 6, 12, 18 or 24 inches in length, is probably the most desirable for general use of any sold. bility to error in its use. However, the limited num- ber of scales which it contains greatly restricts its usefulness. Fig. 120 shows another form of the flat scale, in quite common use in the past, but now virtually dis- carded in favor of more convenient dimensions and shapes. This scale combines with the various divi- sions of an inch the divisions of the protractor, as shown around the margin. The fact that the divisions of an inch for purposes of a scale are located in the middle of the instrument, away from the edge, which makes it necessary to take off all measurement with the dividers, renders the article awkward for use, and \ v. v \ X Vo \ ^TT 1-^ I \w .W.-^ ft/o 7/0 »/0 / / / / / ,/ y •■ '.--■' ' -"> ■ ■/'" s 4 ■> 12 13 14 15 16 Fig. ISO. — Flat Scale with Divisions of the Protractor on the Margins. the arrangement of the divisions of the circle, on the margins, is less satisfactory for use than the circular protractor. Lead f encils. — Various qualities of pencils are sold, some at much lower prices than others, but, all things considered, in this as in other cases, the best are the cheapest. The leading brands are made in two grades or qualities. The ordinary grades employ numbers, 1, 2, 3, etc., to indicate hardness of lead, No. 1 being the softest, and No. 5 being the hardest in common use. A finer grade of pencils, known as poligrades, is marked by letters, commencing at the softest with B B, 26 The New Metal Worker Pattern Book. and ending at the hardest with H H H H H H, while other makes of pencils are marked by systems peculiar to their manufacturer. The draftsman has the choice of round or hexagon shape in all except the finest grades, the latter being made exclusively hexagon. Whatever kind of pencil the draftsman or mechanic uses, he will require different numbers for different purposes. For working drawings, full-sized details, etc., on manila paper, a No. 3 (or F) is quite satis- factory. Some like a little harder lead, and therefore prefer a No. 4 (or H). For lettering and writing in connection with drawings upon manila or ordinary detail paper, a No. 2 (H B) is usually chosen. For fine lines, as in developing a. miter, in which the great- est possible accuracy is required, a No. 5 is very gen- erally used, although many pattern cutters prefer the finer grade for this purpose and use a H I H H H. The quality and accuracy of drawings depend; in a considerable measure, upon the manner in which pencils are sharpened. A pencil used for making fine Fig. 121.— Two Views of Pencil Sharpened to a Chisel Point, straight lines, as, for instance, in the various opera- tions of pattern cutting, should be sharpened to a chisel point, as illustrated in Fig. 121, Pencils for general work away from the edges of the J-square, triangle, etc., should be sharpened to a round point, as shown in Fig. 122. It facilitates work and it is quite eco- nomical to have several pencils at command, sharpened in different ways for different purposes. Where for any reason only one pencil of a kind can be had, both ends may be sharpened, one to a chisel point and the other to a round point. For keeping a good point upon a pencil, a piece of fine sand paper or emery paper, glued upon a piece of wood, will be found very serviceable. A flat file, mill-saw cut, is also useful for the same purpose. Sharpen the pencil with a knife, so far as the wood part is concerned, and then shape the lead as required upon the file or sand paper. Drawing Pens. — Although most of the pattern cutter's work is done with the pencil, there occasion- ally arise circumstances under which the use of ink is desirable. Tracings of parts of drawings are frequently required which can be better made with ink than with pencil. The drawing pen or ruling pen, as illustrated in Fig. 123, is used for drawing straight lines. The drawing pen, whether as a separate instrument or as an attachment to compasses or beam compasses for drawing curved lines, consists of two blades with steel points, fixed to a handle. The blades are so curved that a sufficient cavity is left between them for ink when the points meet close together or nearly so. The space between the points is regulated by means of the screw shown in the engraving, so as to draw lines of any required thickness. One of the blades is provided with a joint, so that, by taking out the screw, the. blades may be completely opened and the points readily cleaned after use. The ink is put between the blades with a common pen, or sometimes by a small hair brush. Tn using the drawing pen it should be slightly inclined in the direction of the line to be drawn, and should be kept uniformly close to the ruler or straight- Fig. 122. — Pencil Sliarpened to a Round Point, Fig. 123. — Ruling Pen. edge during the whole operation of drawing a line, but not so close as to prevent both points from touch- ing the paper equally. Keeping the blades of the pen clean is essential to good work. If the draftsman is careless in this par- ticular, the ink will soon corrode the points to such an extent that it will be impossible to draw fine lines. Pens will gradually wear away, and in course of time they require dressing. To dress up the tips of the blades of a pen, since they are generally worn unequally by customary usage, is a matter of some nicety. A small oil stone is most convenient for use in the operation. The points should be screwed into contact in the first place, and passed along the stone, turning upon the point in a directly perpendicular plane until they acquire an identical profile. Next they are to be unscrewed and examined to ascertain the parts of unequal thickness around the nib. The blades are then to be laid separately upon their backs upon the stone, and rubbed down at the points until they are brought up to an edge of uniform fineness. It is well to screw them together again and pa.ss them over the Drawing Tools and Materials. 27 stone once or twice more to bring up any fault and to retouch them also at the outer and inner side of each blade to remove barbs or frazing, and finally to draw them across the palm of the hand. India Ink. — For tracings, and for some kinds of drawings, which the pattern cutter is obliged to make occasionally, India ink is much better than the pencil, which is used for the greater part of his work. Care is to be exercised in the selection of ink, as poor grades are sold as well as good ones. Some little skill is required in dissolving or mixing it for use. India ink is sold in cakes or sticks, of a variety of shapes. It is prepared for use by rubbing the end of the stick upon the surface of a ground glass, or of a porcelain slab or dish, in a very small quantity of water, until the mixture is sufficiently thick to produce a black line as it flows from the point of the ruling pen. The quality of ink may generally be determined by the price. The common size sticks are about 3 inches long. Inferior grades can be bought as low as 40 cents per stick, while a good quality is worth $1.50 to $2 per stick, and the very best is still higher. How- ever, except in the hands of a responsible and expe- rienced dealer, this method of judging is hardly satisfactory. To a certain extent ink may be judged by the brands upon it, although in the case of the higher qualities the brands frequently change, so that this test may not be infallible. The quality of India ink is quite apparent the moment it is used. The best is entirely free from grit and sediment, is not musky, and has a soft feel when wetted and smoothed. The color of the lines may also be used as a test of quality. With a 230or ink it is impossible to make a black line. It will be brown or irregular in color and will present an irregular edge, as though broken or ragged, while an ink of satisfactory quality will produce a clean line, whether drawn very fine or quite coarse. Various shaped cups, slabs and dishes are in use for mixing and containing India ink. In many re- spects they are like those used for mixing and holding- water colors.' Indeed, in many cases the same articles are employed. The engraving (Fig. 124) shows what is termed an India ink slab, with three holes and one slant. This article is in common use among draftsmen and serves a satisfactory purpose. In order to retard evaporation, a kind of saucers, in sets, is frequently used, so constructed that one piece will form a cover to the other, and which are known in the trade as cabinet sets or cabinet saucers. They are from 2-J- to 3£ inches in diameter and come in sets of six. In the absence of ware especially designed for the purpose, India ink can be satisfactorily mixed in and used from an ordinary saucer or plate of small size. The articles made especially for it, however, are convenient, and Front with Cover On. Top with Cover Off. Fig. 124 —India Ink Slab. in facilitating the care and economical use of the ink are well worth the small price they cost. Several makes of liquid drawing ink are also to be had, which possess the advantage of being always ready for use, thus doing away with the rubbing process. The ink costs about 25 cents a bottle, keeps well, and will answer almost every purpose quite as well as the stick ink. Thumb Ta.ks or Drawing Pins, both names being in common use, are made of a variety of sizes, ranging from those with heads one-quarter of an inch in diam- Fig. 125. — Thumb Tacks, or Drawing Pins, eter up to eleven-sixteenths of an inch in diameter. They are likewise to be had of various grades and qualities. The best for general use are those of Ger- man silver, about three-eighths to five-eighths of an inch in diameter, and with steel points screwed in and riveted Those which have the points riveted only are of the second quality. The heads should be flat> to allow the T-square to pass over them readily. In the 28 The New Metal Worker Pattern Book. annexed cut, Fig. 125, are shown an assortment of kinds and sizes. Those which are beveled upon their upper edges are preferable to those which are beveled underneath. A Box Of Instruments.— Fig. 126 shows a box of in- struments of medium grade, as made up and sold by the trade generally. While it contains some pieces that the pattern cutter has no use for, it also contains the principal tools he requires, all put together in com- pact shape, and in a convenient manner for keeping the instruments clean and in good order. The tray of the box lifts out, there being a space underneath it in which may be placed odd tools, pencils, etc. Tools luay be selected, as recpiired, of most of the large dealers in drawing instruments. It will be found ad- vantageous to the pattern cutter to buy his instruments singly as he requires them, as by so doing he will get only what he recpiires for use, and will probably secure »:- Si A Fig. 126. — .4 Box of Instruments. a better quality in the tools. After he has made his selection, a box properly fitted and lined should be provided for them and can be obtained at a small cost, or made if desirable. India Rubber. — A good rubber with which to erase erroneous lines is indispensable in the pattern cutter's outfit. The several pencil manufacturers have put their brands upon rubber as well as upon pencils, and satisfactory quality can be had from any of them. The shape is somewhat a matter of choice, flat cakes being the most used. A very soft rubber is not so well adapted to erasing on detail paper as the harder varie- ties, but is to be preferred for use in fine drawings on good quality paper. Paper. — The principal paper that the pattern cutter has anything to do with is known as brown detail paper, or manila detail paper. It can be bought of almost any width, from 30 inches tip to 54 inches, in rolls of 50 to 100 pounds each. It is ordinarily sold in the roll by the pound, but can be bought at retail by the yard, although at a higher figure. There are different thicknesses of the same quality. Some dealers indi- cate them by arbitrary marks, as XX, XXX, XXXX; others by numbers 1, 2, 3; and still others as thin, medium and thick. The most desirable paper for the pattern cutter's use is one which combines several good qualities. It should be just as thin as is consistent with strength. A thick paper, like a stiff card, breaks when folded or bent short, and is, therefore, objection- able. The paper should be very strong and tough, as the requirements in use are quite severe. The surface should be very even and smooth, yet not so glossy as to be unsuited to the use of hard pencils. It should be hard rather than soft and should be of such a texture as to withstand repeated erasures in the same spot without damage to the surface. "White drawing paper, which the pattern cutter has occasionally to use in connection with his work, can be had of almost every conceivable grade and in a variety of sizes. The very best quality, and the kinds suited for the finest drawings, come in sheets exclu- sivety, although the cheaper kinds are also made in the shape of sheets as well as in rolls. White drawing paper in rolls can be bought of different widths, rang- ing from 36 to 54 inches, and from a very thin grade up to a very heavy article, and of various surfaces. It is sold by the pound, in rolls ranging from 30 to 40 pounds each, and also at retail by the yard. A kind known as eggshell is generally preferred by architec- tural draftsmen. Drawing paper in sheets is sold by the quire, and at retail by the single sheet. The sizes are generally indicated by names which have been applied to them. The following are some of the terms in common use, with the dimensions which they represent placed op- posite : 17 Cap 13 Demy 15 Medium 17 Royal • 19 Super Royal..... 19 x 27 Imperial 22 x 30 x x x X 20 22 24 Elephant 23 x 28 Atlas...... 26 x 34 Columbier... 23 x 35 Double Elephant. 27 x 40 Antiquarian .. 31 x 53 Emperor 48 x 68 Still another set of terms is used in designating French drawing papers. Different qualities of paper, both as regards thickness, texture and surface, can be had of any of the sizes above named. Drawing Tools and Materials 29 Tracing: Paper and Tracing Cloth.— The pattern cutter has frequent use for tracing paper, and a good article, which combines strength, transparency and suitable surface, is very desirable. Tracing paper is sold both in sheets, in size to correspond to the draw- ing papers above described, and in rolls, to correspond in width to the roll drawing paper. It is usually priced by the quire and by the roll, although single sheets or single yards are to be obtained at retail. The rolls, according to the kinds, contain from 20 to 30 yards. There are various manufacturers of this article, but it is usually sold upon its merits, rather than by any brand or trade-mark. Tracing cloth, or tracing linen, is used in place of tracing paper where great strength, and durability are required. This article comes exclusively in rolls, ranging in width from 18 to 42 inches. There are generally 24 yards to the roll, and prices are made according to the width, or, in other words, according to the superficial contents of the roll. Two grades are usually sold, the first being glazed on both sides and suitable only for ink work, and the second on but one side, the other being left dull, rendering it suitable for pencil marks. Upon general principles, pencil marks are not satis- factory upon cloth, even upon the quality specially prepared with reference to them. It is but a very little more labor or expense to use ink, and a much more presentable and usable drawing is made. Tracing paper may be used satisfactorily with either pencil or pen. ¥ -^e> CHAPTER III, Linear Brawl egc In the production of all great constructive works the drawing plays a most important part. If a piece of machinery, a ship, an aqueduct or a temple is to be built, verbal descriptions would be insufficient direc- tions to the workmen who are to perform the actual labor; drawings become a necessity, because a draw- ing tells exactly what is meant, where words would utterly fail. Therefore, to everybody connected with the constructive trades, to artisans in whatever field, the ability to read, if not to make, a drawing becomes a necessity ; and to those in positions ot authority the ability to make a drawing is the power to convey their ideas to others. That branch of drawing with which the pattern cutter has to deal is of a purely geomet- rical nature and is properly termed orthographic projec- tion. The term orthographic (signifying right line) is well applied because it exactly describes the nature of the work, as will be seen further on. The geometrical drawings made use of in repre- senting any constructive work, whether to a large or a small scale, are of three kinds — viz. : Elevations, sections and plans. The term diagram is sometimes used in connection with this class of drawing, but is not of a specific nature. It means a drawing of the simplest possible character, usually made to demon- strate a principle, and may partake of the properties of either of the above named drawings. An elevation, if the word were judged by its com- mon meaning, would be understood to show the bight of anything. It does this and more. It gives all the vertical and horizontal measurements which appear in the front, side or end which it represents. An elevation supposes the observer to be opposite to and on a level with all points at the same time, and is therefore an impossible view, according to the rules of pictorial art. Being always drawn to scale (including full size), it gives exact dimensions of hight and breadth at any part of the view, but furnishes no view of horizontal surfaces and no means of measuring distances to and from the observer, or in any oblique horizontal direc- tion. An elevation may be called front, side, end or rear, according to the relative dimensions of the object, one of whose faces it represents. Any elevation or vertical section gives two sets of dimensions — i. e., hight and horizontal distance, which lie parallel to the face which it shows. A section, as the word indicates, is a view of a cut or a view of what remains after certain portions have been cut away for the purpose of showing more clearly the interior construction. The idea of a verti- cal section can best be described by supposing that a wire stretched taut, or any perfectly straight blade, was passed vertically down through an object at a given distance from one of its ends or sides, indicated by a line in some other view or views, and the portion not wanted w r as removed. The view made of the section may properly include only the parts cut, or if made to include or show portions that would naturally appear by the removal of the parts, it would properly be called a sectional elevation. Sections may also be taken hori- zontally at any hight above the base or ground line, indicated by a line for that purpose upon one or more of the elevations. Horizontal sections are properly classed with plans. Vertical sections are known as longitudinal or transverse, according as they are taken through the long way of, or across, an object. Elevations or sections may also be constructed upon oblique planes when necessary to more fully show construction. Sections of small portions or members drawn to a large scale or full size are called profiles. They are ap- plied to continuous forms, as moldings, jambs, etc., and are drawn for the purpose of showing the peculiari- ties in form of the parts which they represent. The view which gives all the horizontal distances in whatever direction is called the plan. The name plan applies equally well to a horizontal section or to a top view. In the plan, as in sections and elevations, Linear Drawing. 31 the observer is supposed to be opposite to (i.e. , di- rectly above) all points at the same time. In idea it is the same as a map, the difference between the two terms being in the amount included in the view. In Fig. 128 is given an illustration of the various geometrical views of an object, placed in their proper relation one to another, showing the lines of projec- tion and the lines upon which the different sections are taken. A house placed upon a base has been se- lected as the most suitable object for purposes of explanation in the present case. It has been shown in diagrammatic form — that is, denuded of all cornices, trimmings or projecting parts — so as to demonstrate the principles of projection in the clearest manner possible. It rests with the designer to determine which of the views shall be drawn first, all depending upon the given facts or specifications in his possession. If a house is to be designed, it is most likely that the plan would be drawn first, as arrangement of rooms and amount of ground to be covered would be of the first importance. If a molding be the subject of the de- sign, the profile would be the view in which to first adjust the proportion of its parts. The method of deriving the elevation from the section or obtaining any one view from one or more other views is termed orthographic projection, because by it a system of parallel lines is made use of for the purpose of obtain- ing the same hight (or width, as the case may be) in corresponding parts in the different views. In this connection it is to be understood that each angle or limit of outline in a sectional view is the source of a right line in the elevation. In Fig. 127 is shown, at X, a sectional view or profile of a molding, which should be so drawn that all the faces or sur- faces supposed to be vertical shall lie vertically on the paper; that is, parallel to the sides of the drawing board. To project an elevation, Y, from this section, place the T-square so that the blade lies horizontal — that is, crossing the board from side to side — and bring it to the various angles A, B, C, etc., of the profile, drawing a line from each. The point E, though not an angle, is the lowest visible point or limit of that member of the mold when seen from the front, and is, therefore, entitled to representation in the elevation by a line. In like manner the point D, being the upper limit of a curve, is entitled to representation, but being so situated as to be invisible when viewed from a point in front of the mold, the line is properly made dotted. The lines of projection from the section to the elevation are also shown dotted in the engrav- ing. A vertical line terminates the elevation of the mold at the right or end nearest the section, while the absence of such a line at its left end indicates that it extends indefinitely in that direction. It would also be proper, upon that supposition, to finish the eleva- tion at the left with a broken line. Referring now to Fig. 128, it is most likely that the front elevation would be next drawn after the plan. For this purpose the plan should be so placed upon the board that the part representing the front should be turned toward the bottom of the board, in which position it appears to be turned toward the observer. Place the T-square so that the blade lies vertically upon the board — that is, crossing it from front to back — and bringing it to the different angles or points of the front side of the plan, draw a line ver- tically from each, through that portion of space upon At Fig. 127. — Elevation Projected from Section. the paper allotted to the elevation, all as shown by the dotted lines. Thus each point of the elevation comes directly over the point which represents it in the plan, and the horizontal distance across any part of the new elevation thus becomes exactly the same as that of the plan. The question of bights is here a matter of de- sign and is governed by specifications supplemented by the designer's judgment. With the plan and the front elevation complete the drawing of any other ele- vations or sections is entirely a matter of projection, except as new features might occur in those vieWs which would not appear in either of the views already drawn. If an elevation of the right side is about to be con- structed, lines would be projected horizontally to the right from every point in the front elevation of the ob- ject which would be visible when seen from the right side, thus locating all the bights in the new view. As the horizontal distances in this view must agree with distances from front to back on the plan, they may best be obtained by turning the plan (or so much of it as nec- essary to this view) one-quarter around to the right, so 32 TJie New Metal Worker Pattern Book. .0. h. UJ t I z < to. Dr 33 that the side of which the new elevation is to be drawn will be toward the bottom or near side of the board, as shown at G ; after which lines may be projected with the T-square from the points of the plan into the eleva- tion, intersecting with corresponding lines, as shown. The same result may be accomplished by projecting the lines to the right from the side of the plan, as shown in the top view, until they reach any line paral- lel to the side, as H I. From this line they may be carried around a quarter circle from any convenient center, as N, arriving at a horizontal line, 1ST M, and thence dropped downward, intersecting as before. It will thus be seen that the elevation of the right hand side of any object comes naturally at the right of the front elevation, and the left side elevation, at its left. This idea is best illustrated by supposing that the object in question be placed in a glass box of the dimensions of the base H I J K of the top view, and that the elevation of each side of the object be pro- LONG1TUD1NAL SECTION ON CD TRANSVERSE SECTION ON A-B Fig. 129. — Vertical Sections Derived from Fig. 128. jected upon the adjacent parallel side of the box at right angles to the same, and that afterward all the sides (supposing them to be hinged at the corners) be opened out into one plane, as shown by K L, H and P (the top face of the box being opened upward), thus displaying all the views in one plane as repre- sented by Fig. 128. This idea should not be carried so far as to open the bottom face of the box downward, because this would produce a plan as seen from below, which is never done except in the case of a design of a ceiling or soffit, when it should be spoken of as an inverted plan. In Fig. 129 the transverse section is shown at the right of the longitudinal section, because the view in it is from the right, or in the direction of the arrow in the longitudinal section, showing what would be seen if the house were cut in two on the line A B of the plan and the right hand portion removed. The longi- tudinal section is for the same reason placed at the left of the transverse section — that is, it is a view from the left of the house when placed in the position shown by the transverse section. From the foregoing it is to be understood, therefore, that when a view appears to the right of another it is supposed to show what would be seen when the object is viewed from the right hand end or side of what is shown in the other, the other (or front) view being at the same time a view of the left side of what is shown by the right side elevation. In this class of drawings various kinds of lines are used, each of which possesses a certain significance. The general outlines of the different views should be firm and strong enough to be distinctly visible, with- out being so broad as to leave any doubt as to the ex- act dimensions of the part shown when the rule is ap- plied for purposes of measurement. It is not always necessary that all the lines of projection should be shown. When shown they may appear as the finest possible continuous lines, or as dotted lines such as are shown in Figs. 127, 128 and 129. Lines used in carrying points from a profile to a miter line, or from one line to another for any purpose, are really lines of projection, and for the pattern drafts- man's purposes it may be said that the finer they are drawn the greater the accuracy ob- tained (see Chapter II under the head of Lead Pencils). Dotted lines are also used to represent portions which are out of sight — that is, back of or underneath the other parts which constitute the view under consideration, but which it is necessary to show, as, for instance, a portion of the chimney in longitudinal section Fig. 129 and points D and F in the profile of the mold in Fig. 127. Dotted lines are also used to show a change of position or an alternate position of some part, as, for example, the lines L K and J L show that the side J K of the top view has been swung around on the point K until it occupies the position shown by L K, its ex- tremity J traversing the line J L. When it is neces- sary to use two kinds of dotted lines, those used for one purpose may be made in fine or short dots, while the others may be made a series of short dashes. Lines showing the part of a view through which a section is taken are composed of a series of dots and dashes, as shown by A B, C D, etc., in Fig. 128, and when further distinction is required may be made by gi- I two dots alternating with a short or long dash. 34 The New Metal Worker Pattern Book. When it is desirable to omit the drawing of a con- siderable portion of any view it is customary to termi- nate the incomplete side of such view by an irregular line, as shown above the plan G in Fig. 128. It is customary in all sectional views for the parts which are represented as being cut to be ruled or lined with lines running in an oblique direction, as in Fig. 129. When the section comprises several different pieces lying adjacent to one another, each different part should be lined in a different direction. This rul- ing is understood to mean solidity. In Fig. 129 the walls and base in the different sections are represented as though made of some solid material, as wood or stone, and ruled accordingly. Where it is necessary to represent different kinds of material in the same sec- tion, different systems or kinds of lines may be used for the purpose. Thus solid and dotted lines may be used alternately, as in the base. Coarse and fine rul- ing, or stippling, may also be employed, according to the size of the part, or very small parts may be shown solid black, as window weights, piping or hinges. A heavy line is the only way that a thickness of metal can properly be shown in a section. In the case of a sectional view of a cornice or molding where nothing but the sheet iron appears, it is customary to make use of section lines close to the metal surface, but not to extend them clear across the space which should be filled if the moldings were of stone or other solid mate- rial. By this means a section may be distinguished from what might otherwise be taken for an elevation of a return. In the case of elaborate drawings prepared by an architect color is frequently resorted to as a means of showing the different materials as they appear in the sectional view, yellow or differing shades of brown being used for various kinds of wood, while blue is generally used for iron, gray for stone, red for brick, etc. In the case of drawings showing many different materials it is usual to place a legend in one corner of the drawing showing what each color or style of ruling indicates. It is always advisable to keep the different views, which it is necessary to construct, separate and dis- tinct from one another, drawing them as near to- gether as circumstances will permit, but never allow- ing one view to cover any part of the space upon the paper occupied by the' other view if it can be avoided. One notable exception to this rule is to be observed. It frequently occurs in drawing an elevation of a large surface, as a pediment or side of a bracket, that it is necessary to indicate that some part of it is recessed or raised, or that a certain edge is molded or chamfered, when it would not be necessary to construct an entire sectional view for this purpose alone. To this end it is customary to draw through such mold, chamfer or recess a small section, in which case, if the depression or mold runs horizontally, the section is turned to the right or left, according to convenience, or if it runs obliquely, it is turned in the direction the mold runs. In such a section the line which represents the plane surface also shows the direction of the cut across the mold or line upon which the section is taken. In Fig. 130 is shown an elevation of a portion of a pediment, in which a small section, A B C, is introduced to show the profiles of the moldings. The line B C, which Fig. ISO.— Elevation with Section of Parts. represents the profile of the stile around the panel s shows the line upon which, or the direction in which, the section is taken, said section being turned upon this line obliquely to the left. It is necessary to rule or line this section, the ruling being kept close to and inside the outline or profile. By placing the ruling in- side the profile no doubt can exist as to which parts are raised and which are depressed, for if at D the ruling were upon the other side of .the line from that shown the section D would indicate a depressed panel instead of a raised one. In the solution of the class of problems treated in Chapter VI, Section 1 (Miter Cutting), confusion often arises in the mind of the pattern cutter as to the proper position of a profile or of a miter line, which Linear Drawing. 35 confusion could never occur if all the necessary views were first drawn in accordance with the principles which this chapter is written to explain. A pro- file is always a section, and a miter line is either a part of an elevation projected from the section or part of another section bearing certain relations of hight or breadth to the first. A pattern is likewise always pro- jected — that is, carried off by right lines — from an elevation or plan the same as an elevation is projected from a section. It should also be remembered in this connection that the operation of developing a pattern is not com- pleted until its entire outline is drawn. The line form- ing its termination at the end opposite the miter cut, although simply a straight line, is properly derived from the elevation or plan used, the same as all points and other lines of the pattern. Much trouble is experienced through lack of knowledge of the principles of Linear Drawing, which if thoroughly understood could never result in such mistakes as producing a face miter where a return was intended or using the piece of metal from the wrong side of the miter cut. Too much emphasis cannot be placed upon the im- portance of thoroughly understanding the subject treated in this chapter, as such a knowledge comprehends within itself an answer to the many questions continually arising in the course of the pattern draftsman's labors. ♦ CHAPTER IV. Geometrical Problems. In presenting this chapter to the student no at- tempt has been made to give a complete list of geo- metrical problems, but all those have been selected which can be of any assistance to the pattern drafts- man, and especial attention has been given in their solution to those methods most adaptable to his wants. They are arranged as far as possible in logical order and are classified under various sub-heads in such a manner that the reader will have no difficulty in finding what he wishes by simply looking through the pages, the diagrams given with each being sufficient to indi- cate the nature of the problem and, as it were, form a sort of index. 1. To Draw a Straight Line Parallel to a Given Line and at a Given Distance from it, Using: the Compasses and Straight-Edge— In Fig. 131, let C D be the given line parallel to which it is desired to draw another straight line. Take any two points, as A ami B, in the given line as centers, and, with a radius equal to the given distance, describe the arcs x x and y y. Draw a line touching these arcs, as shown at E F. Then E F will be parallel to C D. 2. To Draw a Line Parallel to Another by the Use of Triangles or Set-Squares.— In Fig. 132, let A B be the line parallel to which it is desired to draw another. Place one side of a triangle or set-square, F 1 , against it, as indicated by the dotted lines. While holding F 1 firmly in this position, bring a second triangle, or any straightedge, E, against one of its other sides, as shown. Then, holding the second triangle firmly in place, slide the first away from the given line, keeping the edges of the two triangles in contact, as shown in the figure. Against the same edge of the first triangle that was placed against the given line draw a second line, as shown by C D. Then C D will be parallel to A B. In drawing parallel lines by this method it is found advantageous to place the longest edges of the tri- angles against each other, and to so place the two in- struments that the movement of one triangle against the other shall be in a direction oblique to the lines to be drawn, as greater accuracy is attainable in this way. 3. To Erect a Perpendicular at a Given Point in a Straight Line by Means of the Compasses and Straight- Edge. — In Fig. 133, let A B represent the given straight line, at the point C in which it is required to erect a perpendicular. From C as a center with any convenient radius strike small arcs cutting A B, as shown by D and B. With D and B as centers, and with any radius longer than the distance from each of these points to C, strike arcs, as shown by x x and y y. From the point at which these arcs intersect, E, draw a line to the point C, as shown, Then E C will be per- pendicular to A B. 4. To Erect a Perpendicular at or near the End of a Given Straight Line by Means of the Compasses and Straight-Edge.— First Method.— In Fig. 131, let A B be the given straight line, to which, at the point P, situ- ated near the end, it is required to erect a perpendic- ular. Take any point ((J) outside of the line A B. With C as center, and with a radius equal to the distance from C to P, strike the arc, as shown, cutting the given line A B in the point P, continuing it till it also cuts in another point, as at E. From E, through the center, C. draw the line E F, cutting the arc, as shown at F. Then from the point F, thus determined, draw a line to P, as shown. The line F P is perpendicular to A B. 5. To Erect a Perpendicular at or near the End of a Given Straight Line by Means of the Compasses and Straight-Edge.— Second Method.— In Fig. 135, let B A be the given straight line, to which, at the point P, it is required to erect a perpendicular. From the point P, with a radius equal to three parts, by any scale, de- scribe an arc, as indicated by x x. From the same point, with a radius equal to four parts, cut the line B A in the point C. From the point C, with a radius equal to five parts, intersect the arc first drawn by the Geometrical Problems. 37 are y y. From the point of intersection D draw the line D P. Then D P will be perpendicular to B A. 6. To Draw a Line Perpendicular to Another Line by the Use of Triangles or Set Squares.— In Fig. 136, let C D be the given line, perpendicular to which it is required to draw another line. Place one side of a triangle, B, against the given line, as shown. Bring another triangle, A, or any straight edge, against the long side or hypolhenuse of the triangle B, as shown. Then move the triangle B along the straight edge or triangle A, as indicated by the dotted lines, until the opposite side of B crosses the line C D at the required sides of the given line A B. A line drawn through these points of intersection, as shown by G H, will bisect the line A B, or, in other words, divide it into two equal parts. 8. To Divide a Straight Line into Two Equal Parts by the Use of a Pair of Dividers.— In Fig. 138, it is re- quired to divide the line A B into two equal parts, or to find its middle point. Open the dividers to as near half of the given line as possible by the eye. Place one jDoint of the dividers on one end of the line, as at A. Bring the other point of the dividers to the line, as at C, and turn on this point, carrying the first E— rr= Fig. 181.— To Draw a Straight Line' Par- allel to a Given Straight Line, and at a Given Distance from it, Using the Com- passes and a Straight-Edge. Fig. 132. — To Draw a Line Parallel to Another by the Use of Triangles or Set Squares. \E/ D C Fig. 133. — To Erect a Perpendicular at a Given Point in a Straight Line, Using the Compasses and Straight- Edge. A F c/ / i^ /p \ y Fig. 134 — To Erect a Perpendicu- lar at or near the End of a Given Straight Line, Using the Compasses and Straight-Edge. First Method. / D/ y X *\ \ X N Fig. 135.— To Erect a Perpendicular at or near the End of a. Given Straight Line. Second Method. Fig. 136. — To Draw a Line Perpen- dicular to Another by the Use of Triangles. point. "When against it, draw the line E F, as shown. Then E F is perpendicular to C D. It is evident that this rule is adapted to drawing perpendiculars at any point in the given line, whether central or located near the end. Its use will be found especially convenient for erecting perpendiculars to lines which run oblique to the aides of the drawing board. 7. To Divide a Given Straight Line into Two Equal Parts, with the Compasses, by Means of Arcs.— In Fig. 137, let it be required to divide the straight line A B into two equal parts. From the extremes A and B as centers, and with any radius greater than one-half of A B, describe the arcs dfand. a e, intersecting each other on opposite around to D. Should the point D coincide with the other end of the line, the division will be correct. But should the point D fall within (or without) the end of the line, divide this deficit (or excess) into two equal parts, as nearly as is possible by the eye, and extend (or contract) the opening of the dividers to this point and apply them again as at first. Thus, finding that the point D still falls within the end of the line, the first division is evidently too short. Therefore, divide the deficit D B by the eye, as shown by E, and in- crease the space of the dividers to the amount of one of D E. Then, commencing again at A, step off as before, and finding that upon turning the dividers 38 Tlie New Metal Worker Pattern Booh. upon the point F the other point coincides with the end of the line B, F is found to be the middle point in the line. Iu some cases it may be necessary to repeat this operation several times before the exact center is obtained. 9. To Divide a Straight Line into Two Equal Parts by the Use of a Triangle or Set Square.— In Fig. 139, let A B be a given straight line. Place a T-square \ ( ?/* / \ / \ / \ / \ 1 \ 1 \ 1 1 i 1 \ \ \ i A 1 1 | R H 1 1 ■■■- D I \ \ \ \ \ \ \ \ / / / / ! t / / / / ; \ e'\ rf Fig. 1S7. — To Divide a Straiqht Live into Two Equal Parts by Means of Arcs. or some straight edge parallel to A B. Then bring one of the right-angled sides of a set square against it, and slide it along until its long side, or hypothenuse, meets one end of the line, as A. Draw a line along the long side of the triangle indefinitely. Reverse the position of the set square, as shown by the dotted lines, bringing its long side against the end, B, of the given Fig. ISS.—To Bisect a Straight Line by the Use of the Dividers. straight line, and in like manner draw a line along its long side cutting the first line. Next slide the set square along until its vertical side meets the intersec- tion of the two lines, as shown at C, from which point drop a perpendicular to the line A B, cutting it at D„ Then D will be equidistant from the two extremities A and B. 10. To Divide a Given Straight Line into Any Num- ber of Equal Parts.— In Fig. 140, let A B be a given straight, line to be divided into equal parts, in this case eight. From one extremity in this line, as at A, draw a line, as either A C or A D, oblique to A B. Set the dividers to any convenient space, and step off the oblique line, as A C, eight divisions, as shown by a b c d, etc. From the last of the points, A, thus obtained, draw a line to the end of the given line, as shown by A A 5 . Parallel to this line draw other lines, from each of the other points to the given line. The divisions Fig. lS9.—To Bisect a Straight Line by the Use of a Triangle. thus obtained, indicated in the engraving by a 3 V c% etc., will be the desired spaces in the given line. It is evident by this rule that it is immaterial, except as a matter of convenience, to what space the dividers are set. The object of the second oblique line in the en- graving is to illustrate this. Upon A C the dividers were set so as to produce spaces shorter than those re- Fig. HO. — To Divide a Given Straight Line into Any Number of Equal Parts. quired in the given line A B, while in A D the spaces were made longer than those required in the given line. By connecting the last point of either line with the point B, as shown by the lines h A 2 and A' A 3 , and draw- ing lines from the points in each line parallel to these lines respectively, it will be seen that the same divi- sions are obtained from either oblique line. 11. To Divide a Straight Line Into Any Number of Equal Parts by Means of a Scale. — It may be more con- venient to transfer the length of a given line to a slip of Geometrical Problems. 39 paper, and by laving the paper across a scale, as shown in Fig. 141, mark the required dimensions upon it, and afterward transfer them to a given line, than to divide the line itself by one of the methods explained for that purpose. ' It may also occur that it is desirable to divide lines of different lengths into the same num- ber of equal parts, or the same lengths of lines into different numbers of equal parts. Such a scale as is shown in Fig. 141 is adapted to all of these purposes. The scale may be ruled upon a piece of paper or upon a sheet of metal, as is preferred. The lines may be all of one color, or two or more colors may be alternated, in order to facilitate counting the lines or following them by the eye across the sheet. In size, the scale should be adapted to the special purposes for which it is intended to be used. By the contrast of two colors Fig HI. — To Divide a Straight Line, into Any Number of Equal Parts by Means of a Scale. in ruling the lines, one scale may be adapted to both coarse and fine work. For instance, if the lines are ruled a quarter of an inch apart, in colors alternating red and blue, in fine work all the lines in a given space may be used, while in large work, in which the di- mensions are not required to be so small, either all the red or all the blue lines may be used, to the exclusion of those of the other color. Let it be required to di- vide the line A B in Fig. 141 into thirty equal parts. Transfer the length A B to one edge of a slip of paper, as shown by A 1 B : , and placing A 1 against the first line of the scale, carry B 1 to the thirtieth line. Then mark divisions upon the edge of the strip of paper opposite each of the several lines it crosses, as shown. Let it be required to divide the same length A B into fifteen equal parts by the scale. Transfer the length A B to a straight strip of paper, as before. Place A' against the first line and carry B 2 against the fifteenth line, as shown. Then mark divisions upon the edge of the paper opposite each line of the scale, as shown. 12. To Divide a Given Angle into Two Equal Parts.— In Fig. 142, let A C B represent any angle which it is Fig. W —To Bisect a Given Angle. required to bisect. From the vertex, or point C, as center, with any convenient radius, strike the arc D E, cutting the two sides of the angle. From D and E as centers, with any radius greater than one-half the length of the arc D E, strike short arcs intersecting at G, as shown. Through the point of intersection, G, draw a line to the vertex of the angle, as shown by F C. Then F C will divide the angle into two equal parts. 13. To Trisect an Angle— No strictly geometrical method of solving this problem has ever been discov- ered. The following method, partly geometrical and partly mechanical, is, however, perfectly accurate and can be used to advantage whenever it becomes neces- sary to find an exact one-third or two-thirds of an angle : Let ABC, Fig. 143, be the angle of which it is Fig. 143. — To Trisect a Given Angle. required to find one-third. Extend one of its sides beyond the vertex indefinitely, as shown by B E, and upon this line from B as center with any convenient radius describe a semicircle A C D, cutting both sides of the angle. Place a straight edge firmly against the 40 Tlie New Metal Worker Pattern Book. extended side as at F, and a pin at the point C. On another straight edge (G) having a perfect corner at E, set off from one end a distance equal to the radius of the semicircle as shown by point x\ and placing this straight edge, with the end upon which the radius was set off, against the other straight edge (F) and its edge near the other end, against the pin at the point C, all as shown, slide it along until the mark x comes to the semicircle establishing the point D. Draw the line D B, then the angle DEB will be one-third of the angle ABC, and C D B will be two-thirds of it. 14. To Find the Center from which a Given Arc is Struck.— In Fig. 144, let A B C represent the given Fig. HA.— To Find the Center from which a Given Arc is Struck. Fig. 140— The Chord and Eight of a Segment of a Circle Being Given, to find the Center from which the Arc may be Struck. arc, the center from which it was struck being un- known and to be found. From any point near the middle of the arc, as B, with any convenient radius, strike the are F G, as shown. Then from the points A and C, with the same radius, strike the intersecting arcs I H and E D. Through the points of intersec- tion draw the lines K M and L M, which will meet in M. Then M is the center from which the given arc was struck. Instead of the points A and C being taken at the extremities of the arc, which would be quite inconvenient in the case of a long arc, these points may be located in any part of the arc which is most convenient. The greater the distance between A and B and B and C, the greater will be the accu- racy of succeeding operations. The essential feature of this rule is to strike an arc from the middle one of the points, and then strike intersecting arcs from the other two points, using the same radius. It is not necessary that the distance from A to B and from B to C shall be exactly the same. 15. To Find the Center from which a Given Arc is Struck by the Use of the Square.— In Fig. 145, let A B C be the given arc. Establish the point B at pleas- ure and draw two chords, as shown by A B and B C. Bisect these chords, obtaining the points E and D. Place the square against the chord B C, as shown in the engraving, bringing the heel against the middle point, D, and scribe along the blade indefinitely. Then place the square, as shown by the dotted lines, with the heel against the middle point, E, of the second chord, and in like manner scribe along the blade, cutting the first line in the point F. Then F will be the center of the circle, of which the are ABC Fig. 145.— To Find the Center from which a Given Arc is Struck, by the Use of the Square. is a part. This rule will be found very convenient for use in all cases where the radius is less than 24 inches in length. 16. The Chord and Hight of a Segment of a Circle being Given, to Find the Center from which the Arc may be Struck.— In Fig. 146, let A B represent the chord of a segment or arc of a circle, and D C the rise or hight. It is required to find a center from which an arc, if struck, will pass through the three points A, D and B. Draw A D and B D. Bisect A D, as shown, and prolong the line H L indefinitely. Bisect D B and prolong I M until it cuts H L, produced in the point E. Then E, the point of intersection, will be the center sought. It will be observed that by producing D C, and intersecting it by either H L or Geometrical Problems 41 I M prolonged, the same point is found. Therefore, if preferred, the bisecting of either A D or D B may be dispensed with. A practical application of this rule occurs quite frequently in cornice work, in the construction of window caps and other similar forms, to fit frames already made. In the conveying of or- ders from the master builder or carpenter to the cor- nice worker, it is quite customary to describe the shape of the head of the frames which the caps are to fit by stating that the width is, for example, 36 inches, and that the rise is 4 inches. To draw the shape thus de- scribed, proceed as follows : Set off A B equal to 36 inches, from the center of which erect a perpendicular, D C, which make equal to 4 inches. Continue D C in the direction of E indefinitely. Draw A D, which bisect, as shown, and draw H L, producing it until it cuts D C prolonged, in the point E. Then with E as center and E D as radius, strike the arc ADB. if. To Strike an Arc of a Circle by a Triangular Guide, the Chord and Hight Being Given.— In Fig. 147, let Fig. llfl. — To Strike an Arc of a Circle by a Triangular Chiide. A D be the given chord and B F the given bight. The first step is to determine the shape and size of the tri- angular guide. Connect A and F, as shown. From F, parallel to the given chord A D, draw F G, making it in length equal to A F, or longer. Then A F Gr, as shown in the engraving, is the angle of the triangular guide to be used. Construct the guide of any suitable material, making the angle of two of its sides equal to the angle AFC Drive pins at the points A, F and D. Place the guide as shown. Put a pencil at the point F. Shift the guide in such a manner that the pencil will move toward A, keeping the guide at all times against the pins A and F. Then reversing, shift the guide so that the pencil at the point F will move toward D, keeping the guide during this operation against the pins F and D. By this means the pencil will be made to describe the arc A F D. It may be interesting to know that if the angle F of the triangu- lar guide be made a right angle, the arc described by it will be a semicircle. By these means, then, a steel square may be used in drawing circles, as illustrated in Fig. 148, the pins being placed at A, B and C. 18. To Draw a Circle Through any Three Given Points not in a Straight Line.— Iu Fig. 149, let A, D and E be any three given points not in a straight line, through which it is required to draw a circle. Con- nect the given points by drawing the lines A D and D E. Bisect the line A D by F C, drawn perpendicular to it, as shown. Also bisect D E by the line G C, as shown. Then the point C, at which these lines meet, is the center of the required circle. 19. To Erect a Perpendicular to an Arc of a Circle, without having Recourse to the Center.— In Fig. 150, let A D B be the arc of a circle to which it is required to erect a perpendicular. With A as center, and with any radius greater than half the length of the given arc, describe the arc x x, and with B as center, and with the same radius, describe the arc y y, intersecting Fig. 14S. — To Describe a Semicircle with a Steel Square, the arc first struck, as shown. Through the points of intersection draw the line F E. Then F E will be perpendicular to the arc, and if sufficiently produced will reach the center from which the arc A B is drawn. 20. To Draw a Tangent to a Circle or Arc of a Circle at a given Point without having Recourse to the Center.— In Fig. 151, let A D B be the arc of a circle, to which a tangent is to be drawn at the point D.- AVith D as center, and with any convenient radius, describe the arc A F B, cutting the given arc in the points A and B. Join the points A and B, as shown. Through D draw a straight line parallel to A B, as shown by E H, then E II will be the required tangent. 21. To Ascertain the Circumference of a Given Circle. — In Fig. 152, let A D B C be the circle, equal to the circumference of which it is required to draw a straight line. Draw any two diameters at right angles, as shown by A B and D C. Divide one of the four arcs, as, for instance, D B, into eleven equal parts, as shown. 42 The New Metal Worker Pattern Book. From 9, the second of these divisions from the point B, let fall a perpendicular to A B, as shown by 9 F. To three times the diameter of the circle (A B or D C) add the length 9 F, and the result will be a very close approximation to the length of the circumference. This rule, upon a diameter of 1 foot, gives a length of about y 3 ¥ ths of an inch in excess of the actual length of the circumference. 22. To Draw a Straight Line Equal in Length to the Circumference of any Circle or of any Part of a Circle- dividers are placed upon the line, no perceptible curve shall exist between them, and, beginning at one end of the curve, step to the other end of the same, or so near the end that the remaining space shall be less than that between the points of the dividers, then beginning at the end of any straight line step off upon it the same number of spaces, after which add to them the remain- ing small space of the curve by measurement with the dividers. This will be found the quickest and most accurate of any method for the pattern cutters' use. Fig. 149. — To Draw a Circle Through any Three Given Points Not in a Straight Line Fig. 150.— To Erect a Perpendicular to an Arc of a Circle. Fig. 151.— To Draw a Tangent to a Circle or Arc. Fig. 152. — To Ascertain the Circumfer- ence of a Given Circle. Fig. 15S. — To Inscribe an Equilateral Triangle within a Given Circle. Fig. 154. — To Inscribe a Square within a Given Circle. Various approximate rules, similar to the one given in the problem above, for performing these operations are known and sometimes used among workmen, but can- not be recommended here because in using them con- siderable time and trouble is required to obtain a result which is not accurate when obtained, thus rendering such methods impracticable. The simplest and most accurate method for obtaining the length of any curved line is as follows : Take between the points of the dividers a space so small that when the points of the The most common rules in use for the construc- tion of polygons, whether drawn within circles or erected upon given sides, are those which employ the straight-edge and compasses only. Other instruments may also be employed to great advantage, as will be shown further on, leaving the student to decide which method is the most suited to any case he may have in hand. Accordingly, the construction of polygons will be treated under three different heads arranged accord- ing to the tools employed. Geometrical Problems. THE CONSTRUCTION OF REGULAR POLYGONS. 43 I.— BY THE USE OF COMPASSES AND STRAIGHT-EDGE. 23. To Inscribe an Equilateral Triangle within a Given Circle.— In Fig. 153, let ABD be any given circle within which an equilateral triangle is to be drawn. From any point in the circumference, as E, with a radius equal to the radius of the circle, describe the arc D C B, cutting the given circle in the points D and B. Draw the line D B, which will be one side of the required triangle. From D or B as center, and with D B as radius, cut the circumference of the given circle, as shown at A. Draw A B and A D, which will complete the figure. 24. To Inscribe a Square within a Given Circle. — In Fig. 154, let A G B D be any given circle within which it is required to draw a square. Draw any two Circle.— In Fig. 156, let A B D E F G be any given circle within which a hexagon is to be drawn. From any point in the circumference of the circle, as at A, with a radius equal to the radius of the circle, de- scribe the arc C B, cutting the circumference of the circle in the point B. Connect the points A and B. Then A B will be one side of the hexagon. With the dividers set to the distance A B, step off in the cir- cumference of the circle the points G, F, E and D. Draw the connecting lines A Gr, Gr F, F E, E D and D B, thus completing the figure. By inspection of this figure it will be noticed that the radius of a circle is equal to one side of the regular hexagon which may be inscribed within it. Therefore set the dividers to the radius of a circle and step around the circumfer- ence, connecting the points thus obtained. Fig. 155 — To Inscribe a Regular Penta- gon within a Given Circle. Fig. 156. — To Inscribe a Regular Hexa- gon within a Given Circle. Fig. 157. — To Inscribe a Regular Hepta- gon within a Given Circle. diameters at right angles with each other, as C D and A B. Join the points C B, B D, D A and A C, which will complete the required figure. 25. To Inscribe a Regular Pentagon within a Given Circle. — In Fig. 155, A D B C represents a circle in which it is required to draw a regular pentagon. Draw any two diameters at right angles to each other, as A B and DC. Bisect the radius A H, as shown at E. With E as center and E D as radius strike the arc D F, and with the chord D F as radius, from D as center, strike the arc F Gr, cutting the circumference of the given circle at the point G. Draw D G, which will equal one side of the required figure. With the dividers set equal to D G, step off the spaces in the circumference of the circle, as shown by the points I K and L. Draw D I, I K, K L and L G, thus com- pleting the figure. ' 26. To Inscribe a Regular Hexagon within a Given 27. To Inscribe a Regular Heptagon within a Given Circle.— In Fig. 157, let F A G B H I K L D be the given circle. From any point, A, in the circumfer- ence, with a radius equal to the radius of the circle, describe the arc BCD, cutting the circumference of the circle in the points B and D. Draw the chord B D. Bisect the chord B D, as shown at E. With D as center, and with D E as radius, strike the arc E F, cutting the circumference in the point F. Draw D F, which will be approximately one side of the heptagon. With the dividers set to the distance D F, set off in the circumference of the circle the points G, H, I, K and L, and draw the connecting lines, F G, G H, H I, IK, K L and L D, thus completing the figure. 28. To Inscribe a Regular Octagon within a Given Circle.— In Fig. 15 S, let B ID F A G E H be the given circle within which an octagon is to be drawn. Draw any two diameters at right angles to each other, 44: Tlie New Metal Worker Pattern Book. as B A and D E. Draw the chords D A and A E. Bisect D A, as shown, and draw L H. Bisect A E and draw K I. Then connect the several points in the circumference thus obtained by drawing the lines D I, I B, B H, H E, E G, G A, A F and F D, which will complete the figure. 29. To Inscribe a Regular Nonagon within a Given Circle. — In Fig. 159, let A H K M be the given circle. Through the center C, draw any diameter A K, which extend indefinitely in either direction. From A as center, with the radius of the given circle, describe an arc, cutting the circumference at B. The arc A B being one-sixth of the circumference, may now be tri- sected, as explained in Problem 13 of this chapter, viz. : Set off on any straight edge the distance E D equal to the radius of the circle, and bringing the straight edge against the point B, slide the point E along the diam- eter extended K, etc. Draw D H, H I, I. J, etc., completing the figure. 31. To Inscribe a Regular Polygon of Fifteen Sides in a Given Circle.— In Fig. 161, let A P L B be the given circle. First draw any two radii, as C A and C B, at right angles to each other, and bisect one of them, as CB, at D, and draw D A. With D as center, and C D as radius, describe an arc, cutting D A at E, and with A as center, and A E as radius, describe an arc E F, cutting the circumference at F. Then will A F be one-tenth of the circumference of the given circle. Now with A as center, and A C as radius, describe an arc C G, cutting the circumference at G. Then, since A G is one-sixth, and A F one-tenth of the circum- ference, F G must be the difference, which is one- fifteenth. Therefore with the dividers set to F Gr, divide the circumference into fifteen equal spaces, as shown by the points H, I, J, etc., and complete the figure by drawing the lines F G, G H, H I, etc. D B-|- Fig, 15S. — To Inscribe a Regular Octa- gon within a Given Circle. 159. — To Inscribe a Regular Nona- gon within a Given Circle. Fig. 160. — To Inscribe a Regular Deca- gon within a Given Circle. circumference, all as shown by E D B, and draw E B. Now from C draw C F parallel to E B, cutting the cir- cumference at F. Then will B F be equal to two- thirds of B A or one-ninth of the circumference. Set the dividers to this distance and space off the circum- ference, obtaining the points G, H, I, etc. Draw the lines B F, F G, G H, etc., completing the figure. 30. To Inscribe a Regular Decagon within a Given Circle.— In Fig. 160, let D A E B be any given circle in which a decagon is to be drawn. Draw any two diameters through the circle at right angles to each other, as shown by B A and D E. Bisect B C, as shown at F, and draw F D. From F as center, with F C as radius, describe an arc C G, cutting F D at G. From D as center, with D G as radius, describe the arc G H, cutting the circumference at the point H. Set the dividers to the distance D H and divide the circle into ten equal spaces, shown by the points I, J, 32. To Inscribe a Regular Dodecagon within a Given Circle. — In Fig. 162, let M F A I be any given circle in which a dodecagon is to be drawn. From any point in the circumference, as A, with a radius equal to the radius of the circle, describe the arc C B, cut- ting the circumference in the point B. Draw the chord A B, which bisect as shown, and draw the line C, cutting the circumference in the point D. Draw A D, which will then be one side of the given figure. With the dividers set to this space step off in the cir- cumference the points B, I, N, H, M, G, L, F, K and E, and draw the several chords, as shown, thus com- pleting the figure. 33. General Rule for Inscribing any Regular Polygon in a Given Circle. — Through the given circle draw any diameter. At right angles to this diameter draw a radius. Divide that radius into four equal parts, and prolong it outside the circle to a distance equal to three Geometrical Problems. 45 of those parts. Divide the diameter of the circle into the same number of equal parts as the polygon is to have sides. Then from the end of the radius prolonged, as above described, through the second division in the diameter, draw a line cutting the circumference. Con- nect this point in the circumference and the nearest end of the diameter. The line thus drawn will be one side of the required figure. Set the dividers to this space and step off on the circumference of the circle outside the circle to the extent of three of those parts, as shown by a b c, thus obtaining the point c. From c, through the second division in the diameter, draw the line c H, cutting the circumference in the point H. Connect H and E. Then H E will be one side of the required figure. Set the dividers to the dis- tance H E and step off the circumference, as shewn, thus obtaining the points for the other sides, and draw the connecting arcs, all as illustrated in the figure. Fig. 161 —To Inscribe a Regular Polygon of Fifteen Sides within a Given Circle. -— %C Fig. 162. — To Inscribe a Regular Dodec- agon within a Given Circle. Fig. I6S.—T0 Inscribe a Regular Undec- agon within a Given Circle by the General Rule. Fig. I64. — Upon a Given Side to Construct an Equilateral Tri- angle. Fig. 165. — To Construct a Triangle, the Length of the Three Sides being Given. Fig. 166 — Upon a Given Side to draw a Regular Pentagon. the remaining number of sides and draw connecting lines, which will complete the figure. 34. To Inscribe a Regular Polygon of Eleven Sides (Undecagon) within a Given Circle by the General Rule. — Through the given circle, E D F G in Fig. 163, draw any diameter, as E F, which divide into the same number of equal parts as the figure is to have sides, as shown by the small figures. At right angles to the diameter just drawn draw the radius D K, which divide into four equal parts. Prolong the radius D K 35. Upon a Given Side to Construct an Equilateral Triangle.— In Fig. 164, let A B represent the length of the given side. Draw any line, as C D, making it equal to A B. Take the length A B in the dividers, and placing one foot upon the point C, describe the arc E F. Then from D as center, with the same radius, describe the arc G BZ, intersecting the first arc in the point K. Draw K C and K D. Then C D K will be the required triangle. 36. To Construct a Triangle, the Length of the Three 46 Tlie New Metal Worker Pattern Book. Sides being Given.— In Fig. 165, let A B, C D and E F be the given sides from which, it is required to con- struct a triangle. Draw any straight line, G H, mak- ing it in length equal to one of the sides, E F. Take the length of one of the other sides, as A B, in the compasses, and from one end of the line just drawn, as G, for center describe an arc, as indicated by L M. Then set the compasses to the length of third side, C D, and from the opposite end of the line first drawn, H, describe a second arc, as I K, intersect- ing the first iii the point 0. Connect G and O H. Then G H will be the required triangle. 37. Upon a Given Side to Draw a Regular Pentagon. — In Fig. 166, let A B represent the given side upon which a regular pentagon is to be constructed. With B as center and B A as radius, draw the semicircle circumference of the circle, obtaining the points M and L. Draw A M, M L and L D, which will com- plete the figure. 38. Upon a Given Side to Draw a Regular Hexagon. — In Fig. 167, let A B be the given side upon which a regular hexagon is to be erected. From A as center, and with A B as radius, describe the arc B C. From B as center, and with the same radius, describe the arc A C, intersecting the first arc in the point C. C will then be the center of the circle which will cir- cumscribe the required hexagon. "With C as center, and C B as radius, strike the circle, as shown. Set the dividers to the space A B and step off the circum- ference, as shown, obtaining the points E, G, F and D. Draw the chords A E, E G, G F, F D and D B, thus completing the required figure. Fig. 167. — Upon a Given Side to Draw a Regular Hexagon. A ^- S B Fig. 168. — Upon a Given Side to Draw a Regular Heptagon. Fig. 169. — Upon a Given Side to Draw a Regular Octagon. A D E. Produce A B to E. Bisect the given side A B, as shown at the point F, and erect a perpendic- ular, as shown by F C. Also erect a perpendicular at the point B, as shown by G H. With B as center, and F B as radius, strike the arc F G, cutting the per- pendicular H G iu the point G. Draw G E. With G as center, and G E as radius, strike the arc E H, cutting the perpendicular in the point H. With E as center, and E H as radius, strike the arc H D, cutting the semicircle A D E in the point D. Draw D B, which will be the second side of the pentagon. Bisect D B, as shown, at the point K, and erect a perpendic- ular, which produce until it intersects the perpendic- ular F C, erected upon the center of the given side in point F. Then C is the center of the circle which circumscribes the required pentagon. From C as cen- ter, and with C B as radius, strike the circle, as shown. Set the dividers to the distance A B and step off the 39. Upon a Given Side to Draw a Regular Heptagon. — In Fig. 168, A B represents the given side upon which a regular heptagon is to be drawn. From B as center, and with B A as radius, strike the semicircle A E D. Produce A B to D. From A as center, and with A B as radius, strike the arc B F, cutting the semicircle in the point F. Through F draw F G per- pendicular to A B, which extend in the direction of C. From D as center, and with radius G F, cut the semi- circle in the point E. Draw the line E B, which is another side of the required heptagon. Bisect E B, and upon its middle point, H, erect a perpendicular, which produce until it meets the perpendicular erected upon the center of the given side A B, in the point C. Then C is the center of the circle which will circumscribe the required heptagon. From C as center, and with C B as radius, strike the circle. Set the dividers to the distance A B and step off the circumference, as Geometrical Problems. 47 shown, obtaining the points K, N, M and L. Draw the connecting arcs A K, K N, 1ST M, M L and L E, thus completing the figure approximately correctly. 40, Upon a Given Side to Draw a Regular Octagon.— In Fig. 169, let A B represent the given side upon which a regular octagon is to be constructed. Produce A B indefinitely in the direction of D. From B as center, and with A B as radius, describe the semicircle A E D. At the point B erect a perpendicular to A B, as shown, cutting the circumference of the semicircle in the point E. Bisect the arc E D, obtaining the point F. Draw F B, which is another side of the re- quired octagon. Bisect the two sides now obtained and erect perpendiculars to their middle points, Gr and H, which produce until they intersect at the point C. C then is the center of the circle that will circumscribe thus obtaining the point G, and draw B Gr, which will be another side of the required figure. From the middle points, H and K, of the two sides now obtained, erect perpendiculars, which produce until they inter- sect at L. Then L is the center of a circle which will circumscribe the required nonagon. From L as center, with A L as radius, describe the circle A M Q. Set the dividers to the space A B and divide the circle in nine equal spaces, as shown by the points M, N, 0, etc., and draw the connecting lines GrM, MN, NO, OP, etc., thus completing the figure. 42. Upon a Given Side to Draw a Regular Decagon. — In Fig. 171, let A B be the given side upon which a regular decagon is required to be drawn. Produce the line A B indefinitely in the direction of D, and L _ .k Fig. 170. — Upon a Given Side to Draw a Regular Nonagon. Fig. 171 — Upon a Given Side to Draw a Regular Decagon. l\ /I \ / I \ ' I \ -- F E Fig. 172.— Upon a Given Side, to Draw a Jiegulir Polygon having fifteen b ides. the octagon. From C as center, and with C B as radius, strike the circle, as shown. Set the dividers to the space A B and step off the circumference, obtaining the points L, K, M, and N". Draw the connecting arcs A L, L K, K M, M 0, O E" and 1ST F, thus com- pleting the required figure. 41. Upon a Given Side to Draw a Regular Nonagon. — In Fig. 170, let A B be any given side upon which it is required to draw a regular nonagon. Produce A B indefinitely in the direction of D. Then from B as a center, and with A B as radius, draw the semicircle A C D, and from D as a center, and with the same radius, strike an arc, cutting the circumference at 0. Extend the line AB indefinitely in the direction of E, and trisect the arc C D, obtaining the point F. The method of doing this is all explained in Problems 13 and 29 of this chapter. Bisect C F, or, what is the same thing, set off from D on D C the distance F C, from B as a center, and with B A as the radius, de- scribe the semicircle AHD. From its center point B erect the perpendicular line B H, which bisect in the point F, and draw F D. From F as a center, and with F B as radius, describe the arc B Gr, cutting F D at Gr, and from D as center, with D Gr as radius, describe the arc Gr E, cutting the semicircle at E, and draw B E. Then B E will be another side of the decagon. Upon the middle points P and Q of the two sides now obtained, erect perpendiculars, which produce until they intersect the point at C. Then C is the center from which a circle can be drawn which will circum- scribe the required decagon. From C as a center, and with C A as a radius, describe the circle, as shown. Set the dividers to the side A B and divide the circle, obtaining the points I, J, K, etc., as shown, and draw the lines E figure. I, I J, J K, etc., thus completing the 48 Tlie New Metal Worker Pattern Book. 43. Upon a Given Side to Draw a Regular Polygon Having Fifteen Sides.— In Fig. 172, let A B be the given side on which it is desired to draw a regular polygon. Extend the line A B indefinitely in the direction of C, and from B as a center, and with A B as a radius, de- scribe the semicircle ADC. From C as a center, and with the same radius, describe an arc cutting the circumference in D and extend the arc indefinitely in the direction of E. Draw the line D C. Then from the point C draw C E at right angles to D C, cutting the arc just drawn at E. Bisect C E at F and draw F D. From F as center, with C F as radius, de- scribe an arc cutting F D at Gr. From D as center, with D G as radius, describe an arc cutting the semi- circle at H, and draw H B, which will be another side of the polygon. From the middle points, I and J of the two sides, erect lines perpendicular thereto, pro- a q"b d Fig. 173. — Upon a Given Side to Draw a Regular Dodecagon. ducing them till they intersect at K. Then will K be the center of a circle which will circumscribe the re- quired polygon. From K as center, with K A as radius, describe the circle A M P V. Set the dividers to the space A B, and divide the circle into equal spaces, as shown by the points L, M, N, etc., and draw the lines H L, L M, M N, etc., thus com- pleting the figure. 44. Upon a Given Side to Draw a Regular Dodecagon. — In Fig. 173, let A B represent the given side upon which a regular dodecagon is to be drawn. Produce A B indefinitely in the direction of D. From B as center, and with B A as radius, describe the semicircle A F D. From D as center, and with D B as radius, describe the arc B F, cutting the semicircle in the point F. Draw F D, which bisect by the line V B, cutting the semicircle in the point E. Then E B is another side of the dodecagon. From the middle points of the two sides now obtained, as G and H, erect perpendiculars, as shown, cutting each other at the point C. This point of intersection, C, then is the center of the circle which will circumscribe the required dodecagon. From C as center, and with C B as radius, strike the circle, as shown. Set the dividers to the distance A B and space off the circumference, thus ob- taining the points L, P, M, S, 1ST, R, 0, K and I. Draw the connecting lines L P, P M, M S, S N, N R, R 0, OK, KI and I E, thus completing the figure. 45. General Rule by which to Draw any Regular Polygon, the Length of a Side Being Given.— With a radius equal to the given side describe a semicircle, the circumference of which divide into as many equal parts as the figure is to have sides. From the center by which the semicircle was struck draw a line to the Fig. 174.— Upon a Given Side to Construct a Regular Polygon of TJiirteen Sides by the General Rule. second division in the circumference. This line will be one side of the required figure, and one-half of the diameter of the semicircle will be another, and the two will be in proper relationship to each other. There- fore, bisect each, and through their centers erect per- pendiculars, which produce until they intersect. The point of intersection will be the center of the circle which will circumscribe the polygon. Draw the circle, and setting the dividers to the length of one of the sides already found, step off the circumference, thus obtaining points by which to draw the remaining sides of the figure. 46. To Construct a Regular Polygon of Thirteen Sides by the General Rule, the Length of a Side being Given.— In Fig. 174, let A B be the given side. With B as center, and with B A as radius, describe the semicircle A F G. Divide the circumference of the semicircle Geometrical Problems. 49 into thirteen equal parts, as shown by the small figures, 1, 2, 3, 4, etc. From B draw a line to the second division in the circumference, as shown by B 2. Then A B and B 2 are two of the sides of the required figure, and are in correct relationship to each other. Bisect A B and B 2, as shown, and draw D C and E C through their central points, prolonging them until they inter- sect at the point C. Then C is the center of the circle which will circumscribe the required polygon. Strike the circle, as shown. Set the dividers to the space A B, and step off corresponding spaces in the circum- ference of the circle, as shown, and connect the several points so obtained by lines, thus completing the figure. 47. Within a Given Square to Draw a Regular Octa- gon. — In Fig. 175, let ADBE be any given square within which it is required to draw an octagon. Draw the diagonals D E and A B, intersecting at the point C. From A, D, B and E as centers, and with radius equal to one-half of one of the diagonals, as A C, strike the several arcs H 1ST, G K, I M and L 0, cutting the sides of the square, as shown. Connect the points thus obtained in the sides of the square by drawing the lines G 0, II I, K L and M N, thus completing the figure. For general use a very convenient scale may be constructed, as shown in Fig. 176, from which half the length of one side of a polygon of any number of sides and of any diameter in inches and fractions of M A N~ E Fig. 175.— Within a Given Square to Draw a Regular Octagon. inches may readily be obtained. Draw the vertical line B and divide it into inches and parts of an inch. From these points of division draw horizontal lines ; from the point draw the following lines and at the following angles from the horizontal line P : A line at 75° for polygons having 12 sides. " 72° " " 10 " " 67*° " « 8 " A line at 60° for polygons having 6 sides. " 54° " "5 " " 45° " " 4 '< The figures on B will designate the radius of the inscribed circle measured from 0. The distance from B on any horizontal line to the oblique line de- Fig. 176 — Scale for Constructing Polygons of any Number of Sides, the Diameter of the Inscribed Circle Being Given in Inches. — Half Full Size, noting the required polygon will be half the length of a side of the polygon of the diameter indicated by the figure at the end of the horizontal line assumed. The distance from measured upon the oblique line to the assumed horizontal line will be the radius of the cir- cumscribed circle. In the engraving three polygons are drawn show- ing the application of the scale. II— BY THE USE OF THE T-SQUARE AND TRIAN- GLES OR SET-SQUARES. In the chapter upon terms and definitions under the word degree (clef. 68) and in some of those immedi- ately following the dimensions of the circle are de- scribed and their use explained; and in the chapter upon Drawing Tools and Materials (on page 21) the tri- angles or set-squares in common use are described and illustrated. As all regular polygons depend, for their construction, upon the equal division of the circle, some explanation of the application of the foregoing will serve to fix a few facts in the mind of the student and thus prepare him for the use of the set-square. 50 Hie New Metal Worker Pattern Book. A well-known and easily demonstrated geometrical principle is that the sum of the three interior angles of a triangle is equal to two right angles, or in other words, as a right angle is one of 90 degrees, if the three angles of any triangle be added together their sum will equal 180 degrees. Hence, if one of the angles of a set- square be fixed at 90 degrees (which is done for con- venience in drawing perpendicular lines) the sum of the two remaining angles must also be 90 degrees, and, if then the two other angles be made equal, each will be 45 degrees, which is the half of 90 degrees. If, however, one of the other angles is fixed at 30 (one-third of 90 degrees), the remaining angle must be 60 degrees, as 30 -f- 60 = 90. By means, then, of the 45-degree and the 30 X 60-degree triangles, the draftsman has at his command of the 45-degree triangle, as A E, is placed against the blade of the T-square, and the vertical division of the circle is drawn along the other short side C E. In Fig. ITS the vertical and horizontal divisions of the circle, A B and C D, are drawn as before, after which one of the shorter sides of the 45-degree triangle is placed against the T-square, and the long or oblique side E F is brought to the center of the circle and another division Gr I is drawn. By reversing the posi- tion of the triangle the last division H K is drawn, thus dividing the circle into eight equal parts. In Fig. 179, after drawing the divisions A B and C D as before, the 30 X 60-degree triangle is placed in the position shown at A E F, and the division E N is drawn along its hypothenuse or oblique side. By re- versing the position of the triangle, still keeping the Fig. 177. — Circle Divided into Four Equal Parts by the Use of a Triangle or Set-Square. Fig. 178. — Circle Divided into Eight Equal Parts by the Use of a 45-degree Triangle. Fig. 179. — Circle Divided into Twelve Equal Parts by the Use of a 80 x 60- degree Triangle. the means of drawing lines at angles of 90, 60, 45 and 30 degrees, and by combination 75 degrees (45 -4- 30) and 15 degrees (90 — 75). With the 45-degree angle he can bisect a right angle, and with the 30 and 60-degree angles he can trisect it. The pattern draftsman sometimes finds it con- venient to have a set-square in which the sharpest angle is one of 22-^ degrees (one-half of 45) for use in drawing the octagon in a certain position which will be referred to later. In Figs. 177, 178, 179 and 180 are illustrated the application of the foregoing, in which the circle is divided, by the use of the triangles above described, into four, eight and twslve equal parts. In Fig. 177 the horizontal division A B of the circle is drawn by means of the T-square placed against the side of the drawing board, after which one of the shorter sides side A F against the blade of the T-square, the divi- sion J K may be drawn. Changing the position of the triangle now so that its shortest side comes against the blade of the T-square, as shown dotted at Gr H F, the division Gr M is drawn, and again reversing its posi- tion, still keeping its shortest side against the T-square, the last division I L may be drawn, thus dividing the circle into twelve equal parts. In Fig. ISO the circle is divided into eight equal parts, but differing from that shown above in this respect that, while in Fig. 178 two of the divisions lie parallel with the sides of the drawing board, in the latter case none of the divisions are parallel with the sides of the board or can be drawn with the T-square ; but if this method is used in drawing an octagon, as shown dotted in Fig. 180, four of the sides of the oc- tagon can be drawn with the T-square and the other (v-diin triad Problems. 51 four with the 45-degree triangle. The position of the 22-J- X 67-J-degree triangle in drawing the divisions of the circle is shown at A B C and DEC. while the posi- tion of the 45-degree triangle in drawing the oblique sides of an octagon figure is shown at F. It will thus be seen that the 22^ X 67^-degree triangle is available in drawing accurately the miter line for all octagon miters. As a triangle in whatever form it may be con- structed is intended to be used by sliding it against the blade of the T-square, all the angles above men- tioned are calculated with reference to the lines drawn by the T-square. In practical use it will be found in- convenient in drawing such lines to actually bring the point of a set-square to the center of a circle. A better method, and one which makes use of the same principles, is shown in Fig. 181. The blade of the Fig. ISO. — Circle Divided into Eight Equal Parts by the Use of a 22% x 67%-degree Triangle. T-square is placed tangent to or near the circle, as shown by A B. One side of a 45-degree triangle is placed against it, as shown, its side C F being brought against the center. The line C F is then drawn. By reversing the triangle, as shown by the dotted lines, the line E D is drawn at right angles to C F, thus dividing the circle into quarters. A similar use of the 30 X 60-degree triangle is shown in Fig. 182, by which a circle is divided into six equal parts. Bring the blade of the T-square tangent to or near the circle, as shown by A B. Then place the set-square as shown by G B M, bringing the side G- B against the center of the circle, drawing the line D L. Then place it as shown by the dotted lines, bringing the side A H against the center, scribing the line F E. Then, by reversing the set-square, placing the side G M against the straight-edge, erect the per- pendicular C I, completing the division. The follow- ing are a few of the problems to which these principles may be advantageously applied. 48. To Inscribe an Equilateral Triangle within a Given Circle.— In Fig. 183, let D be the center of the given circle. Set the side E F of a 30-degree set-square T-square, as shown, and move it against the along D F Fig. lSt— Proper Method of Using a i5-degree Triangle. until the side E G touches D. Mark the point B upon the circumference of the circle. Beverse the set-square so that the point E will come to the right of the side F G and move it along in the reversed position until the side E G again meets the point D, and mark the point C. Now move the T-square upward until it touches the point D, and mark the point A. Then A B and C are points which divide the circle into three equal parts. The triangle may be easily completed from this stage by drawing lines connecting A B, B C and C A, with any straight-edge or rule, but greater accuracy is obtained by the further use of the set- square, as follows : Place the side F G of the set- square against the T-square, as shown in Fig. 184, Fig. 182. — Method of Using a 30 x 60-degree Triangle in Dividing the Circle. and move it along until the side E G touches the points A and C, as shown. Draw A C, which will be one side of the required triangle. Set the side E F of the set-square against the T-square, and move it along until the side F G coincides with the points C and B. Then draw C B, which will be the second side of the trianerle. 52 The New Metal Worker Pattern Book. Place the side F G of the set-square against the T- square, with the side E F to the right, and move it along until the side E G coincides with the points A and B. Then draw A B, thus completing the figure. The same results may be accomplished with less work by first establishing the point A by bringing the T-square against the center, and then using the set- square, as shown in Fig. 184. The different methods are here given in order to more clearly illustrate the use of the tools employed. Fig. 183. Fig. 184. To Inscribe an Equilateral Triangle within a Given Circle. 49. To Inscribe a Square within a Given Circle — Let D, in Fig. 185, be the center of the given circle. Place the side E F of a 45-degree set-square against the T-square, as shown, and move it along until the side E G meets the point D. Mark the points A and B. Reverse the set-square, and in a similar manner mark the points C and H. The points A, H, B and C are corners of the required square. Move the T- square upward until it coincides with the points A and H and draw A H, as shown in Fig. 1S6. In like man- ner draw C B. With the side E F of the set-square against the T-square, move it along until the side G F coincides with the points B and H, and draw B H. In a similar manner draw C A, thus completing the figure. 50. To Inscribe a Hexagon within a Given Circle. — In Fig. 187, let be the center of the given circle. Place the side E F of a 30-degree set-square against the T-sq uare ) as shown. Move the set-square along until the side E G meets the point 0. Mark the points A and B. Reverse the set-square, and in like manner mark the points C and D. With the side F G of the set-square against the T- s q uare > move it along until Fig. 185. Fig. 186. To Inscribe a Square uithia a Given Circle. the side E F meets the point 0, and mark I and H. Then A, H, D, B, I and C represent the angles of the proposed hexagon. From this stage the figure may be readily finished by drawing the sides by means of these points, using a simple straight-edge; but greater ac- curacy is attained in completing the figure by the further use of the set-square, as shown in Fig. 188. With the side E F of the set-square against the T-square, as shown, draw the line H D, and by mov- ing the T-square upward draw the side C I. Reversing the set-square so that the point F is to the left of the point E, draw the side A H, and also, by shifting the Geometrical Problems. 53 T-square, the side I B. "With the edge E F of the set-square against the T-square, move it up until the side G F coincides with the points B and D, and draw the side B D. In like manner draw A C, thus com- pleting the figure. In this figure, as with the triangle, the same results may be reached by establishing the points H and I, by means of a diameter drawn at right angles to the T-square, as shown in the engravings, and, using it as a base, employing the set-square, as shown in Fig. 188. The first method shown is, how- Fig. 187. Fig. 188. To Inscribe a Regular Hexagon within a Given Circle. ever, to be preferred in many instances, on account of its great accuracy. 51. To Inscribe an Octagon within a Given Circle- In Fig. 189, let K be the center of the given circle. Place a 45-degree set -square as shown in the engraving, bringing its long side in contact with the center, and mark the points E and A. Keeping it in the same po- sition, move it along until its vertical side is in contact with K and mark the points D and H. Beverse the set-square from the position shown in the engraving, and mark the points G and G. Move the T-square up- ward until it touches the point K, and mark the points B and F. Then A, H, G, F, E, D, C and B are cor- ners of the octagon. The figure may now be readily completed by drawing the sides, by means of these points, using any rule or straight-edge for the purpose, Fig. 189. — To Inscribe a Regular Octagon within a Given Circle. all as shown by A H, H G, G F, F E, E D, D C, C B and B A, or by means of a 22-J- X 6T£-degree set- square. 52. To Draw an Equilateral Triangle upon a Given Side.— In Fig. 190, let A B be the given side. First bring the line A B at right angles to the blade of the T-square. Then set the edge C B of a 30-degree set- square against the T-square, and move it along until the edge B D meets the point B, and draw the line B F. Beverse the set-square, still keeping the side G B against the T-square, and move it along until the Fig. 190.— To Draw an Equilateral Triangle upon a Given Side. side B D meets the point A, and draw the line A F, thus completing the figure. 53. To Draw a Square upon a Given Side.— In Fi°- 191, let A B be the given side drawn at right angles 54 TJie New Metal Worker Pattern Booh. to the blade of the T-square. Set the edge E F of a 45-degree set-square against the T-square, as shown, and move it along until the side E G meets the point B, and draw B I indefinitely. Beverse the set-square, and, bringing the side E G against the point A, draw A Fig. 191. — To Draiv a Square upon a Given Side. F indefinitely. Bring the T-square against the point B and draw B F, producing it until it meets the line A F in the point F. In like manner draw A I, meet- ing the line B I in the point I. Then, with the set- square placed as shown in the engraving, connect I and F, thus completing the required figure. 54. To Draw a Regular Hexagon upon a Given Side. —In Fig. 192, let A B be the given side in a vertical position. Set the edge G H of a 30-degree set-square against the T-square, as shown, and move it along Fig. 192. — To Draw a Regular hexagon upon a Given Side. until the edge I G coincides with the point A, and draw the line A D indefinitely. Reverse the set- square, still keeping the edge G H against the T-square, and move it along until the side I G coin- cides with the point B, and draw B E indefinitely. These lines will intersect in the point O, which will be the center of the required figure. Still keeping the edge G H of the set-square against the T-square, move it along until the perpendicular edge I H meets the point 0, and through draw F C indefinitely. With the set-square in the position shown in the engraving slide it along until the edge I G meets the point B, and draw B C, producing it until it meets the line F C in the point C. Reverse the set-square, still keeping the edge G H against the T-square, and draw the line C D, producing it until it meets the line A D in the point D. Slide the set-square along until the side I H meets the point D, and draw the line B E, meeting the line B E in the point E. Move the set- square along until the edge I G meets the point A, and draw the line A F, meeting the line C F in the point F. Now bring the set-square to its first position and Fig. 193.— To Draw a Regular Octagon upon a Given Side. slide it along until the edge I G meets the points F and E, and draw F E, thus completing the required figure. 55. To Draw a Regular Octagon upon a Given Side- In Fig. 193, let C D be the given side, drawn perpen- dicular to the blade of the T-square. Place one of the short sides of a 45-degree set-square against the T-square, as shown in the engraving. Move the set- square along until its long side coincides with the point C. Draw the line C B, and make it in length equal to C D. With the T-square draw the line A B, also in length eqiial to C D. Reverse the set-square, and bring the edge against the point A. Draw A H in length the same as C D. Still keeping a short side of the set-square against the T-square, slide it along until the other short side meets the point H, and draw H G, also of the same length. Then, using the long side of the set-square, draw G F of corresponding length. By means of the T-square draw F E, and by .reversing the set-square draw E D, both in length Geometrical Problems. 55 equal to the original side, C D, joining it in the point D, thus completing the required octagon. 56. To Draw an Equilateral Triangle about a Given Circle —In Fig. 1 94, let O be the center of the given circle. Place the edge E F of a 30-degree set-square against the T-square, as shown, and move it along un- til the edge F G meets the center 0, and mark the point A upon the circumference of the circle. Reverse the set-square, still keeping the edge E F against the T-square, and in like manner mark the point B. Move Fig. lit I. Fig. 195. To Draw an Equilateral Triangle about a Given Circle. the T-square upward until it meets the point 0, and mark the point C. The required figure will be de- scribed by drawing lines tangent to the circle at the points A, B and C, which may be done in the manner following, as indicated in Fig. 195 Place the edge E G- of the set-square against the T-square, and slide it, along until the edge F Gr touches the circle in the point B. Draw I K indefinitely. Reverse the set-square, keeping the same edge against the T-square, and move it along until its edge F G touches the circle in the point A, and draw I L, intersecting I K in the point I, the other end being indefinite. Then, placing the edge F E of the set-square against the T-square, bring its edge E Gr against the circle in the point C, and draw L K, intersecting I D in the point L and I K in the point K, thus completing the figure. The first part of this operation is not really necessary. The sides of the set-square simply can be brought tangent to the circle, as in Fig. 195. 57. To Draw a Hexagon about a Given Circle.— In Fig. 196, let be the center of the given circle. Place Fig. 196. Fig. 197. To Draw a Hexagon about a Given Circle. the edge E F of a 30-degree set-square against the J-square, and slide it along until the edge F Gr meets the point 0, and mark the points B and A. Reverse the set- square, still keeping the edge E F against the T-square, and in like manner mark the points C and D. Bring the edge of the T-square against O, and mark the points I and K. Then C, A, K, D, B and I are six points in the circumference of the circle, corresponding to the six sides of the required figure. The hexagon is com- pleted by drawing a side tangent to the circle at each of these several points, which may be done by using 56 The New Metal Worker Pattern Booh. the set-square as follows, and as shown in Fig. 197. "With the edge E G of the set-square against the T-square, bring the edge F G against the circle at the point C, as shown, and draw L M indefinitely. Re- verse the set-square, and in like manner bring it against the circle at the point A, and draw M N, cutting L M in the point M, and extending indefinitely in the direc- tion of N. Slide the set-square along until the edge E F meets the circle in the point K, and draw N P, intersecting M N in the point 1ST, and extending in the Fig. 198. Fig. 199. To Draw an Octagon about a Given Circle. direction of P indefinitely. With the set-square in its first position slide it along until the edge F G meets the circle in the point D, and draw R P, cut- ting N P in the point P, but being indefinite in the direction of E. Reverse the set-square, and in like manner draw R S tangent to the circle in the point B, cutting P R in the point R, and extending in the direction of S indefinitely. Slide the set-square along until its edge E F meets the circle in the point I, and draw S L, cutting R S in the point S and L M in the point L, thus completing the required figure. In this problem, as in the previous one, if care be taken the first part of the operation can be dispensed with by simply placing the triangle in proper position and draw- ing the sides of the figure tangent to the circle, as shown in Fig. 197. 58. To Draw an Octagon about a Given Circle. — In Fig. 19S, let be the center of the given circle. With the edge E F of a 45-degree set-square against the T- square, as shown, move it along until the side E G meets the point 0, and mark the points A and B. Reverse the set-square, and in like manner mark the points C and D. Slide the set-square along until the vertical side G F meets the point 0, and mark the points H and I. Move the T-square up until it meets the point 0, and mark the points K and L. Then A, I, D, L, B, H, C and K are points in the circumfer- ence of the given circle corresponding to the sides of Fin. 2V0. — to Draw a Square about a Given Circle. the required figure. The octagon is then to be com- pleted by drawing lines tangent to the circle at these several points, as shown in Fig. 199, which may be done by the use of the set-square, as follows : With the edge E F of the set-square against the T-square, as shown, bring the edge E Gr against the circle in the point D, and draw M N" indefinitely. Sliding the set- square along until the vertical edge F Gr meets the circle in the point L, draw 1ST P, cutting M N in the point N, and extending in the opposite direction in- definitely. Reverse the set-square, and bringing the edge E G against the circle in the point B, draw P R, cutting N P in the point P, and extending indefinitely in the direction of R. Move the T-square upward un- til it meets the circle in the point H, and draw the line S R, meeting P R in the point R, and extending in- definitely in the opposite direction. Then, with the set-square placed as shown in the engraving, move it Geometrical Problems. 57 until its edge E G meets the circle in the point C, and draw S T, meeting S R in the point S, and continuing indefinitely in the direction of T. With the set-square in the same position, move it along until its edge G F meets the circle in the point K, and draw T IT, cutting S T in the point T, and extending in the opposite di- rection indefinitely. Reverse the set-square, and bring- ing its long side against the circle in the point A, draw U V, cutting T U in the point U, and continuing in- definitely in the opposite direction. Bring the J- souare against the circle in the point I, and draw V M, connecting U V and M N in the points V and M re- spectively, thus completing the figure. The above rule will be found very convenient for use, although, as the student may discover, the first part of the opera- tion is not absolutely necessary. 59. To Draw a Square about a Given Circle.— In Fig. 200, let be the center of the given circle. Place [M D = / 0/ c Fig. SOI.— To Draw a Square upon a Given Side. the blade of the T-square against the point 0, and draw the line A B. With one of the shorter sides E F, of a 45-degree set-square against the T-square, and with the other short side against the point 0, draw the line DOC. Move the T-square upward until it strikes the point C, and draw the line H C I. Move it down until it strikes the point D, and draw the line E D K. With the side E F of the set-square against the T-square, as shown in the engraving, bring the side E G against the point A, and draw E A H. In like manner bring it against the point B, and draw K B I, thus completing the figure. It is to be observed that the several lines composing the sides of the square are tangent to the circle in the points A C B and D re- spectively. The only object served by drawing the diameters A B and C D is that of obtaining greater accuracy in locating the points of tangency. 60. To Draw a Square upon a Given Side.— Let A B of Fig. 201 be the given side placed parallel to one side of the drawing board. Place one of the shorter edges of a 45-degree set-square against the J-square, as placed for drawing the given side, and slide it along until the long edge touches the point A, and draw the diagonal line A C indefinitely. Place the T-square so that its head comes against the left side of the board, as shown by the dotted lines in the engraving, and, bringing the blade against the point A, draw A D in- definitely. Then bringing the blade against the point B, draw B C, stopping this line at the point of inter- section with the line A C, as shown at C. Bring the T-square back to the original position and draw the line C D, thus completing the figure. In the case of a large drawing board, unless the figure is to be located very near one corner of it, or in the case of a drawing board of which the adjacent sides are not at right angles, it will be desirable to use the right angle of the set-square, instead of changing the T-square from one side to the other, as above described. The object of drawing the diagonal line A C is to determine the length of the side C B. This also may be done by the use of the compasses instead of the set-square, as fol- lows : From B as center, with B A as radius, describe the arc A O C. Place the T-square as shown by the dotted lines, and, bringing it against the point B, draw B C, producing it until it intercepts the arc A O C in the point C. The remaining steps are then to be taken in the manner above described. III.— BY MEANS OF THE PROTRACTOR. The protractor, which has been already described and illustrated (see Fig. 116, Chapter II), is an instru- ment for measuring angles. The usual form of this instrument is a semicircle with a graduated edge, the divisions being more or less numerous, according to its size. In instruments of ordinary size the divisions are single degrees, numbered by 5s or by 10s, while in larger sizes the divisions are made to fractions of degrees. Since the protractor by its construction affords the means of measuring or of setting off any angle whatso- ever, it is especially useful in circumscribing or in- scribing polygons, or of erecting them upon a given side. As its use is of infrequent occurrence among pattern draftsmen, only a few problems in inscribing will be given, which will be sufficient to enable the reader to apply it in other cases that may arise. 61. To Inscribe an Equilateral Triangle within a Given Circle.— In Fig. 202, let O be the center of the given circle. Through O draw a diameter, as shown by 58 TJie New Metal Worker Pattern Book. COD. Place the protractor so that its center point shall coincide with 0, and turn it until the point mark- ing 60 degrees falls upon the line COD. Then mark points in the circumference of the circle corresponding to (zero) and 120 degrees of the protractor, as shown by B and E respectively. Draw the lines C E, E B and B C, thus completing the required figure. The reasons for these several steps are quite evident. The circle consists of 360 degrees. Then each side of an equilateral triangle must represent one-third of 360 degrees, or 120 degrees. Assume the point C for one of the angles, and draw the line COD. Then, by the nature of the figure to be drawn, D must fall opposite the center of one side. Therefore, since 60 is the half of 120 (the length of one side in degrees), place 60 opposite the point D, and mark and 120 for the other angles, then complete the figure by drawing the lines Fig. SOS. — To Inscribe an Equilateral Triangle within a Given Circle. as shown. Since in many cases the protractor is much smaller than the circle in which the figure is to be con- structed, it becomes necessary to mark the points at the edge of the instrument, and carry them to the cir- cumference by drawing lines from the center of the circle through the points, producing them until the circle is reached. 62. To Inscribe a Square within a Given Circle.— In Fig. 203, let be the center of the given circle. Through draw a diameter, as shown by C D. Place the protractor so that its center point coincides with 0, and turn it until the point marking 45 degrees falls upon the line COD. Mark points in the circum- ference of the circle corresponding to 0, 90 and 180 degrees of the protractor, as shown by F, G and E re- spectively. From G, through the center 0, draw G O H, cutting the circumference of the circle in the point H. Then E, G, F and H are the angles of the required figure, which is to be completed by drawing the sides E G, G F, F H and H E. Since the circle is composed of 360 degrees, one side of an inscribed square must represent one-fourth part of 360 degrees, or 90 degrees. The half of 90 degrees is 45 degrees. Hence, in set- ting the protractor, the point representing 45 degrees was placed opposite the point in which it is desired the center of one of the sides shall fall, or, in other words, upon the line COD. Then, having marked points 90 degrees removed from each other, or, as explained above, opposite the points 0, 90 and 180 of the pro- tractor, as shown by F, G and E, the fourth point was obtained by the diagonal line. It is evident that H must fall opposite G, upon a line drawn through the center. Or the protractor might have been moved around, and a space of 90 degrees measured from either Fig. SOS.— To Inscribe a Square within a Given Circle. F or E, which, as will be clearly seen, would have given the same point, H. 63. To Inscribe an Octagon within a Given Circle.— Through the center O of the given circle, Fig. 204, draw a diameter, A O B, upon which the center of one side is required to fall. Place the protractor so that its center point shall coincide with the center O, and turn it so that the point representing 22£ degrees shall fall on the line A O B. Then mark points in the circumference of the circle corresponding to 0, 45, 90, 135 and 180 degrees of the protractor, as shown by E, G, H, I and F. Beverse the protractor, and in like manner mark the points M, L and K ; or these points may be obtained by drawing lines from I, H and G respectively through the center O, cutting the circumference in M, L and K. The figure is to be completed by drawing the sides F I, I H, H G, G E, Geometrical Problems. 59 E M, M L, L K and K F. Since the circle consists of 360 degrees, one side of an octagon must represent 45 degrees, or one-eighth of 360. The half of 45 is 22-J-. Hence, the point of the protractor representing 22-J- degrees was placed upon the line A B, which represents the center of one side of the required figure. Having thus established the position of one side, the other sides of the figure are located by marking points in the circumference of the circle opposite points in the protractor at regular intervals of 45 degrees. 64. To Inscribe a Dodecagon within a Given Circle.— In Fig. 205, let be the center of the given circle. Fig. W4.—T0 Inscribe an Octagon within a Given Circle. Through draw the diameter A B, at right angles to which one of the sides of the polygon is required to be. Set the protractor so that the center point of it coincides with the center 0, and revolve it until the point marking 15 degrees falls upon the line A B. With the protractor in this position, mark points in the circumference of the circle opposite the points in the protractor representing 0, 30, 60, 90, 120, 150 and 180 degrees, as shown by E, F, G, H, I, K and L. Then these points will represent angles of the required polygon. The remaining angles may be obtained by placing the protractor in like position in the opposite half of the semicircle, or they may be determined by drawing lines from the points F, Gr, H, I and K through the center O, producing them until they cut the circumference in the points M, N, P, R and S, which are the remaining angles. The figure is now to be completed by drawing the sides, as shown. In a do- decagon, or twelve-sided figure, each side must occupy a space represented by one-twelfth of 360 degrees, or 30 degrees of the protractor. As the side F E was re- quired to be located in equal parts upon opposite sides of A O B, the middle of one division of the protractor representing a side (that is, 15 degrees, or one-half of 30 degrees) was placed upon the line A O B. Having thus established the position of one side, the others are measured off in manner above described. p R Fig. S05. — To Inscribe a Dodecagon within a Given Circle. In making use of the protractor to erect a regular polygon upon a given side, the exterior angle, or angle formed by an adjacent side with the given side ex- tended, as E B D in Figs. 168, 170 and 171, is found by dividing 360 degrees by the number of sides in the required polygon ; while the interior angle, or angle between any two adjacent sides on the inside of the polygon, as E B A in the same diagrams, is the supplement of that angle, or, in other words, is found by subtracting the exterior angle from 180 degrees. Thus to find the exterior angle by means of which to construct a regular decagon, divide 360 degrees by 10; which gives 36 degrees; while the interior an 4 / j \ >> / / \ * / / Fig. 227— Eye of the Volute in Fig. 226 Enlarged. 230 and wind a thread around it. Make a loop, E, in the end of the thread, in which place a pencil, as shown. Hold the spool firmly and move the pencil around it, unwinding the thread. A curve will be de- scribed, as shown in the dotted lines of the engrav- ing. It is evident that the proportions of the figure top, E A at the bottom and A B at the side, the length of A B, which determines the width of the scroll, being given. Bisect A B, obtaining the point C. Let the distance between the beginning and ending of the first revolution of the scroll, shown by a e, be established at pleasure. Having determined 1 4 , 3 8 7 5 B 1 o Fig. 2Sl.—To Draw a Scroll to a Specified Width. Fig. 232.— The Center of Fig. 231 Enlarged. this distance, take one-eighth of it and set it off up- ward from C on the line A B, thus obtaining the point b. From b draw a horizontal line of any convenient length, as shown by b h. With one point of the com- passes set at b, and with b A as radius, describe an arc cutting the line b h in the point 1. In like manner, from the same center, with radius b B, describe an arc cutting the line b h in the point 2. Upon 1 2 as a base erect a square, as shown by 1 2 3 4. Then from 1 as Fig. 228. — To Draw a Spiral from Centers. Fig. 229. — Enlarged View of the Eye of the Spiral in Fig. 228. Fig. 230.— To Draw a Spiral by Means of a Spool and Thread. wee determined by the size of the spool. Hence a larger or smaller spool is to be used, as circumstances require. 85. To Draw a Scroll to a Specified Width, as for a Bracket or Modillion. — In Fig. 231, let it be required to construct a scroll which shall touch the line D B at the center, with 1 a as radius, describe an arc, a b ; and from 2 as center, with 2 b as radius, describe the arc b c. From 3 as center, with radius 3 c, describe the arc c d. From 4 as center, with radius 4 d, describe the arc d e. If the curve were continued from e, being: struck from the same centers, it would run parallel to 70 The New Metal Worker Pattern Book. itself ; but as the inner line of the scroll runs parallel to the outer line, its width may be set off at pleasure, as shown by a a', and the inner line may be drawn by the same centers as already used for the outer, and con- tinued until it is intersected by the outer curve. To find the centers from which to complete the outer curve, construct upon the line of the last radius above used (4 e) a smaller square within the larger one, as shown by 5 6 7 8. This is better illustrated by the larger diagram, Fig. 232, in which like figures repre- sent the same points. Make the distance from 5 to 8 equal to one-half of the space from 4 to 1, making 4 to 8 equal the distance of 5 to 1. Make 5 to 6 equal the distance from 8 to 5. After obtaining the points 5, 6, 7, etc., in this manner, so many of them are to be used as are necessary to make the outer curve inter- sect the inner one, as shown at g. Thus 5 is used as a center for the arc ef, and 6 as a center for the arc f g. If the distance a a' were taken less than here given, it is easy to see that more of the centers upon the small square would require to be used to arrive at the intersection. "^- CHAPTER V. Pried pies of Pattern Ctatttaj To any one wishing to pursue pattern cutting as a profession it is essential not only that lie know how to solve a large number of intricate problems, but that lie understand thoroughly the principles which under- lie such operations. It is, therefore, appropriate, be- fore introducing pattern problems, that some attention should be given to the explanation of such principles in order that the reasons for the steps taken in the demonstrations following may be readily understood. Underlying the entire range of problems peculiar to sheet metal work are certain fundamental principles, which, when thoroughly understood, make plain and simple that which otherwise would appear arbitrary, if not actually mysterious. So true is this that noth- ing is risked in asserting that any one who thoroughly comprehends all the steps in connection with cutting a simple square miter is able to cut any miter what- soever. Since almost any one ean cut a square miter, the question at once arises, in view of this statement, why is it that he cannot cut a raking miter, or a pin- nacle miter, or any other equally difficult form? The answer is, because he does not understand how he cuts the square miter. He may perform the operation just as he has been taught, and produce results entirely satisfactory from a mechanical standpoint, without be- ing intelligent as to all that he has done. He does not comprehend the why and wherefore of the steps taken. Hence it is that when he undertakes some other miter he finds himself deficient. There is a wide difference between the skill that produces a pattern by rote — by a mere effort of the memory — and that which reasons out the successive steps. One is worth but very little, while the other renders its possessor independent. It is with a desire to put the student in possession of this latter kind of skill, to render him intelligent as to every operation to be performed, that the present chapter is written. The forms with which the pattern cutter has to deal may be divided, for convenience of description, into three general classes : I. The first of these embraces moldings, pipes and regular continuous forms, and may be called forms of parallel lines, or as a shorter and more convenient name to use, parallel forms. II. The second, which will be called regular taper- ing; forms, comprehends all shapes derived from cones or pyramids, or from solids having any of the regular geometric figures as a base and which terminate in an apex. HI. The third class will be called irregular forms, and will include everything not classified under either of the two previous heads. Many of these might be properly called transition pieces — that is, pieces which have figures of various outlines placed at various angles as their bases, and have figures with differing outlines variously placed, as their upper terminations, thus forming transitions, or connecting pieces between the form which lies next them at one end and the adjacent form on the other end. While pieces of metal of any shape necessary to form the covering of a solid of any shape may prop- erly be called patterns, the shapes of pieces necessary to form the joints between moldings meeting at an angle are known distinctively as miters. This name applies equally well in sheet metal work if the two arms of the molding are not of the same profile, or to a single arm coming against any plain or irregular sur- face. These forms comprise the first class referred to above and, so far as principle is concerned, come under the same general rules, which will be subsequently given. Conical forms, with very little taper, coming against other forms are also said to miter with them. In fact, the word miter has come into such general use that it is often applied to any joint between pieces of metal ; but the term can scarcely be considered as cor- rect when the forms have very much taper. The principle involved in the development of such patterns, however, is the same as that applied to the develop- ment of the surfaces of all other regular tapering forms, 72 The New Metal Worker Pattern Book. referred to above as the second class, whose character- istics will be considered in their proper chapter. The method employed for developing the patterns for forms of the third class has been termed triangula- tion, and is adopted on account of its simplicity, as it does away with the reduction or subdivision of an irregular form into a number of smaller regular forms, each one of which would have to be treated separately and perhaps by a different method. In fact, there are some shapes which have arisen from force of circum- stances which it would be impossible to separate into regular parts, and even if they could be so separated such a course would result in tedious and complicated operations. After principles have been thoroughly explained the problems in this work will follow in three sections or departments of the final chapter, arranged according to the above classification. This is one of the instances in which the pattern cut- ter is required to be something of an architectural draftsman, and to this end a chapter on Linear Draw- ing (Chap. Ill) has been introduced, in which atten- tion is given to this phase of the work, and to which the student is referred. The arrangement of the problems in each of the sections of the succeeding chapter will be made with reference to these two conditions, the simpler ones being placed before those in which preliminary draw- ing is required. Parallel FormtiSo (MITER CUTTING.) Since in sheet metal work a molding is made by bending the sheet until it fits a given stay, a molding may be defined mechanically as a succession of paral- Fig. 233.— Profile of a Molding. Fig. 234.— A Stay. Fig. 235.— A Reverse Stay. Two conditions exist in regard to the work of developing patterns of all forms, no matter to which of the three classes above defined they may belong : First — In very many cases a simple elevation or plan of the intersecting parts, together with their profiles,, is all that is necessary to begin the work of developing the pattern — that is, the plan or elevation, a3 the case may be, shows the line (either straight or curved) which represents the surface against which another part is to be fitted ; in other words, the much sought for ' ' miter line. ' ' Second — In numerous other instances, however, no view can be drawn either in elevation, oblique or otherwise, or in plan, in which the miter or junction 1 of the parts will appear as a simple straight or curved line against which the points can be dropped. In such cases it becomes necessary to do some preliminary work in order to prepare the way to the actual work of laying out the pattern. A view of the joint must be developed by means of intersections of lines which will show it as it appears in connection with the eleva- tion or plan to be used in developing the pattern. lei forms or bends to a given stay, and, so far as the mechanic is concerned, any continuous form or ar- rangement of parallel continuous forms, made for any purpose whatever, may be considered a molding and treated under the same rules in all the operations of pattern cutting. Keejung this fact in mind all paral- lel forms will be considered as moldings and that word will be used in the demonstrations, remembering that a difference in name simply means a difference of profile, but not a difference in treatment or principle. A molding may be defined theoretically as a form or surface generated by a profile passed in a straight or curved line from one point to another, this profile being the shape that would be seen when looking at its end if the molding were cut off square. A prac- tical illustration of this may be given as follows : In Fig. 233, let the. form shown be the profile of some molding. If this shape be cut out of tin plate or sheet iron, as shown in Fig. 234, it is . called a stay. For the purpose of this illustration, as will appear fur- ther on, a stay, the reverse of the one shown in Fig. 234, or, in other words, the piece cut from the face or Principles of Pattern Cutting. 73 outside of the shape represented in that figure, as shown in Fig. 235, will be required. Having made a reverse stay, or ' ' outside stay, ' ' as it is sometimes called, Fig. 235, take some plastic material — as potters' clay — and, placing it against any smooth surface, as of a board, place the stay against the board near one end in such a position that its ver- tical lines are parallel with the ends of the board, and move this reverse stay in a straight line along the face of the board until a continuous form is obtained in the clay corresponding to the profile of the stay, all as illustrated in Fig. 236. By this operation will be produced a molding in accordance with the second definition above given. The purpose in introducing this illustration is to show more clearly than is other- wise possible the principles upon which the different Fig. 236. — Generating a Molding in Plastic Material by Means of a Reverse Stay. parts of a molding are measured in the process of pat- tern cutting. Suppose that the form produced as illustrated in Fig. 236 be completed, and that both ends of the molding be cut off square. It is evident, upon in- spection, that the length of a piece of sheet metal necessary to form a covering to this molding will be the length of the molding itself, and that the width of the piece will be equal to the distance obtained by measuring around the outline of the stay which was used in giving shape to the molding. Now with a thin-bladed knife, or by means of a piece of fine wire stretched tight, let one end of the clay molding just constructed be cut off at any angle. By inspection of the form when thus cut, as clearly shown in the upper part of Fig. 237, it is evident that the end of a pattern to form a covering of this model must have such a shape as will make it when formed up conform to the oblique end of the molding or model. To cut such a pattern by means of a straight line drawn from a point corresponding to the end of the longer side of the mold, to a point corresponding to the end of the shorter side of it, would not be right, evidently, because certain parts of the covering, when formed up, fold down into the angles of the molding, and therefore would require to be either longer or shorter, as the case might be, than if cut as above de- scribed. It is plain, then, that some plan must be devised by which measurements can be taken in all these angles or bends, and at as many intermediate points as may be necessary, in order to obtain the right length at all points throughout its width. This can be done quite simply as follows : Divide the curved parts of the stay into any con- venient number of equal parts, and at each division cut a notch, or affix a point to it. Eeplace the stay in the position it occupied in producing the molding shown in Fig. 236 and pass it again over the entire length of the model. The points fastened to the stay will then leave tracks or lines upon the surface of the molding. Now, by means of measurement upon the different lines thus produced, the length of the molding at all of the several points established in the stay may be obtained. All this is clearly illustrated in Fig. 237. In the upper right hand corner of the illus- tration is shown the stay prepared with points, by moving which as above described lines are left upon the face of the molding, as shown to the left Now, upon a sheet of paper fastened to a draw- ing board, draw a vertical line, as shown by A B in Fig. 237, and upon that line set off with the dividers the width of each space or part of the profile or stay — . that is, make the space 1 2 in the line A B equal to the space 1 2 in the stay, and 2 3 in the line A B equal to 2 3 of the stay, and so continue until all the spaces are transferred — and from the points thus ob- tained in A B draw lines at right angles to it indefi- nitely, as shown to the left. The lines an dspaces upon the paper will then correspond to the lines and spaces upon the clay molding made by the points fastened to the stay. Next, measure with the dividers the length of the molding upon each of the lines drawn upon it, and set off the same lengths upon the corresponding 74 The New Metal Worker Pattern Book. lines drawn upon the paper. This gives a series of points through which a line may be traced which will correspond in shape to the oblique end of the molding. Thus, set off from A B on the line 1 on the paper the length of the molding, measured from its straight end to its oblique end, upon the line produced by point 1 'of the stay upon its face : and upon each of the other lines on the paper set off the length of the molding on the corresponding line on its face, meas- uring from the square end each time, which is represented by the line A B of the drawing. By this means are ob- tained points through which, if a line be traced, as shown by C D, the pattern of the covering will be described. The line A B, containing measurements from the profile, is called the " stretchout line," and the lines drawn through the points in it and at right angles to it are mathe- matically known as ordinates, but will in this work be called " measuring lines." Now, what has been clone in Fig. 237 illustrates what is called." miter cut- ting," which in other words consists in describing upon a flat surface the shape of a given form or envelope, so that when the envelope is cut out of the flat sur- face and formed up to the stay from which its stretchout was derived, the finished molding will fit against a given surface at a given angle previously specified. The pattern shown in the lower part of Fig. 237, which has been obtained by means of a clay model, and measurements for which were obtained from the lines drawn on the surface of the clay model — maybe obtained just as well from a draw- ing. The question then is, how can the same results be obtained by lines drawn upon a flat surface as were obtained by measurements on lines drawn along the surface of a molding ? In moving the stay along the clay molding, cer- tain lines were made by means of the points affixed. If the reader will carefully examine Fig. 237 he will notice that the lines upon the molding made by this means corresponded in number and position with the points in the profile when it is laid flat on its side, in a position exactly opposite the end of the model, as shown. Hence, if the profile be drawn upon paper and in line with it, the . elevation terminated by the oblique line, which represents the surface against which it is required to miter, the same results can be accom- plished, care only being necessary that the relative positions of the parts be correctly maintained. This is illustrated in Fig. 238, which is to be compared with Fig. 237, and shows : First, that the profile A is drawn in correct position. Next, that from it the elevation F C D Gr of the molding is pro- Fig. 237.- The Use of Lines in Obtaining the Envelope of a Molding from a Model of the Same. jected, as follows : Use the T-square in the general position shown by B in the engraving, bringing it against the several points in A in order to draw the lines. Draw a line for each of the angles in the profile A, and also one corresponding to each of the inter- mediate points in the curved parts of the stay. Draw the line F Gr, representing the oblique cut, and the line C D, representing the straight end. Then it will be seen that F C D G of Fig. 238, so far as lines are concerned, is exactly the same as the molding made of clay, shown in Fig. 237. The line F Gr, by the definition of a miter, is the ' ' miter line ' ' of this Principles of Pattern Cutting. 75 molding. It represents the surface against which the end of the molding is supposed to fit. Next lay off a stretchout of the profile A, in the same manner as de- scribed in connection which Fig. 237, all as shown by H K in Fig. 238, through the points in which draw measuring lines at right angles to it, or, what is the same, parallel to the lines of the moldings. Now, make each of these lines equal in length to the line of in the position shown by the dotted lines in Fig. 238. Therefore, instead of using the dividers proceed as follows: Place the T-square as shown at E, and, bringing it successively against the points in F G, cut measuring lines of corresponding number by means of a dot or short dash placed across the line. Then a line traced as before through the points of intersection thus obtained, as shown from L to M, will be the shape of the pattern necessary to make it fit against a surface placed at the angle represented by the miter line F G. By this illus- tration it is shown that the T-square may be used with great advantage in transferring measurements under almost all circumstances. Since now the T- square is to be used instead of the dividers to locate the points in the pat- terns, the stretchout line is not needed as a starting point from which to meas- ure lengths and may, therefore, be located at will. For convenience, it should be placed as near to the miter line as possible. Hence, in practical work, supposing that the molding rep- Fig. S3S.— Obtaining the Envelope of a Molding from a Draiving of the Same by the Use of the T-Square. corresponding number drawn across the elevation from CDtoFG. If, as suggested in the previous illustration — that is, by using a pair of dividers to measure the length of the molding from C D to F G on the several lines — these lengths be set off on corresponding lines drawn from the stretchout line H K, a pattern will be ob- tained in all respects corresponding to the pattern shown in Fig. 237, already referred to. By inspection of the result thus obtained, however, it will be seen that each point in L M is directly under the point of corresponding number in line F G, and that the same thing may be accomplished by using the T-square placed resented by F C D G is not a very short piece, the stretchout line, instead of being opposite the end C D, would be placed somewhere near the line of the p blade of the T-square when in its posi- tion at E. Should the arm required be short, a line drawn opposite the square end will serve the double purpose of a stretch-out line and of the outline of the square end of the pattern. By further inspection of Fig. 238, it will be seen that, instead of drawing the lines from the points in the profile A the entire length of the molding, as there shown, all that is necessary to the operation is a short line corresponding to each of the points of the profile, extending only across the miter line F G. The use of these lines, it is evident, is only to locate intersections upon the miter line. In other words, all that is needed is the points in the profile A transferred to the miter line F G. The operation of transferring these points by short lines, as above described, is termed ' ' drop- ping the points " from the profile to the miter line. If, instead of the molding terminating against a plane surface, as shown by F G in Fig. 238, it be re- quired to develop a pattern to fit against an irregular 76 The New Metal Worker Pattern Book. surface, the method of procedure would be exactly the same, simply substituting for the straight line F G a representation of that surface. From this it will be seen that all that is required to develop the pattern of any miter is that a correct representation (elevation or plan) of the molding be made, showing the angle of the miter, and that a profile be so drawn that it shall be in line with the elevation of the molding — its face Fig. 239. — Comparison Between a Butt Miter and a Miter Between Two Moldings at Any Angle. being so placed as to agree with the face of the mold- ing — and that points from the subdivisions of the pro- file be carried parallel to the molding, their intersec- tions with the miter line being marked by short lines. In order to more clearly indicate the point desired by this summary of requirements, suppose that upon each of two pieces of molding made of wood, miters at the same angle be cut (right and left) by means of a saw, and that they be then placed together, as shown in Fig. 239. Now, if a piece of sheet iron, for ex- ample, be slipped into the joint, as shown by A, and then one arm of the miter be removed what is left will be exactly what is shown in Fig. 238. In other words, a miter between two straight pieces of molding of the same profile is exactly the same as a miter of the same mold against a plane, and, hence, the operation of cutting the pattern in such a case as shown in Fig. 239 is identical with that described in Figs. 237 and 238. From this it is plain to be seen that the central idea in miter cutting is to bring the points from the profile against the miter line, no matter what may be its shape or position, and from the miter line into a stretch-oi;t prepared to receive them. Inasmuch as all moldings, if they do not member or miter with dupli- cates of themselves, must either terminate square or against some dissimilar profile, it follows that the two illustrations given cover in principle the entire cata- logue of miters. The principles here explained are the funda- mental principles in the art of pattern cutting, and their application is universal in sheet metal work. It would be difficult to compile a complete list of miter problems. New combinations of shapes and new con- ditions are continually arising. The best that can be done, therefore, in a book of this character, is to pre- sent a selection of problems calculated to show the most common application of principles which, care- fully studied, will so familiarize the student with them that he will have no difficulty after-ward in working out the patterns for whatever shapes may come up in his practice, whether they be of those specifically il- lustrated or not. From the foregoing the following summary of requirements, together with a general rule for cutting all miters whatsoever, are derived : Requirements There must be a plan, elevation or other view of the shape, showing the line of the joint or surface against which it miters, in line with which must be drawn a profile or sectional view of same, and this profile must be prepared for use by having all its curved portions divided into such a Fig. 2Jfl. — Usual Method of Cutting a Square Return Miter. number of spaces as is consistent with accuracy and convenience. It may be remarked here that the division of the profile into spaces is only an approximate method of obtaining a stretch-out. As theoretically the straight distance from one of the assumed points to another upon a curved line is less than the distance measured around the curve, and the shorter the radius of the Princijoles of Pattern Cutting. 77 curve the greater is this difference (a chord is less than the arc which it subtends,) hence the greater the num- ber of points assumed the greater will be the accuracy, and a curve of short radius should be divided more closely than one of longer radius. The profile thus represents practically a succession of plane surfaces. Rule. — 1. Place a stretch-out of the profile on a line at right angles to the direction of the molding, as shown in the plan, elevation or other view, through the points in which draw measuring lines parallel to the molding. 2. Drop lines from the points in the profile to the miter line or line of joint, carrying them in the direction of the molding till they intersect said line. 3. Drop lines from the inter- sections thus obtained with the miter or joint line on to the measuring lines of the stretch-out, at right angles to the direction of the mold- ing. In making the applica- tion of this rule the student must not forget that the word profile covers a vast Fig. 241. — Comparison Between the Short or Usual Method of Cutting a Square Miter and the Method Prescribed by the Bide. range of outlines, varying from a simple straight line to an entire section of a roof or even more, where large curved surfaces are to be treated, and that a rule that applies to one can be applied to the others equally well. The student who gives careful attention to these rules will at once remark that the operation of cutting a common square miter — that is, a miter between the moldings running across two adjacent sides of a square building, for example — does not employ a miter line, and, therefore, appears to be an exception. Yet it has been, remarked that a, thorough understanding of how a square miter is cut comprehends within itself the science of miter cutting. The square return miter — for such is the distinctive name applied to the kind of square miter in question — is an exception to the general rule only in the sense that it admits of an abbreviated method. The short rule for cutting it is usually the first thing a pattern cutter learns, and the operation is very generally explained to him without any reason being given for the several steps taken. In many cases it would bother him to cut the pattern by any other than the short method, even after he had obtained considerable proficiency in his art. Hence it is that, to all who have any previous knowledge of pattern cutting the rules above set forth seem inade- quate, or, to put it otherwise, are a formula to which there are exceptions. To clear up these doubts in the mind of the stu- dent an illustration of the short method of cutting a square miter is here introduced, and afterward the long method, or the plan which is in strict accordance with the rule above given, will be presented, combined with the short method, thus showing the relationship and correspondence between the two. Fig. 240 shows the usual method of developing a square return miter, being that in which no plan line is employed. The profile A B is divided into any convenient number of spaces, as indicated by the small figures in the en- graving. The stretch-out E F is laid off at right angles to the lines of the moldings, and, through the points in it, measuring lines are drawn parallel to the lines of moldings. From the points established in the profile lines are dropped cutting corre- sponding measuring lines. Then the pattern or miter cut G H is obtained by tracing a line through these points of intersection. In this operation it will be noticed that the stipulations of the first part of the rule have beea fully complied with — that is, the stretch-out line has been drawn at right angles to the lines of the molding, and measuring lines have been drawn parallel to those lines, but it would seem that the second and third parts of the rule as given are not applicable. Apparently no miter line has been employed, but the points have been dropped directly from the profile into the measur- ing lines. 78 The New Metal Worker Pattern Book. In order to make this clear Fig. 241 is here in- troduced in which the proper relation of parts is shown and in which the pattern is developed according to rule, and in which is also shown the short method and how it is derived from the long method. As the angle of a return miter can only be shown by a plan, the plan becomes the first necessity accord- ing to the rule and is shown in the cut by H F K M G L, F G showing the line upon which the two arms of the molding meet — that is, the miter line. The profile A B appears duly in line with one arm of the plan II F G L. This arm, then, is the part of which the pattern is about to be developed ; accordingly the stretch-out line is then drawn at right angles to this arm, as shown at C D' ) and the measuring lines drawn parallel to the arm. The second part of the rule is now carried out ; that is, lines are dropped from the points in the profile A B to the miter line F G and from thence at right angles to F H into the measuring lines, thus obtaining the pattern C E'. In the upper part of this figure another stretch-out, C D, is introduced into which lines have been dropped directly from the points in the profile, thus producing the pattern at C E, making this part of the figure a reduplication of the method employed in the previous figure. By comparison it will be seen that the two patterns C E and C E' are identical. Since the two arms of the miter are identical and at right angles to each other, the miter line must bisect the angle H F K and be at an angle of 45 degrees to either of the two faces H F and F K. From this it appears at once that the pro- jection of any and all points upon F G from the plan line G L toward H is exactly the same as from the plan line G M toward K and that the relationship be- tween C E and the miter line, and C E' and the miter line, is, therefore, the same. Dropping points from a profile against a line inclined 45 degrees, as F G, and thence on to a stretch-out, gives the same result as dropping them on the stretch-out in the first place. Hence it is that the portion of the operation shown in the lower part of the engraving may be dispensed with. This relationship could never occur were the angle of the miter anything else than a right angle. Another and perhaps simpler explanation of this is given in connection with Problem 3, in Section 1 of Chapter VI. A very common mistake made by beginners in attempting to apply the general rule for cutting miters as given, is that of getting the miter line in a wrong position with reference to the profile. For example, instead of drawing a complete plan, as shown by L H F K M in Fig. 241, by which the miter line is located to a certainty, and in connection with which it is a simple matter to correctly place the profile, it is not uncommon to attempt the operation by drawing the miter line only, placing it either above, below or at one side of the profile. The mistake is made by hav- ing the line at the side of the profile when it should be either above or below it, and vice versa. Fig. 242 illustrates a case in point. The engraving was made Fig. 24%. — -4 Square Face Miter Produced Where a Square Return Miter was Intended. from the drawing of a person who attempted to cut a square return miter by the rule, using a miter line only. By ]}lacing the miter line E F at the side in- stead of below the profile, a square face miter- — such as would be used in the molding running around a panel or a picture frame — was produced in place of what was desired. In order to avoid such errors the reader is recom- mended to a careful perusal of the chapter on Linear Drawing (Chapter III), where the relation existing be- tween plans, elevations and sections or profiles is thor- ougly explained. It is better to draw a complete plan, as shown in Fig. 241, thus demonstrating to a cer- Principles of Pattern Cutting. 79 tainty the correct relationship of the parts, than to save a little labor and run the risk of error. As remarked in the earlier part of this chapter, some labor is often necessary before the requirements mentioned above in connection with the rule can be fulfilled. Sometimes a miter line must first be de- veloped, and sometimes the profile of a molding must undergo a change of profile known as raking. It is believed that the principles underlying these opera- tions are made sufficiently clear in connection with the problems in which they are involved not to need es- pecial explanation in this connection. Suffice it to say that, in many instances, half the work is done in the getting ready. FormSo Regiaflar Taperta (FLARING WORK.) This subject embraces a large variety of forms of frequent occurrence in sheet metal work, and the de- velopment of their surfaces comes under an altogether different set of rules than those applied to parallel forms. Before entering into the details of these methods it will be best to first define accurately what is here included by the use of the term. These forms include only such solid figures as have for a base the circle or any of the regular polygons, as the square, triangle, Fig. 24S. — A Right Cone Generated by the Revolution of a Right- Angled Triangle about its Perpendicular. hexagon, etc. ; also figures though of unequal sides that can be inscribed within a circle, and all of which terminate in an apex located dh - ectly over the center of the base. While the treatment of these forms has been said to be altogether different from that of parallel forms (.here are some points of similarity to which the stu- dent's attention is called that may serve to fix the methods of work in his memory. Whereas in parallel forms the distances of the various points in a miter are measured from a straight line drawn through the mold near the miter for that purpose, as G D, Fig. 238, the distances of all points in the surfaces of tapering solids produced by the intersection of some other surface are measured from the apex upon lines radiating therefrom; and Fig. 2U-—A Right Gone with Thread Fastened at the Apex to which are Attached Points Marking the Upper and Lower Bases of a Frustum. whereas the distance across parallel forms (the stretch- out) is measured upon the profile, the distance across tapering forms is measured upon the perimeter of the base. Patterns are more frequently required for por- tions of frustums of these figures than for the com- plete figures themselves and the methods of obtaining the pattern of coverings of said frustums is simply to develop the surface of the entire cone or pyramid and by a system of measurements take out such parts as are required. As the apex of a cone is situated in a perpendic- ular line erected upon the center of its base, it must of necessity be equidistant from all points in the cir- cumference of the base. In works upon solid geometry the cone is de- scribed as a solid generated by the revolution of a right-angle triangle about its vertical side as an axis. This operation is illustrated in Fig. 243, in which it will be seen that the base E D of the triangle C E D is the radius which generates the circle forming the base of the cone, and that the hypothenuse C D in like manner generates its covering or envelope. 80 The New Metal Worker Pattern Book. If a plane be passed through a cone parallel to the base and at some distance above it, the line which it produces by cutting the surface of the cone must also be a circle, because it, like the base, is perpen- dicular to the axis. The portion cut away is simply another perfect cone of less dimensions than the first, Fig. 245.— Frustum of a Right Cone, the Dotted Lines Shoiving the Portion of the Cone Removed to Produce the Frustum. while the. portion remaining is called a frustum of a cone. AFC, Fig. 244, is a cone, and BDEC, Fig. 245, is a frustum. The line B E, Fig. 244, shows where the cone is cut to produce the frustum. If, having a solid cone of any convenient material, as wood, a pin be fastened at the apex C of the same, as shown in Fig. 244, and a piece of thread be tied Fig. 246.— Envelope of the Cone and Frustum Described by the Pin and Thread in Fig. 244. thereto, to which are fastened points B and A, corre- sponding in distance from the apex to the upper and lower bases of the frustum, and the thread, being drawn straight, be passed around the cone close to its surface, the points upon the thread will follow the lines of the bases of the frustum throughout its course. If then, taking the thread and pin from the cone, and fastening the pin as a center upon a sheet of paper, as shown in Fig. 246, the thread be carried around the pin, keep- ing it stretched all the time, the track of the points fastened to the thread will describe upon the paper the shape of the envelope of the frustum, as shown by Gr D E F. By omitting the line produced by the upper of the two points, the envelope of the complete cone Gr C F will be described. The length of the arc Gr F described by the point A attached to the thread may be determined by measuring the circumference of the base of the cone by any means most available. The usual method is to take between the points of the dividers a small space and step around the circumfer- ence of the circle of the base and set off upon the circle of the pattern the same number of spaces. Fig. 247. — Unfolding the Envelope of a Right Cone. The development of the envelope of a cone may be further illustrated by supposing that, in the case of the wooden model, it be laid upon its side upon a sheet of paper and rolled along until it has made one complete revolution ; a point having been previously marked upon the line of its base by which to deter- mine the same. The base B, Fig. 247, thus becomes stretched out as it were, describing the line C D upon the paper, while the apex A, having no circumfer- ference, remains stationary at the point A 1 . The lines G A' and D A 1 represent the contact of the side of the cone at the beginning and at the finish of one revolu- tion. As in the case of dividing the profile in parallel forms, this method is, theoretically, only approximate in accuracy, but the difference is so slight practically that it is not worth considering. Of course, the shorter Principles of Pattern Cutting. 81 the spaces are the greater is the accuracy. This method has, however, another significance which will be pointed out later on, which will help to simplify the solution of all tapering forms. Fig. 243. — A Cone Truncated Obliquely. If it is required that the cone should be truncated obliquely, as shown in Fig. 248, it will be seen that all the points in the upper line of the frustum are at different distances from the base, or, what amounts to the same thing, from the apex of the original cone, hence some method of measuring these distances must be devised. To explain the principles here involved more Fig. 249.— Plan and Elevation from which to Construct a Wooden Cone for Purposes of Illustration. clearly, suppose that a cone be cut from a solid block of wood and of a hight and width to agree with some par- ticular drawing, as, for instance, the one shown in Fig. 249. Divide the circle of the base E F upon the drawing into a convenient number of parts or spaces and mark the same number of points and spaces upon the edge of the base of the wooden cone, and from each of these points draw upon the sides of the wooden cone straight lines running to its apex. A correct elevation of these lines upon the draw- ing may be obtained by carrying lines from the divisions or points in the plan of the base vertically till they strike the line of the base B C in the elevation, as shown in Fig. 250, thence to the apex A, cutting the line G H. Now, if by means of a saw the upper part of the wooden cone be removed, being cut to the required angle as shown by the oblique line G II in the draw- ing, an opportunity is given, by the lines upon the Fig. 250. — Method of Obtaining the Lines upon the Elevation. part of the cone cut away, of measuring accurately the distance of each point of the curve thus produced from the apex. Then as all points in the base B C are equidistant from the apex A, to lay out the pattern of this frustum, first describe an arc of a circle whose radius is equal to the length of the side (or slant hight) of the cone A B, Fig. 250. Make this arc in length equal to the cir- cumference of the base B C of the cone by means of the points, as previously described. To avoid con- fusion number these points 1, 2, 3, etc., from the start- ing point B, and from each of these points draw lines to the center of the arc, all as shown in Fig. 251. Now, replacing that portion of the cone which was cut away so as to identify the lines upon its sides The New Metal Worker Pattern Book. by the numbers at the base, the length of each line from the apex down to the cut can be measured by the dividers and transferred to the lines of the same num- bers in the diagram, Fig. 251, as shown between G and H. All this no doubt is quite simple when the model is at hand upon which to make the measurements. It is quite evident that it will not do to measure the dis- tance upon the drawing, Fig. 250, from the apex A to the points of intersection on the line G H because the sides of the cone having an equal slant of flare all around, the lines upon the drawing do not represent the real distances except in the case of the two outside lines ; the slant hight of a cone or any part of a cone being greater than the vertical hight of same part. But as these two outside lines do represent the correct Fig. 251.— Method of Deriving the Pattern of a Frustum from the Wooden Model. slant of the cone on all sides, either one of them may be taken as a correct line upon which to measure these distances; that is, as a vertical section through the cone upon any or all of the lines drawn upon its sides. To make it a perfect section upon any one of these lines, say line 5, it is simply required that the position of the point of intersection of line 5 with the line G H be shown, which is done by carrying this point horizontally across till it strikes the side of the cone A B at 5, as illustrated in Fig. 250. The result of repeating this operation upon all the other lines is as though a thread or wire were stretched from the apex down along the side of the cone to the point B in the base and the cone were turned upon its axis, and as each line upon the side passes under the thread, the point where it cuts the intersecting plane G H where marked thereon, thus collecting all the points into one section as it were. This operation is fully shown in Fig. 252, to which is added the development of the pattern, which is exactly the same as that shown in Fig. 251, the dis- tances of the points between G and H from A being obtained in this case from the points upon the line A B, instead of from the model, as before. The points on A B are transferred to lines of corresponding num- ber in the pattern by means of the compasses, as shown. Should the frustum of which a pattern is required Fig. 252.— Method of Deriving the Pattern from the Drawing. have both its upper and lower faces oblique to the axis of the cone a level base can be assumed at a con- venient distance below the lower face of the frus- tum from which the circumference can be obtained and then both the upper and lower faces of the frus- tum can be developed by the method just described. A right cone having an elliptical base might seem to belong in the same class with regular tapering forms, but as the distance from its apex to the various points in the perimeter of its base is constantly varying, it is therefore placed in the class with irregular forms in Principles of Pattern Cutting. 83 the following section of this chapter, where it will be duly discussed. But as tapering articles of elliptical shape are of frequent occurrence, and as the circle is much easier made use of than the ellipse, siich articles are usually designed with approximate ellipses com- posed of arcs of circles. This method is in many cases especially desirable, as articles so designed have an equal amount of flare or taper on all sides, which would not be the case if they were cut from elliptical cones. It will thus be seen that an article designed in that manner is the envelope of a solid composed of as many portions of frustums of right cones as there were arcs of circles used in drawing its plan. In Fig. 253 is shown the usual method of draw- ing the plan and elevation of an elliptical flaring ar- ticle, the outer curve of the plan ACBD being the shape at M N of the elevation, while the inner curve I G V J is the plan at the top K L. As many centers may be employed in drawing the curves of the plan of such an article as desired, all of which is ex- plained in the chapter on Geometrical Problems (Chap. TV.), Problems 73, 76 and 78. To simplify matters only two sets of centers have been employed in the present drawing, all as indicated by the dotted lines drawn from the various centers and separating the different arcs of circles. Reference to the plan now shows that that portion of the article included between the points E Fig. 263. — Usual Method of Draiuing an Elliptical Flaring Article C W V G H is a position of the envelope of a cone the radius of whose base is D C and whose apex is located at a point somewhere above D ; and likewise that that portion included between the points X A E H I J is part of a cone the radius of whose base is A F and whose apex is somewhere upon a line erected at F. Thus four sectors cut from cones of two differ- ent sizes go to make up the entire solid of which the article shown in Fig. 253 is a frustum. To determine the dimensions, then, of such cones it is necessary to construct a diagram such as that shown in Fig. 254, which is in reality a section upon the line ED of the plan, in which P and P R are respectively equal to E D and E F of the plan. At points and R, Fig. 254, erect perpendicular lines J and R Z indefinitely. Upon J set off S equal to the straight hight O K of the frustum, Fig. 253, and Fig. 254. — Diagram Constructed to Determine the Dimensioyis of the Cones, Portions of which are Combined to Make up the Article Shown in Fig. 253. draw S U parallel to P, which make equal in length toDH. A line drawn through the points P and U will then represent the slant or taper of the frustum, as shown at M K of the elevation, and if continued till it intersects with the perpendiculars from O and P will determine the respective hights of the two cones, as shown by Z and J. Then P JO is the triangle which, if revolved about its vertical side J 0, will generate the cone from which so much of the figure as is struck from the centers G and D in Fig. 253 is cut; and P Z R is the triangle which if revolved about its vertical side Z R will generate the cone from which the end pieces of the article are taken. To present this before the reader in a more forcible manner, several pictorial illus- trations are here introduced in which the foregoing operations are more clearly shown. In Fig. 255 is shown a view of the plan of the base A C B D of Fig. 253 in perspective, in which the reference letters are the same as at corresponding parts of that plan, and upon which is represented, in its correct position, a I sector of the larger cone from which the side portions 84 The New Metal Worker Pattern Book. of the frustum are taken. Thus the triangular sur- faces FDE and F D W, being sections of the cone through its axis, correspond to the triangle J P of the diagram, Fig. 254. In Fig. 256 two additional sectors from the smaller cone previously referred to are represented as standing upon the adjacent portions of the plan from which their dimensions were derived. Thus C F and H D, the center lines of their bases, correspond respectively to A F and Y B of the plan, Fig. 253, and the triangles L F Gr and M II K, being radial sections of the cones, correspond with the tri- angle ZEPof the diagram. In Fig. 257 is presented the opposite view of the combination seen in Fig. 256, Fig. S55. — Perspective View of the Plan in Fig. 253, with a Sector of the Larger Cone in Position. showing at C B and D A the joining of their outer surfaces or envelopes. As previously remarked, two sets of centers only were employed in constructing the plan, Fig. 253, for the sake of simplicity. Had a third set of centers been made use of the arrangement of sectors of cones shown in Figs. 256 and 257 would have been supple- mented by a pair of sectors, cut from a cone of inter- mediate size, which would have been placed on either side of the large sector between it and the smaller ones, all being joined together upon the same general principle as before explained. Beference to Fig. 220 in the chapter on Geometrical Problems shows at J L P, P S W and W TJ V what the relative position of their bases would be. If it be desired to complete the solid, which has been begun in Fig. 256, it will first be necessary to cut away that portion of the middle sector which stands over the space F H B, Fig. 256. Such a cut might be begun upon the line F H, and passing vertically through the points L and M would finish through the curved surface of the further or curved side of the sector. The cut thus made between the points L and M is shown at D C in the other view, Fig. 257, and is by virtue of the conditions a hyper- bola. (See Def. 113, Chap. I.) The piece necessary to complete the solid would then be a duplicate of the shape remaining after making the above described cut, the outer surface of which is shown by A B C D of Fig. 257. The complete solid would then have the appearance shown in Fig. 258. Fig. 256. — The Same Plan Showing Ttvo Sectors of the Smaller Cone in Position Joining the Larger One. By thus resolving the solid from which the ordi- nary elliptical flaring article is cut into its component elements the process of developing its pattern may be more readily understood. This process may now be easily explained by returning to the string and pin method which was made use of in connection with the simple cone in the earlier part of this section. In Fig. 257 is shown a line some distance above the base representing the top of the frustum shown by K L in the original elevation, Fig. 253. It also shows a pin fastened at the apex of the middle conical sector to which is attached a thread carrying points G- and H representing the irpper and lower surfaces of the frustum. Now, if the string be drawn tight and passed along the side of the larger sector of the cone from A to B the points will follow the upper and lower bases of the frustum. When the point B is Principles of Pattern Cutting. 85 reached, if the finger be placed upon the thread at the apex of the lesser cone, shown at C, and the progress of the thread be continued, the points will still follow the lines of the bases of the frustum. If the pin and Fig. 257. — Opposite View of Parts Shown in Fig. 256, with String Attached to a Pin at the Apex of the Larger Sector, thread be taken from the cone and transferred to a sheet of paper, as shown in Fig. 259, the pin A being used as a center and the thread as a radius, the points will describe the envelope of the frustum. First, the radius is used full length, as shown by A L K, and arcs L M and K H are drawn in length respectively Fig. S5S. — The Completed Solid of which the Ordinary Ellipitical Flaring Article is a Part. equal to their representatives H G V and E C W of the original plan, Fig. 253. Then a second pin is put through the string, as shown at B, thus reducing the radius to the length of the side of the lesser cone, and arcs are struck in continuation of those first de- scribed, making the length of the additional arcs equal to those of their corresponding arcs HI J and E A X of the original plan. As the lengths of the sides of the larger and Fig. 259. — The Pin and Thread taken from Fig. 257 and Used in Describing the Envelope. smaller cones above made use of are by construction equal to J P and Z P, the hypothenuses of the tri- angles, Fig. 254, by whose revolution they were generated, those distances may therefore be taken at once from that diagram by means of the compasses and used as shown in Fig. 259. Reference has been made above to the difference between the circumference of the circle of the base obtained by means of the points and spaces (which method becomes a necessity to the pattern cutter) and -An Arc Compared with its Chord. An explanation of this differ- next class of regular tapering the real circumference, ence will lead to the figures — viz. : pyramids. In the accompanying diagram, Fig. 260, ABC represents the arc of a circle of which the straight line A C is the chord, being the shortest distance between the two points A and C. Therefore, when dividing a circle by means of points for purposes of measure- ment, the pattern cutter is in reality using a number of chords instead of the arcs which they subtend. 86 The New Metal Worker Pattern Book. In the practice of obtaining the circumference or stretch-out of a circle the space assumed as the unit of measure should be so small that there is no perceptible curve between the points and, of course, no practical difference between the length of the chord and the length of the arc. It will thus be seen that the circle representing the base of a cone has in reality become in the hands of the pattern cutter a many sided polygon and that the cone is to him a many sided pyramid. As one of the conditions in describing a regular polygon is that its angles shall all lie in the same circle, so the angles or hips of a pyramid must lie in the surface of the cone whose base circumscribes the base of the pyramid and whose apex coincides with the apex of the pyramid. Viewed in this light then, the lines which were drawn upon the outside of the wooden cone for the purpose of measurement in the illustration used above become the angles or hips of a pyramid and may be used for that puipose in exactly the same manner. In developing the pattern of a frustum of a cone the line connecting the points between Gr and H, Fig. 251, is supposed, of course, to be a curved line, while in the case of a pyramid (the points or angles of the pyramid being further apart and the sides of a pyramid being flat instead of curved) the lines of the pattern connecting the points would be straight from point to point. Irregmlar Forms (TRIANGULATION.) In some classes of sheet metal work certain forms arise for which patterns are required, but which cannot be classified under either of the two previous sub- divisions. Their surfaces do not seem to be generated by any regular method. They are so formed that although perfectly straight lines can be drawn upon them (that is, lines running parallel with the form), such straight lines when drawn would not be parallel with each other ; neither would they slant toward each other with any degree of regularity. While in the systems described in the two previous portions of this chapter distances between lines running with the form measured at one end of an article govern those at the other end, in the forms considered in this department these distances are continually varying and bear no such relation to each other. Thus in parallel forms (moldings) the distance between any two lines running with the form is the same at both ends of the article, while in conical shapes all lines running with the form tend toward a common center or vertex, so that the distances between such lines at one end of the article (provided it does not reach to the vertex) bear a regular proportion to the distances between them at the other end. Hence, in the development of the pattern of an irregular form it becomes necessary to drop all previously described systems and simply pro- ceed to measure up its surfaces, portion by portion, adding one portion to another till the entire surface has been covered. To accomplish this end one of the most simple of all geometrical problems is made use of. to which the reader is referred (Chap. IV., Problem 36) — viz. : To construct a triangle, the lengths of the three sides being given. As from any three given dimensions only one triangle can be constructed, this furnishes a correct means of measurement ; and the solution of this prob- lem in connection with a regular order and method of obtaining the lengths of the sides of the necessary tri- angles constitutes the entire system. To carry out this system it simply becomes necessary to divide the surface of any irregular object into triangles, ascertain the lengths of their sides from the drawing, and re- produce them in regular order in the pattern, and hence the term Triangulation is most fittingly applied to this method of development of surfaces. In all articles whose sides lie in a vertical plane, distances can be measured in any direction across their sides upon an elevation of the article, but when the sides become rounded and slanting the length of a line running parallel with the form cannot be measured either upon the elevation or the plan. The elevation sives the distance from one end of the line to the other vertically or as it appears to slant to the right or left, but the distance of one end of the line forward or back of the other can only be obtained from the plan which while supplying this dimension does not give the hight. Consequently the true length of any straight line lying in the surface of any irregular form can only be ascer- tained by the construction of a right-angle triangle whose base is equal to the horizontal distance between the required points, and whose altitude is equal to the vertical distance of one point above the other, the hypothenuse giving the true distance between the points, or, in other words, the required length of the line. For illustration, Fig. 261 shows an article which may be called a transition piece, the base of which, Principles of Pattern Cutting. S7 A B C D of the plan, is a perfect circle lying in a horizontal plane, E H of the elevation. Its upper sur- face, however, IST P Q of the plan, is elliptical in shape and besides being placed at one side of the center is also in an inclined position, as shown by F G of the elevation. To the right of this plan is another drawing of the same, A' B' C D', turned one-quarter around from which, and the elevation, is projected another view, J' K' L M, which may be called the perimeter at the top. As F G, the distance across the top, is greater than N P (its apparent width in the plan), the curve 1ST P Q evidently does not give the correct distance around the top, and therefore a correct view of the top must be obtained. The method of accomplishing this does not differ from many similar operations described in connection with parallel forms and is clearly shown in the drawing. Considering N P Q as a correct plan or horizontal projection of Ml v/ / / l / y /TRUE PROFILE/ / /OF TOP / ] H ijrhh-Li //}' //// /I /" l ''Hi // / / 1/ 3 i 5 9(07 10 8 DIAGRAM OF DOTTED LINES IOC Fig. 262. Fig. 261. Plans, Elevations, etc., of an Irregular Shaped Article, Illustrating the Principles of Triangulation. front and which will assist in obtaining a more perfect conception of the shape of the article. A comparison of the three views shows that the slant of the sides is different at every point, and that the only dimensions of the article which can be measured directly upon the drawing are the circumference of the base and the slant hight, as given at E F, H G and L M. Before a pattern of its side can be developed it will be necessary to ascertain its width (or distance from base to top) at frequent intervals and also its the top, one-quarter of it, as !N", may be divided by any convenient number of points and their distances from N P set off upon the parallel lines drawn from N" P", thus obtaining 0" N", one-quarter of the cor- rect curve. It is more likely, however, that the cor- rect shape of the top N" 0" P" would be given, from which it would be necessary to obtain its correct appearance in the plan, which would be accomplished by drawing the normal curve in its correct relation to the line F G, as shown by 1ST" O" P", when the raking 88 The New Metal Worker Pattern Book. process could be reversed, thereby developing the curve N P one-half of the plan of top. Preparatory to obtaining the varying width of the pattern of the side, a number of points must be fixed upon in the curves of both top and bottom from which to take the measurements. As one-quarter of the top is already divided into spaces, another quarter, P, may be divided into the same number of spaces (also dividing O" P" into the same space as 0" N"). If N" 0" P" is the normal curve of the top it would very naturally be divided into equal spaces by the dividers, as is usual in such cases, while the spacing in N P would be the result of the operation of raking. It is advisable to have the spaces in N"0"P" all equal to each other, as it is from this curve that the stretch-out of the top of the pattern is to be derived, the conven- ience of which will become apparent when the pattern is developed. The quarter P is used in connection with the quar- ter N, because these two combined constitute a half of the top curve lying on one side of the line A C of the plan which divides the article into symmetrical halves, it being only necessary, when the shape of an article permits, to obtain the pattern of one-half and then to duplicate by any convenient means to obtain the other half. The corresponding half of the plan of the base, therefore, A B C, must also be divided into the same number of equal spaces as were used at the top, all as shown in the drawing, and both sets of points should be numbered alike, beginning at the same side. Having thus fixed the points from which measure- ments across the pattern of the side are to be taken, next draw lines across the plan connecting points of like number, as shown by the full lines in the plan. This divides the entire side of the article into a num- ber of four-sided figures ; but as it is necessary, as shown above, to have it divided into triangles, each four-sided figure may now be redivided by a line drawn through its opposite angles, thus cutting it into two triangles. In other words, each point in the base should be connected with a point of the next lower 'number (or higher, according to circumstances) in the curve of the top, and these lines should be dotted in- stead of full lines for the sake of distinction and to avoid confusion in subsequent parts of the work. Thus 1 of the base is connected by a dotted line with 0' of the top, 2 of the base with 1' of the top, etc. In respect to which is the best way to run the dotted lines, common sense will be the best guide. Thus, in the space bounded by the lines 4 4' and 5 5', it is plainly to be seen that there would be greater ad- vantage and less liability of error in connecting 5 of the bottom curve with 4' of the top than in crossing the line from 4 of the bottom to 5' of the top, for the rea- son that in the former case the triangles produced would be less scalene or acute. The next step is to devise a means of determining the true lengths which these lines represent or, in other words, their real length as they could be measured if a full size model of the article were cut from a block of wood or clay iqjon which these lines had been marked, as shown upon the drawing. The lines upon the plan, of course, only show the horizontal distances between the points which they connect. The vertical night above the base of any of the points in the upper curve can easily be found by measuring from its position upon the line F G of the elevation perpendicularly to the base E H. Therefore, having both the vertical and the horizontal distance given between any two points, it is only necessary to construct with these dimensions a right angle triangle, and the hypothenuse will give their true distance apart. Thus in Fig. 262 ah is equal to the line 4 4' of the plan, while a c is made equal to 4 4' of the elevation. Consequently c h represents the true distance between the points 4' of the top and 4 of the base. Therefore, to obtain alb of these hypothenuses in the simplest possible manner, it will be necessary to construct one or two diagrams of triangles. To avoid confusion it is better to make two ; one for obtaining the distances represented by the full or solid lines drawn across the plan and the other for those of the clotted lines. To do this extend the base line EH of the elevation, as shown at the left, at any convenient points, in which, as B. and S, erect two perpendicular lines. Project lines horizontally from all the points in F G, cutting these two lines as shown, and number the points of intersection. (Some of the figures are omitted in the drawing for lack of sj)ace.) From E set off on the base line distances equal to the lengths of the solid lines of the plan 1 1', 2 2', 3 3', etc., numbering the points 1, 2, 3, etc., as shown, and connect jioints of similar number upon the base with those upon the perpendicular. From S set off on the base line dis- tances equal to the lengths of the dotted lines of the plan 1 0', 2 1', 3 2', etc., and number them to corre- spond with figure upon the line of the base ABC. Thus make 1 S equal to 1 0' of the plan, 2 S equal to 2 1' of the plan, 3 S equal to 3 2', etc., and connect Principles of Pattern Cutting. 89 each point in the base with the point of next lower number upon the perpendicular by a dotted line, as 1 on the base with on the perpendicular, 2 with 1, 3 with 2, etc. The entire surface of the piece for which Fig. 26$.— Top, Back and Bottom for a Model of One-half the Article Shoivn in Fig. 261. a pattern is required has thus been cut up into two sets of triangles, one set having the spaces upon the base line ABC, which are all equal, for their bases, and the other set having the spaces in the curve N" 0" P" of the top, also equal to each other, as their bases, and each separate triangle having one solid line and one dotted line as its sides. In all of this work the student's powers of mental conception are called into play. The shape of the sur- face, which is yet to be developed, has been spoken of as if it ideally existed— in fact, it must exist in the mind or imagination of the operator in order to make him intelligent as to what he is doing. If this fails him, he can resort to a model which can easily be con- structed (full size or to scale, according to convenience) as follows : Describe upon a piece of cardboard or metal the shape E F Gr H, Fig. 2G1, to which add on its lower side, E H, one-half of the plan of the bottom, ABC, with the curve NOP and the solid lines con- necting it with the outside curve traced thereon. Also add on its upper side, F G, one-half the shape of top, N" 0" P", marking the points 1, 2, 3, etc., upon its edge. Now cut out the entire shape in one piece, as shown in Fig. 263, and bend the same at right angles, on the lines F Gr and E H. Small triangles of the shape and size of each of the triangles shown in the diagram of solid lines, Fig. 261, as B, 1 1 E, 2 2E, etc., can now be cut out and placed upon the portion representing the bottom, each with its base upon the solid line which it represents, at the same bringing the apex of each to the corresponding number on the top. These can be fastened in place by bits of sealing wax, or if cut from metal the whole can be soldered together. The hypothenuses of the various triangles will thus represent the true distances across the pattern upon the solid lines of the plan, while the distances upon the dotted lines can be represented by pieces of thread or wire, placed so that each will reach from the point at the base of one of the triangles to the point at the top of the one next it. If constructed of metal two or three triangles will suffice to give the model sufficient rigidity, and the remaining points can be connected by pieces of wire, using a different kind of wire to represent the distances on the dotted lines. In Fig. 261, is shown a pictorial representation of a model constructed, as above described, from the draw- ings shown in Fig. 261. In the illustration the tri- angles 2, 5 and S only are shown in position, their hypothenuses connecting points of similar number in the upper and lower bases. The other points are rep- resented as being connected by wires or threads repre- senting both the solid and the dotted hypothenuses in the diagrams of triangles in Fig. 261. Such a model if constructed will give a general idea of the shape of the entire covering, and at the same time of the small pieces, or triangles, of which the covering is composed, with all the dimensions of each. If all of the spaces formed upon this skeleton surface could be filled in Fig. 264— Perspective View of Cardboard Model of One-half the Article Shown in Fig. 261. with pieces of cardboard or metal just the size of each and the whole removed together and flattened out (each piece being fastened to its neighbor at the sides), it would constitute the required pattern, the same as will be subsequently obtained by measurements taken from the drawing, and as shown in Fig. 265. 90 The New Metal Worker Pattern Book. Having by means of the diagrams of triangles in Fig. 261 obtained the lengths of all the sides it is now- only necessary to construct successively each triangle in the manner described in Chapter IV, Problem 36, remembering that the last long side of each triangle used is also the first long side of the next one to be constructed. Therefore, at any convenient place draw any straight line, A N of Fig. 265, which make equal to the real distance from A to N, Fig. 261, which has been found to be the distance of the diagram of solid lines. To conduct this operation with the great- est economy and ease it is necessary to have two pairs of dividers, which shall remain set, one to the spaces upon the plan of the base ABC, and the other to the spaces upon N" 0" P", and a third pair for use in taking varying measurements. From A of Fig. 265 as a center, with a radius equal to 1 of the plan, Fig. 261, describe a small arc, and from N as a center, with a radius equal to the true distance from N to 1 of the plan, which has been found to be 1 of the diagram of dotted lines, describe another arc, cutting the first one as shown at the point 1, Fig. 265. The triangle thus constructed represents the true dimensions of one indicated by the same figures of the plan. Next from N of the pattern as a center, with a radius equal to N" 1 of true profile of top, Fig. 261, describe a small arc, which cut with one struck from point 1 of pat- tern as a center, with a radius equal to 1 1 of the dia- gram of solid lines, thus locating point 1' of pattern. This triangle is, in turn, succeeded by another whose sides are next in numerical order, that is 1 2 of the base and 1 2 of the diagram of dotted lines. Thus the operation is continued, always letting the spaces of the circumference of base succeed one another at one side of the pattern, and the spaces upon the true profile of top succeed one another at the other side of the pat- tern, until all the triangles have been laid out as shown by AN P C, Fig. 265, which will complete one-half the entire pattern. It is not necessary to draw all of the dotted or solid lines across the pattern, as the points where the small arcs intersect are all that are really needed in obtaining the outlines of the pattern, but it is often advisable to draw them as well as to number each new point as obtained, in order to avoid confusion and insure the order of succession. In dividing the curves of top and bottom into spaces, such a number of points should be taken as will insure the greatest accuracy, as in the case of dividing a profile. Thus too few would give too short a stretch-out, while if the spaces were too small error in transferring their lengths might result, which would be increased as many times as there were spaces. Under the head of transition pieces may be in- cluded a large number of forms having various shaped polygonal or curved figures as their upper and lower surfaces, placed at various angles to each other, some- times centrally located as they appear upon the plan and sometimes otherwise. It often happens that one surface or termination is entirely outside the other in that view, forming an offset between pipes of differing sizes and shapes. Sometimes such an offset takes a curved form, constituting a curved elbow of varying section throughout its length, in which case it consists of a number of pieces, each with a different shape at either end. With such forms may be classed the ship Fig. 265.— One-half Pattern of Side of Article Shown in Fig. 281. ventilator, whose lower end is usually round and hori- zontal and whose upper end is enlarged and elliptical and stands in a vertical position, the whole being com- posed of five or six pieces. In such cases, when the shape and position of the two terminating surfaces only are given, it becomes necessary to assume or draw as many intermediate surfaces as there are joints required, each of such a shape that the whole series will form a suitable transition between two extreme shapes. It may be remarked, that what have been spoken of here as "surfaces" do not necessarily mean surfaces of metal forming solid ends to the pieces described, but simply outlines upon paper to work to, as more often the "surface" is really an opening. Still another class of forms demanding treatment by triangulation result from the construction of arches Principles of Pattern Cutting. 91 cut through curved walls, as when an arch of either round or elliptical form, as a door or window head, is placed in a circular wall in such a manner that its sides or jambs are radial, or tend toward the center of the curve of the wall. It will be seen that the soffit of such an arch is similar in shape to the sides of a transi- tion piece, having what might be called its upper and lower surfaces curved and placed vertically. In such cases it is best to consider the horizontal plane passing through the springing line of the arch as the base from which to measure the hights of all points assumed in the outer and inner curves. It is believed that a sufficient number of this gen- 7 P Fig. 266. — Elevations and Plan of an Elliptical Cone. eral class of problems will be found in the third section of the chapter on Pattern Problems to enable the care- ful student to apply the principles here explained to any new forms that might present themselves for his consideration, remembering that any form may be so turned as to bring any desired side into a horizontal position to be used as a base, or that an upper hori- zontal surface can be used as a base as well as a lower. The operations of triangulation undoubtedly re- quire more care for the sake of accuracy than those of any other method of pattern cutting, for the reason that there is no opportunity of stepping off a continuous stretchout, at once, upon any line, either straight or curved. It is therefore not to be recommended if the j subject in hand admits of treatment by any regular method without too much subdivision. Triangulation is not introduced as an alternate method, but as a last resort, when nothing else will do. Besides the various forms of transition pieces, an- other class of forms is to be treated under this head, which might almost be considered as regular tapering articles. They include shapes, or frustums cut from shapes, which terminate in an apex, but whose bases cannot be inscribed in a circle, as irregular polygons, figures composed of irregular curves as well as the per- fect ellipse. A solid whose base is a perfect ellipse and whose apex is located directly over the center of its base (in other words, an elliptical cone) is perhaps the best typical representative of this class of figures. If the base of such a cone be divided into quarters by its major and minor axes, it will be seen at once that all of the points in the perimeter of any one quarter will be at different distances from the apex of the cone, because they are at different distances from the center of base or the intersection of the two axes. This is clearly shown in Fig. 266, in which are shown the two elevations and the plan of an elliptical cone. The side elevation shows K E to be the distance of the apex from the point P in the jslan of the base, while the end elevation shows K' D to be the distance of the apex from the point D of the base, or the true distance rep- resented by X D of the plan. If one-quarter of the plan of the base, as D P, be divided into any convenient number of equal spaces and lines be drawn to the center X, as shown, each line will represent the horizontal distance of a point in the perimeter from the apex ; and if a section of the cone be constructed upon any one of these lines, as, for in- stance, line 4 X, or, in other words, if a right angle triangle be drawn, of which 4 X is the base and Pi K the altitude, the hypothenuse will be the true distance of the point 4 from the apex. Therefore, to ascertain the distances from the apex to the various points in the circumference of the base construct a simple diagram of triangles, as shown in Fig. 267, viz. : Erect any perpendicular line, as X M, equal in hight to E K of the elevation; from X, on a horizontal line X P, as a base, set off the various distances of the plan, X 1, X 2, X 3, etc., numbering each point, and from each point draw a line to M. These hypothenuses will then represent the distances of the various points in the perimeter of the base from the apex of the cone ; or in other words, the sides of a number of triangles forming the envelope of the cone, the bases of which triangles 92 The New Metal Worker Pattern Book. will be the spaces 1 2, 2 3, etc., upon the plan. As all of these triangles terminate at a common apex or center, instead of laying out each one separately to form a pattern, as in the case of an article of the type shown in Fig. 261, the simplest method is as follows : pi^SiOlii Fig. 267.— Diagram of Sections on the Radial Lines of the Plan in Fig. 266, to which is Added the Pattern of One-quarter of the Envelope. From M, of Fig. 267, as a center, with radii corre- sponding to the distances from M to points on P X, as M 1, M 2, M 3, etc., describe arcs indefinitely, as shown to the left ; then taking the space used in step- ping off the plan between the points of the dividers, place one foot upon the arc drawn from point S, as at D, and swing the other foot around till it cuts the arc drawn from point 7 ; from this intersection as a center swing it around again, cutting the arc from 6 ; or in other words, step from one arc to the next till one- quarter of the circumference has been completed. As the spaces in the base are equal, it is clearly a matter of convenience whether this last ojDeration is Fig. 268. — Frustum of an Elliptical Cone. begun upon arc 8, stepping first to arc 7, then to arc 6, etc., or whether it is begun upon arc 1, stepping first to arc 2, then to 3, etc., till complete. A line traced through these points, as A D, will give the cut at the base of the envelope, and ADM will be the envelope of one-quarter of the cone. In Fig. 26S is shown a perspective view of the frustum of the cone shown in Fig. 266, the upper sur- face A B being shown in Fig. 266 by the lines G H and X 0. If the envelope of such a frustum is desired the cut which its upper surface would make through the envelope of the entire cone could be obtained in exactly the same manner as that of its lower base, be- cause the upper surface of the frustum is in reality the base of the cone, which remains above after the lower part has been cut away. But as part of the operation has already been performed in obtaining the cut at the base, it is most easily accomplished as follows : First draw radial lines from the point M of the diagram of 15:-=_-_-=-_^4T 7 * \ \ \\\ * i i \"\Y\ 5 1 \ \ \ V\ 11 \ \\v> /// / / f L M J \°v \ \ A r u-h-4f Fig. 269.— Elevation of the Frustum of an Elliptical Cone. triangles, Fig. 267, to each of the points previously obtained in the cut at the bottom of the envelope, between A and D ; also draw a horizontal line at a hight above the base X P equal to E L, Fig. 266, cut- ting the hypothenuses M 1, M 2, etc., as shown by Gr BL Now place one foot of the dividers at the point M, and bringing the other foot successively to the various points of intersection of the line G H with the various hypothenuses, describe arcs cutting the radial lines in the envelope of corresponding number. A line traced through the points of intersection, as B C, will give the cut at the top of the envelope of the frustum, of which AD is the bottom cut. If the cut at the top of the frustum is to be oblique instead of horizontal, a means must be devised for Principles of Pattern Cutting. 93 measuring the distance from the apex at which the oblique plane cuts each of the hjpothenuses, or in other words, each of the lines drawn from the apex of the cone to the various points in its base. In Fig. 269, E S T F is the elevation of an oblique frustum of an elliptical cone, whose apex is at K, and whose base is the same and has been divided in the same manner as that shown in Fig. 266. Erect lines from each of the points in the curve of one-half the plan D A to the base line E F of the elevation, thenc^ carry them toward the apex K, cut- ting the line S T ; the vertical hight of the points upon S T can then most easily be measured by carrying them horizontally, cutting the center line R K of the cone, where to avoid confusion they should be numbered to Fig. 270. — Diagram of Sections on the Radial Lines of the Plan in Fig. 269, with the Pattern of One-half the Envelope. correspond with the points of the plan from which each was derived. These points may now be transferred in a body by any convenient means to the vertical line X/ M' of the diagram of triangles, Fig. 270, seeing that each point is placed at the same distance from M' that it is from the point K of Fig. 269. A horizontal line from any one of the points on the line X' M' extended to the hypothenuse of corresponding number will then give the correct distance of that point from the apex cf the cone. The diagram M' X' D' is a duplicate of M X P of Fig. 267, and the lower outline of the en- velope is the same as that shown in Fig. 267. It will be noted, however, that half the stretchout of the base is necessary in this case to give all the essentials of the pattern of the envelope, while one-quarter was sufficient for the previous operations. When all the points in the uppei line of the frustum have been obtained in the diagram they may be transferred to the various radial lines in the envelope, from M' as a center, by the use of the compasses as before, all as shown in the draw- ing. If the apex of the cone were not located directly over the crossing of the two axes of the ellipse — that is, if the cone were scalene or oblique instead of right — the method of obtaining its envelope, or parts of the same, would not differ from the foregoing. Lines drawn from the points of division in the circumference of the base to the point representing the position of the apex in the plan will be the horizontal distances used in constructing a diagram of triangles, which dis- tances can be used in connection with the vertical hight of the cone, as before, in obtaining the various hypothenuses. If the apex of a scalene cone be located over the line of either axis of the ellipse, either within the perimeter of the base or upon one of those lines continued outside the base, one-half the pattern of the entire envelope will have to be obtained at one operation ; but if the apex is not located upon either of those lines in the plan, then the entire envelope must be obtained at one operation, as no two quarters or halves of the cone will be exactly alike. The method of obtaining the envelope of any scalene cone, even though its base be a perfect circle, is governed by the same principles as those employed in the above demonstrations. It will be well to remember that any horizontal section of a scalene cone is the same shape as its base, which fact can be used to advantage in determining the best method to be employed in obtaining the envelope of any irregular flaring surface that may be presented. If, for instance, the plan of any article, whose upper and lower surfaces are horizontal, shows each to con- sist of two circles or parts of circles of different diame- ters not concentric, it is evident that the portion of the envelope indicated by the circles of the plan is part of the envelope of a scalene cone. An illustration of this is given in Fig. 271, which shows a portion of an article having rounded corners and flaring sides and ends, but with more flare at the end than at the side. The plan shows the curve of the bottom corner A B to be a quarter circle with its center at X, and that of the top CD to be a quarter circle with its center at Y. The rounded corner A B D G is then a portion of the envelope of a frustrum of a scalene cone, and the method of finding the dimensions of the complete cone is quite simple and is as follows : First draw a line, Z X, through the centers of the two circles in the plan, 94 Tlxe New Metal Worker Pattern Booh. at right angles to which project an oblique elevation, as shown below, making the distance between the two lines E F and G H equal to the hight of the article. Lines from X and M of the plan of the bottom fall upon G H, locating the points X' and H, while lines from Y and N of the top locate the points Y' and F in the upper line of the oblique elevation. A line drawn through Y' and X', the centers of the circles, will then represent the axis of the cone in elevation, which can be continued to meet a line drawn through the points F and II, representing the side of the cone, thus locat- ing the apex Z' of the scalene cone. The point Z' can then be carried back to the plan, as shown at Z, thus locating the apex in that view. As the line N Z rep- resents the horizontal distance between the point F and the apex Z' of the cone, so lines drawn from Z to any number of points assumed in the curve of the base C D will give the horizontal distances between those points and the apex, to be used as the bases in a dia- gram of triangles similar to that shown in Fig. 267, while V Z' gives their hight. Having drawn a dia- gram of triangles the pattern follows in the manner there shown. For greater accuracy in the case of a very tapering cone, the circles of the plan can be completed, as shown dotted, and their points of intersections with the line Z 1ST can be dropped into oblique elevation, as seen at S and T, through which a line can be drawn to meet a line through F and H with greater accuracy than one through Y' and X', as the angle in the former case is twice as great. In the above methods of obtaining the envelopes of what, may be termed irregular conical forms, it will be clearly seen that the operation of dividing the curve of the base into a great number of spaces really re- solves the conical figure into a many sided pyramid, and that the lines connecting the apex with the points in the base, which have been referred to as hypothe- nuses, are really the angles or hips of the pyramid. It is therefore self evident that any method of de- velopment which is applicable to a many sided pyra- mid is equally applicable to one whose sides are fewer in number, with the only difference, however, that the lines representing the angles or hips in the case of a pyramidal figure mean angles or sharp bends in the pattern of the envelope, while in the case of the conical envelope the bends are so slight as to mean only a con- tinuous form or curve. It is believed that the foregoing elucidation of the principles governing the development of the surfaces of irregular shaped figures is sufficiently clear to make the demonstrations of this class of problems, given in Chap. YI, Section 3, easily understood by the student, as well as to enable him to apply them to any new forms that may present themselves for solution. This chapter is intended to present, under its three different heads, all the principles necessary to guide the student in the solution of any problem that may Fig. 271.— Elevations and Plan of an Article, the Corner of which is a Portion of a Scalene Cone. arise. Its aim is to teach principles rather than rules, and the student is to be cautioned against arbitrary rules and methods for which he cannot clearly under- stand the reason. His good sense must govern him in the employment of principles and in the choice of methods. There is hardly a pattern to be cut which cannot be obtained in more than one way. Under some conditions one method is best, and under other conditions another, and careful thought before the Principles of Pattern Cutting. 95 drawing is begun will show which is best for the pur- pose in hand. The list of problems and demonstrations in the chapter which follows is believed to be so comprehen- sive that therein will be found a parallel to almost any- thing that may be required of the pattern cutter, and it is believed that he will have no difficulty in applying them to his wants. *m H Up CHAPTER VI. Pattern Problems Every effort has been put forth in the preceding chapters of this book to prepare the student for the all important work which is to follow — viz. , the solution of pattern problems. It is always advisable in the study of any subject to be well grounded in its funda- mental principles. For this reason a chapter on Linear Drawing has been prepared to meet the requirements of the student in pattern cutting, which is preceded by a description of drawing materials and followed by a solution of the geometrical problems of most frequent occurrence in bis work. But the most important chapter is the one immediately preceding this, in which , the theory of pattern cutting is explained, and which, if thoroughly understood, will render easy the solution of any problem the student may chance to meet. The selection of problems here presented is made sufficiently large and varied in character to anticipate, so far as possible, the entire wants of the pattern cut- ter, and the problems are so arranged as to be con- venient for reference by those who make use of this part of the book without previous study of the other chapters. In the demonstrations, only the scientific phase of the subject will be considered; consequently, all al- lowances for seams, joints, etc., as well as determining where joints shall be made, are at the discretion of the workman. In some of the problems it has been necessary to assume a place for a joint, but if the joint is required at a place other than where shown, the method of procedure would be slightly varied while the principle involved would remain the same. Each demonstration will be complete in itself, al- though references to other problems, principles, etc., will be made where such references will be of advan- tage to the student. As stated in the preceding chapter, the problems will be classed under three different heads according to the forms which they embody — viz. : First, Parallel Forms ; Second, Regular Tapering; Forms, and Third, Irregular Forms. SECTION 1 Parallel ForoiSc (MITER CUTTING). The problems given in this section are such as occur in joining moldings, pipes and all regular con- tinuous forms at any angle and against any other form or surface, and in fact include everything that may legitimately be termed Miter Cutting. In the problems of this class two conditions exist, which depend upon the nature of the work. Accord- ing to the first, a simple elevation or plan of the inter- secting parts shows the miter line in connection with the profile, which is all that is necessary to begin at once with the work of laying out the patterns. It frequently happens, however, that moldings are brought obliquely against sloping or curved surfaces in such a manner that no view can be drawn in which the miter line will appear as a simple straight line. Hence it becomes necessary to produce by the inter- section of lines a correct elevation of the intersections of the various members of the molding, which when done results in the much sought miter line. Or it may be necessary to develop a correct profile of some oblique member or molding in order to effect a perfect miter. Thus some preliminary drawing must be done before the work of laying out the miter patterns can be prop- erly begun, which constitutes the second condition above referred to and forms the great reason why the pattern draftsman should understand the principles of projec- Pattern Problems. 97 tion, which have been simplified for his benefit in Chapter III. In the arrangement of the problems those which fulfill the first condition will precede those of the second, and all of a similar nature will, so far as pos- sible, be placed near together, so that the reader, knowing the kind that is wanted, will be able to find it with little difficulty. It will also be to his advantage before reading any of the problems in this chapter to read carefully the Eequirements and the general Rule governing this class of problems given in Chapter V on pages 76 and 77. PROBLEM I. A Butt Miter Against a Plain Surface Oblique in Elevation. Let A B L K in Fig. 272 be the elevation of a portion of a cornice, of which C D is the profile and A B the angle or inclination of the surface against which the cornice is required to miter. Divide the curved parts of the profile into spaces in the usual manner, and from all points in profile draw lines parallel with A K, cutting the miter line A B. On any con- venient line, as E F, at right angles to the cornice, lay off a stretchout of the profile C D, space by space as they occur, through the points in which draw the measuring lines, all as indicated by the small figures. Placing the T-square at right angles to the lines of the cornice, or, what is the same, parallel to the stretchout line, bring it successively against the points in the miter line A B and cut measuring lines of corresponding number, as indicated by the dotted lines. A line traced through these points, as indicated by H G, will be the pattern required. Fig. 272. — A Butt Miter Against a Plain Surface Oblique in Elevation i 13 In Fig. 273 be the Fig. 27S.—A Butt Miter Against a Plain Surface Oblique in Plan. PROBLEM 2. A Butt Miter Against a Plain Surface Oblique in Plan. Let A B L K in plan of the cornice which is required to miter against a vertical surface stand- ing at any angle with the lines of the cornice, the angle being shown by A B. Draw the profile C D in position corresponding to the- lines of the cornice, all as indicated. Sj)ace the profile in the usual manner, and through the points draw lines jDarallel to the direction of the cornice, cutting the miter line A B. On any convenient line at right angles to the lines of the cornice lay off the stretchout E F of the jjro- file C D, through the points in which draw measuring lines in the usual manner. Placing the T-square at right angles to the cornice, or, what is the same, parallel to the stretchout line E F, bring it successively against the points in A B and cut the corresponding measuring lines. A line traced through the points of intersection thus ob- tained, shown by H G, will be the pattern required. 98 The New Metal Worker Pattern Book. PROBLEM 3. A Square Return Miter, or a Miter at Right Angles, as in a Cornice at the Corner of a Building. In Fig. 274, let A B D C be the elevation of a cornice at the corner of the building for which a miter at right angles is desired. As has been explained in the chapter on the Principles of Pattern Cutting (page 77), the process of cutting a miter for a right angle admits of certain abbreviations not employed when other Fig. 274- — A. Square Return Miter, as in a Cornice at the Corner of a Building. angles are required. The demonstration here intro- duced is calculated to show the method of obtaining the pattern for a square miter with the least possible labor. Divide the profile A B into any convenient number of parts, as shown by the small figures. At right angles to the lines of the molding, and in con- venient proximity to it, lay off the stretchout E F, through the points in which draw measuring lines in the usual manner, parallel to the lines of the cornice, producing them far enough to intercept lines dropped vertically from points in A B. Place the T-square at right angles to the cornice, or, what is the same, parallel to the stretchout line, and, bringing it successively against all the points in the profile A B, cut measuring lines of corresponding numbers. Then a line traced through these points, as shown by G H, will be the pattern sought. The reason for this is as follows : As the angle of this miter cannot be shown in any other view than a plan, the plan is the correct view from which to derive the pattern ; having drawn which, as ■7 ZJ Fig. £75. — Plan of a Square Return Miter. shown in Fig. 275, the operation of developing the pattern becomes exactly the same as in the previous problem (Fig. 273). In Fig. 274, A B D C represents the elevation of a portion of a cornice, while A B rep- resents the profile of the return or receding portion against which the piece A B D C is required to miter, or, in other words, the miter line. As the profiles of the face piece and of the return piece are of course the same, the outline A B becomes at once the profile and the miter line ; therefore that portion of the rule which says, " drop the points from the profile on to the miter line," must be omitted. All that remains then is to drop the points at once into the stretchout. PROBLEM 4. A Return Miter at Other Than a Right Angle, as in a Cornice at the Corner of a Building. In Fig. 276, let A B C D be the elevation of a portion of cornice, and let G H K be the plan of any angle around which the cornice is to be carried, a pattern being required for an arm of the miter. Complete the plan by drawing the lines E F and F L, inter- secting at F, giving the correct projection of the mold- ing from G H and H K, and then draw the miter line between the joints H and F. It will be observed that Pattern Problems. 99 the arm G H F E has been projected directly from the profile A B, thus placing profile and plan in correct rela- tion to each other. Divide the profile A B in the usual man- ner into any conven- -A Return Miter at Other than a Right Angle, as in a Cornice at the Corner of a Building. ient number of parts, and from the points thus ob- tained drop lines vertically on to the miter line in the plan F H, as shown. At right angles to this arm of the cornice, as shown in plan, lay off a stretchout of the profile, as shown by N" M, through the points in which draw the usual measuring lines, as indicated. Place the T-square parallel to this line, or, what is the same, at right angles to E F, and, bringing it suc- cessively against the points in F H, cut measuring lines of corresponding num- bers. Then a line traced through the points thus obtained, as shown by O P, will be the pattern sought. As inti- mated at the outset of this problem, the angle GHK represents any angle what- ever, and the course to be pursued is exactly the same whether it be acute or obtuse. Of course the more acute the angle GHK the longer will the miter line H F become, as may be ascer- tained by experiment, producing a cor- responding increase in the projection of the different parts of the pattern from the line N M. PROBLEM 5. A Butt Miter Against a Curved Surface. In Fig. 277, let A B be the pi-ofile of any cornice and D K H C be the elevation of the same showing the curved surface D, against which it is required to miter. The principle herein involved is exactly the same as that in Problem 1. Space the profile in the usual manner, and through the points draw lines cutting C D. At right angles to the line of cornice lay off the stretch- out L M, as shown, through the points in which draw measuring lines in the usual manner. Place the J-square parallel to the stretchout line, or, what is the same, at right angles to the lines of the cornice, and, bringing it against the several points in C D, cut the corresponding measuring lines, as shown. In the event of a wide space, as shown by a' b 1 in the eleva- tion, the curve between these points may be trans- ferred to the pattern by means of a piece of tracing paper, or, if it is a regular curve, its radius may be used as shown by G and G' and the arrow points. A line traced through the several points of intersection, as shown by E F, will be the shape of the required pattern. Fig. 277.— A Butt Miter against a Regular Curved Surfaae. 100 The New Metal Worker Pattern Book. 278. — The Patterns for a Hip Finish in a Curved Mansard Roof , the Angle of the Hip being a Right Angle. Pattern Problems. 101 PROBLEM 6. The Pattern for a Hip Finish in a Curved Mansard Roof, the Plan of the Hip Being a Right Angle. The solution of all problems concerning mansard roofs, and especially those in which the roof surface is curved, calls for much good judgment on the part of the pattern cutter, for the reason that the original designs that come into his hands are seldom drawn mathematically correct. The upper part of a mansard dome, such as is shown in Fig. 278, as it curves away from the eye, becomes so much flattened in appearance that, if drawn correctly, it might, to any but an expert draftsman, create a false impression of the design intended ; hence the original drawing must often be taken for what it means rather than for what it says. The engraving represents an elevation of a curved hip molding occurring in a roof, of which E D is the vertical hight and M 2 K 3 is a section. The first step to be described is the method of obtaining the pattern of the fascias of the hip molding. For this purpose is shown in the drawing such a representation of it as would appear if the two fascias formed a close joint upon the angle of the roof, supposing that the hip molding or the bead is to be added afterward on the outside over this joint. The part to be dealt with may be considered the same as though it were the section of a molding, instead of a section of a roof, and the operations performed are identical with those employed in cutting a square miter. Space the profile H K into any convenient number of parts, introducing lines in the upper part in connection with the ornamental corner piece, shown b} r L D, at such intervals as will make it possible to take measurements required to describe the shape of it in the pattern. From this profile, by means of the points just indicated, lay off a stretchout, as shown by H 1 K 1 , and through the points draw the usual measuring lines. Bring the T-square against the several points in II Iv, and cut the corre- sponding lines drawn through the stretchout just described. Then a line traced through these points, as shown by H 2 K 2 , will be the outside line of the fascia. For the inside line take the given width of the fascia and set it off from this line at intervals, measur- ing at right angles to it, as indicated by A 1 B 1 , and not along the measuring lines of the stretchout, as would be indicated by A 1 C. Then a line traced through these points, as shown from M 1 to L 1 , will be the inside line of the fascia strip. The points in the ornamental corner piece from L 1 to D 1 are to be obtained from the elevation, in case a correct elevation is furnished the pattern cutter, by measurement along the lines drawn horizontally through the several points in L D, which are transferred to the measuring lines of corresponding number in the stretchout already referred to. Or the shape from L 1 to D' may be described arbitrarily upon the pattern at this stage of the operation, according to the finish required upon the roof. The latter method is the preferable one. The method of constructing the elevation, by working back from the outline thus established, is clearly indicated by the dotted lines in the engraving. From the several points in the profile II K horizontal lines are drawn, as shown, and from the intersections of the inside line of the pattern of the fascia piece with the various measuring lines, as above described, lines are dropped, cutting these horizontal lines of correspond- ing numbers. Then a line traced through these points, shown from M to L, will be the inside line of the fascia piece in elevation. To cut the flange strip bounding the fascia and corner piece, commonly called the sink strip, an elevation of which is shown in the section from M 2 to D 2 , the following method will be the simplest, and at the same time sufficiently accurate for all purposes : Draw the line Gr F approximately parallel to the upper part of the section M 2 ~D% making it indefinite in length, which cut by lines drawn from the several points in M 2 D 2 , at right angles to it, as shown. From F G, upon the several lines drawn at right angles to it, set off spaces equal to the distance upon lines of corresponding number from D E to the line M L of the elevation. Then a line traced through these points, as indicated by M 3 1/, will constitute a pro- file of this flange strip. In like manner set off in contin- uation of it, the lengths measured from points in the ornamental corner piece to D E, all as shown by L 3 D 3 F. From this profile lay off a stretchout parallel to G F, as shown by M 4 D 4 , through the points in which draw- measuring lines in the usual manner. Place the T-square parallel to the stretchout line, and, bringing it successively against points in both the inner and the outer lines of the elevation of the flange strip, as shown from M 2 D 2 , cut the measuring lines of corre- 102 The New Metal Worker Pattern Book. sponding number. Then lines traced through these points of intersection, as shown from M" to D", will be the pattern of the flange strip bounding the edge of the fascia. PROBLEM 7. Miter Between Two Moldings of Different Profiles. To construct a square miter between moldings of dissimilar profiles requires two distinct operations. The miter upon each piece is to be cut as it would ap- pear when intersected by the other molding. Let A B and A 1 B 1 in Figs. 279 and 280 be the profiles of two moldings, between which a square miter is required. As, of course, the two arms of the miter are different, it will be necessary to draw an elevation of each show- proper outline against which it is to miter, with the profile A B, project from it an elevation, as shown by FCDE, Fig. 279, terminating such elevation by the profile of the other molding, A 1 B", as shown by F E. Then, as in the case of Problems 1 and 6, the line F E becomes the ing the Beginning, therefore, through these points, as shown by F l E 1 , will give the shape qf the cut on the piece A B to fit against the profile E F. For the other piece proceed in the same manner, reversing the order of the profiles. From its profile A 1 B 1 produce the elevation K M N L, Fig. 280, completing same by means of the profile of the first molding, A B, as shown by M N. Divide A 1 B' m the usual manner. Through the points draw lines cut- ting M N. At right angles to this piece lay off the stretchout P of the profile A 1 B 1 , through the points in which draw measuring lines, as shown. With the J-square at right angles to the line K M or N L, and brought against the points in M 1ST, cut corresponding measuring lines drawn through OP. A line traced Fig. £79. Fig. 280. Miter between Two Moldings of Different Profiles. miter line, and the method of procedure is the same as in those problems. Divide A B into any convenient number of parts in the usual manner, from which carry lines horizontally against F E. At right angles to the lines of the molding lay off a stretchout, G H, of the profile A B, through the points in which draw the usual measuring lines. Bring the T-square against the points of intersection in the line E F, and cut the corresponding measuring lines. Then a line traced through these points, as shown by M 1 W, will be the shape of the end of the piece required to fit against the profile M N. In the event of the points obtained by spacing the profiles A B and A 1 B 1 not meeting all the points in the profiles F E and M N necessary to be marked in the pattern, then lines must be drawn back- ward from such points in profiles M N" and E F, cut- ting the profile A 1 B 1 or A B, as the case may be. Corresponding points are then to be inserted in the Pattern Problems. 103 stretchouts, through which measuring lines are to be drawn, which, in turn, are to be intersected by lines dropped from the points. An illustration of this occurs in Fig. 280, where it will be seen that no point obtained by the dividing of the profile A' B 1 strikes the point X of the miter line, which is absolutely necessary to the shape of the pattern. Therefore, after spacing the profile, a line is drawn from X back to A 1 B 1 , foring the point No. 6^-. In turn this point is transferred to the stretchout P, also marked 6£, from which a measur- ing line is drawn in the same manner as through the other points in the stretchout, upon which a point from X is dropped, as shown by X 1 . In actual practice such expedients as this must be resorted to in almost every case, because usually there is less correspondence be- tween the members of dissimilar profiles, between which a miter is required, than in the illustration here given. By this means profiles, however unlike, can be joined. PROBLEM 8. A Butt Miter Against an Irregular or Molded Surface. Let B A in Fig. 281 be the profile of a cornice, against which a molding of the profile, shown by G II, is to miter, the latter meeting it at an inclination, as indi- Fig. 281. — A Butt Miter against an Irregular or Molded Surface. cated by C D. Construct an elevation of the oblique molding, as shown by C D F E, in line with which draw the profile G H. Divide G H in the usual man- ner into any convenient number of parts, and through the points draw lines parallel to the lines of the in- clined molding, cutting the profile B A, all as indicated by the dotted lines. At right angles to the lines of the molding, of which a pattern is sought, lay off a stretch- out, M N, in the usual manner, through the points in which draw measuring lines. Place the T-square at right angles to the lines of the inclined molding, or, what is the same, parallel to the stretchout line, and, bringing it against the points of intersection formed by the lines drawn from the profile G H across the profile B A, cut the corresponding measuring lines. In the event of any angles or points occurring in the profile B A which are not met by lines drawn from the points in G H, additional lines from these points must be drawn, cutting the profile G H, in order to establish corresponding points in the stretchout. Thus the points 3 and 13 in the profile G H are inserted after spacing the profile, as described in Problem 7, because the points with which they correspond in the profile B E are angles which must be clearly indicated in the pattern to be cut. Having thus cut the measuring lines corresponding to the points in the profile B A,- draw a line through the points of intersection, as shown, by P. Then P will be the shape of the pattern of the incline cornice to miter against the profile A B. 104 The New Metal Worker Pattern Booh. PROBLEM 9. The Pattern of a Rectangular Flaring: Article. In Fig. 282, let C A B E be the side elevation of the article, of which F I K M is the plan at the base and G II L N" the plan at the top. Let it be required to produce the pattern in one piece, the top included. Make II 1 L 1 N l G 1 in all respects equal to II L N" G of the plan. Through the center of it likewise draw RP indefinitely, and through the center in the opposite direction draw S indefinitely. From the lines IP L 1 and G 1 N 1 set off T O and W S respectively, each in length equal to the slant hight of the article, as shown by G A or E B of the elevation. Through and S respectively draw I 1 K 1 and F 1 M 1 , parallel to II 1 L 1 and G 1 N 1 , and in length equal to the corresponding sides in the plan I K and F M, placing one-half that length each way from the points and S. In like manner set off V P and TJ R, also equal to C A, and draw through R and P the lines F 2 I 2 and K 2 M 2 , parallel to the ends of the pattern of the top part as already drawn, and in length equal to I F and K M of the plan. Draw I 1 H 1 , K' L 1 , K 2 IV, W N 1 , M' N 1 , F 1 G', F 2 G' and P H 1 , thus completing the pattern sought. In the same general way the pattern may be described, including the bottom instead of the top, if it be required that ■way. Considering this problem in the light of miter cut- ting proper, I H G F and F G N M may be regarded as the plan of two similar moldings of which A C is the profile, I II, G F and N M being the miter lines. T is the stretchout line, drawn at right angles to F M, while I 1 K' and H' L' are the measuring lines representing respectively the points C and A of the profile. The points F and G are then dropped into their respective measuring lines, thus locating the points I 1 ELEVATION. Fig. 2S2. — The Pattern of a Rectangular Flaring Article. and IF at one end of the pattern, while points K 1 and L 1 are derived from M and N at the other end. PROBLEM 10. Patterns of the Face and Side of a Plain Tapering: Keystone. Let A B D C in Fig. 283 be the elevation of the face of a keystone, and G E 2 F 2 K of Fig. 284 a sec- tion of the same on its center line. Sometimes problems occur which are so simple that it is not apparent that their solution is an ex- emplification of any rule. That this, with others in which plain surfaces form the largest factors, may be so designated, will be sufficient excuse for a brief ref- erence to first principles. This problem is generally- referred to as finding the "true face" of the keystone, because, the face being inclined, the elevation ABC D does not represent the ' ' true face " or " true ' ' dimensions of the face. To state the case, then, in con- formity with the rule, A B and C D are the upper and Pattern Problems. 105 lower lines of a molding, of which E J F 5 of Fig. 284: is the profile, and A C and B D are the surfaces against Fig. 283. Patterns of the Face and Side of a Plain Tapering Keystone. which it miters, or the miter lines. Therefore, to lay out the pattern, draw any line, as E' F', at right angles to A B for a stretchout line, upon which lay off the stretchout taken from the profile W F 3 , Fig. 284, which in this case consists of only one space, as shown by E 1 F' ; through the points E 1 and F 1 draw the hori- zontal lines A 1 B' and C D 1 , which are none other than the measuring lines. Then, with the T-square placed parallel with the stretchout line, drop the points from the miter lines A C and B D into lines of correspond- ing letter, which connect, as shown by A 1 C 1 and B 1 D 1 , which completes the pattern. In developing the pattern for the side, W G and F 3 K are the lines of the molding, B D of Fig. 283 its profile and E 3 F 3 the miter line. Hence upon any vertical line, as L K 1 , lay off the stretchout of profile B D, locating the points M' and IT, all as shown by L M H l Iy 1 , through which points draw the measuring lines ; then, with the T-square placed parallel to L K', drop the points E 3 and F 3 into lines of corresponding letter, as shown by E 3 F\ As the vertical lines at Gl- and K represent the position of surfaces against which the side is required to fit at the back, bring the T-square against each, thus locating them in the pattern at G' and K', as shown. As the side must also fit over the molding of the arch an opening must be cut in it corresponding in shape to the profile of the arch molding 1ST, which is given in the sectional view. It is therefore only necessary to transfer this profile to the pattern, placing the top at the measuring line M and the bottom at the measuring line H', all as shown at N 1 . PROBLEM II. Patterns for the Corner Piece of a Mansard Roof, Embodying: the Principles Upon Which All Mansard Finishes are Developed. One of the first steps in developing the patterns for trimming the angles of a mansard roof is to obtain a representation of the true face of the roof. In other words, inasmuch as the surface of the roof has a slant equal to that shown in the profile of the return, the length of the hip is other than is shown in the eleva- tion, and this difference in dimensions extends in a pro- portionate degree to the lines of the various parts form- ing the finish. Not only are the vertical and oblique dimensions different, but, as the result of this, the angle at A is different from that shown in a normal ele- vation. Hence, it is of the greatest importance to ob- tain a " true face " or elevation of the roof as it would appear if swung into a vertical position, which may be accomplished as follows : In Fig. 285, let A E F C be the elevation of a mansard roof as ordinarily drawn, and let A 1 G be the profile showing the pitch drawn in line with the eleva- tion. Set the dividers to th< length A 1 Gf, and from A 1 as center, strike the arc G Gr 1 , letting G 1 fall in a vertical line from A 1 . From G 1 draw a line parallel to the face of the elevation, as shown by G 1 G 1 , and from the several points in the hip finish, as shown by C and K, drop lines vertically, cutting G" C in the points C 1 and K 1 , as shown. From these points carry lines to corresponding points in the upper line of the 106 The New Metal Worker Pattern Book. elevation, as shown by C 1 A and K 1 h. Then A C F 1 E represents the pattern of the surface shown by A F E of the elevation. In cases where the whole hight of the roof cannot be put into the drawing for use, as B 1 draw the horizontal line, as shown by B' B', and from B drop a vertical line cutting this line, as shown, in the point B\ By inspection of the engraving it will be seen that the point B 3 falls in the line A C obtained Elevation ' Fig. 285.— The Plain Surfaces of a Mansard Roof Developed. above described, the same result may be accomplished by assuming any point as far from A as the size of the drawing will permit, as B, and treating the part between A and B as though it were the whole. That is, from A, in a vertical line, set off A B", equal to A B. From in the previous operation, thus demonstrating that the latter method of obtaining the angle by which to pro- portion the several parts results the same as the method first described, and therefore may be used when more convenient. PROBLEM 12. A Face Miter at Right Angles, as in the Molding Around a Panel. In Fig. 286, let A B D C represent any panel, around which a molding is to be carried of the profile at E and E 1 . The miters required in this case are of the nature commonly called "face" miters, to dis- tinguish them from other square miters, which can only be shown in a plan view. A correct elevation of the panel A B D C, with the lines of the molding carried around the same, determines the miter lines A F and G C, which, in connection with the profiles at E and E 1 are all that is necessary to the development of the pat- Pattern Problems. 107 tern. The two profiles are here drawn, thus constitut- ing an entire section of the panel, because it is usual, for constructive reasons, to cut the two moldings with the intervening panel in one piece where the width of Fig. 286. — A Face Miter at Right Angles, as in the Molding Around a Panel. the metal will permit it. Divide the two profiles in the usual manner into the same number of parts, from which points draw lines parallel to the lines of the molding, cutting the miter lines, as shown. For the pattern of the side corresponding to A B lay off a stretchout at right angles to it, as shown by H K, through which draw measuring lines in the usual man- ner. Place the T-square at right angles to A B, or, what is the same, parallel to the stretchout line Ii K, and, bringing it successively against the several points in the miter line A F, cut measuring lines of corre- sponding number. Then a line traced through these points, as shown by L M, will be the pattern sought. The other pattern is developed in like manner. It is usual to draw the stretchout lines, K H and K 1 H' across the lines of the moldings which they represent, beginning the stretchouts at the inner lines of the mold- ing, thus : Point 10 of profile E would be located at V, while point 10 of profile E 1 would be at ~W. While this is apt to produce some confusion of lines in actual practice, it gives the entire profile in one continuous stretchout for the purpose alluded to above — that of cutting the entire width of the panel in one piece. Should it be desired to make one of the moldings separate from the rest, an additional point for the pur- pose of a lap is assumed at one of the moldings, as 11 of profile E 1 . The pattern for the end piece, A C, may be derived without drawing an additional profile, as its profile and stretchout are necessarily the same as that of the other two arms ; therefore reproduce H K on a line at right angles to A C, as shown by JST O, through the points in which draw measuring lines in the usual manner, producing them sufficiently far in each direction to intercept lines dropped from the points in the two miter lines. Place the T-square at right angles to A C, and, bringing it successively against points already in A F and C G, cut measuring lines of corresponding numbers. Then lines traced through the intersections thus formed, as shown by P R and S T, will be the shape of the pattern of the end piece. It may be noticed in the last operation that drop- ping the points from either of the miter lines, as A F, into the measuring lines is, in fact, only continuing in the same direction the lines previously drawn from the profile E to the line A F; and that in reality the shape of the cut at P R is developed without the assistance of the miter line, thus giving another instance of the fact that any square miter can be cut by the short method when the relation of the parts is understood. 108 The New Metal Worker Pattern Booh. PROBLEM 13, The Patterns of the Moldings Bounding; a Panel Triangular in Shape. In Fig. 287, let D E F be the elevation of a triangular panel or other article, surrounding which is a molding of the profile, shown at Gr and Gr 1 . Construct an elevation of the panel molds, as shown by ABC, and draw the miter lines A D, B E and C F. For the patterns of the several sides proceed as follows : Draw a profile, Gr, placing it in correct relative position to the side D F, as shown. Divide it into any con- of the three sides, at convenient points, draw stretch- out lines, as shown by H I, H 1 I 1 and H 2 F, through the points in which draw the usual measuring lines. With the T-square parallel to each of the several stretchout lines, or, what is the same, at right angles to the respective sides, bringing the blade successively against the points in the several miter lines, cut the corresponding measuring lines, all as indicated by the Fig. 287.— The Patterns of the Moldings Bounding a Triangular Panel. venient number of parts in the usual manner, and through these points draw lines, as shown, cutting the miter lines F C and A D. In like manner place the profile Gr 1 in a corresponding position relative to the side E F. Divide it into the same number of parts, and draw lines intersecting those drawn from the first profile in the line F C, also cutting the line E B. By this operation points are obtained in the three miter lines A D, E B, F C, from which to lay off the patterns in the usual manner. At right angles to each dotted lines. Then lines traced through the points of intersection thus obtained will describe the patterns required. A 1 C 1 F 1 D 1 will be the pattern for the side A D F C of the elevation, and likewise C 2 B 2 E 2 F 2 is the pattern for the side described by similar letters. Placing another profile in the molding A B D E would, if divided the same as the others, only result in another set of intersections at the points already existing on the lines A D and B E, as occurred on Pattern Problems. 109 the line F C, hence to save labor one profile in this case is all that is really necessary, the points being carried around from that and dropped into the three stretchouts respectively. PROBLEM 14. The Patterns of a Molding: Mitering Around an Irregular Four-Sided Figure. In Fig. 288, let A B C D be the elevation of an ir- regular four-sided figure, to which a molding is to be fitted of the profile shown by K. Place a duplicate profile against the side opposite, as shown, from which in these several stretchouts draw measuring lines in the usual manner, producing them until they are equal in length to the respective sides, the pattern of which is to be cut. Placing the T-square at right angles to the Fig. 288.— The Patterns of a Molding Mitering Around an Irregular Four-Sided Figure. project the lines necessary to complete the elevation of the molding as it would appear when finished, all as shown by E F G H. Draw the several miter lines B F, C G, D H and A E. Divide the two profiles into the same number of parts in the usual manner, through the points in which draw lines parallel to the lines of the molding in which they occur, cutting the miter lines, as shown. At right angles to each of the several sides lay off a stretchout from the profile, as shown by L M, L 1 M 1 , L 3 M 2 , L 3 M 3 . Through the several points lines of the several sides, or, what is the same, parallel to the stretchout lines, bring it against the points in the miter lines, cutting the corresponding measuring lines, all as indicated by the dotted lines. Then the lines traced through these points of intersection will give the several patterns required. Thus E' H 1 D 1 A 1 will be the pattern of the side E H D A of the eleva- tion ; B? D" C G 1 will be the pattern of the side H D C G ; G 3 F' B 1 C 3 that of F B C G ; and F 3 B 3 A 3 E 3 that of the remaining side. 110 The New Metal Worker Pattern Book. PROBLEM 15. The Patterns of Simple Gable Miters. In Fig. 2S9, let A B K and BKEbe the angles of the miters at the foot and peak of a gable. Draw profiles of the required molding in correct relation to both the horizontal and inclined moldings, as shown at II and H 1 , through the angles of which draw the other parallel lines necessary to complete the ele- vation. Their intersection at the base of the gable produces the miter line B C, while the miter line at the top of the gable is a vertical line, because the two sides of the gable, K B and K K, are of the same pitch. The profile H is so placed as also to repre- sent the return at the side at its proper distance from B. Divide the profile H in the usual manner into any convenient num- ber of equal parts. Place the T-square parellel to the lines in the horizontal molding, and, bringing it successively against the points in the profile, cut the miter line B C, as shown. At right angles to the lines of the horizontal cornice draw the stretchout E F, through the points in which draw the usual measuring lines, as shown. Reverse the T-square, letting the blade lie parallel to the stretchout line E F, and, bringing it against the several points of the profile H, cut the corresponding measuring lines. Then a line traced through these points of intersection, as shown from G to V, will be the pattern of the end of the horizontal cornice mitering with the return. In like manner, with the T-square in the same position, bring it • against the points in the miter line B C, and cut corresponding measuring lines drawn through the same stretchout. Then a line traced through the points of intersection thus obtained, as shown by T IT, will be the pattern of the end of the horizontal cornice mitering against the inclined cornice. Divide the pro- file II 1 into any convenient number of equal parts, all as indicated by the small figures. Through these points draw lines cutting the miter line B C, and also the miter line K L at the top. At right angles to the lines of the raking cornice place a stretchout, E 1 F 1 , of the profile H 1 , through the points in which draw the usual measuring lines, as shown. Place the T-square parallel to this stretchout line, and, bringing it suc- Fig. 389.— The Patterns of Simple Gable Miters. cessively against the points in B C and K L, cut the corresponding measuring lines, all as indicated by the dotted lines. Through the points thus obtained trace lines, as indicated by M N and P. Then M N will be the pattern for the bottom of the raking cornice mitering against the horizontal, and P will be the pattern for the top of the same. The pattern shown at G V will also be the pattern for the return miter- ing with A D of the elevation, it being necessary only to reverse it and to establish its length. Pattern Problems. PROBLEM 16. ill The Pattern for a Pedestal of Which the Plan is an Equilateral Triangle. should be drawn so as to show one side in profile and the plan placed to correspond with it. Draw the miter lines E and G 0. Divide the profile B D into spaces of convenient size in the usual manner, and number them as shown in the diagram. From the points thus obtained drop lines, cutting E and G 0, as shown. Lay off the stretchout N P at right angles to the side E G, and through the points in it draw measuring lines. Place the J-square at right angles to E G, and, bring- ing it successively against the points in the miter lines E O and G 0, cut the corresponding measuring lines. A line traced through these points will be the pattern, as shown by H L M K. The principle involved in this and several follow- ing problems is exactly the same as that of the preced- ing regular and irregular shaped panels. In this case the shape of the article is shown in plan instead of ele- Pattern Fig. 290.— The Pattern for a Pedestal of which the Plan is an Equilateral Triangle. Let A B D C in Fig. 290 be the elevation of a pedestal or other article of which the plan is an equi- lateral triangle, as shown by F E G. This elevation vation, and the profile is too large to permit of its being drawn within the plan, as were the profiles of the panel moldings in their elevations. 112 The New Metal Worker Pattern Booh. PROBLEM 17. The Pattern for a Pedestal Square in Plan. In Fig. 291, let A B D C be the elevation of a pedestal the four sides of which are alike, being in plan as shown by E H G F, Fig. 292. Since the plan is a rectangular figure the miters involved are square miters, or miters forming a joint at 90 degrees. A square miter admits of certain abbreviations, the rea- sons for which are explained in Problem 3, as well as in Chapter V, under the head of Parallel Forms. The abbreviated method which is here illustrated is always The plan is introduced only to show the shape used. of the article, and is not employed directly in cutting Fig. 292.— The Plan of Square Pedestal. the pattern. Space the profiles, shown in the eleva- tion by A C and B D, in the usual manner, numbering the points as shown. Set off a stretchout line, L R, at right angles to the base line C D of the pedestal, through the points in which draw measuring lines. Place the T-square parallel to the stretchout line, and, bringing it successively against the points in the two profiles, cut the corresponding lines drawn through the stretchout. A line traced through these points, as shown by L M N K, will be the pattern of a side. Fig. 291.— The Pattern for a Pedestal, Square in Plan. PROBLEM 18. The Patterns for a Vase, the Plan of Which is a Pentagon. In Fig. 293, let S C K T be the elevation of a vase, the plan of which is a pentagon, as shown C 1 C R P. The elevation must be drawn in such a man- ner that one of the sides will be shown in profile. Draw the plan in line and in correspondence with it. Divide the profile into spaces of convenient size in the Pattern Problems. 113 usual manner and number them. Draw the miter lines C 1 H 1 and C 2 H 2 in the plan, and, bringing the T-square successively against the points in the profile, drop lines across these miter lines, as shown by the dotted lines in the engraving. Lay off the stretchout M N at right angles to the piece in the plan which the case of a complicated profile, or one of many dif- ferent members, to drop all the points across one sec- tion of the plan C H' H 2 Q" would result in confusion. Therefore it is customary, in practice, to treat the pattern in sections, describing each of the several pieces of which it is composed independently of the Fig. 293.— Pattern for the Upper Part. The Patterns for a Vase, the Plan of which is a Pentagon. corresponds to the side shown in profile in the eleva- tion. Through the points in it draw the usual measur- ing lines. Place the T-square parallel to the stretch- out line, and, bringing it against the several points in the miter lines which were dropped from the elevation upon them, cut the corresponding measuring lines drawn through the stretchout. A line traced through the points thus obtained will describe the pattern. In others. In the illustration given the pattern has been divided at the point H, the upper portion being developed from the profile and plan, as above, while the lower part is redrawn in connection with a section of the plan, as shown in Fig. 294. Corresponding letters in each of the views represent the same parts, so that the reader will have no trouble in perceiving just what has been done. Instead of redrawing a por- 114 The New Metal Worker Pattern Booh. tion of the elevation and plan, as has been done in this case, sometimes it is considered best to work from one profile rather than to redraw a portion of it, as that always results in more or less inaccuracy. Therefore, after using the plan and describing a part of the pattern, as shown in the operation explained above, a piece of clean paper is pinned on the board, cover- ing this plan and pattern, upon which a duplicate plan is drawn, from which the second section of the pattern is obtained. Great care, however, is neces- sary in redrawing portions of the plan to insure accuracy. PROBLEM 19. The Pattern for a Pedestal, the Plan of Which is a Hexagon. 4 sides, drawn so that one of the sides will be shown in profile. Place the plan below it and corresponding with it. Divide the profile shown in the elevation into any convenient number of spaces in the usual manner, and, to facilitate reference to them, number them as shown. Bring the T-square against the points in the profile and drop lines across one section of the plan, as shown by H X M. At right angles to this section of the plan lay off the stretchout line N 0, through the points in which draw the usual meas- uring lines. Place the T-square parallel to the stretchout line, and, bringing it successively against the points in the miter lines H X and M X, cut the corresponding measuring lines, as indicated by the dotted lines. Then a line traced through the points Fig. 295.— The Pattern for a Pedestal, the Plan of which is a Hexagon. In Fig. 295, let C D F E be the elevation of a pedestal which it is desired to construct of six equal thus obtained will be the required pattern, as shown by P STE. Pattern Problems. 115 PROBLEM 20. The Pattern for a Vase, the Plan of Which is a Heptagon. sides will be shown in profile. In line with it draw the plan, placing it so that it shall correspond with the elevation. Space the profile L P in the usual manner, and from the points in it drop lines crossing one sec- tion of the plan, cutting the miter lines K S and II V, as shown. Lay off a stretchout, A B, at right angles to the side of the plan corresponding to the side of the vase shown in profile in the elevation. Through the points in it draw the usual measuring lines. Place the T-square parallel to this stretchout line, and, bringing it successively against the points in the miter lines, cut the corresponding measuring lines, as shown. A line traced through these points, as shown by K O Fig. 296. — The Pattern for a Vase, the Plan of which is a Heptagon. In Fig. 296, let E L P G be the elevation of the I "W U, will be the pattern of one of the sides of the vase, constructed in such a manner that one of its | vase. PROBLEM 21. The Patterns for an Octagonal Pedestal. Let K H G W L in Fig. 297 be the elevation of a pedestal octagon in plan, of which the pattern of a section is required. This elevation should be drawn in such a manner that one side of it will appear in profile. Place the plan so as to correspond in all respects with it. Divide the profile G W, from which the plan of the side desired is projected, in the usual manner, and from the points in it drop points upon each of the miter lines F T and P U in the plan. Lay off a stretchout, B E, at right angles to the side of the plan corresponding to the side of the article shown in profile in the elevation, and through the points in it draw the usual measuring lines. Place the T-square- parallel to the stretchout line, and, bringing it suc- cessively against the points dropped upon the miter lines from the elevation, cut the corresponding measur- ing lines. A line traced through the points thus obtained will describe the pattern of one of the sides of which the article is composed. In cases where the profile is complicated, consisting of many members, and where it is very long, confusion will arise it all the points are dropped across one section of the plan, as above described. It is also quite desirable in many cases to construct the pattern in several pieces. In 118 The New Metal Worker Pattern Book. such cases methods which are described in connection with Problem 18 may be used with advantage. In the present case the pattern is constructed of two the pattern is cut by means of a part of the plan redrawn above the elevation, thus allowing the use of the same profile for both. The same letters refer F_ Fig. 297.— The Patterns for an Octagonal Pedestal. pieces, being divided at the point S of the profile. The lower part of the pattern is cut from the plan drawn below the elevation, while the upper part of to similar parts, so that the reader will have no diffi • culty in tracing out the relationship between the dif- ferent views. Pattern Problems. PROBLEM 22. The Patterns for a Newel Post, the Plan of Which is a Decagon. 117 In Fig. 29S, let WTJSPOKTVbe the eleva- tion of a newel post which is required to be constructed in ten parts. Draw the plan below the elevation, as shown. The elevation must show one of the sections «s 23 p the plan, as shown by G X II , and cutting the two miter lines G X and H X. Lay off the stretchout line C D at right angles to Gr II, and through it draw the customary measuring lines. Place the T-square parallel to the stretchout, and, bringing it against the several points in the miter lines G X and H X, cut the corre- sponding measuring lines. A line traced through the points thus obtained will describe the pattern. In order to avoid confusion of lines, which would result from drop- ping points from the entire profile across one section of the plan, a duplicate of the cap A 1 W is drawn in Fig. 299 in connection with a section of the plan, as shown Fig. 299.— Pattern of Cap. *3D Fig. 298. — The Patterns for a Neivel Post, the Plan of which is a Decagon. or sides in profile, and the plan must be placed to cor- respond with the elevation. Space the molded parts of the profile in the usual manner, and from the points in them drop lines crossing the corresponding section of by Gr 1 X' H 1 , which are employed in precisely the same manner as above described, thus completing the pattern in two pieces, the joint being formed at the point num- bered 11 of the profile and the stretchout. 118 The New Metal Worker Pattern Book. PROBLEM 23. The Patterns for an Urn, the Plan of Which is a Dodecagon. In Fig. 300, let X A G II be the elevation of an urn to be constructed in twelve pieces. The elevation must be drawn so as to show one side in profile. Con- struct the plan, as shown, to correspond with it and the several points in the miter lines N X and O X, cut the corresponding measuring lines. A line traced through the points thus obtained will describe the pattern sought. In this illustration is shown a method sometimes resorted to by pattern cutters to avoid' the confusion resulting from dropping all the points across one section of the plan. The points from 13 to 20 inclusive are dropped upon the line X. The stretchout C D is drawn in exactly the middle of the pattern — that is, it is drawn from X, the central point of the plan. Points are transferred by the J- square from X to the measuring lines on one side of V Plan yj Fig. SOO.—The Patterns for an Urn, the Plan of which is a Dodecagon. draw the miter lines. Divide the profile A S G into spaces in the usual manner, and from the points thus obtained drop lines across one section, N X 0, of the plan. Lay off the stretchout C D at right angles to the side N of the plan. Place the T-square parallel to the stretchout, and, bringing it successively against the stretchout, the points on the other side being ob- tained by duplicating distances from C D on the several lines. The points 1 to 13 are dropped on N X only. The stretchout E F is laid off at right angles to the side M N from the point X, and, the T-square being set parallel to E F, the points are transferred to the Pattern Problems. 119 measuring lines on one side of E F, while the distances on the opposite side are set off by measurement, as de- scribed in the first instance. This plan will be found ad- vantageous in complicated and very extended profiles. PROBLEM 24. The Pattern for a Drop Upon the Face of a Bracket. In Figs. 301 and 302, methods of obtaining the return strip fitting around a drop and mitering against the face of a bracket are shown. Similar letters in the two figures represent similar parts, and the follow- II K, as shown by P, and on P lay off a stretch- out, through the points in which draw the usual measuring lines. From the points in the profile F Gr carry lines in the direction of the molding — that is, The Pattern for a Drop upon the Face of a Bracket. ing demonstration may be considered as applying to both. Let A B D C be the elevation of a part of the face of the bracket, and H K L a portion of the side, showing the connection between the side strip of the drop E F Gr and the face of the bracket. To state the case simply, F Gr is the profile and N" M the miter line, because N M is the outline of the surface against which the side strip miters. Then, following the rule, divide F Gr into any convenient number of parts in the usual manner, as shown by the small figures. Produce parallel to K M — intersecting the face of the bracket N M. Eeverse the T-square, placing the blade parallel to the stretchout line O P, and, bringing it suc- cessively against the points in 1ST M, cut the cor- responding measuring lines, as indicated by the dotted lines. Then a line traced through these several points of intersection, as shown by E' P, will be the pattern of the strip fitting around E F Gr and mitering against the irregular surface N M of the bracket face. 120 The Isew Metal Worker Pattern Book. PROBLEM 25. The Pattern of a Boss Fitting; Over a Miter in a Molding*. Let A B in Fig. 303 be the part elevation of a pediment, as in a cornice or window cap, over the miter and against the molding and fascia in which a boss, FKGH, is required to be fitted, all as shown by N E D of the side view. The outline F K G H of the boss is to be con- sidered as the profile of a molding running in the direc- tion shown by D E in the side view, and mitering against the surface of the cornice shown by IS!" E. For the 'natterns proceed as follows: Divide so much of the profile of the boss K F H G as comes against the cornice, shown from K to F, into any convenient number of parts, and from these points draw lines parallel to D E — that is, to the direction of the mold- ing under consideration — until they intersect the miter line N E, which in this case is the profile of the cornice molding. As the boss is so placed over the angle in the cornice molding that the distance from K to F is the same as that from K to G, the part of the boss K G will be an exact duplicate of K F and may be duplicated from the pattern of K F without another side view drawn especially for it, which would have to be done if the boss was otherwise placed. Therefore, extend the line N D upon which to lay off a stretchout of Iv F H G, dividing the portion K 1 F 1 into the spaces shown at K F of the profile, through which draw the usual measuring lines. Make the jDor- tion F 1 G' equal in length to the part F H G and, lastly, the portion G' K a a duplicate of F' K 1 reversed, as shown. Place the T-square parallel to the stretch- out line K 1 K", and, bringing it against the several points in N 0, cut corresponding measuring lines, as Fig. SOS. — The Pattern of a Boss Fitting Over a Miter in a Molding. shown. Then lines traced through these points of in- tersection, as shown by K 1 L M K 3 , will be the re- quired pattern. PROBLEM 26. The Patterns for a Keystone Having- a Molded Face With Sink. In Fig. 304, let E A B F be the front elevation of a keystone, as for a window cap, of which KLMP S R is a sectional view, giving the profile of the mold- ing M N P, over which it is required to fit. The sink in the face extends throughout its entire length, and is shown by G H D C, its depth being shown by the line K T of the section. E F H G and A B D C thus become moldings, of which E A and F B are the parallel lines, E F, G II, C D and A B the miter lines, and K R the profile. Likewise C G H D becomes a molding, of which G BZ and C D are the miter lines and K T the profile. Therefore, to obtain the pattern of the face pieces, divide the profile of the face K R into any convenient number of spaces, and from the points thus obtained carry lines across the face of the keystone, as shown. At right angles to the top of the keystone lay off a stretchout of K R, as shown by K 3 R 1 , through which draw the usual measuring lines. Placing the T-square parallel to the stretchout line, and bringing it successively against the points in the lines C D and A B bounding the face strip, cut the corresponding measuring lines. Then a line traced through these points, as shown by C 3 A 3 B 3 D 3 , will be the pattern for this part. In developing the pattern for the sink the usual method would be to divide K T into equal spaces, carrying lines across the face, and thence into the stretchout : but since this would result in confusion of Pattern Problems. 121 lines, the same points as were established in K E have been used, which are quite as convenient as the others mentioned, save that the points in K T must be ob- tained from the points in K B, by carrying lines back to K T, as shown, and in laying off the stretchout each individual space must be measured by the dividers. K 2 c 3 S04. — The Patterns for a Keystone Having a Molded Face with Sink. At right angles to the line H D of the keystone lay off a stretchout of K T, as shown by K 1 T 1 , through the points in which draw the usual measuring lines. Place the T-square at right angles to the lines across the face of the keystone, and, bringing it successively against the points in the lines G H and C D, forming the sides of the sink, cut the corresponding measuring lines drawn through K 1 T 1 . Then lines traced through these points, as indicated by Gr 1 H l and C 1 D', will form the pattern of the required sink piece. For the pattern of the piece forming the sides of the sink in the face of the keystone, K E T becomes the elevation of a molding running in the direction of E T, of which K E and Iv T are the miter lines and C D the profile. Hence, at any convenient place above or below the sectional view, lay off the stretchout of the line C D, as determined by the lines drawn across it in the first operation, all as indicated by C 2 D\ Through the points in C D" draw measuring lines in the usual man- ner. The next operation, in course, would be to drop lines from the points in the profile to the miter lines ; but as this has already been done by the lines of the first operation, it is only necessary to place the J- square at light angles to the measuring lines, and bring it successively against the several points in the lines K E and K T, and cut the corresponding measur- ing lines, as shown. Then a line traced through these points, as indicated by K 3 B 2 and K 3 T 2 , will be the pattern of the piece required. For the side of the keystone, KLSR becomes the face of a molding, of which A B is the profile and K E the miter line at one side, and L M and P S the miter lines at the other. From this point forward the problem is, in principle, the same as Problem 10. For convenience, and to avoid confusion, it is best to asain make use of the same set of lines instituted in the first part of the demonstration. Therefore, lay off the stretchout A 1 B l equal to A B, putting into it all the points occurring in A B, through which draw measur- ing lines in the usual manner. Place the J-square at right angles to these measuring lines, and, bringing it Successively against the points in the line Iv E, and likewise against L M and P S of the back, cut corre- sponding measuring lines, as shown. Then a line traced through these points of intersection, as shown by W M 1 L 1 K 4 E 2 S 1 P 1 O 1 , will be the outline of the required pattern, with the exception of that part lying between 1ST and O 1 , which make a duplicate of N" 0. By examination of the points in A 1 B 1 and the lines drawn through the same and making comparison with the points in A B, it will be seen that in order to locate accurately the position of the profile of the window cap molding MSOP, two additional points, as shown by a; 1 and?/ 1 , have been introduced, corresponding to x and y, the points of intersection between the extreme lines of the cap molding itself and the side of the keystone A B, as shown in the elevation by the curved lines of that molding. In practice it is frequently necessary to introduce extra points in operations of this character. 122 The New Metal Worker Pattern Book. PROBLEM 27. The Pattern of a Square Shaft to Fit Against a Sphere. In Fig. 305, let H A A' K be the elevation of a square shaft, one end of which is required to fit against the ball D F E. Draw the center line FL, upon which locate the center of the ball G. Continue the sides of the shaft across the line of the circumference of the ball indefinitely. From the points of intersection be- tween the sides of the shaft and the circumference of the ball, A or A', draw a line at right angles to the sides of the shaft, across the ball, cutting the center line, as shown at B. Set the dividers to G B as radius, and from G as center, describe the arc C C, cutting the sides in the points C and C. Then HCC'K will be the pattern of one side of a square shaft to fit against the given ball. Fig. S05. The Pattern of a Square Shaft to Fit Against a Sphere PROBLEM 28. To Describe the Pattern of an Octagon Shaft to Fit Against a Ball. Let H F K in Fig. 306 be the given ball, of which G is the center. Let D" C C 3 D 3 E represent a plan of the octagon shaft which is required to fit against the ball. Draw this plan in line with the center of the ball, as indicated by F E. From the angles of the plan project lines upward, cutting the circle and con- stituting the elevation of the shaft. From the point A or A 1 , where the side in profile cuts the circle, draw a line at right angles to the center line of the ball F E, cutting it in the point B, as shown. Through B, from the center G by which the circle of the ball was struck, describe an arc, cutting the two lines drawn from the inner angles C 2 C 3 of the plan, as shown at C and C 1 . Then MCC'N will be the pattern of one side of an octagon shaft mitering against the given ball H F K. If it be desired to complete the eleva- tion of the shaft meeting the ball, it may be done by carrying lines from C and C horizontally until they meet the outer line of the shaft in the points D and D 1 . Connect C 1 and D 1 , also C and D, by a curved line, the lowest point in which shall touch the hori- zontal line drawn through B. Then the broken line D C C D 1 will be the miter line in elevation formed by the junction of the octagonal shaft with the ball. Fig. S06.—The Pattern of an Octagon Shaft to Fit Against a Ball. Pattern Problems. 123 PROBLEM 29. The Patterns of an Octagonal Shaft, the Profile of Which is Curved, Fitting over the Ridge of a Root. In Fig. 307 is shown the elevation and plan of the shaft of a finial of the design shown in Fig. 30S. The shaft is octagon throughout, and if it were designed to stand upon a level surface, the method of obtaining its patterns would be the same in all respects as that de- F Gr E of the plan, into any number of parts in the usual manner, and from these points carry lines verti- cally crossing the miter lines Gr E and G F. From the center Gr draw E' M' at right angles to E F, upon which line lay off a stretchout of the profile J L, drawing measuring lines through the points. Place the T-square, parallel to the stretchout line, and, bringing it successively against the points in G E and G F, cut corresponding meas- uring lines, as shown, and Fig. 307.— Plan, Elevation and Patterns. The Patterns of an Octagonal Shaft, Curved in Profile, Fitting over a Ridge. scribed in Problem 21. As shown by the line KmK, however, its lower end is designed to fit over the ridge of a roof or gable, to obtain the patterns of which pro- ceed as follows : Construct a plan of the shaft at its largest sec- tion, as shown by A B C D E F, from the center of which draw miter lines, as shown by Gr E and G F. Divide the profile of the shaft J L, corresponding to through the points thus ob- tained trace lines, all as indi- cated in the drawing. This gives the general shape of the pattern for the sides of the shaft. By inspection of the plan and elevation together, it will be seen that to fit the shaft over the roof some of the sections composing it will require different cuts at their lower extremities. Two of the sections will be cut the same as the pattern already described. They correspond to the side marked A B and E F in the plan. Two others, indicated in the plan by CD and H I, will be cut to fit over the ridge of the roof, as shown in the elevation by n m n. The remaining four pieces, shown in plan by B C, D E, F I and A H, will be cut obliquely to fit against the pitch of the roof, as shown by n in the elevation. For the sides C D and H I, shown in the center of the elevation, it will be seen that the line drawn from 1 touches the ridge in the point m, while the line drawn from 3 corresponds to the point at which the side terminates against the pitch of the roof. Therefore, in the pattern draw a line from the center of it, on the measuring line 1, to the sides of it, on the- measuring line 3, all as shown by m 1 n 1 and in u'. Then these are the lines of cut in the pattern corre- sponding to m n and m n of the elevation. By further inspection of the elevation, it will be seen that for the remaining four sides it is necessary to make a cut in the pattern from one side, in a point corresponding to 3 of the profile, to the other, in a point corresponding to 1 of the profile, all as shown by n 0. Taking corre- sponding points, therefore, in the measuring lines of the pattern, draw the lines n' o\ as shown. Then the original pattern, modified by cutting upon these lines, will constitute the pattern for the four octagon sides. 124 The New Metal Worker Pattern Booh. PROBLEM 30. To Construct a Ball in any Number of Pieces, of the Shape of Gores. Draw a circle of a size corresponding to the- re- quired ball, as shown in Fig. 309, which divide, by any of the usual methods employed in the construction of polygons, into the number of parts of which it is desired to construct the ball, in this case twelve, all as shown by E, F, G, H, etc. From the center draw radial lines, R E and R F, etc., representing the joints between the gores, or otherwise the miter lines. If the polygon is inscribed, as shown in the illustration, it will be observed that the joint or miter lines will lie in the surface of the sphere and that therefore the middle of the pieces, as shown at W, C and u\ will fall inside the surface of the sphere a greater or less distance according to the number of gores into which the sphere has been divided, and that therefore it becomes necessary to construct a section through the middle of one of the sides for use as a profile from which to obtain a stretchout. It will be well to distinguish here between absolute accuracy and something that will do practically just as well and save much labor. This profile, if made complete, would have for its width the distance W u\ while its hight or distance through from R to a point opposite would be equal to the diameter of the circle, or twice the distance R II. As one-quarter of this section will answer every pur- pose, it may be constructed with sufficient accuracy as follows : Supposing R E F to be the piece under con- sideration, draw a line parallel to its center line R C conveniently near, as A V, upon which locate the points A and V by projection from C and R, as shown by the dotted lines. From the point V erect the line B V perpendicular to V 1 A, and make B V equal to the radius of the circle, or R V ; then an arc of a circle cutting the points B and A will complete the section. This can be done by taking the radius R U between the points of the compasses and describ- ing an arc from the point V, whose distance from V is equal to the distance u l TJ. To develop the pat- tern divide B A into any convenient number of equal parts, and from the divisions thus obtained carry lines across the section E R F at right angles to a line drawn through its center, and cutting its miter lines, all as shown in R E and R F. Prolong the center line R C, as shown by S T, and on it lay off a stretchout obtained from B A, through the points in which draw measuring lines in the usual manner. Place the T-square parallel to the stretchout line, and, bringing it successively against {he points in the miter lines R E and R F, cut the corresponding measuring lines, as shown. A line traced through these points will give the pattern of a section. If, on laying out the plan of the ball, the polygon had been drawn about the circle, instead of inscribed, as shown in the engraving, it is quite evident that a quarter of Fig. S09. — To Construct a Ball in any Number of Pieces, of the Shape of Gores. the circle would have answered the purpose of a profile. These }3oints, with reference to the profile, are to be observed in determining the size of the ball. In the illustration presented, the ball produced will corre- spond in its miter lines to the diameter of the circle laid down, while if measured on lines drawn through the center of its sections it will be smaller than the circle. The patterns for a ball made up of zones or strips having parallel sides will be found in Section 2 of this chapter (Regular Tapering Forms). Pattern Problems. PROBLEM 31. The Pattern of a Round Pipe to Fit Against a Roof of One Inclination. 125 Fig. SlO—The Pattern of a Round Pipe to Fit Against a Roof of One Inclination. In Fig. 310, let A B be the pitch of the roof and C F D E the profile of the pipe which is to miter against it. Let Gr P H be the elevation of the pipe as required. Draw the profile in line with the eleva- tion, as shown by C F D E, and divide it into any con- venient number of equal parts. Lay off a stretchout in the usual manner, at right angles to and opposite the end of the pipe, as shown by I K, and draw the measuring lines. Place the T-square parallel to the sides of the pipe, and, bringing it successively against the divisions of the profile, cut the pitch line, as shown by A B. Eeverse the T-square, placing it at right angles to the pipe, and, bringing it successively against the points in A B, cut the corresponding measuring lines. A line traced through the points thus obtained, as shown by L M N, will finish the pattern. PROBLEM 32. The Pattern of an Elliptical Pipe to Fit Against a Roof of One Inclination. In Fig. 311, let NCDO be the elevation of an elliptical pipe fitting against a roof, represented by A B. Let E F G Q be the section or profile of the pipe. Draw the profile in convenient proximity to the elevation, as shown, and divide it into any convenient number of equal parts. Place the T-square parallel to the sides of the pipe, and, bringing it against the points in the profile, drop lines cutting the roof line A B, as through the points in it draw measuring lines in the usual manner. Eeverse the J-square, placing it at Fig. SU.—The Pattern of an Elliptical Pipe to Fit Against a Roof of One Inclination. shown. Opposite to the end of the pipe, and at right angles to it, lay off a stretchout, as shown by II I, and right angles to the pipe, and, bringing it successively against the points in A B, cut the corresponding 126 The New Metal Worker Pattern Booh. measuring lines, as indicated. A line traced through these points, as shown by K L M, will be the required pattern. In the illustration the long diameter of the ellipse, or E G, is shown as crossing the roof. The method of procedure would be exactly the same if the pipe were placed in the opposite position — that is, with the short diameter Q F crossing the roof. In such case the profile should be turned so that Q F is across the roof, or parallel to C D, and the elevation duly pro- jected from it. The pipe might with equal facility be placed so that the long diameter should lie at any oblique angle desired. PROBLEM 33. The Pattern of an Octagon Shaft Fitting: Over the Ridge of a Roof. In Fig. 312, let A B C be the section and D II G I E the elevation of an octagon shaft mitering against a roof, represented by the lines F G and G K. Place the section in line with the elevation, as shown, and from the angles drop lines, giving T V and U W of the elevation. Drop the point G back on to the section, thus locating the points 9 and i. Opposite the end of the shaft, and at right angles to it, draw a stretchout line, as shown by S R, and through the points in it draw measuring lines in the usual man- ner. Place the T-square at right angles to the shaft, and, bringing it successively against the points in the G, representing the ridge of the roof, cut the corre- sponding measuring lines. Then a line traced through the points thus obtained, all as shown by P N M L Fig. S12.—The Pattern of an Octagon Shaft Fitting Over the Ridge of a Roof. roof line formed by the intersection with it of the angle lines in the elevation, and also against the point in the engraving, will be the lower end of the pattern required. Pattern Problems. 127 PROBLEM 34 The Pattern of a Round Pipe to Fit Over the Ridge of a Roof. Let A B C in Fisr. 313 be a section of the roof and D S B T E an elevation of the pipe. Draw a profile of the pipe in line, as shown by F G H. Since both inclinations of the roof are to the same angle, Fig. SIS. — The Pattern of a Round Pipe to Fit Over the Ridge of a Roof. both halves of the pattern will be the same. There- fore space off the half of the profile which miters against one slope of the roof, and lay off the stretch- out of the same upon the stretchout line I K, drawn at right angles to the lines of the pipe, which may be duplicated in a reverse order for the other half, as shown. Draw measuring lines through these points in the usual manner. Place the T-square parallel to the sides of the pipe, and, bringing it against the points in the profile, cut the roof line, as shown from B to T. Beverse the T-square, placing it at right angles to the lines of the pipe, and, bringing it successively against the points dropped upon the roof line, cut the corresponding measuring lines. A line traced through the points, as shown by L M N P, will form that end of the pattern which meets the roof. PROBLEM 35. An Octagon Shaft Mitering Upon the Ridge and Hips of a Roof. In Fig. 314 are shown the front and side elevations of a hipped roof, below which are placed plans, each turned so as to correspond with the elevation above it. Before the pattern of the shaft can be developed it will be necessary to obtain a correct elevation of its inter- section with the roof. Therefore, considering the plan Fig. S14.—The Pattern of an Octagon Shaft Fitting Over the Ridge and Hips of a Roof. An octagonal shaft is required to be mitered down upon this roof, so that its center line or axis shall inter- sect the apex of the roof C, as shown upon the plans. of the shaft as the profile of a molding, number all its points in both plans, beginning, for convenience, at the ridge of the roof, and including the points where the 128 The New Metal Worker Pattern Book. oblique sides cross the hips of the roof, as shown by the small figures 1 to 11. The next step is to project lines upward into the elevations from each of these points, continuing them till they intersect the lines of the roof, as shown by the vertical dotted lines. From each of these intersections in either view lines can be projected horizontally to the other view till they in- tersect with lines of corresponding number. Thus the points 9 and 10 cut the line of the hip in the front ele- vation at the point B, which, being carried across to the side view and intersected with lines from points 9 and 10 from the plan below it, give the correct posi- tion of those points in the side view. In like manner the intersection of lines from points 6 and 7 in the side view, with the hip line at D, give the correct hight of those points iu the front view. Points 5 and S, being upon the hips, must appear in the elevations at points where the vertical lines from them cut the hip lines in the elevations. Lines connecting these points (5, 6, 7 and 8, and 8, 9, 10 and 11) will complete the eleva- tions. In case all sides of the roof have the same pitch and the shaft is a regular octagon, all the angles of the shaft except 2 and 11 will intersect the roof at the same hight, in which case it will only be necessary to draw the front view. But should the slope of the front of the roof be different from that of the sides, it will be necessary to follow the course above described. To develop the pattern, draw any horizontal line, as E F, upon which place the stretchout of the octagon shaft obtained from the plan, as shown by the small figures, through which draw the usual measuring lines at right angles to it, and intersect the measuring lines with lines of corresponding numbers drawn horizontally from the intersections in the elevation. A line traced through these intersections, as shown by X Y Z, will be the desired pattern. PROBLEM 36. The Pattern of a Flange to Fit Around a Pipe and Over the Ridge of a Roof. In Fig. 315, let A B G be the section of the roof against which the flange is to fit, and let P S B be the elevation of the pipe required to pass through the flange. Let the flange in size be required to extend from A to G over the ridge B. Since both sides of the roof are of the same pitch, both halves of the opening from the point B will be the same. Therefore, for convenience in obtaining both halves of the pattern at one operation, the line B C may be continued across the pipe toward A 1 , and used in place of B A, the dis- tance from B on either line to the side B being the same. Under these conditions it will be seen that the process of describing the pattern is identical with that in the previous problem. Make B A 1 equal to B A, and proceed in the manner described in the problem just referred to. Divide the profile DEFG into any number of equal parts in the usual manner, and from the points so obtained carry lines vertically to the line A' C, and thence, at right angles to it, indefinitely. Also carry lines in a similar manner from the points A 1 and C. Draw II L parallel to A 1 C. Make H I the width of the required flange, and draw I K parallel to H L. Through that part of the flange in which the center of the required opening is desired to be draw the line A 5 C, crossing the lines drawn from the pro- file. From each side of this line, on the several Fig. S15. — The Pattern of a Flange to Fit Around a Pipe and Over the Ridge of a Roof. Pattern Problems. 129 measuring lines, set off the same distance as shown upon the corresponding lines between D F and D E F, as shown. A line traced through the points thus obtained, as shown by D 1 E 1 F 1 G' 5 will be the required opening to fit the pipe. Through the center, across the flange, draw the line N M, which represents the line of bend corresponding to the ridge B of the section of the roof. PROBLEM 37. The Pattern of a Flange to Fit Around a Pipe and Against a Roof of One Inclination. Let L M, Fig. 316, be the inclination of the roof and P E T S an elevation of the pipe passing through it. N then represents the length of the opening which is to be cut in the flange, the width of which will be the same as the diameter of the pipe. Let A B D C be the size of the flange desired, as it would appear if viewed in plan. Immediately in line with the pipe draw the profile G H I K, putting it in the center of the plan of the flange A B D C, or otherwise, as required. Divide one-half of the profile in the usual manner, and carry lines vertically to the line L M, representing the pitch of the roof, and thence, at right angles to it, indefinitely. Carry points in the same manner from A and B. Draw C D 1 parallel to L M. Make C A' equal to A C, or the width of the required flange, and draw A 1 B' parallel to C 1 D\ Then C A« B 1 D 1 will be the pattern of the required flange. Draw E 1 F 1 through it at a point corresponding to E F of the plan, crossing the lines drawn from the profile. From E 1 F' set off on each side, on each of the measuring lines crossing it, • the width of opening, as measured on corre- sponding lines of the plan, measuring from E F in the plan to the profile. Through the points thus obtained draw a line, which will give the shape of the opening to be cut, all as shown by G' H' V K\ Fig. 315.— The Pattern of a Flange to Fit Around a Pipe and Against a Roof of One Inclination. 130 The New Metal Worker Pattern Book. PROBLEM 38. The Pattern for a Two-Piece Elbow. In Fig. 317, let A C B D be the profile of the pipe in which the elbow is to be made. Draw an elevation of the elbow with the two arms at right angles to each other, one of which is projected directly from the pro- file, as shown by E G I H K F. Draw the diagonal line G K, which represents the joint to be made. Divide the profile into any convenient number of equal parts. Place the T-square parallel to the lines of the arm of the elbow, opposite the end of which the profile has been drawn, and, bringing the blade successively against the several points in the profile, drop corre- sponding points on the miter or joint line K G, as shown by the dotted lines. Opposite the end of the same arm, and at right angles to it, lay off a stretchout line, M N, divided in the usual manner, and through the divisions draw measuring lines, as shown. Place the blade of the T-square at right angles to the same arm of the elbow, or, what is the same, parallel to the stretchout line, and, bringing it successively against the points in K G, cut the corresponding measuring lines, as shown. A line traced through these points, as indicated by E P 0, together with M N, will form the required pattern. Fig. S17.—The Pattern for a Two-Piece Elbow. PROBLEM 39. The Patterns for a Two-Piece Elbow in an Elliptical Pipe.— Two Cases. The only difference to be observed in cutting the patterns for elbows in elliptical pipes, as compared with the same operations in connection with round pipes, lies with the profile or section. The section is to be placed in the same position as shown in the rules for cutting elbows in round pipe, but it is to be turned broad or narrow side to the view, as the requirements of the case may be. In Figs. 318 and 319 are shown elevations and profiles of two right angled two-piece elbows in elliptical pipes. In Fig. 318 the broad side of the ellipse is presented to view, while Fig. 319 shows the narrow side, as indicated by the respective positions of the profiles. Although the results in the two cases are different in consequence of the position of the profiles, the method of procedure is exactly the same. Similar parts in the two drawings have been given the same reference letters and figures, so that the following demonstrations will apply equally well to either : Let A C E F D B be the elevation of the elbow and H G K I its section. Draw C D, the miter line. Divide the profile ia the usual manner, as indicated by the small figures, and by means of the T-square placed parallel to the arm, drop points upon the miter line, as shown. Opposite the Pattern Problems. 131 end of the arm lay off a stretchout, M N, and through the points in it draw the usual measuring lines. points in the miter line, cut the corresponding meas- uring lines. A line traced through these points, Fig MA Fig. 819. .4 Two-Piece Elbow in Elliptical Pipe. Reverse the T-square, placing it at right angles to the arm, and, bringing it in contact with the several as shown by L P 0, will constitute the required miter. PROBLEM 40. The Patterns for a Three-Piece Elbow. In Fig. 320, let E M L I H K N F be the ele- vation of a three-piece elbow. The drawing of a three-piece elbow, at any angle whatever, should be so constructed that the middle section or portion bears the same angle with reference to the two arms. Since the two arms in the present instance are at right angles (90 degrees) to each other, the middle section must therefore be drawn at an angle of 45 degrees to both. Make its diameter the same as that of the two arms, and draw the miter lines M N" and L K. Draw the profile A B C in line with the arm from which the pattern is to be taken, as shown, and divide it into any convenient number of equal parts. Place the blade of the T-square parallel to this arm of the elbow, and, bringing it against the points in the profile, drop cor- responding points upon the miter line L K. At right 1.32 Tlie New Metal Worker Pattern Book. angles to L I draw a stretchout, as E S, through the divisions in which draw measuring lines in the usual manner. Placing the T-square at right angles to L I, and bringing it successively against the points 'in the miter line L K, cut the corresponding measuring lines, drop like divisions upon M N". At right angles to L M lay off a stretchout of the profile A B C, as shown by P 0, through the points in which draw measuring lines in the usual manner. Reversing the position of the set-square so that its long side shall come at right Fig. 320.— A Three-Piece Elbow. as shown. Then the line TUT, traced through the points thus obtained, forms in connection with S R the pattern of an end section. Place the 45-degree set square against the blade of the T-square so that its oblique or long side shall coincide with the lines of the middle section of the elbow, and, bringing it against the points in L K, angles to M L, or, what is the same, parallel to the stretchout line, bringing it successively against the several points in the miter lines M 1ST and L K, and cut the corresponding measuring lines. Then lines traced through these points, as shown by D X Y and G W Z, will be the pattern of the middle section. PROBLEM 41. The Patterns for a Four-Piece Elbow. In constructing the elevation of a four-piece elbow, first draw the profile ABC, from which pro- ject one of the arms of the elbow, as shown by the lines A F and C G, Fig. 321. At right angles to this lay off the other arm of the elbow, MLNI, continuing the lines of each until they intersect. Through the points of intersection draw the diagonal line a d. Establish the point a on this diagonal line at con- Pattern Problems. 133 venience, and from it draw the lines a b and a c at right angles to the two arms of the elbow respectively. From a as center, and with a b as radius, describe the arc bfe c, as shown, which divide into three equal parts, thus obtaining the points / and e. Through / Fig. SSI. — A Four-Piece Elboiv. and e, to the center a, draw the lines / a and e a, which will represent the centers of the middle sec- tions of the elbow, at right angles to which the sides of the same are to be drawn. Through/, and at right angles to fa, draw L K, meeting M L in the point L, and stopping on the line a d at the point K. Through e, and at right angles to e a, draw a line, commenc- ing in the point K and terminating in G where it meets the line E G. In like manner draw the lines of the inner side of the elbow, as shown by F H and II I. Draw the miter or joint lines F G, II K and L I, as shown. For the patterns proceed as fol- lows : Divide the profile into any convenient number of equal parts. Place the T-square parallel to E G, and, bringing the blade against the points in the pro- file, drop corresponding points upon the miter line F G. Change the T-square so that its blade shall be parallel to the lines of the second section of the elbow, and, bringing it against the ooints in F G, cut corre- sponding points on II K. Opposite the end of and at right angles to the lower arm of the elbow, lay off the stretchout line P, as shown, through the divi- sions in which draw the usual measuring lines. Place the T-square at right angles to the arm of the elbow, and, bringing it successively against the points in the miter line F G, cut the corresponding measuring lines. Then a line traced through the points thus obtained, as shown from E to T, will with P constitute the pattern of one of the arms. Produce a e, repre- senting the middle of the second section in the elbow, as shown by Y "W, upon which lay off a stretchout, and through the points in the same draw measuring lines. Placing the T- s q i,iare parallel to a e, or, what is the same, at right angles to the second section of the elbow, bring it against the several points in the miter lines H K and F G, and cut the corresponding measur- ing lines. Then lines traced through the points thus obtained, as shown from X to Z and Y to S, will give the pattern. PROBLEM 42. The Patterns for a Five-Piece Elbow. To construct tne elevation of a five-piece elbow, first draw the profile, as A B C, Fig. 322, from which project one of the arms of the elbow, as shown at the left by E S R D, continuing its lines indefinitely. At right angles to this lay off the other arm, continuing its lines till they intersect those of the horizontal arm, or till their outer lines intersect, as at g. Draw g a at an angle of 45 degrees to either arm, upon which establish the point a with reference to the curve which it is de- sired the elbow shall have, and from it, at right angles to the two arms of the elbow respectively, draw a b and a c. From a as center, with a b as radius, describe the arc bfedc, which divide into four equal parts, thus obtaining the points d, e and/, and draw d a, e a and / a. Then these lines represent center lines of the sev- eral sections of which the elbow is composed, at right angles to which their sides are to be drawn. It may be here remarked that the number of 134 Hie New Metal Worker Pattern Book. center lines made use of in dividing the quarter circle b c represents the number of pieces in the elbow. Therefore, to draw an elevation of an elbow in any uumber of pieces, construct the quadrant abc as above described, then divide I c into such a number of parts that the number of lines drawn to a (including a b and a c) shall equal the number of pieces required. Thus the five lines a b, af, a e, a d and a c are the center lines of the five pieces of which the elbow shown in Fig. 322 is constructed. Although the two extreme lines a b and a c are not, strictly speaking, center lines, their relation to the adjacent miter lines is the same as mat of the other lines radiating from a. Through/, and at right angles to fa, draw V S, joining the side of the arm E S in the point S, and joining a corre- sponding line drawn through e in the point V. In like manner draw the line T R, representing the inner side of the same section. The remaining sections are to be obtained in the same way. As but one section is necessary for use in cutting the patterns, the others may or may not be drawn, all at the option of the pattern cutter. Draw the miter or joint lines S R, V T, etc. Divide the profile (or one-half of it) in the usual manner. Place the T-square parallel to the lines of the arm, and, bringing the blade against the several points in the profile, drop corresponding points upon the miter line S R. Shift the T-square so that the blade shall be parallel to the part V S R T, and trans- fer the points in S R to V T, as shown. For the pat- tern of the arm, at right angles to it lay off a stretch- out of A B C, as shown by F G, through the points in which draw the usual measuring lines. Place the T-square at right angles to the arm, and, bringing it against the points in R S, cut the corresponding meas- uring lines, as shown. Then a line traced through these points, as shown from H to I, will be the pattern. For the pattern of the piece S V T R prolong the line af, as shown by L K, upon which lay off a stretchout, through the points in which draw the measuring lines in the usual manner. Placing the T-square at right angles to S V, or, what is the same, parallel to the stretchout line, bring it against the several points in If / 1 >. 1 \ 1 11 l \ ' . 1 jl 1 \ 1 / Fig. 322 —A Five-Piece Elbow. the lines R S and T V, and cut the corresponding measuring lines. Then lines traced through the points thus obtained, all as shown by 1ST P M, will be the pattern sought. PROBLEM 43. The Patterns for a Pipe Carried Around a Semicircle by Means of Cross Joints. In Fig. 323, let F E D be the semicircle around which a pipe, of which A C B is a section, is to be carried by means of any suitable number of cross joints, in this instance ten. Divide the semicircle F E D into the same number of equal parts as there are to be joints, which, as just stated, is to be ten, all as etc., and draw lines from shown by D, 0, P, R, S, E each point to Z. As there are to be ten joints there must necessarily be eleven pieces, therefore, according to the directions given in the previous problem, the semicircle must be divided into such a number of equal parts that the number of lines radiating from Z Pattern Problems. 135 shall be eleven, all as shown, each line serving as the center line of a piece. From D toward the center Z set off the diameter of the pipe A B, as shown by the point A 1 . From Z as center, with the radius Z A 1 , draw the dotted line representing the inner line of the pipe, and cutting the radial lines previously drawn in the points O 1 , P 1 , etc. Through and O 1 draw lines at right angles to Z and continue them in either direction till they intersect with the lines drawn through P and P 1 on the one side and through D and A 1 on the othex. Each pair of lines is to be drawn at corresponding to the full sections composing the body of the pipe. For the pattern of the end section pro- ceed as follows : Divide the profile A C B in the usual manner into any convenient number of equal parts, and from the points thus obtained carry lines upward at right angles to Z D, cutting T' T. Prolong the line Z D, and upon it place a stretchout from the profile A C B, perpendicular to which draw measur- ing lines in the usual manner. With the T-square placed parallel to Z D, and brought successively against the points in 1" T, cut the measuring lines of Fig. SSS.—A Pipe Carried Around a Semicircle by Means of Cross Joints. right angles to its respective radial or center line. Through the points of intersection draw the lines T T 1 , U U', etc., which will represent the lines of the joints or miters. It will appear by inspection that the point U is equidistant from P and 0, and that U' is also equidis- tant from P 1 and 1 , and that therefore the lines U IP, T T 1 , etc., if continued inward must arrive at the center Z. Thus the joint lines, like the center lines, must radiate from the center of the semicircle. Draw the profile of the pipe A C B directly below and in line with one end of the pipe, all as shown in the engraving. As may be seen by inspection of the diagram, two patterns are required, one corresponding to the half section occurring at the end, and the other corresponding numbers. Then a line traced through the points of intersection thus obtained, as shown by I K L, will be the shape of the miter cut, and G I K L H will be the complete pattern for one of the end pieces. For the pattern of one of the large pieces, as U V V 1 IP, lay off a stretchout of A C B upon its center line extended, as shown by M 1ST, and through the points in it draw measuring lines in the usual man- ner. Place the T-square parallel to U Y and, bringing it against the points in U IT, cut the line V V. Next place the T-square parallel to the stretchout line, and, bringing it against the several points in the miter lines IT 1 U and V V, cut the corresponding meas- uring lines, all as shown, thus completing the pat- tern. 136 The New Metal Worker Pattern Book. PROBLEM 44. The Patterns for an Elbow at Any Angle. Let D F H K L I G E in Fig. 324 be the eleva- tion of a pipe in which elbows are required at special angles. In convenient proximity to and in line with Fig. 324. — An Elbow at Any Angle. one end of the pipe draw a profile, as shown by A B C, which divide in the usual manner. Placing the J-square parallel to the first section of the pipe, and, bringing it against the several points in the profile, drop corresponding points upon F G. Shift the T-square, placing it parallel to the second section, and, bringing it against the several points in F G, drop them upon H I. At right angles to the first section lay off a stretchout of A B C, as shown by T IT, through the points in which draw the customary measuring lines. Placing the J-square at right angles to this section of the pipe, and bringing it against the several points in F G, cut the corresponding measuring lines. Then the line ELS traced through these points will, with the line T U, be the pattern sought. The pattern for the opposite end is to be obtained in like manner, all as shown by M 1ST P, and therefore need not be described in detail. For the pattern of the middle section lay off a stretchout, W Y, at right angles to it, with the cus- tomary measuring lines. Placing the T-square at right angles to the section, bring it successively against the points in G F and I H, and cut the correspond- ing measuring lines, as shown. Then lines traced through these points, as shown by Y X Z Q, will be the pattern sought. The positions of the longi- tudinal joints in the several sections of this elbow, as well as those of all others, are determined by the order in which the measuring lines drawn through the stretchout are numbered. In the present instance the joints are allowed to come on the back of the pipe, or, in other words, upon D F H K, which corresponds to the point 1 in the profile. Hence, in numbering the measuring lines in the several stretch- outs, point I is placed at the commencement and ending, while if it were desired to have the joint in either piece come on the opposite side, or at a point corresponding to 9 of the profile, the stretchout would have commenced and ended with that figure, the Pattern Problems. 13? figure 1 in that case coming, in regular order, where 9 now occurs. The effect of such a change upon any of the patterns here given would, be the same as if they were cut in two upon the line 9 and the two halves were transposed. PROBLEM 45. The Patterns for a Bifurcated Pipe> the Two Arms Being: the Same Diameter as the Main Pipe, and Leaving; It at the Same Angle. In Fig. 325 is shown an elevation of a bifurcated pipe, all arms being of the same diameter. In this problem, as in many others, it becomes necessary to first make a correct drawing of the intersection of the parts showing the miter lines correctly; after which of the miter lines will at once be determined. Thus the intersection of the three bisecting lines at E gives the point at which the miter lines starting from the points P, E and K must meet. In line with the upper end of the pipe draw a Fig. 325. — The Pattern for a Bifurcated Pipe. the method of laying out of the miter patterns is the same as that employed in several other problems immediately preceding this. If, in this case, each arm of the pipe be divided longitudinally into two equal parts, as shown by the center lines, and each half be considered as a separate molding the correct position profile of it, as shown by A C B. A profile will also be needed in one of the oblique arms, a half only being shown at A' C B' on account of the limited space. For the pattern of the upper portion of the pipe, divide the profile A C B into any number of equal spaces, and place the stretchout of the same on 138 The New Metal Worker Pattern Book. any line drawn at right angles to S P, as shown by the continuation of S D to the left, and draw the usual measuring lines. Next drop the points from the profile A C B parallel with S P till they cut the miter line PRE; then placing the T-square at right angles to S P, drop the points from the miter line P E into measuring lines of corresponding num- ber. A line traced through these points of intersection, as shown from E" to P', will give the miter cut on the lower end of the pipe S D E P, one-half of which only is shown in the engraving. The pattern for the piece E F J K is obtained in exactly the same manner, and might be obtained, so far as the half indicated by C B' on profile is concerned, from the original profile, by simply continuing the lines through to the miter line J F, as shown. For simplicity, therefore, the profile A' C B' is divided into the same number of equal parts as the original profile, and a stretchout of it is placed upon any line, as T IT, drawn at right angles to E F. The points are then dropped from the profile both ways, cutting the miter lines KEE and J F ? after which, with the T-square placed parallel to T TJ r they can be dropped into the measuring lines of the stretchout. Lines traced through the points of inter- section -will constitute the required pattern, as shown by K' E' E' R" K" X W V. PROBLEM 46. The Patterns for the Top and Bottom of a "Common" Skylight Bar. In Fig. 326, A B represents a portion of the pro- file of the ridge bar, or of the ventilator forming the top finish of a skylight, against which the upper end of a " common ' ' bar is required to miter ; and C D represents the profile of the curb or finish against which the lower end of the bar miters. The parallel oblique lines connecting the two show the side eleva- tion of the bar whose profile is shown at E F F 1 . As the profile consists of two symmetrical halves, either half, as E F or E F 1 , may be chosen to work from, and as it contains no curved portions it is simply necessary to number all of its points or angles, and then to place a complete stretchout of the same upon any line drawn at right angles to the lines of the molding, as G H, and to draw the usual measuring lines, all as shown. As a properly drawn elevation shows the intersection of the points of the profile with the two miter lines A B and C D 1 , it is only neces- sary to place the T" s q uare parallel to the stretchout lines G H, and bring it successively against the points in A B and C D', and cut corresponding measuring lines, as shown at I J and K L. Straight lines con- necting the points of intersection will complete the pattern, as shown at I J L K. The length of the pattern, which is here shown indefinite, must be determined by a detail drawing, in which the rise M B and the run M D' are conectly given. The patterns for the ' ' jack ' ' bar and for the " hip " bar will be given later among those problems in which the development of the miter line and the J/ Fig. SS6.—The Patterns for a " Common " Skylight Bar. raking of the profile are necessary, with which they are properly classed. Pattern Problems. 139 PROBLEM 47. The Patterns for a T-Joint Between Pipes of the Same Diameters. Let D F G H M I K E in Fig. 327 be the eleva- tion of two pipes of the same size meeting at right B' 4 Fig. S27.—A T-Joint between Pipes of the Same Diameter. angles and forming a T, of which ABCD and A 1 B' C D' are profiles drawn in line with either piece. As the two profiles are alike, and as the end of one piece (D E F K) comes against the side of the other piece (G I M H), both halves of D E F K, B A D and B C D, will miter with one-half, B 1 C D', of the piece G I M H. By projecting the points B and B' from the profiles through their respective elevations the point L is found, which being connected with the points F and K gives the miter lines. Space the profile ABCD into any number of equal parts and lay off the stretch- out N at right angles to the pipe of which ABC Dis the profile, as shown, through the points in which draw the usual measuring lines. Set the T-square at right angles to this pipe, and, bring- ing the blade against the several points on the miter lines, cut the corresponding measuring lines drawn through the stretchout, as indicated by the clotted lines. Then NF'UTWO will be the pattern for the upper piece. As both halves of this piece (dividing now upon the line A C) will be alike only one-half of the profile (A B C) has been divided, but the stretchout is made complete. For the pattern of the other piece, divide its profile into any convenient number of equal parts and lay off the stretchout on the line B T, drawn at right angles to the pipe. Placing the T-square parallel with the pipe drop points upon the miter lines from that portion of the profile (B 1 C D") which comes in line with them ; then place the blade of the T-square at right angles to the pipe, and, bringing it against the several points in the miter lines, cut the corresponding measuring lines, as shown by the dotted lines. A line, X Y Q Z, traced through these points will bound the opening to be cut in the pattern for the lower pipe. From the points 1 in the stretchout draw the lines R P and T S, in length equal to the length of the pipe. Connect P S. Then PETS will be the required pattern. The seam in the pipe may be located as shown in the engraving, or at some other point, at pleasure. 140 The New Metal Worker Pattern Book. PROBLEM 48. The Patterns for a Square Pipe Describing a Twist or Compound Curve. As problems of this nature frequently occur in connection with hot air pipes, grain chutes, etc., this problem is given as embodying principles which can often be made use of. The upper opening of the pipe in this case is required to be in a horizontal plane, while the lower opening is in a vertical position and placed at a given distance below and to one side of the top, the pipe describing a quarter turn when viewed from either the top or the front. To more fully illustrate the nature of the prob- lem, a perspective view of it is shown in Fig. 328, in which the pipe is represented as being contained within a cubical shaped solid. The solid, of which the pipe is represented as forming a part, is shown in outline, the pipe itself being shaded to show its form, while upon the front and lower side of the solid are shown in dotted lines the front elevation and plan of the pipe. Thus G F T C represents the front view of a solid just large enough to contain the pipe, in which A B C D shows the position of the lower opening, and A B E F D C shows the curve of the pipe as seen from the front. Gr H S F is the top of the solid in which the upper opening N P S E is situated. The curve of the pipe in plan has been projected to the lower face of the solid by vertical lines, B L, and others not shown, and is shown by C J K L M D. To state the case simply, then, A B E is the profile of the piece of metal forming the top of the pipe, while DML and C J K are the two miter lines, or the plans of the intersecting surfaces, and C D F is the profile of the lower side of the pipe intersecting the same miter lines. The top and bottom pieces being developed, it is only necessary to reverse the operation and con- sider the lines of the plan DML and C J K as the profiles of the front and back pieces respectively, while ABE and CDF become the miter lines or elevations of the intersecting surfaces. A part of these operations are carried out in detail in Fig. 339, where the elevation and the plan are drawn directly in line with each other; the various points being represented by the same letters in the two illustrations. For the pattern of the top piece divide its profile A B E by any convenient number of points (1, 2, 3, etc.), from which drop lines ver- tically cutting the two miter lines D' M and C J of the plan, as shown (the figures of the plan 2 to 11 have no reference to this part of the operation). Upon B 8, drawn at right angles to the direction of the mold, lay off the stretchout of ABE, through which draw the usual measuring lines. With the J-square placed parallel to B 8 and brought against the several points in the two miter lines cut lines of corresponding num- ber ; lines traced through the points of intersection, as shown by E T and U S, will give the pattern of the top piece. It will be noticed that owing to the contrary relation of the two curves it is necessary to have the points of the profile occur more frequently near B than E, as otherwise they would intersect the miter Fig. 828. — Perspective View of a Pipe Describing a Twist or Compound Curve. line D' M too far apart near D', while they would occur more frequently than is necessary near M. As there is no curve from A to B of the profile, that part of the pattern from B to S will be a duplicate of the plan view, consequently the curve from B to the measuring line drawn from S may be traced from the plan. The development of the pattern for the lower Pattern Problems. 141 side of the pipe is not given, but it would be accom- plished in exactly the same manner as that of the top piece, using CDFas the profile instead of A B E. For the pattern of the front piece of the pipe, divide its profile L M D' by any convenient number the T-square placed parallel to Q 1 and brought against the various points in B E and D F cut corresponding measuring lines. Lines traced through the points of intersection, as shown by Q P and N, will give the required pattern. S 1 2 3 4 5 6 7 Fig. 329. — Patterns for a Pipe Describing a Compound Curve. of points 1, 2, 3, 4, etc., from which drop lines ver- tically, cutting the two miter lines D F and B E, as shown. Upon Q 1, drawn at right angles to the direc- tion of the mold, place the stretchout of L M D', through which draw the usual measuring lines. With The pattern of the back piece not given in the illustration can be developed in exactly the same man- ner as that of the front by using C J K as the profile and proceeding otherwise the same as in the fore- going. 142 The New Metal Worker Pattern Book. PROBLEM 49. The Construction of a Volute for a Capital* It is sometimes desirable in designing capitals of large size to construct the volutes of the same of strips of metal cut and soldered together. The principal characteristic entering into the design of the volute, and that which distinguishes it from an ordinary scroll, consists in a pulling out or raising up of each succes- sive revolution of the scroll beyond the former, thus producing a ram's horn effect. This feature of its de- sign is also frequently embodied in the construction of scrolls used to finish the sides of large brackets or head blocks, such as may be seen by reference to Fig. 87 on page 12. As all volutes, except those of the Ionic order, always occur under the corners of the abacus and project diagonally from the bell of the capital, their forms can only be correctly delineated in a diagonal elevation. In Fig. 330 is shown a diagonal elevation of a portion of the bell and abacus of a capital with the volute. Immediately below the same, DACB shows one-quarter of the plan of the capital, turned to corre- spond with the elevation, in which the various curves of the volute have been carefully projected from the elevation, as shown by the dotted lines. As the pat- tern cutter is dependent upon the drawing of the plan for his miter lines, considerable care must be given to this part of the work. On account of the small scale necessary in drawing Fig. 330, an enlarged view of the plan of the helix of the volute, as seen from below, is shown in Fig. 331, in which the various curves can be followed throughout their course. The volute as here given consists of two side pieces or scrolls, an outside cover or face strip, an in- side cover and two narrow strips to fill the space where the second curve of the scroll projects beyond the first. The outside cover or face strip extends from F of the elevation to G, where it is met by the inside face strip, which begins at H. To obtain the pattern for the in- side cover, divide the profile from H to Gr into any convenient number of equal spaces, and lay off a stretchout of the same upon the center line of the volute in plan, A B, extended toward K, as shown by the nine spaces on tne upper side of the line. Drop lines vertically from each of these points intersecting the upper line of the side of the scroll in plan. Place the T-square parallel to the stretchout line B K, and bringing it successively against the points in the plan, drop lines cutting corresponding lines of the stretch- out. Then a line traced through the points of inter- section, as shown from I to J, wdl give the shape of the side of the strip to cover the space between the points H and Gr of the elevation. A similar course is to be pursued in obtaining the outside cover or strip extending from F to Gr. This stretchout consists of fourteen spaces, and is shown on the lower side of the center line A K, the pattern being shown from L to M. The pattern for the remaining strip consists of a stretchout of seven pieces taken from the profile be- tween G and the termination of the scroll line. Points from this part of the profile are intersected with two miter lines in the plan, one forming the outer line of the strip, or its finish against the more projecting part of the scroll, and the other forming its finish against the lower scroll or inner edge of its first or outer curve. In Fig. 331 the lines showing the projection of the inner part of the volute beyond the outer curve are clearly seen. In the lower half the lines correspond- ing to the points 1 to 7 of the profile are shown by cor- responding numbers. Lines dropped from the points on both these lines to corresponding lines of the stretchout will give the pattern as shown from M to N. By inspection of the drawing it will be seen that the outline of the volute, as given in the elevation, does not represent exactly the "true face" of the scroll. As the variations in the angle of the side of the central part or helix of the scroll are only such as can be produced by the springing of the metal necessary to bring it into shape, no allowance need be made for such variation in cutting the pattern directly from the eleva- tion. Careful measurements of the stem or lower part of the volute, as shown in the plan, however, show that the distances from point 9 to points a and b, if laid off on a line parallel to A B, would reach to points a 2 Pattern Problems. U5 and b\ These points projected back into the elevation locate them in that view at a and b\ Therefore the outline of the back of the stem will have to be ex- tended as shown by the dotted line from F to a % . This and need not be repeated here. The correct outline, from G to b 3 is omitted to avoid confusion with the figures. To avoid confusion of lines in dropping the points from the different parts of the profile to the miter lines PATTERNS Fig. 330,— The Construction of a Volute for a Capital. outline can be accurately obtained, if deemed necessary, by the raking process described in connection with a number of other problems in this section of this chapter, and thence to the stretchout, only the first and last of each series or stretchout have been shown by dotted lines in the drawing. 144 The Neiu Metal Worker Pattern Book. PROBLEM 50. The Pattern for a Pyramidal Flange to Fit Against the Sides of a Round Pipe Which Passes Through Its Apex. A pictorial illustration of the flange fitting against the sides of the pipe, as stated above, is shown in Fig. 832. In Fig. 333 K L M represents the elevation of Ml | III III III III III 1 III 1 III | Fig. S3S. — Pattern for a Pyramidal Flange to Fit Against a Round Pipe. pyramid, and PRTS elevation of the pipe that is to pass through it, A B D C being plan of pipe and pyra- mid. As the pyramid has four sides, each side will miter or fit against one-quarter of the profile of the pipe, as will be seen by reference to the plan. Again, as each side consists of two symmetrical halves, as shown by the dotted line dividing the side B D, one- eighth of the profile of the pipe (as Gr I) is all that need be used in obtaining the pattern. Therefore, divide Gr I into any convenient number of parts and carry ver- tical lines to L M, which represents one side of the pyramid, and then, from these points and the points L and M carry lines at right angles to it indefinitely, as shown. L M in the elevation represents the complete length of one side of the pyramid, as it would be if not cut by the pipe. Lay off on the line from M the length of one side of the base of the pyramid, as B D in the plan, as shown by M M 1 . Bisect M M' at F, from which point draw F E parallel to L M, cutting the line from point L at E. The lines from E to the points M and M 1 would give the pattern of one side of the pyramid if it were not to be cut by the pipe. It simply remains now to measure the width of the pat tern at the various points ofjthe curved portion, which Fig. 832.— Perspective View of Pyramidal Flange. can be done by measuring the distance of each point in the profile Gr I, from the center line of the side B D in plan, and setting off these distances upon lines of corresponding number drawn through the pattern from the line L M, measuring each time from the center line E F. Thus the distance of point 4 from the center line in plan is set off from the center line of the pat- tern each way upon line 4, and coincides with this point as previously established by the lines drawn from E to M and M 1 . The distance of the point 3 from the center line in the plan is set off from the center line of pattern each way upon line 3 of the pattern. Point 2 is established in the same manner. A line traced through the points 4 3 2 12 3 4 completes the pat- tern. Pattern Problems, PROBLEM 51. 145 The Patterns for a Square Pyramid to Fit Against the Sides of an Elliptical Pipe Which Passes Through Its Center, In Fig. 334, A B C D shows the plan of a square pyramid, whose apex, if completed, would be at E. F H I J shows the horizontal section of an elliptical pipe, against the sides of which the sides of the pyra- mid are required to be fitted. From the side A B (or patterns will be necessary, one for A B Gr S to fit against the broad side of the pipe, and another for B G T C to fit against what might be termed the edge or narrow side of the pipe. To obtain the pattern of the side of the pyramid shown by B Gr T D c c 2 Fig. 334. — The Patterns for a Square Pyramid to Fit Against the Sides of an Elliptical Pipe, D C) of the plan is projected a front elevation, in which KLMN shows the broad side of the pipe. To the right another or side elevation is projected, in which the narrow view of the pipe is shown by OPQE. An inspection of the plan will show at once that two (or B E C, if the pyramid were complete), first divide that portion of the profile of the pipe from Gr to H by any convenient number of points, as shown by the small figures, from which, together with B and E, project lines vertically to the elevation above, cut- 146 The New Metal Worker Pattern Book. ting that side in profile as shown from E 1 to B\ At right angles to E 1 B 1 carry lines from each of the points indefinitely, as shown. At any convenient distance •away, cut these lines by any line, as E 3 V 3 , drawn parallel to E 1 B 1 . Upon each of the lines drawn from the points in E 1 B 1 , set off from E 3 V s the distances oxpon lines of corresponding number in the plan meas- ured from E Y. Thus upon line 5 of the pattern set ■off either way from its intersection with the line E 3 V s a length equal to the distance of point 5 of the plan from the line E V. Upon line 4 of the pattern set off distances equal to that of point 4 from E V of the plan, etc. Also make V s C 3 and V 3 B 3 equal to V C and V B of the plan. Lines drawn from C 3 and B 3 toward E 3 will meet the points previously set off on line 5 of the pattern, indicated by T 1 and G 1 , and will constitute the sides or hips of the pattern, and a line traced through the points set off on lines 1 and 5 inclusive will give the shape of that portion of the pattern to fit against the pipe. An exactly similar course is to be pursued in ob- taining the pattern of the side of the pyramid ASGB (or A E B of the complete pyramid), whose profile is shown by B 2 E 2 of the side elevation, showing the nar- row view of the pipe. The pattern is shown at A' B 4 G 3 S 2 , and the operation is clearly indicated by the lines oi projection. If it is desired to complete the elevations by show- ing the lines of intersection of the sides of the pipe with the sides of the pyramid shown respectively in each elevation, as from c to b and e to/, it can be ac- complished as follows : To obtain the line c b, erect lines vertically from points 6, 7 and 8 (not shown), passing through the space between c and b in the front elevation, upon each of which set off the hight of each point as measured upon lines of corresponding number from B 2 C 2 to B 2 E 2 , as shown from B toward e, in the side eleva- tion ; then a line traced through the points thus obtained will give the line c b. In the same manner lines from the points 1,2,3 and 4 can be carried at right angles to B 2 C 2 into the side elevation, upon which to set off hights of corresponding points as measured from A' B' to B' E', as shown between a and b in the front elevation ; then a line traced through the points will give the line ef. PROBLEM 52. The Patterns tor a Rectangular Pipe Intersecting: a Cylinder Obliquely In Fig. 335, let A B C represent the plan of a drum or cylinder, and BEDC the plan of rectangular pipe, the profile of which is shown by F G II I. In the elevation, J K L M represents the drum, NOPQ the rectangular pipe, and K n the angle at which they are to intersect. Draw the end view, or plan, of circular drum in line with the elevation, as shown. Also extend n and P a so a line dropped from point C of plan will cut them, as shown by N and Q. Then n 1ST Q a is the joint between the drum and pfpe, as shown in elevation. For the pattern of rectangular pipe proceed as follows : Divide B C of plan into any convenient number of equal parts, and from these points carry lines horizontally cutting E D. Also from the points in C B drop lines vertically cutting Q P and N 0. On P extended lay off a stretchout of profile F G H I, as shown by I I', transferring the spaces in E D to H G and F I', and through the points in it draw the usual measuring lines, as shown. Place the J-square parallel with the stretchout line 1 1', and, bringing it successively against the points in the miter lines N n Q q, cut the corresponding measuring lines, as indicated by the dotted lines. Lines traced through the points thus obtained, as indicated by ihgfi', will give the desired pattern. It will be observed that I H h i is a duplicate of P Q N, and that GF/^ is also a dupli- cate, only in a reversed position. The points in hg of pattern are derived from Q q, as the points in / i' of pattern are derived from IS!" n. If the size of the work is such as to render it inconvenient to drop points from the elevation to the pattern by means of the T- square, the stretchout line I I' can be drawn where convenient, the usual measuring lines erected and the distances from P to points in 1ST n and Q q transferred by means of the dividers to lines of similar number drawn from the stretchout line. For the pattern or shape of opening in drum, pro- ceed as follows : On L M extended, as E U, lay off a Pattern Problems. 147 stretchout of B C of plan, and from the points thus ob- tained erect the usual measuring lines, as shown. Place ing lines of corresponding number. Through the points thus obtained trace the lines V W and Y X ; PLAN Fig. SS5.— Patterns for Rectangular Pipe Intersecting a Cylinder Obliquely. l i< the T-square parallel with M L, and, bringing it suc- cessively against the points 1ST n and Q q, cut measur- then V W X Y will be the shape of the required open- ing; in the side of the drum. PROBLEM 53. The Pattern lor the Intermediate Piece of a Double Elbow Joining: Two Other Pieces Not Lying- in the Same Plane. In Fig. 336 is shown a front and side view of a somewhat complicated arrangement of elbows such as sometimes occurs when pipes have to be carried around beams or through limited openings. An inspection of the drawing will show that once the correct angle of the different elbows is ascertained the development of the miters will be quite simple, and is the same as those occurring in several of the problems preceding 148 Tlxe New Metal Worker Pattern Book. this. The lower section of the pipe rises vertically to the first elbow, B, from which it must be carried up- ward a distance equal to C M, to the left a distance equal to B M, as shown in the front view, and back a distance equal to o C, as shown by the side view. methods employed in drawing the two views shown in Fig. 336 will be of assistance to the pattern cutter. According to the principles of projection each indi- vidual point must appear at the same hight in both ele- vations, and at the same distance right or left and for- FRONT VIEW SIDE VIEW Fig. 330.— Elevations of Double Elbow. D K i \ 1C Fig. 338.— Diagram Used in Obtaining Correct Side View of Upper Eibow, Fig. 337.— Correct Side View of Lower Elbow. 1 2 3 Fig. 340.— Method of Obtaining the Pattern of Middle Portion in One Piece. Fig. 339.— Correct Side View of Upper Elbow. The Pattern for the Intermediate Piece of a Double Elbow Joining Two Other Pieces Nut Lying in the Same Plane. From the elbow C it then rises vertically, as seen in front, but really toward the observer as shown by the side view. The problem then really consists in find- ing the correct angles of the elbows, and becomes a question of draftsma.nship rather than of pattern cut- ting. Some suggestions then with regard to the ward or back, with reference to the center lines of the plan. As front and side views are here required, begin by first placing the given plan in two positions, turning those sides of it to the bottom which corre- spond to the sides required in the elevations, and proceed by erecting the center lines of the differ- Pattern Problems. 149 ent pieces in their proper positions and building the pipe around them, so to speak. The plan being a circle, the different sides can only be indicated by numbering the joints, as will be seen by referring to the plans, point 2 appearing in front in the front elevation, and point 3 appearing in front in the side elevation. The plans having been so arranged and corresponding parts in both given the same number, proceed now to erect the center line of the lower sec- tion, making the hight of the first bend, B, the same in both views, as indicated by the dotted horizontal line. From this point the center line is continued in both views, giving it its proper inclination to the left in the front view, and to the right in the side view, all accord- ing to the specified requirements, thus establishing the point C, making it agree in hight in both views. From this point the pipe appears inclined only in the side view, which means that it leans toward the observer in the front view. Next draw the outlines of the pipe at equal distances from the center line and on either side of it throughout the entire course of the pipe in both views, deriving them from the points of plans 1 and 3 in the front view and 2 and 4 in the side view. Their intersection in the front view will give definitely the positions in the miter of points 1', l 2 , and 3', 3 1 , and in the side view of points 2', 2 3 , and 4', 4 a . As point 3' has been established in the front view, if a line be carried horizontally across till it intersects the line from point 3 of the side view, it will give the hight of point 3' in the miter, as shown in the front view. In the same manner a horizontal line from 1' in front, inter- secting the perpendicular from point 1 in plan of side, will give the true hight of point 1' in the side view. A careful inspection of the dotted lines of Fig. 336 will make the subsequent operations necessary to the com- pletion of the elevations clear to the reader without further explanation. Since neither of the views gives a true side view of the intermediate piece, one must be constructed from the facts now known, so as to get the true angle of the elbow B. By dropping a vertical line from the point C of the front view into the plan it will appear that the horizontal distance between the points C and B would be measured by the line E P of the plan ; but by further reference to the side eleva- tion the position of the point C is found to be to the right of its center line by a distance equal to B C of the plan ; therefore, if this distance be set off on the vertical line from the point E in the plan below the front view, which is indicated by E C, the point C will •determine the true position in the plan of the point C of the elevations, and the distance C P will be its horizontal distance from B. Since, now, its vertical distance can easily be obtained from either front or side elevation, a new diagram can now be easily constructed which shall contain the proper dimensions to obtain a correct side view of this elbow. Proceed, then, to construct diagrams shown in Fig. 337, making C M equal to C M, Fig. 336, M B equal to C P of the plan, Fig. 336 ; a line connecting the points C and B will represent the center line of the intermediate portion of the pipe and give its true relation to the vertical por- tion whose center line is represented by B H, Fig. 337. By drawing the outlines of the pipe at the re- quired distance on either side of the center lines B H and B C, a correct side view of the miter is obtained. Since, as has been referred to above, the tipper portion of the pipe appears vertical in one view and inclined in the other (see Fig. 336), a correct side view of the upper elbow is more difficult to be obtained. While different methods may be devised for obtaining it, the following is perhaps the simplest : As the upper sec- tion of the pipe, as shown by Fig. 336, is of indefinite length, any point may be assumed, as D, from which to take measurement for obtaining the angle of the upper elbow. Since the true length of the line C B of either elevation has already been obtained and given in Fig. 337, and since the true length of the part C D can be derived from the side view of Fig. 336, it is necessary only to obtain the true distance between the points D and B of the elevations to obtain the proper angle at the point C. By dropping a vertical line from the point D to a horizontal line drawn from the point C in the side view, Fig. 336, the horizontal distance be- tween C and D may be obtained. By tranferring this distance, o C, to the plan of the front view, and locat- ing its distance from C, as indicated by D, this point will give the true position of the point D in the plan, and the line D P will give the true horizontal distance between the points D and B. In Fig. 338 let the distance C be equal to the line D P of Fig. 336. At point erect a perpendicular, D, making the dis- tance O D equal to o D of the side elevation, Fig. 336. From the point C drop a perpendicular, C B, making that distance equal to the vertical hight between the points C and B, as measured on line C M of the front view ; a diagonal line connecting the points D and B will readily be seen to give the true distance between the points bearing those letters in Fig. 336 Proceed now to construct the triangle shown in Fig. 339, mak- ing C B equal to C B of Fig. 337. From C as a center, 150 Tlie New Metal Worker Pattern Book. with a radius equal to C D as obtained from the side view in Fig. 336, draw a small arc, which intersect with the arc drawn from the point B, with a radius equal to B D as obtained in Fig. 338 ; this will give the correct angle of the upper elbow at C. A complete view of the miter may be obtained by further adding outlines of the pipe at equal distances on either side of the center lines, and connecting their angles, as shown by the line b f. Having now obtained two correct side views of the two elbows, the problem of obtaining the patterns for the same can be solved by the regular method. To obtain the pattern for the middle portion in one piece further calculations, however, will be re- quired. This, of course, could be obviated by making a slip joint in the middle portion of the pipe, by means of which the two elbows could be made separate, and then simply turned upon each other till the required angle is obtained. But as it might be desirable to make the pattern of the middle jDortion in one piece some means must be employed of ascertaining just how far one elbow would have to be turned upon the other were they made separately. As the seam in pipe con- taining elbows is usually made at either the shortest or the longest point of the miter, it may be easily seen, by an inspection of Fig. 336, that a line from the shortest point, or throat, b of the upper miter of the piece in question, would not meet the longest point, or point a, Fis'. 337, in the miter of the other end, and some means must be devised for obtaining the real position of these points, of which the following is perhaps the simplest : From either of the points D or B, Fig. 339, draw a line through the point b, continuing it to the further side of the triangle, as indicated by the line B X. Lay off the distance D X upon the line D C of the side view, Fig. 336, thereby locating the position of the point X in that view. Aline connecting this point with point B must intersect the miter line 2 2 , 4 = , in this view at the same point which it does in Fig. 339, thereby locating its position just as much as in Fig. 339. This point having been obtained, its equivalent upon the lower miter may be found by means of a line drawn parallel to the center line of the middle portion, intersecting it at the point g, from which point it can be carried vertically to the plan, as shown by Z, where its distance from other points can be measured with accuracy. The position of the point a in Fig. 337 will readily be seen to be at point h in the plan of the front view, Fig. 336. By transferring the point Z from the plan of the side view to the plan of the front view, which can be done by measuring its distance from either of the points 2 or 3, the t'elative position of the points h and Z upon the same circle will be apparent. Fig. 340 shows a diagram, in which a correct side view of the two elbows is shown, giving the proper distance between the points B and C. Considering the lower one to be in its proper and fixed position, the profile is constructed and divided into points for the purpose of obtaining a stretchout and the miter pattern according to the usual method, the stretchout being shown upon the line E F in the profile and point 8 will readily be seen to correspond with point h in the plan of the front view. The posi- tion of the point Z in the same plan can be obtained by measuring its distance from point h and transferring it to Fig. 340, as indicated by M. As the point b of the upper elbow is in relation to the highest point, or a, of the lower elbow as the point M is to the point 8 in the profile, it becomes necessary to place the point S in the stretchout of the upper elbow as far from the point 8 on the stretchout of the lower one as the dis- tance from 8 to M in the profile, which is shown by m in the stretchout. The stretchout of the upper elbow is thus moved, as it were, in its relation to the stretchout of the lower elbow, that portion of it which extends beyond the point 1 at the left end being added to the other so as to make the seam continuous. The points are then dropped from the profile to the two miter lines, and thence into measuring lines of corre- sponding number in the stretchout. Lines traced through the points of intersection, as shown byYPR X, will be the required pattern. The miters for the upper and lower sections would, of course, be inverted duplicates of the adjacent ends of the middle piece. Pattern Problems. 151 PROBLEM 54. A Joint Between Two Pipes of the Same Diameter at Other Than Right Angles. Let L F D E K I H M of Fig. 341 represent the elevation of two pipes of the same diameter meeting at the angle M H I, for which patterns are required. Draw the profile or section A' B 1 C 1 in line with the branch pipe, and the section A B C in line with the main pipe. As hoth pipes are of the same diameter, and the end of one piece comes against the side of the other piece, both halves of the branch pipe (dividing at the point B) will miter with one-half, B D, of the main pipe. By projecting lines through the elevations of each piece from the points B or 4 of their respective profiles the point G is obtained, which, being connected with points F and H, gives the required miter line. Space both the profiles into the same number of equal divisions, com- mencing at the same point in each. For the pattern of the arm proceed as follows : Lay off the stretchout O N opposite the end of the arm and draw the usual meas- uring lines at right angles through it, as shown. Place the J- square at right angles with the arm, or, what is the same, parallel with the stretchout line, and, bringing the blade successively against the points in the miter line F G H, cut the corresponding measuring lines. Through the points thus obtained trace the line PEST, which will form the end of the pattern required. For the pattern of the main pipe proceed as follows : Opposite one end lay off the stretchout, as shown by V Y, and opposite the other end lay off a corresponding line, as shown by U X. Connect U V and X Y. From so many of the points in the stretchout line V Y as represent points in the half of the profile BAD draw the usual measuring lines. With the T-sqaare placed parallel to the mold- ing D I, drop the points from the profile onto the miter line F G H ; then, placing it at right angles to the molding, drop lines from the points in the miter line intersecting the corresponding measuring lines. A line traced through these points of intersection, as F 1 Z H 1 W, will describe the shape required. The position of the seam in both the arm and the main pipe is determined by the manner of numbering the spaces in the stretchout. In the illustration the seam in the arm is located in the shortest part, or at a point corre- sponding to 1 of the profile. Accordingly, in number- XL — MY Fig. 241.— A Joint between Two Pipes of the Same Diameter at Other than Right Angles. ing the divisions of the stretchout, that number is placed first. In like manner the 'seam in the main pip© is located at a point opposite the arm. Therefore, in 152 The New Metal Worker Pattern Book, numbering the spaces in the stretchout commence at 1, which, as will be seen by the profile, represents the part named. If it were desirable to make the seam come on the opposite side of the main pipe from where it has been located — that is, come directly through the opening made to receive the arm — the numbering of the stretchout would have been begun with 7. In that case the opening FWH'Z would appear in two halves, and the shape of the pattern would be as though the pres- ent pattern were cut in two on the line 7 and the two pieces were joined together on lines 1„ By this expla- nation it will be seen that the seams may be located during the operation of describing the pattern wherever desired. It is not necessary, as prescribed at the out- set of this problem, that both profiles should be spaced off exactly alike. Any set of spaces will answer quite as well, provided there be points in each exactly half way between A and B of either profile — that is, where points 4 are now located. They are spaced alike in this case to show that lines dropped from points of the same number in each profile arrive at the same point on the miter line, and that therefore when both pipes are the same diameter and their axes intersect, one profile may be used for the entire operation. Note — In the nineteen problems immediately following, the conditions are such that it will be necessary to obtain the miter line from the data given by the operation of raking before the straight- forward work of laying out the patterns can be begun. However, as certain parts of the work of raking the miter line and of laying out the pattern are common to both operations, the two are usually carried along together, and therefore such points and spaces should be assumed upon the profiles at the out- set as will be required in the final stretchout. PROBLEM 55. To Obtain the Miter Line and Pattern for a Straight Molding Meeting a Curved Molding of Same Profile. 3-4 Fig. 21f2.— -The Miter Line between a Curved and a Straight Molding of the Same Profile, In Fig. 342, let F G J K represent a piece of straight molding joining a curved mold, G H I J, the profiles of the straight and curved molding being the same. To obtain the miter line or line of joint, G J, proceed as follows : Draw the profile in line with the straight molding, as shown by C D E, and divide into any convenient number of parts. From the divi- sions in the profile draw lines parallel to F G in the direction of the miter indefinitely, and also in the opposite direction, cutting the vertical line C E of the profile, as shown by the small figures, which corre- spond in number to the divisions on the profile. From B, the center from which the curved molding is struck, draw the line B A through the molding, as shown. Transfer the hights of the various points of the profile as obtained on the line C E to the line A B, placing the point E at the point o of the intersection of the lower line of the curved molding with the line A B, all as shown by x o. Then, with B as a center, draw arcs from the divisions on the line x o, intersecting lines of corresponding numbers drawn from the profile parallel to the lines of the straight molding. A line traced through these intersections, as shown by G J, will be the required miter line, and, as will be seec, is not a straight line. To obtain the pattern for the Pattern Problems. 153 straight molding, draw the line L N at right angles to it, upon which place the stretchout of the profile C D E, as shown by the small figures. At right angles to the stretchout line L N, and through the points in it, draw the usual measuring lines. With the T-square placed at right angles to K J, bring it successively against the points forming the miter line G J, and cut lines of corresponding number in the stretchout. Then a line traced through these points of intersection will form the miter end of the pattern shown by L M N 0. The methods employed in obtaining the patterns for the curved portions are treated in Problem 127. PROBLEM 56. A T-Joint Between Pipes of Different Diameters. In Fig. 343 it is required to make a joint at right angles between thf smaller pipe D F G E and the larger fig. S43. — A 1-Joint between Pipes of Different Diameters. pipe HKLI. For this purpose both a side and an end view are necessary. As the two pieces forming the T are of different sections this problem really consists of two separate operations, but as certain steps can be used in both operations the following course will be most economical. At a convenient distance from the end of the smaller pipe in each view draw a section of it. Space- these sections into any suitable number of equal parts, commencing at corresponding points in each, and Get- ting off the same number of spaces, all as shown by A B C and A 1 B 1 C. From the points in A B C draw lines down- ward through the body of the large pipe indefinitely. From the points in A 1 B 1 C 1 drop point onto the profile of the large pipe, as shown by the dotted lines. For the pattern of the smaller pipe the requirements are its profile A B 1 C and the line F 1 " G 1 , which is the outline of the surface against which it miters, and therefore its miter line. Therefore, take the stretchout of A 1 B 1 C and lay it off at right angles opposite the end of the pipe, as shown by V W. Draw the measuring lines, as shown. Then, with the T-square set parallel to the stretchout line, and brought succes- sively against the points between F' and G 1 upon the profile of the large pipe, cut corresponding measuring lines, as shown. Then a line traced through these points, as shown from X to Y, will form the end of the pattern. For the pattern of the larger pipe the stretchout is taken from the profile view F 1 G 1 L' and laid off at right angles to the pipe opposite one end, as shown by 1ST P. A corresponding line, M 0, is drawn opposite the other end, and the connecting lines M 1ST and P are drawn, thus completing the boundary of the piece through which an opening must be cut to meet or miter with the end of the smaller pipe. According to the rule given in Chapter V, a profile and a miter line are necessary. The profile F 1 G 1 L 1 has already been stated, but no line has yet been drawn in the elevation 154 TJte New Metal Worker Pattern Booh. of the larger pipe which shows its connection with the smaller pipe. This can only be found by projecting lines from the points dropped upon F' G 1 through the elevation till they intersect with lines previously drawn from the profile A B C, as shown between F and G. F G then constitutes the miter line. For economy's sake, then, the spaces 1 to 4 previously obtained in the profile are duplicated upon the stretchout, as shown, to which are added as many more (4 to 10) as are neces- sary. As the points 1 to 4 have already been dropped upon the miter line in its development it is now only necessary to drop them parallel to the stretchout line into measuring lines of corresponding number, when a line traced through the points of intersection, as shown by E S T U, will give the pattern of the opening required. It may be noticed that the development of the miter line F G is not really necessary in this case, as the points are really dropped from the profile ABC right through the elevation till they intersect the measuring lines. This happens in consequence of the arm or smaller pipe being at right angles to the larger one. Different conditions are shown in Problems 57 and 58 following. PROBLEM 57. The Joint Between Two Pipes of Different Diameters Intersecting at Other Than Right Angles. Let ABC, Fig. 344, be the size of the smaller pipe, and YFZ the size of the larger pipe, and let H L M be the angle at which they are to meet. Draw an elevation of the pipes, as shown byGKIONMLH, placing the profile of the smaller pipe above and in line with it, as shown, also placing a profile of the larger pipe in line with its elevation, as shown.. In this problem the profiles of the moldings or pipes are given, but the line representing their junction must be ob- tained before going ahead. To obtain this miter line, first place a duplicate of the profile of the smaller pipe in position above the end view of the larger pipe, as shown by A 1 B' C, the cen- ters of both being on the same vertical line, C N'„ Divide both profiles of the small pipe into the same number of spaces, commencing at the same point in each. From the points in A B C project lines indefinitely through the elevation of the arm, as shown. From the points in A 1 B 1 C 1 drop lines on to the profile of the large pipe, and from the points there obtained cany lines across to the left, producing them until they intersect corresponding lines in the elevation. A line traced through these several points of intersection gives the miter line K L, from which the points in the two patterns are to be obtained. For the pattern of the small pipe proceed as follows : Opposite the end lay off a stretchout, at right angles to it, as shown by E F. Through the points in it draw the usual measuring lines, as shown. In the developing of the line K L the points have already been dropped upon the miter line. It therefore only remains to carry them into the stretchout, which is done by placing the T-square at Fig. SU.—Tlie Joint between Two Pipes of Different Diameters Intersecting at Other than Right Angles. Pattern Problems. 155 right angles with the pipe, and, bringing it successively against the points in the miter line K L, cut the corre- sponding measuring lines, as shown by the dotted lines. A line traced through the points thus obtained will give the pattern of the end of the arm, as indi- cated. For the pattern of the large pipe proceed as fol- lows : Opposite one end, and at right angles to it, lay off a stretchout line, as shown by PS. In spacing off this stretchout it is best to transfer the spaces from 4 to 4 as they exist, as by so doing measuring lines will result which will correspond with points already exist- ing in the miter line K L, thereby saving labor as in the case of the smaller pipe, and also avoiding con- fusion. The other points in the profile are taken at convenience, simply for stretchout purposes. Draw a corresponding line, P T, opposite the other end, and connect P R and T S. In laying off the stretchout R S, that number is placed first which represents the point at which it is desired the seam shall come. For the shape of the opening in the pattern, draw measur- ing lines from the points 4, 3, 2, 1, 2, 3, 4, as shown, and intersect them by lines dropped from corresponding points in the miter line. Through the points thus ob- tained trace the line TJ V W X, which will represent the shape of the opening required. PROBLEM 58. The Joint Between an Elliptical Pipe and a Round Pipe of Larger Diameter at Other Than Right Angles.— Two Cases. In Fig. 345 J K L M is the side elevation of the round pipe and E F G H that of the elliptical pipe joining the larger pipe at the angle F G J. In the Wj Fig, S45 —The Joint between an Elliptical Pipe and a Round Pipe of Larger Diameter at Other than Right Angles. First Case. The Major Axis of the Elliptical Pipe Crossing the Round Pipe. end elevation T S I shows the profile of the round pipe and UEST the intersection of the elliptical pipe whose profile is shown at A B C D and 1ST P Q, respectively, in the side and end views. From an in- spection of the drawings it will be seen that the side elevation shows the narrow view of the elliptical pipe, while the end elevation shows its broad view, or in other words, that the profile of the elliptical pipe is so placed that its major axis crosses the round or larger pipe. In Fig. 346 the elevations show the same pipes intersecting at the same angle, but with the difference that the profile of the elliptical pipe is so placed that its minor axis crosses the round pipe. The reference letters and figures are the same in the two drawings and the following demonstration will apply equally well to either : By way of getting ready to lay out the miter, it will first be necessary to obtain a correct elevation of the miter line or intersection between the two pipes, as shown, from H to G. To do this divide the two profiles ABCD and N P Q into the same number of equal parts, commencing at the same points in each. Draw lines from the points in N P Q, parallel with U T, cutting T S. In a similar manner draw lines in- definitely from the points in A B C D, parallel with 156 The New Metal Worker Pattern Booh. HE, as shown. From the points in T S draw lines parallel with M J, which produce until corresponding lines from the two profiles intersect. Through the several points of intersection thus obtained draw the right angles with H E, or parallel with V W, and brought successively against the points in the miter line H G, cut corresponding measuring lines. A line traced through the points thus obtained, as shown by w» Fig. $46. — Second Case. The Minor Axis of the Elliptical Pipe Crossing the Round Pipe. miter line H G. For the pattern of E F Gr H proceed as follows : On E F extended, as V W, lay off a stretchout of profile ABCD, through the points in which draw the usual measuring lines at right angles to the stretchout line. With the T-square placed at X Y Z, will give the miter cut required, and VWXY Z shows the entire pattern. The method of obtaining the shape of the open- ing in the round pipe is exactly similar to that de- scribed in the several preceding problems. PROBLEM 59. A T-Joint Between Pipes of Different Diameters, the Axis of the Smaller Pipe Passing to One Side of That of the Larger. The principle here involved and the method of procedure are exactly the same as in Problem 56, but the whole of the profiles must be used instead of the halves, because the two axes or center lines of the pipes do not intersect. In Fig. 347, let A B C be the size of the small pipe and F 1 H 1 M 1 be the size of the large pipe, between which a right-angled joint is to be made, the smaller pipe being set to one side of the axis of the large pipe, as indicated in the end view. Draw an elevation, as shown byDFILMKGE. Place a profile of the small pipe above each, as shown by A B C and A' B' C, both of which divide into the same number of equal parts, commencing at the same point in each. Place the T-square parallel to the small pipe, and, bringing it successively against the points in the profile A 1 B 1 Pattern Problems. 157 C, drop lines cutting the profile of the large pipe, as shown, from F 1 to H' ; and in like manner drop lines from the points in the profile ABC, continuing them through the elevation of the larger pipe indefinitely. For the pattern of the small pipe set off a stretchout --10 -■li --12 _ 13 R Fig. 31,7. — A T-Joint between Pipes of Different Diameters, the Axis of the Smaller Pipe Passing to One Side of that of the Larger. line, V "W, at right angles to and opposite the end of the pipe, and draw the measuring lines, as shown. These measuring lines are to be numbered to corre- spond to the spaces in the profile, but the place of . beginning determines the position of the seam in the pipe. In the illustration given the seam has been located at the shortest part of the pipe, or, in other words, at the line corresponding to the point 10 in the section. Therefore commence numbering the stretchout lines with 10. Place the T-square at right angles to the small pipe, and, bringing the blade suc- cessively against the points in the pro- file of the large pipe from F 1 toH 1 , cut the corresponding measuring lines, as shown. A line traced through the points thus obtained, as shown by X Y Z, will form the end of the required pattern. For the pattern of the large pipe, lay off a stretchout from the profile shown in the end view, beginning the same at whatever point it is desired to locate the seam, which in the present instance will be assumed on a line corresponding to point 13 in the pro- file. After laying off the stretch- out, opposite one end of the pipe, as shown on R, draw a corresponding line opposite the other, as shown by N P, and connect N O and P E, thus completing the outline of the pattern, through which an opening must be cut to miter with the end of the smaller pipe. In spacing the profile of the large pipe, the spaces in that portion against which the small pipe fits are made to correspond to the points obtained by dropping lines from the profile of the small pipe upon it, as shown by 1 to 7 inclusive. This is done in order to furnish points in the stretchout correspond- ing to the lines dropped from the profile A B C, as shown. No other measuring lines than those which represent the portion of the pipe which the small pipe fits against are required in the stretchout. Accord- ingly the lines 1 to 7 inclusive are drawn from R, as shown, and are cut by corresponding lines dropped from ABC. A line traced through the several points of intersection gives the shape ST U, which is the opening in the large pipe. If it be necessary for any purpose to show a correct elevation of the junction be- tween two pipes, the miter line F H G is obtained by c intersecting the lines dropped from ABC with cor- responding lines carried across from the same points obtained on the profile F 1 IT, by dropping from A 1 B 1 C 1 , explained in Problems 56, 57 and 58, and all as shown by the dotted lines. As remarked in Problem 56, this line is not abso- lutely necessary, but is of great advantage in illustrat- ing the nature and principles of the work to be done. 158 Tlie Neiv Metal Worker Pattern Book. PROBLEM 60. A Joint at Other Than Right Angles Between Two Pipes of Different Diameters, the Axis of the Smaller Pipe Being Placed to One Side of That of the Larger One. In Fig. 348, let C B 1 A 1 be the size of the smaller pipe, and D' E 1 I' the size of the larger pipe, between which a joint is required at an angle represented by W F K, the smaller pipe to be placed to the side of the larger. Draw an eleva- tion of the pipes joined, as shown by VDGHIKFW. As in the preced- ing problems, the miter line or line giving a correct elevation of the junction of the pipes must be developed before the actual work of laying out the miter pat- terns can be begun, therefore place a profile or section of the arm in line with it, as shown by C B 1 A', and opposite and in line with the end of the main pipe draw a section of it, as shown by D 1 E 1 F. Directly above this section draw a second profile of the small pipe, as shown by C B A, placing the center of it in the required position relative to the center of- the profile of the large pipe. Divide the two profiles of the small pipe into the same number of equal spaces, commencing at the same point in each. From the divisions in C B 1 A' drop lines parallel to the lines of the arm indefinitely. From the divisions in C B A drop lines until they cut the profile of the large pipe, as shown by the points in the arc D 1 E'. From these points carry lines horizontally to the left, producing them until they intersect the corresponding lines from C B 1 A 1 . A line traced through these points of in- tersection, as shown by D E F, will be the miter line between the two pipes. For the pattern of the arm proceed as follows : Lay off a stretchout at right angles to and opposite the end of the arm, as shown by B P, and through the points in it draw the usual measuring lines. Place the T-square at right angles to the arm, and, bringing it successively against the points already in the miter line, cut the correspond- ing measuring lines. A line traced through these points, as shown by UTS, will form the required pattern. For the pattern of the main pipe draw a stretch- out line opposite one end of it, as shown by M 0, numbering the divisions in it with reference to locat- ing the seam, which can be placed at any point desired. The spaces of the profile between D' and E 1 should be transferred to the stretchout point by point as they occur, as by so doing measuring lines will be Fig. S4S.—A Joint at other than Right Angles betiveen Two Pipes of Different Diameters, the Axis of the Smaller Pipe being Placed to One Side of that of the Larger One. obtained which will correspond to the points already in the miter line. Draw a line corresponding to the Pattern Problems. 159 stretchout line opposite the other end of the pipe, as shown by L N, and connect L M and N 0. Through the points in the stretchout line corresponding to the points between D' and E 1 of the profile draw measuring lines, as shown by 10, 11, 12, 13, 14, 15 and 1. Place the T-square at right angles to the main pipe, and, bring- ing the blade against the points in D E F successively, cut the measuring lines of corresponding number, all as shown by the dotted lines. A line traced through these points of intersection, as shown near the middle of M L 1$ O, will give the shape of the opening to be cut in the pattern of the main pipe. PROBLEM 6i. The Patterns for a Pipe Intersecting: a Four-Piece Elbow Through One of the Miters. In Fig. 349, let A B C D E E' D' C B' A 1 repre- sent the four-pieced elbow in elevation, F G H J its Fig. $49. — Pattern for the Pipe Intersecting an Elbow Through One of the Miters. profile, and KLMN the elevation of the pipe which intersects the elbow through a miter joint. In line with the pipe draw the profile of same, as indicated by P R S. Extend F H of the profile of elbow, upon which as a center line draw another profile of the small pipe, as shown by O 1 P 1 R 1 S 1 . Divide both profiles of the small pipe into the same number of parts, commencing at the same points in each, as S and S 1 . Now parallel to F P 1 of the profile draw lines from the points in O 1 P 1 R 1 S 1 intersecting the profile F G H J, as shown. A profile should properly be drawn in its correct relation to the part of which it is the section. As the part C D D' C is about to be considered first, the pro- file should be placed with its center line F H at right angles to C D ; but as in a regular elbow of any num- ber of pieces the miter lines all bear the same angle with the sides of the adjacent pieces, the profile may for convenience be placed in proper relation to one of the end pieces, after which lines may be carried from it parallel to the side it represents to the miter line, thence from one miter line to another, always keeping parallel to the side, continuing this throughout the entire elbow if necessary. Therefore parallel to D E of the elevation draw lines from the points in G H of the profile, cutting the miter line D' D, and continue these lines parallel to D C and C B. From the points in the profile OPES draw lines parallel with L K intersecting lines of corresponding numbers drawn from G H. A line traced through these intersections will give the miter line K Z 1ST. From the point Z in the miter line carry a line back to the profile of the pipe, as indicated by Z a. This gives, upon the pro- file of the pipe, the point at which the miter line K 1ST crosses the miter line of the elbow C C 1 , so that it can be located upon the stretchout line, where it is marked a 1 . For the pattern of the pipe KLMN proceed as follows : At right angles to K L draw the line M 1 M 2 , upon which lay off the stretchout of P R S, as shown by the small figures, through the points in which, and at right angles to it, draw the 160 Tlie New Metal Worker Pattern Book. usual measuring lines, which, intersect with lines of corresponding numbers drawn at right angles to the line of the pipe L K from the intersections on the miter line KZN. A line traced through the inter- sections thus obtained, as shown by M 1 N 1 K 1 W W, will be the recpuired patternfor the intersecting pipe. To avoid confusion of lines in developing the patterns of the intersected pieces of the elbows a duplicate of those parts, as shown by B C D D' C B', is given in Fig. 350, in which the miter line K Z N is also shown. The profiles FGHJ and O 1 P 1 R 1 S' are presented merely to show the relationship of parts, as the patterns are obtained from the miter line KZN, in connection with the stretchout of as much of the profile as is covered by the intersection. It is not necessary to include in this operation the entire elbow pattern, therefore only such a part of the pattern will be developed as is contained in profile from V to H. For the pattern for that portion of elbow shown in elevation by U Z N or V H of profile, proceed as follows : At right angles to C D of elevation draw the line R S, upon which lay off the stretchout of V H of the profile, as indicated by the small figures, through which draw the usual measuring lines at right angles to it, which intersect with lines of corresponding num- bers drawn from the intersections on the miter line Z N at right angles to C D. Trace a line through the intersections thus obtained, as shown by U 3 Z 3 N 1 . Then will U 3 Z 3 represent the pattern for that part of elbow shown in elevation by U Z, and Z 3 N 1 be the pattern for the cut on the miter line Z N. The pat- tern for the other half of opening shown by N 1 X V 2 S is simply a duplicate of the half just obtained re- versed. Then X N' Z 3 shows the shape to be cut out of what would otherwise be a regular elbow pattern. The point a in the profiles O 1 S 1 and V II is so near the line drawn from the point 4 that separate lines are not shown, and on this account when obtaining the shape of K 1 Z 1 the points 4 and a are shown on the same line. In order to show that the pattern is produced by the regular method — that is, by the intersection of points from the miter line into lines of corresponding- number in the stretchout — it should be noted that the profile and stretchout of the piece already developed is properly designated by the figures 1, 2, 3, a, 5, 6, while that of the piece next to be considered is properly designated by the figures 1, 2, 3, 4a, 5, 6, the point 4 not occurring in the first piece at all, while the points 4 and a both fall upon the same line in the stretch- out of the second piece, all of which is clearly shown. The pattern of the cut on the miter line K Z is obtained in the same manner as for Z N. At right angles to B C draw the line R 1 S 1 , upon which place the stretchout of V H of the profile, as shown. N R // 1^ B' D ELEVATION Fig. 350. — Patterns for the Pieces of an Elbow Intersected by the Pipe. Through the points in the stretchout and at right angles to same draw the usual measuring lines, which intersect with lines of corresponding numbers drawn from the intersections on the miter line K Z, at right angles to B C. Trace a line through the intersections thus obtained, as shown by K 1 Z 1 IT". Then will Z 1 IP represent the pattern for that part of elbow shown in elevation by Z U, and Z 1 K' be the pattern for the cut on the miter line Z K. The pattern for the other half of opening shown by K' X 1 V 1 S 1 can be obtained by duplication. Then will X 1 K 1 Z 1 repre- sent the shape to be cut out of the regular elbow pattern. Pattern Problems. PROBLEM 62. The Pattern for a Gable Molding; Mitering- Agfainst a Molded Pilaster. 16] Let N X V E in Fig. 351 be the elevation of a gable molding of which A B C D is the profile, and K M L be the elevation of a molded pilaster against straight from N to E, as would be the case if the side of the pilaster were perfectly flat and projected further than the gable molding. It will therefore be neces- Fig. 251. — The Pattern for a Oable Molding Mitering Against a Molded Pilaster. which it is required to miter. The profile of the pilaster is shown by J I H in the plan, where a profile of the gable mold A 1 B 1 C D 1 is also shown and so placed as to show the comparative projection of the various points in each. By an inspection of the plan and elevation it will be seen that the miter line or joint between the molding and the pilaster will not be sary to first obtain a correct elevation of the miter, after which the pattern can be obtained in the usual simple manner. To do this divide the profiles in the plan and elevation into the same number of equal parts, com- mencing at the same points in each, as shown by the corresponding figures. From the divisions in the pro- 162 The New Metal Worker Pattern Booh. file in plan carry lines to the left, parallel to H A ! , until they cut the side of the pilaster H I J, as shown. From these intersections drop lines at right angles to H A 1 indefinitely, as shown. From the divisions in the profile in elevation draw lines parallel to N X until they intersect corresponding lines drawn from H I in plan. A line traced through these intersections, as shown by N F E, will be the required miter line, or intersection of the gable molding with the upright pilaster at the angle O 1ST X. Foi the pattern of the gable molding proceed as follows : At right angles to the lines of the gable molding draw the stretchout line A 2 D 2 , upon which place the stretchout of the profile of the gable mold- ing, through which draw the usual measuring lines, which intersect with lines of corresponding number drawn from the points in the miter line N FE at right angles to the lines of the gable molding. A line traced through these intersections, as shown by N G E Q , will be the required pattern. Although the roof strip A B of the gable mold- ing is perfectly straight, points will have to be intro- duced between A and B for the purpose of ascertaining the shape of the cut from X to F, its intersection with the side of pilaster. The simplest method of obtain- ing these points is to derive them from the points be- tween B 1 and C, as shown by 0' to 5' in the plan. They can then be transferred to their proper place in the stretchout, as shown, between A = and B\ By so doing points of like number fall in the same place on the pro- file H I, and the vertical lines dropped therefrom can be intersected with F N for the pattern of the roof strip and with the other lines from F to E for the pattern of the face of the mold, all of which is clearly shown. PROBLEM 63. The Patterns for an Anvil. It frequently occurs that sheet metal reproductions ' of various emblems or tools are desired for use as orna- ments or signs. In the following problem is shown how the various pieces necessary to form an anvil may be obtained. The description, of course, only applies to the several sides, as a representation of the horn can only be obtained by hammering or otherwise stretch- ing the metal. In Fig. 352 is shown a side and end elevation and two plans of the anvil, exclusive of the horn, the plans being duplicates and so placed as to correspond re- spectively with the side and the end views. Before the pattern of the side piece JNBG can be developed the line P Q E S, which is the result of the miter- ing together of the two forms shown by U V W of the plan and Z X T of the end view, must be obtained. Therefore divide the curved portion Z X T of the profile of the side into any convenient number of equal spaces, as shown by the small figures, and from the points thus obtained drop lines vertically cutting W V U', the profile of the gore piece. Transfer the points thus obtained on W V U 1 to¥YU of the other plan, and from these points erect lines vertically through the elevation of the side, and finally intersect them with lines of corresponding number drawn from the points originally assumed in Z T. Then a line traced through the points of intersection, as shown by O P Q E S, will be the required miter line. To obtain the pattern of the side, first lay off a stretchout of the profile Z T, as shown, upon v q, through the points in which draw the usual measuring lines. M M 1 /1 M 1 2 3 i i \ 1 1 1 ELEVA TION i i 1 '! i i 1 '! I n : v' i i i i i i 1 1 ' 1 1 1 1 ! m m' i i i i i i 1 1 1 1 ! 1 1 1 1 ijL -1 1 1 1 1 / 1/ PATTER N FOR ■\ 1 \i 1 / /, FRONT Y r° Xi £ 184 The New Metal Worker Pattern Book. the article, as shown by H L K G. Only the profile H V W L of the elevation is needed for the purpose of considered before the article is constructed. As the projection of each of the sides upon the plan is dift'er- Fig. 873.— The Patterns for an Elliptical Vase Constructed in Twelve Pieces. pattern cutting, but the other lines are desirable in process of designing, in order that the effect may be ent when measured from the center C on lines at right angles to the lines of the sides, it will be necessary Pattern Problems. 185 first to develop the profiles of each of the varying sides from the normal profile II V W L. Therefore, divide II V W L in the usual manner, and from the several points in it drop lines across its corresponding section (No. 1) of the plan. Across the second section in the plan, from the points already obtained in U C, draw lines parallel to O II, the side of it cutting C, and produce them until they meet A C, which is drawn from C at right angles to U produced. Then the points in A C give the jjrojections from which to obtain a profile of the section numbered 2. In like manner continue the points from C across the third section in the plan, parallel to M, the side of it cutting M C, and pro- duce them until they cut C B, which is drawn from C at right angles to M produced. Then C B contains the points requisite in obtaining a profile of the third section. Continue the points in C M across the fourth section, cutting its other miter line C P. From C draw C D at right angles to the side P M of the sec- tion, cutting the lines drawn across section 4. Then upon C D will be found the points necessary to determine the profile of the fourth pattern. Pro- duce the line of the base of the elevation indefinitely, as shown by C C" C 3 , and also the line of the top A' B 2 D 3 . From the several points in the profile H V W L draw lines indefinitely, parallel to the lines just de- scribed and as shown in the diagram. From C, upon the base line produced, set off points corresponding to the points in C A of the plan, making the distance from C in each instance the same as the distance from C in the plan. Number the points to correspond with the numbers given to the points in the profile HTf L, from which they were derived. In like manner from C 2 set off points corresponding to the points in C B of the plan, numbering them as above described. From C 3 set off points corresponding to those in CD of the plan, likewise identifying them by figures in order to facilitate the next operation. From C erect the perpendicular C A 1 ; likewise from C 2 and C 3 erect the perpendiculars C 2 B 2 and C 3 D 3 . From each of the points laid off from C, and also from each of those laid off from C 2 and C 3 , erect a perpendicular, producing it until it meets the horizontal line drawn from the profile H V W L of corresponding number. Then lines traced ; through these several intersections will complete the profiles, as shown. Perpendicular to the side of each section in the plan lay off a stretchout taken from the profile corresponding to it, just described, and through the points in the stretchouts draw measuring lines in the usual manner, all as shown by E F, E 1 F' E 2 F 2 and E 3 F 3 . Place the "]"-scpiare parallel to each of these stretchout lines in turn, and, bringing it against the several points in the miter lines bounding the sections of the plan to which they correspond, cut the measur- ing lines in the usual manner. Then lines traced through the points of intersection thus obtained, all as shown in the diagram, will complete the patterns. PROBLEM 82. The Patterns for a Finial, the Plan of which is an Irr-egular Polygon. In the central portion of Fig. 374 is shown the plan B C D E F G H, upon which it is required to construct a finial, the only other view given being a section through one or the sides, being that numbered 1 on the plan. The section of side ABC, or No. 1, is shown above and in line with the plan of the same, and is marked Profile No. 1, and is a section on the line A M, which is drawn at right angles to B C of the plan. To obtain the pattern of A B C of plan, or No. 1, divide the profile K L in the usual manner, and, with the T-square placed parallel with C B of plan and brought successively against the several points in profile K L, drop lines cutting the miter lines A B and A C. On A M extended, as Al Ml, lay off a stretchout of K L of profile, through the points in which draw the customary measuring lines. Place the T-square parallel to the stretchout line Al Ml, and, brinaino- it against the several points in the miter lines A B and A C, cut corresponding measuring lines. Tracing lines through the points thus obtained, as shown bv 186 The New Metal Worker Pattern Book. Al CI Bl, will give tlie pattern of part of article shown on plan by A B C. at right angles to each — that is, since AN, AO and A P, drawn at right angles respectively to D, D E PROFILE NO. 4 PROFILE NO. 3 PROFILE NO.1 PROFILE NO. 2 Fig. 374.— Pattern for a Finial, the Plan of Which is an Irregular Polygon. Since the point A in the plan is not equidistant from all the sides of the same, when measured on lines and E F, differ in length from each other and from A M a correct section must be obtained for each Pattern Problems. 187 of the other sides before their patterns can be developed. These different sections can be most conveniently obtained at one operation in the following manner : "With the T-square placed parallel with D C, and brought successively against the points in A C, draw lines cutting A D and A N. Then the points in AN can be used to obtain a profile of section No. 2. Also continue the points from A D across the third section of the plan, and parallel with D E, and produce them until they cut A E, also A 0, which is drawn from A at right angles to D O produced. Then A contains the points necessary in obtaining a profile of the third section. Continue the points from A E across the fourth section of the plan, and parallel with E F, cut- ting A P and A F. Then the points in A P can be used to obtain a profile of section No. 4. "While the projection of the several points in each of the new profiles can be obtained respectively from the lines A N, A and A P, the hights of the several points must be the same in all and must be derived from the normal profile K L. Therefore continue J L, which represents a horizontal line of profile No. 1 , in either direction, as shown by L4 L2. From the several points in profile No. 1 draw lines parallel with L4 L2, extending them indefinitely in either direction. At any convenient position on L4 L2 set off points corresponding to the points in A N of the plan, as shown at J2 L2, numbering them to correspond with the points in A N and in the normal profile. From each of the points in J2 L2 erect lines perpendicular to the same, intersecting lines of corresponding number drawn from K L. Then a line traced through the points of intersection, as shown from K2 to L2, will be the cor- rect section on A N of the plan, from which to obtain a stretchout of piece No. 2. The sections of pieces No. 3 and No. 4 are ob- tained in a similar manner from A and A P. J3 L3 is a duplicate of A and J4 34 of A P. Perpen- diculars are erected from each of the points cutting horizontal lines of corresponding number, thus devel- oping K3 L3 and K4 L4. To obtain the pattern of A D C (No. 2) continue A N downward indefinitely, upon which lay off a stretchout of K2 L2, as shown by A2 N2, through the points in which draw the usual measuring lines. Place the J-square parallel with A2 N2, and, bringing it against the several points in A C and A D, cut measuring lines of corresponding numbers. Lines traced through these points, as shown by A2 C2 and by A2 D2, will be the pattern sought. The stretchouts for pieces Nos. 3 and 4 are taken respectively from profiles 3 and 4. A3 03 is the stretchout of K3 L3 and is laid off on a continuation of A 0, while A4 P4 is taken from K4 L4 and is set off on a continuation of A P. The remaining opera- tions are the same as those employed in obtaining the other pieces. PROBLEM 83. Pattern for a Three-Piece Elbow, the Middle Piece Being: a Gore. Let A B C D E F G in Fig. 375 be the elevation of a three-piece elbow to any given angle, as G F E, the middle piece of which, BCH, forms a gore extend- ing around one-half the diameter. The lines H B and H C are drawn parallel respectively to the ends of the two outer pieces, therefore the patterns for the end pieces will be straight from H to C and H to B and mitered from H to F. To obtain the pattern for one of the ends, as F H CDE, divide N K L into any convenient number of equal parts. "With the J-square at right angles to N L, carry lines from the points in N K L, cutting the miter line F H C, as shown. On any line, as E D extended, lay off a stretchout of N K L, as shown by e d, through the points in which draw the usual measuring lines, as shown. With the T-square brought successively against the points in F H C, cut corresponding measuring lines, as shown. A line traced through the points of intersection, as shown bj/h" c, will be the half pattern of end, as represented in elevation by F H C D E, or in profile by N K L. The other half of the pattern can be obtained by dupli- cation. 188 Tire New Metal Worker Pattern Book. Since H C is drawn parallel to E D, the distance H J is less than one-half the diameter of the normal profile, or less than L, therefore it will be necessary before obtaining the pattern of B H C to obtain a cor- rect section on line H J of elevation. To do this first place the T-square parallel with B C and carry lines from the points in H C, cutting H J and II B. ISText draw any line, as K' M' of the section, and erect the perpendicular H' J'. From II', on H' J', set off the spaces in H J of elevation, transferring them point by point. Through the points thus obtained draw lines parallel with K' M', as shown. With the dividers take the distance across K L or L M, on the several lines drawn parallel with K M, and set off the same distance on lines of corresponding number drawn throuo-h H' J'. Thus H' M' and H' K' are the same as K and M. A. line traced through the points thus obtained, as shown by K' J' M', will be the section desired. For the pattern of HBC, lay off on HJ extended, as h h', a stretchout of K' J' M' of section, through which draw the usual measuring lines. With the T-square placed parallel with H J, and brought successively against the points in B H and C H, cut corresponding measuring lines drawn through h h', as indicated by the dotted lines. Lines drawn through these points of intersection, as shown by h b h' c, will be the pattern of the part shown in elevation by B II G. H' SECTION Fig. S75.— Pattern for a Three-Piece Elbow, the Middle Piece Being a Gore. PROBLEM 84. The Patterns of a Tapering Article which is Square at the Base and Octagonal at the Top. A B D C in Fig. 376 shows the plan of the article at the base, IKLMHGFE represents the shape at the top, E 3 H 2 D 2 C 3 is an elevation of one side. In order to obtain the slant night of the octagonal sides it will be necessary to construct a diagonal section or ele- vation. Therefore extend the lines of the base C 3 D 2 and top E 3 H 2 , as shown, to the left, through which draw a vertical line, as B 1 C\ Upon the line of the base set off each way from C 2 a distance equal to A E or E D of the plan. In like manner upon the line of the top, set off from B 1 each way a distance equal to one-half I G. Draw V A' and G' D 1 , thus completing a diagonal section. If it is desired to complete a diagonal eleva- tion, set off E 2 F 2 equal to E F of the plan and draw lines to C 2 , as shown. To obtain the pattern of one of the smaller sides, produce the diagonal line B C, upon which set off the length or stretchout of I 1 A"', as shown by N C, and draw the measuring line E 1 F 1 . By means of the T-square, as indicated by the dotted lines, set off E 1 F' equal to E F of the plan and draw C E 1 and C F 1 . Then E' C F 1 is the pattern of one of the smaller sides Pattern Problems. 189 Fig. 377.— Pattern in One Piece. For the pattern of one of the larger of the article sides, draw R P perpendicular to the side A C, upon which set off P, in length equal to E 3 C 3 of the ele- vation, at right angles to which through and P draw measuring lines. By means of the J-square, as shown by the dotted lines, make A 2 C 4 equal to A C of the plan. In like manner make F E 4 equal to I E of the plan. Connect A 5 F and C 4 E 4 . Then A 2 F E 4 C 4 will be the pattern of one of the larger sides of the article. If for anv reason the pattern is desired to be all in one piece the shapes of the different sides may be laid off adjacent to each other, the large and small sides alternating, all as indicated by i i' a a 1 , Fig. 377. Fig. 376.— Elevations, Plan and Patterns. Tapering Article Which is Square at the Base and Octagonal at the Top. PROBLEM 85 The Patterns of a Finial, the Plan of which is Octagon with Alternate Long and Short Sides. In Fig. 37S, let A L M N P R S T be the ele- vation of the finial corresponding to the plan which is shown immediately below it. The elevation is so drawn as to show the profile of one of the long sides, for the pattern of which proceed in the usual manner. Divide the profile A L M N P into any number of convenient spaces, as shown by the small figures, and from the points thus obtained drop lines across the corresponding section in the plan, cutting the miter lines DEC and D" F C, as shown. A duplicate of the part E C F of the plan is shown below by E 1 C 2 F', and in the demonstration C 2 E 1 and C 2 F 1 are to be consid- ered the same in all respects as C E and C F. The same may be said of the two parts of the stretchout line bearing like letters; the division having been made on account of the extreme length which the pat- tern would have if made in one piece. Perpendicular to D D 2 lay off a stretchout, as shown by G H, through the points in which draw measuring lines in the usual manner. Place the J-square parallel to the stretchout line, and, bringing it against each of the several points in D E C and D 2 F C, cut the corresponding measuring lines. Then a line traced through these points of intersection will be the pattern sought. For the pattern of the short sides a somewhat dif- ferent course is to be pursued. As the distance from C to the line K E is greater than that from C to E F a profile of the piece as it would appear if cut on the line C D must first be obtained. To do this proceed as follows : From the points in C E, dropped from the 190 Tlie New Metal Worker Pattern Book, Fig. 378.— Elevation, Plan and Patterns. The Patterns of a Finial, the Plan of Which is Octagon with Alternate Long and Short Sides. 31+7 4 '6 B' 5 , 7 Fig. 379.— Diagonal Section. profile, carry lines parallel to E K across D, cutting C K, as shown. At any convenient place lay off B 1 P', Fig. 379, in length equal to C D of the plan, on which lay off points corresponding to the points ob- tained in C D, and for convenience in the succeeding operations number them to correspond with the nam- Pattern Problems. 191 bers in the profile from which they are derived. At B 1 erect the perpendicular B' A', equal to B A of the elevation. From the several points in the profile of the elevation draw horizontal lines cutting the central vertical line A B, as shown. Setoff points in A 1 B 1 in Fig. 379 to correspond, and through these points draw horizontal lines, which number for convenience of iden- tification in the following steps. From the several points in B 1 P 1 carry lines vertically, intersecting correspond- ing horizontal lines. Then a line traced through these points, as shown by A 1 L' M' N ! O 1 P\ will be the profile of the short side on the line C D of the plan. After obtaining the profile as here described, for the pattern of the short side proceed as follows : Perpen- dicular to K E of the short side, or on C D extended, lay off a stretchout of the diagonal section A' O 1 of Fig. 379, as shown by C 1 D', through the points in which draw measuring lines in the usual manner. Place the T-square parallel to the stretchout line, and, bring- ing it against the several points in the miter lines D K C and DEC bounding the short side in the plan, cut the corresponding measuring lines. Then a line traced through these points, as shown in the diagram, will be the required pattern. PROBLEM 86. The Pattern for a Gore Piece Forming a Transition from an Octagon to a Square, as at the End of a Chamfer. In Fig. 380, let F F F F represent the plan of the square portion of a shaft and A A A A that of the Pattern Fig. 380.— The Pattern for a Gore Piece Forming the Transition from an Octagon to a Square. octagon portion. Let D P C be the elevation of the gore piece which is required to form the transition be- tween the two shaDes. The outline C D, which repre- sents the intersection of the gore piece with the side of the shaft, may be of any contour whatever at the pleasure of the designer, the method of laying out the pattern being the same no matter what its outline. By reference to the plan it will be seen that the lines of the molding, of which C D shows only the termination, run octogonally, or in the direction of A A. There- fore, before a stretchout of the piece can be obtained a correct profile must be developed on a line at right angles to its lines — that is, on the line E F. To do this proceed as follows : Divide the line C D, as it appears in the elevation, into any convenient number of spaces, as shown by 1, 2, 3, i, etc. From the points thus obtained drop lines down ttpon the side of the plan A F, which should be placed in line below the ele- vation. Continue the lines from the side A F across the corner, as shown, all parallel to A A of the octagon, crossing E F, and number the lines to correspond with the numbers of the points in the elevation from which they were derived. Draw the vertical line G H at a convenient distance from P D, and cut G H by lines drawn at right angles to it from the points in C D, as shown by the connecting dotted lines. G II then may be considered to represent the point F in the plan, or 11 of the numbers on the line E F. From G H, on each of the several lines drawn through it, lay off a distance equal to the space from E to the corre- sponding number in the same plan. Thus lay off from Gr H on line 1 a distance equal to 11 1 on E F, and on line 2 a distance equal to 11 2 of E F, and so on for each of the lines through G H. Then a line traced through these points, as shown by I H, will be the 192 The New Metal Worker Pattern Book. profile of the gore piece, or trie shape of its section when cut by the line E F. Prolong E F, as shown by K L, and lay off on the latter a stretchout of the profile I II, the spaces of which must be taken from point to point as they occur, so as to have points in the stretchout corresponding to the points on the miter lines A F, previously derived from C D. Tnrough the points thus obtained draw the usual measuring lines, as shown. Place the T-square at right angles to the measuring lines, or, what is the same, parallel to E F, and, bringing it against the points in A F and F A, cut the corresponding lines drawn through the stretchout. Lines traced through these points, as shown, will constitute the pattern. PROBLEM 87. The Pattern for a Gore Piece in a Molded Article, Forming a Transition from a Square to an Octagon. In Fig. 381, let A B D C represent the elevation ol an article of which Cr H I J is the half plan at the base and K L M NOP the half plan at the top. A C of the elevation is the normal profile or profile of one of the square sides, and L II and M II of the plan show the miter lines between the square sides and the gore piece. C E and D F, the elevations of the miter lines II M and I N, are shown as part of the design, but are not necessary in cutting the pattern. As only the normal profile, which would be used in cutting the pattern of one of the square sides, is shown in the elevation, the first step will be to obtain from this a profile of the gore piece, or in other words, a section upon its center line, R H of the plan. Divide the profile A C into any convenient number of parts, and from the points obtained drop lines at right angles to A B, cutting the miter line L II in plan, as shown. From the intersections obtained on the miter line L H draw lines parallel to L M, as shown, cutting the other miter line II M, and continue them indefinitely. At any convenient position outside the plan draw the line A 1 A 2 parallel to H R, and draw a duplicate of the profile A C in the same relative position to A 1 A 2 that A G holds to A B, and divide the same into the same spaces as A C, all as shown by A 1 0. From the points in A 1 C draw lines parallel to A 1 A 2 , cutting lines of corresponding number drawn through the plan of the gore piece. A line traced through these intersections, as shown from A 2 to C 2 , will be the profile of the transition piece from which to obtain the stretchout for the pattern. To obtain the pattern proceed as follows : Upon R 1 R 2 , a continuation of H R, place the stretchout of the profile A 2 C 2 , as shown by the small figures, through which draw the measuring lines, as shown. These are now to be intersected by lines drawn from points of corresponding number upon the miter lines H L and H M. Lines traced through the points of intersection, 01 Fig SSI. — The Pattern for a Gore Piece in a Molded Article, harming shown by R T and R S, will give the desired pattern. ] a Transition from a Square to an Octagon. PROFILE OF GORE PIECE. Pattern Problems. PROBLEM 88. 193 The Patterns for a Raking 1 Bracket. This is one of the many instances which calls for special draftsmanship on the part of the pattern cutter. Frequently the architect's drawings give only a detail of a bracket for the level cornice of a building:, while the scale elevations show one or more of the gables to be finished with raking brackets. In such cases the detail of the " level " bracket and the pitch of the roof are the only available facts from which to produce the required bracket. In Fig. 382, let M X or P be drawn at the re- quired angle, with reference to any horizontal line, to represent the pitch of the gable cornice. The first step is to redraw the normal side elevation of the level bracket so that its vertical lines shall be at right angles to the lines of the rake, all as shown at L Q P. Next, at any convenient distance from this draw two vertical lines, as M and N 1 P 1 , the horizontal distance between which shall be the required face width of the bracket. Lines projected parallel to the rake from the various angles in the profile between these vertical lines will complete the front elevation of the raking bracket. The additional lines E G and F H representing the sink in the face, A C showing the depth of the panel in side, and TJ D giving the depth of the sink in the face, will be understood from the drawing. To construct a side view of the raking bracket, or, what is the same thing, the pattern for the side (includ- ing the bottom of the sunken panel and the sink strips U D Z in the face), all hights must be measured upon one of the vertical lines of the face view, as M 0. To avoid confusion, however, and make room for other patterns, another vertical line, X 1 P 2 , will serve as well. Divide the curved portions IT to P of the face of the normal profile into any convenient number of small spaces for use in this and subsequent parts of the oper- ation. From all the points in the profile of face carry lines parallel to the rake through the side view and continue them till they intersect the vertical line X' P\ From the points thus obtained in the line X 1 P 2 carry lines indefinitely horizontally, as indicated. Upon each of the lines so drawn lay off from the line X 1 P 2 a distance or distances equal to the distance or distances upon the corresponding lines drawn across the normal side of the bracket. Through the points thus obtained trace lines, which will give the several shapes in the sides of the brackets corresponding to the shapes shown in the side of the normal bracket. It may be necessary to introduce in the several profiles of the normal bracket other points than those derived from spacing the profile. Use as many such points as may be necessary to deter- mine the position of all points in the side being con- structed. Then X 1 N 2 P 2 will be the pattern of the side of the bracket, and U 2 Z 2 D 2 will be the pattern of the strip forming the sides of the sink shown in the face by EFHG, and b l a 1 d l c 1 will be the shape of the panel in the side of the bracket. For the patterns of the several pieces forming the face of the bracket the profiles are to be found in the normal side view, from which stretchouts can be ob- tained when wanted, and laid out at right angles to the lines of the rake ; while the miter lines of any part are the vertical lines of the face view corresponding to that part of the profile under consideration. For the strip PEGS, forming that part of the face at the side of the sink, lay off a stretchout of its profile U Z at right angles to the lines of the rake, as shown by u* z\ through the points in which the usual measuring lines are drawn. Drop the points from the profile to the miter lines E S and E G ; then, with the T-square placed at right angles to the lines of the rake, and brought successively against the points in E S and E G, the corresponding measuring lines are cut. Then lines traced through these points of intersection, as shown by E 1 S 1 and E' G 3 , form the pattern for that piece. For the piece forming the face of the bracket below the sink, as shown in the elevation by S P 1 Z 1 , pro- ceed in like manner. A stretchout of its profile, as indicated by D P, is laid off at right angles to the lines of the rake, through which the usual measuring lines are drawn. The points in D P are then carried parallel to the rake, cutting the miter lines S and Z' P'. The T-square is then placed at right angles to the lines of the rake, and brought against the several points in the sides S and Z 1 P 1 , by which the corresponding measurina; lines are cut. In like manner it is brought against the points G and H, by which the shape of the part extending up to meet the sink is determined. Then lines traced through these several points of inter- section, as shown by H 3 Z 3 P 3 0' S 2 G 4 , form the pattern for that part of the face of the bracket. The upper part of the face of the Dracket, shown in the face view 194 Tlie New Metal Worker Pattern Booh by N 1 IT' E M, being a flat surface, as indicated in the side view N U, is obtained by pricking directly from the face view of the bracket, no development of it being necessary. To avoid confusion of lines, the sink piece E F H profile, as shown by u' d% is laid off at right angles to the lines of the rake, and through the points in it the usual measuring lines are drawn. The T-square is then placed at right angles to the lines of the rake, and, be- ing brought successively against the points in the sides Fig. 084. — Lower Return of Bracket Head. Fig. SS2. — The Patterns for a Raking Bracket. G is transferred to the right, as shown, by E 1 F 1 H 1 G ! . The profile of it, as indicated in the side view by U D, is divided into any convenient number of spaces, and through the points lines are drawn, cutting the miter lines E 1 G 1 and F 1 H'. The stretchout of this E 1 G 1 and F 1 H', the -corresponding measuring lines are cut. Then lines traced through these points of inter- section, as shown by E 2 G" F 3 H", constitute the pattern of the bottom of the sink. Of the strips bounding the panel of the side in the Pattern Problems. 195 bracket, the piece corresponding to b c in tlie side view, being vertical, is obtained by pricking directly from its elevation in tlie face view of the bracket, A B D 1 C being the shape. For the other straight strip bounding this panel, shown in the side view by a b, the length is laid off equal to a b, while the width is taken from the face view, equal to the space indicated by A B. For the strip representing the irregular part a to c proceed as follows : Divide the profile a d c into any convenient number of parts, from the joints in which carry lines crossing the face view of the same part, as indicated by A B D' C. At right angles to the lines of the rake lay off a stretchout of the profile just named, as indicated by a" c 3 , through the points in which draw the usual measuring lines. Place the T-square at right angles to the lines of rake, and, bringing it against the several points in the line A C and B D', cut the corresponding measuring lines drawn through the stretchout. Then lines traced through the several points of intersection thus formed, as indi- cated by A 1 C 3 and B' D 3 , will be the pattern of the curved strip forming part of the boundary of the panel in the side view of the bracket. Of the three pieces of molding forming the head of the bracket, the profile of the piece across the face is normal, as shown at L N, while that of the two side pieces, or returns, requires to be modified or raked before a square miter with the face piece can be effected. These principles will be further explained in Problems 91 to 94. The first step will be to draw a correct elevation of the head, which includes raking the profiles of the upper and lower returns. Divide the normal profile L N into convenient spaces, and from the points thus obtained carry lines indefinitely parallel to the rake across the top of the face view of the bracket. Draw duplicates of the nor- mal profile, placing them in a vertical position directly above where the new sides are required to be, as shown by n I and k m. Divide these two profiles into the same number of parts employed in dividing the normal profile, and from these points drop lines vertically, intersecting those drawn from L N". Then lines traced through these points of intersection, as shown by L 1 1ST 1 and K M, will be respectively the profiles of the moldings on the upper side and on the lower side of the bracket. Lay off a stretchout of the profile LN at right angles to the line of the rake and through the points in it draw the usual measuring lines. With the blade of the T-square at right angles to the lines of the rake, and brought successively against the several points in the profile N' L 1 and K M, cut the measuring lines drawn through the stretchout. Then lines traced through the points of intersection thus obtained, as shown by L. 3 ISP and K 1 M', will be the shape of the ends of the molding forming the front of the bracket head. Before laying out the pattern for the return mold- ing forming the upper side of the bracket head a cor- rect side elevation of it must be drawn. A duplicate of the profile L 1 1ST 1 is transferred to any convenient place, as shown at 1/ N 4 in Fig. 383, and parallel lines from its angles are extended to ihe right, as shown, making L 3 Q 1 equal to L Q of the side view of the bracket. At Q 1 repeat the outline L 3 N 4 , which represents the intersection of the bracket head with the bed mold of the cornice. L' N 1 of Fig. 382 is then the cor- rect profile and the lines L 3 1ST 4 and Q' X 3 are the miter lines of this return ; however, as both the miter lines are identical with the profile, the stretchout q x may be taken from either one, the other being divided into the same number of spaces as the first, which is easier than dropping the points from one to the other. The T-square may then be placed at right angles to the lines in the molding and brought successively against the points in the lines L 3 1ST 4 and Q 1 X 2 , and the cor- responding measuring lines intersected. Then lines traced through these points, as shown by L 4 N 6 and Q 3 X 3 , will form the pattern. The pattern for the return molding of the head occurring on the lower side of the bracket is obtained in the same manner. A duplicate of the profile K M of the face view of the bracket is drawn at any con- venient place, as shown by K 3 M 3 in Fig. 38-4. The proper length is given to the molding by measuring upon the side view of the bracket, and a duplicate of the profile is drawn at the opposite end. Space the profile K 3 M 3 into any convenient number of parts, as indicated by the small figures, and in like manner di- vide the profile K s M 3 into the same number of parts. At right angles to the line of the molding lay off a stretchout of these profiles, as shown by k 1 in', through which draw the usual measuring lines. With the blade of the T-square at right angles to the lines of the molding, and brought successively against the several points in the profiles K 3 M 3 and K 3 M 3 , cut the corre- sponding measuring lines. Then a line traced through these points of intersection, as shown by K 6 M 5 and K 4 M 4 , will constitute the pattern of the return mold- ing, or the lower side of the bracket. 196 Tlie Neiu Metal Worker Pattern Book. PROBLEM 89. The Pattern for a Raised Panel on the Face of a Raking; Bracket. In the solution of the problem stated above, and which is given in Fig. 385, the first requisite is the design or outline of the side of the normal bracket, as such an outline is really a section through the raking bracket upon a line at right angles to the rake. NST shows the side view of a normal bracket, or the bracket as it would appear in a level cornice, the part from G to H being molded as shown by the shaded profile, which profile, being a section on line a b of the normal bracket, is given complete at J and called the nor- mal profile. The first step is to derive from these factors a front elevation of the molded panel upon the face of the raking bracket. To accomplish this first divide the profile of the panel molding into any con- venient number of equal parts, as shown in the section shaded in the side of the normal bracket, and through these points draw lines parallel to the face of the bracket, producing them until they cut the upper sur- face against which the panel terminates, and in the opposite direction until they meet the vertical surface in the lower part of the bracket against which the panel terminates at the bottom. From the points thus ob- tained in the horizontal surface near the top of the bracket and in the vertical surface near the bottom of the bracket draw lines at right angles to the face, thus transferring the points to the line representing the outer face of the panel, as shown from G to II. These points will be used a little later in develop- ing the view of the panel at right angles to the face. Next, from the points already obtained in the line rep- resenting the vertical surface near the bottom of the bracket carry lines parallel with the rake, extending them across the front elevation of the bracket. In the diagram, to avoid confusion, these lines terminate at the intersections shown from A to B, but in actual work they would be extended across the front eleva- tion, thereby making also the intersections shown from C to D. At any convenient place in line with the front elevation of the raking bracket draw the normal profile, as shown below the elevation, and divide it into spaces corresponding to the spaces used in dividing the profile in the side view. From the points thus obtained carry lines vertically, intersecting those just drawn from the side of the normal bracket across the front elevation. A line traced through the points of intersection gives the outlines shown at A B and C D. These outlines constitute a front elevation of the lower end of the molded panel, or the view as seen from a point exactly in front of the face of the raking bracket when finished and in its proper or final position. The outline or shape of the upper end of the panel would appear as a simple straight line in this view because it miters against a surface which is horizontal from front to back. AECDFE shows the entire front view of the molded panel. This view furnishes the means for the next step, which is to obtain a view at right angles to the face G H, and at the same at right angles to the lines of the rake 1ST 0. To do this, first continue the lines from the normal profile of panel in their vertical course till they intersect the upper line of the panel B F. These lines are omitted through the face of the bracket, the points only being indicated on the line E F. From the points thus established in E F, and from the points derived in the outlines A B and C D, carry lines at right angles to the raking cornice, producing them indefinitely, as shown. At right angles to the raking cornice, at any convenient place, draw the line H 1 and G 1 , setting off on it spaces corresponding to those established in H G, already described. Through the points in H' G 1 draw lines at right angles to it to the left, producing them until they intersect lines al- ready drawn from the outlines A B and C D and the points in the line E F. Through the points of inter- section thus obtained, as indicated by 1 7 in the lower left hand corner, 8 14 in the lower right hand corner, 8, 9, 10, etc., in the upper right hand corner, and 1, 2, 3, 4, etc. , in the upper left hand corner, trace lines, thus completing a view of the panel piece at right angles to its face. The next step to be taken is to develop a true profile of this panel, or in other words, a section at right angles to its lines, from which to obtain a stretchout for the required pattern. To do this, first assume any line, as P 0, at right angles to the lines of the view just obtained as the surface of the panel in the new profile. Upon this line extended, as at K, draw a duplicate of normal profile so that the points 1 and S shall lie in it. Divide the profile K into the same number of spaces as in previous instances, and from these points carry lines through the face view in- tersecting them with lines of corresponding number, as Pattern Problems. 19T Fig. 3S5.—The Pattern for a Raised Panel on the Face of a Raking Bracket 198 Tlie New Metal Worker Pattern Book. shown at L P and Q R. Then LPQE will be the true profile of the moldings along the face of the raking bracket. The student will observe that only half the profile is shown at K, as both halves are alike, one- half will answer all purposes if it be kept in mind while making the intersections by number that the points 1-7 in one profile are 14-8 in the other. At any con- venient place lay off the stretchout of the true profile, as shown to the left by the line L M. Through the points in this line draw the usual measuring lines, as shown. Then, with the blade of the T-square placed parallel with the stretchout line and brought against the several points of intersection at the corners of the " View at Right Angles to the Face," cut correspond- ing measuring lines. Lines traced through the points thus obtained will produce the pattern shape, as shown, PROBLEM 90. The Patterns for a Diagonal Bracket Under Cornice of a Hipped Roof. In Fig. 3S6 is shown a constructive section of the cornice of a hipped roof, under which the bracket L fits against the planceer and over the bed molding C. Fig. 387 shows an inverted plan of the angle of such a cornice, including two normal brackets B and C, and the diagonal bracket D, of which the patterns are re- quired. At A, in line with one arm of the cornice in plan, is also shown a duplicate of the profile of the normal bracket. E F represents the miter line of the planceer over which the diagonal bracket is required to fit. Two distinct operations are necessary in obtaining the patterns of the bracket D, one for the face pieces and the other for the sides. As the bracket is placed exactly over (or more properly speaking under) the miter in the cornice, one-half its width must be drawn on either side of the miter line, as shown in Fig. 387. Each half of its face thus becomes a continuation of the moldings forming the faces of the course of normal brackets of which it is a part. Therefore the normal profile X 8 of the bracket A is the profile to be used, and I Gr and J F form the miter lines for one half the face. The usual method in obtaining the pattern for the face piece would be to divide the profile of A into any convenient number of spaces and lay off a stretchout of the same upon any line drawn at right angles to the direction of the mold — that is, at right angles to I J or G F — after which lines should be dropped from the profile upon the miter lines and thence into the stretch- out. However, as the miter is a square miter, the short method is available ; hence the stretchout line is drawn at right angles to the horizontal line of the ele- vation X X, as shown at H Gr. The usual measuring lines are drawn and intei'sected with lines from points of corresponding number on the profile. Lines traced through the points of intersection, as shown by K M and L N, will give the pattern for half the face. The operation of obtaining or "raking" the pat- tern of the side is exactly similar to that employed in Problem 88, with the difference that while in Problem 88 the side is elongated vertically, in the present in- stance (the cornice remaining horizontal, and the bracket being placed obliquely) it is elongated laterally or horizontally. The operation is also complicated by the addition of a profile at the back edge of the bracket Fig. S86.— Sectional View of the Cornice of a Hipped Roof, Showing Bracket. where it is required to fit over the bed molding of the cornice. To obtain the pattern of the side it is first necessary to ascertain the correct horizontal distances between the various points of the profile. The points already made use of in obtaining the face may be used for this purpose. Therefore, drop lines from each of these points vertically, intersecting the side of the bracket, or, what is the same thing, the center line E F, as shown in the plan, Fig. 387, by 1', 2', 3', etc. The Pattern Problems. 199 profile at the back of the bracket in the elevation must also be divided into a convenient number of spaces, as shown by the small figures, which must also be dropped upon E F, as shown, and numbered correspondingly. transfer the points and spaces from E F. Now from each point in the line E' F', erect lines vertically, in- tersecting lines of corresponding number previously drawn to the right from the elevation. Thus, lines drawn upward from the intersections 1, 2, 3, 4, etc., on the line E' F' intersect with horizontal lines 1, 2, 3, 4, etc., while lines drawn upward from the intersec- tions 1', 2', 3', 4', etc., on the line E' F' intersect with horizontal lines l',2', 3', 4', etc. Lines traced through the points of intersection, as shown by R S P, will be the required pattern of the side. If it be desirable to ascertain the exact ancle to which to bend the edges or flanges of the bracket to fit against the planceerit may be accomplished in the following manner: Extend P of the pa.ttern of the side till it intersects the line from X of the side eleva- Firj, SS7. — Inxertcd Plan of Cornice and Method of Obtaining Patterns. From each of the points in the profile of the elevation carry lines indefinitely to the right, as shown. At any convenient point at the right of the plan, draw another plan of the diagonal bracket, so placed that its sides shall be parallel with the horizontal line X X of the elevation, all as shown, and upon its center line E' F' tion, as shown at Y. Upon the solid line X X in diagonal elevation establish any point, as T. Through the point T and at right angles to Y F draw a line in- tersecting the line Y P at U. As the angle of the plan shown in Fig. 387 is a right angle, construct a right angle, ABC, Fig. 388, 200 Tlie New Metal Worker Pattern Booh. and bisect it, obtaining the miter line B L. Now take the distance from Y to T m diagonal elevation, and place it on the miter line B L in Fig. 388, from B to D. At rignt angles to B L draw a line through the point D, intersecting the sides of the right angle A B Fig. S88.— Diagram for Obtaining Angles for Bending the Flanges. C at E and F. Now take the distance T U in diag- onal elevation and set it off from D toward B, locating the point H. Connect the points E, H and F ; then will the profile E H F in Fig. 388 represent a section across the hip at right angle to its rake and will also be the angle to be used in putting the straight parts of the face together, as shown Dy E' H' F' in Fig. 389. The angle which the sides of the bracket make with the planceer will be the complement of the angle H E D of Fig. 38S and may be obtained as follows : Paral- lel to B L, in Fig. 388, and through the point E, draw Fig. SS9. — Perspective View of Finished Bracket. I K, representing the vertical side of the bracket; then will the angle J E I represent the profile required for bending the flanges on the side of the bracket, the pro- file being shown in position by I' E' J' in Fig. 389. In Fig. 389 is shown a perspective view of the finished bracket as seen from below. PROBLEM 91. To Obtain the Profile of a Horizontal Return, at the Foot of a Gable, Necessary to Miter at Right Angles in Plan With an Inclined Molding: of Normal Profile, and the Miter Patterns of Both. In the elevation B C E D, and plan FGHKLI, of Fig. 390 is presented a set of conditions which necessitate a change of profile in either the horizontal or raking molding, in order to accomplish a miter joint at I H in the plan. In other words, the condi- tions are such that with a given profile, as shown by A', in the raking molding, the profile of the horizontal molding forming the return will require to be modi- fied, as shown by the profile A 2 , in order to form a miter upon the line I H in the plan. The reason for this is easily found. If a vertical line be erected from point 9 in profile A 2 it will be seen that each line emanating from a point in the nor- mal profile A 1 becomes depressed after passing this vertical line, more or less, according as its distance away from this line increases, all in proportion to the amount of rake or incline of the face molding, as shown by the dotted lines. If, on the contrary, the profile A 2 be considered as the normal profile, the pro- file A 1 will have to be changed or "raked," in thi3 case increased in hight, in proportion to the inclina- tion. (These conditions are treated in the succeeding problem.) The vertical hight of the profile of the re- turn may be measured in the side elevation and com- pared with that of the inclined molding by measuring across the latter at right angles to the line B C. In this problem it is assumed that the profile as well as the pitch, or rake, of the cornice B are established and that the profile of the horizontal re- turn is to be modified, or "raked," to suit it. To obtain this profile, first draw the normal profile in. the raking cornice, as shown by A 1 , placing it to corre- spond to the lines of the cornice, as shown. Draw another profile corresponding to it in all parts, directly above or below the foot of the raking cornice, in line with the face of the new profile to be constructed, placing this profile A so that its vertical lines shall cor- respond with the vertical lines of the horizontal cor- Pattern Problems. 201 nice. Divide the profiles A and A 1 into the same number of parts, aud through the points thus obtained draw lines, those from A 1 being parallel to the lines of the raking cornice, and those from A intersecting them vertically. Through these points of intersection of like numbers trace a line, which gives the modified profile, as shown by A 2 . Then A J is the profile of the horizontal return, indi- cated by G II I F in the plan. It is also the elevation of the miter line I H of the plan. Therefore at any convenient point at right angles to the lines of the raking cornice lay off the stretchout M N of the i^rofile A 1 , through the points in which draw measuring lines in the usual manner. Place the T-square at right angles to the lines of the raking cornice, and, bringing it suc- cessively against the points in the profile A 2 , cut the corresponding measuring lines just described. Through the points of intersection trace a line, as shown by OPE. Then OPE will be the shape of the lower end of the raking cornice mitering against the return. For the pattern of the return proceed as follows : Construct a side elevation of the return, as shown by S V IT T, mak- ing the profile V U the same as the profile A" of the elevation. Let the length of the return correspond to the return, as shown in the plan by F I. In the pro- file V U set off points corresponding to the points in the profile A 3 as shown from B to D. At right angles to the elevation of the return lay off a stretchout of V IT, or, what is the same, of the profile A 3 , as shown by W X, through the points in which draw measuring lines in the usual manner. Placing the T-square parallel to this stretchout line, and bringing it success- ively against the points in V IT, cut tne corresponding measuring lines. Then a line traced through these Fig. $90.— To Obtain the Profile of a Horizontal Return at the Foot of a Gable, Necessary to Miter at Right Angles in Plan unth an Inclined Molding of Normal Profile, and the Patterns of Both. points of intersection, as usual, from Y to Z, will be the pattern of the horizontal return. PROBLEM 92. To Obtain the Profile of an Inclined Molding: Necessary to Miter at Right Angles in Plan with a Given Horizontal Return, and the Miter Patterns of Both. The conditions shown in this problem are similar to those in the one just demonstrated. In this, how- ever, the normal profile is given to the horizontal re- turn, and the profile or the raking cornice is modified to correspond with it. To obtain the new profile pro- ceed as follows: Divide the normal profile A", Fig. 391, into any convenient number of parts in the usual manner, and from these points carry lines parallel to 202 The New Metal Worker Pattern Book. the lines of the raking cornice indefinitely. At any convenient point outside of the raking cornice, and at sq uare number of spaces. With the T-square at right angles to the lines of the raking cornice, and brought success- ively against the several points in this profile, cut corresponding lines drawn through the cornice from the profile A 1 . Then a line traced through these points of intersection, as shown by A 3 , will be the profile of the raking cornice. For the pattern of the foot of the raking cornice mitering against the return, take the stretchout of the profile A 3 and lay it off on any line at right angles to the raking cornice, as shown by P 0. Through the points in this stretchout line draw the usual measuring lines, as shown. With the Fig. 391— To Obtain the Profile of an Inclined Mold- ing Necessary to Miter at Right Angles in Plan with a Given Horizontal Return, and the Pat- terns of Both. H K J right angles to its lines, construct a duplicate of the normal profile, as shown by A 3 , which divide into like at right angles to the lines of the raking cor- nice, or parallel to the stretchout line, bring it successively against the points in the pro- file A 1 , which is also an elevation of the miter, and cut the measuring lines drawn through the stretchout P O. Then a line traced through the points of intersection, as shown by B' R 1 , will be the miter pattern of the foot of the raking cornice. For the pattern of the return proceed as follows : Construct an elevation of the return, as shown by F 1 G 1 K 1 H 1 , in di- mensions making it correspond to F G K 11 of the plan. Space the profile A of the re- turn in the same manner as A 1 . At right angles to the lines in the return cornice draw any straight line, as M N on which lay off its stretchout, through the points in which draw measuring lines in the usual manner. Place the T-square at right angles to the lines of the return cornice, and, bringing it successively against the points in the profile A, cut the correspond- ing measuring lines. Through the points of intersec- tion trace a line, as shown by G 3 K\ In like manner draw a line corresponding to F 1 H 1 of the side eleva- tion. Then F 3 G 3 K 3 H 3 will be the pattern of the horizontal return to miter with the raking cornice, as described. PROBLEM 93. To Obtain the Profile of the Horizontal Return at the Top of a Broken Pediment Necessary to Miter with a Given Inclined Molding:, and the Patterns of Both. In Fig. 392, C B D represents a portion of the elevation of what is known as a " broken pediment, ' ' the normal profile of whose cornice is shown at A 1 . With these conditions existing it becomes necessary to obtain new profiles for the returns at both the top and the foot. The method of raking the return at the foot has been described in'Problern 91, and the method of raking the return at the top is exactly the same. If, Pattern Problems. 203 in the designing of the pediment, the normal profile should oe placed in the return at the foot, as is some- times necessary, then the profile of the inclined mold- ing must be first obtained, which in turn must be con- sidered as a normal profile and used as a basis of ob- taining the third profile, that of the return at the top. In Fig. 392, let A 1 be considered as the normal profile of the inclined molding. Divide A 1 into any convenient number of parts in the usual manner, and through these points draw lines parallel to the lines of the cornice indefinitely. At any convenient point out- side of the cornice, and in a vertical line with the point at which the new profile is to be constructed, draw a duplicate of the profile of the raking cornice, as shown by A, which space into the same number of parts as A 1 , already described. From the points in A draw lines vertically, intersecting lines drawn from A 1 . Then a line traced through these several points of intersec- tion, as shown by A", will constitute the profile of the horizontal return at the top and also the miter line as -shown in elevation. If the normal profile were in the horizontal return at the foot of the pediment and the modified profile in the position of A 1 , it would be immaterial whether the normal profile or a duplicate of the modified profile were in the place of A by which to obtain the intersecting lines, as the projection of the points only is to be considered in this opera- tion, and that is the same in both cases. For the pattern of the inclined molding proceed as follows : At right angles to the lines of the raking cornice lay off a stretchout of the profile of the raking cornice A 1 , as shown by F G, through the points in which draw measuring lines in the usual manner. Place the T-square at right angles to the lines of the raking cornice, and, bringing the blade successively against the points in the profile A 2 , which is the miter line in the elevation, cut the corresponding measuring lines, and through these points of intersection trace a line, as shown by G H. Then G- H will be the pat- tern- of the top end of the raking cornice to miter against the horizontal return. For the pattern of the horizontal return the usual method would be to con- struct an elevation of it in a manner similar to that described for the return at the foot of the gable in the preceding demonstrations ; the equivalent of this, how- ever, can be done in a way to save a considerable por- tion of the labor. As the view of the miter line is the same in both the front and the side elevation the pattern may be de- veloped from the front just obtained in the following manner, with the result, however, that the pattern will be reversed : Draw the line K M perpendicular to the Fig. 392. — To Obtain the Profile of the Horrizontal Return on the Top of a Broken Pediment Necessary to Miter with a Given Inclined Molding, and the Patterns of Both. lines of the horizontal return, as it would be if shown in elevation. Upon K M lay off a stretchout of the profile A ! , all as shown by the small figures, and through the points draw the usual measuring lines. With the "["-square parallel to the stretchout line K M 204 The New Metal Worker Pattern Book. bring the blade successively against the points in the profile A', cutting the corresponding measuring lines. Through these points of intersection trace a line, as shown by N L, which will be the pattern of the end of the horizontal return to miter against the gable cornice, as shown. PROBLEM 94. To Obtain the Profile and Patterns of the Returns at the Top and Foot of a Segmental Broken Pediment. The preceding three problems treat of the various miters involved in the construction of angular pedi- ments. In Fig. 393 is shown an elevation of a curved or segmental broken pediment in which the normal profile is placed in the horizontal return at the foot. The profiles for the curved molding and for the return at the top can both be obtained at one operation in the following manner: Divide the normal profile ABC into any convenient number of parts, and from the points thus obtained draw lines at right angles to the horizontal line C F of elevation, as shown. At any convenient point draw G H, at right angles to A G, cutting them. With Q, the point from which the curve of the molding was struck, as center, strike arcs from the points in A B C, extending them in the direction of D indefinitely. From any convenient point in the arc A D, as L, draw a line to the center Q. From L draw L M, at right angles to L Q, upon which, beginning at L, set off the distances contained in H G, as shown by the small figures in L M. From the points of intersection where arcs struck from Q cut L Q draw lines at right angles to L Q. From the points in L M, and at right angles to it, drop lines cutting those of similar number drawn at right angles to L Q. A line traced through these points of inter- section, as shown by M K, will be the profile of curved molding. It will be observed that the points for obtaining the profile are where the perpendiculars dropped from L M intersect the lines drawn at right- angles to L Q, and not where the perpendiculars dropped from L M intersect the arcs. For the profile D E draw N D, parallel to J, or at right angles to N 0, and, starting from D, set off on D N the same points as are in G H. Drop perpen- diculars from these points to the arcs of similar num- bers drawn from A B, when a line traced through the points of intersection will form the desired profile, as show by D E. The normal profile is also drawn above G II and NDatX and Z to show that the same result is obtained by using the points in G H to set off on L M and N D as would be obtained by dropping the points from the profiles. The patterns for the returns would be obtained as described in the previous prob- lems. Fig. S9S.—To Obtain the Profiles and Patterns of the Returns at the Top and Foot of a Segmental Broken Pediment. Problems describing the method of obtaining the pattern for the blank for the curved molding will be found in Section 2 of this chapter. Pattern Problems. PROBLEM 95. From the Profile of a Given Horizontal Molding-, to Obtain the Profile of an Inclined Molding: Necessary to Miter with it at an Octagon Angle in Plan, and the Patterns for Both Arms of the Miter. Another example wherein is required a change of profile in order to produce a miter between the parts is shown in Fie;. 394. In this case the ansrle shown S94.— From the Profile of a Given Horizontal Molding to Obtain the Profile of an Inclined Molding Necessary to Miter with it at an Octa- gon Angle in Plan, and the Patterns for Both Arms of the Miter. in plan between the abutting members is that of an octagon, as indicated by B C D. To produce the modified profile and to describe the patterns proceed as follows: In the side B C draw the normal profile A, as indicated, and in the corresponding side, as shown in elevation by N L K, draw a duplicate profile, as shown by A 1 . Divide both of these profiles into the same num- ber of parts, and from the points in each carry lines parallel to the lines of mold- ing in the respective views, producing the lines drawn from profile A until they meet the miter line C X. From the points thus obtained in C X erect lines vertically until they meet those drawn from profile A 1 , intersecting as shown from to L. Through these points of intersection draw the line O L, which will be the miter line in elevation corresponding to C X of the plan. From the points in L carry lines parallel with the raking molding in the direction of P indefinitely. At any convenient point outside of the raking cornice draw a duplicate of the normal profile, as shown by A 2 , placing its vertical line at right angles to the lines of the raking cornice. Divide the profile A" into the same number of spaces as employed in A and A', and from these points carry lines at right angles to the lines of the raking cornice, intersecting those of corresponding number drawn from the points in L. Trace a line through these intersections, as shown from B to S. Then E S will be the required profile of a raking cornice to miter against a level cornice of the profile A at an angle indicated by BCD in the plan, or an octagon angle: Forthe pattern of. the level cornice, at right angles to the arm B C in the plan lay off a stretchout of the profile A, as shown by E F, through the points in which draw the usual measur- ing line. With the T-square at right angles to B C, bringing the blade suc- cessively against the several points in X C, cut corresponding measuring lines drawn through E F. Then a line traced through these points, as shown from H to G, will be the required pattern of the hori- zontal cornice. In like manner, for the pattern of 206 Tlie New Metal Worker Pattern Booh. the raking cornice, at right angles to its lines lay off a stretchout of the profile E S, as shown by U T, through the points in which draw measuring lines in the usual manner. With the T-square at right angles to the lines of the raking cornice, and brought success- ively against the points in the miter line L, as shown in elevation, cut the corresponding measuring lines. Then a line traced through the points thus obtained, as shown by W V, will be the required pattern for the rakins; cornice. PROBLEM 96. From the Profile of a Given Inclined Molding:, to Establish the Profile of a Horizontal Molding to Mite; with it at an Octagon Angle in Plan, and the Patterns for Both Arms. In Fig. 395, let BCD be the which the two moldings are to join, in elevation, and A or A 1 the nor- mal profile of the raking mol To form a miter between mokliin meeting; under these conditions angJ Fig. S95.—From the Profile of a Given Inclined Mold, to Establish (he Profile of a Horizontal Molding to Miter with it at an Octagon Angle in Plan, and the Patterns for Both Arms. change of profile is required, profile for the horizontal arm To obtain the modified and the miter line in elevation proceed as follows : Draw the normal profile A with its vertical side parallel to the lines in the plan of the arm E X D C, corresponding to the front of the elevation. Draw a dupli- cate of the normal profile in correct position in the elevation, as shown by A 1 . Divide both of these profiles into the same number of parts, and through the points in each draw lines parallel with the plan and with" the elevation respectively, all as indicated by the dotted lines. From the points in the miter line of the plan C E, obtained by the lines drawn from the profile A, carry lines vertically, inter- secting the lines drawn from A 1 . Then a line traced through the inter- sections thus obtained, as shown from N to 0, will be the miter line in ele- vation. From the points in 1ST carry lines horizontally along the arm of the horizontal molding N U Y, as shown. At any convenient point outside of this arm, either above or below it, draw a duplicate of the nor- mal profile, as shown by A 2 , which divide into the same number of parts as before, and from the points carry lines vertically intersecting the lines drawn from N 0, just •described Then a line traced through these points of intersection, as shown by T S, will give the required modified profile. For the patterns of the arm Y 1ST U proceed as follows: At right angles to the same, as shown in plan by "W E C B, lay off on any straight line, as G F, a stretchout of the profile T S, all as shown by the small Pattern Problems. 207 figures V, 2 3 , 3 ! , etc. Through these points draw measuring lines in the usual manner. With the T-square parallel to the stretchout line, and brought against the points of the miter line E C in plan, cut corresponding measuring lines, as indicated by the dotted lines, and through these points of intersection trace a line, as shown by K H. Then K H will be the shape of the end of Y N TJ to miter against the raking molding. It will be easily understood that the points as found upon the line E C are just the same as would be obtained there if the newly obtained profile were drawn into the plan of the arm C B W E and the points were dropped from it to the line E C according to the rule. For the pattern of the raking molding, at right angles to the arm N Z V O in the elevation lay out a stretch- out, L M, from the profile A'. Through the points in this stretchout draw measuring lines in the usual manner. Place the T-square parallel to the stretchout line, and, bringing it against the several points in the miter line in elevation N 0, cut corresponding measur- ing lines, as indicated by the dotted lines. Then a line traced through these points of intersection, as shown by P E, will be the shape of the cut on the arm N Z V to miter against the horizontal molding. PROBLEM 97. The Miter Between the Moldings of Adjacent Gables of Different Pitches upon a Pinnacle with Rectangular Shaft. The problem presented in Figs. 396 and 397 is one occasionally arising in pinnacle work. The figures represent the side and end elevations of a pinnacle which Fig. S96. — Side Elevation of Rectangular Pinnacle, Showing the Miter Between the Moldings of Adjacent Gables. is rectangular, but not square. All of its faces are finished with gables whose moldings miter with each other at the corners, and which are of the same bight in the line of their ridges, as indicated by L M and L 1 M 1 . Whatever profile is given to the molding in one face of such a structure, the profile of the gable in the adjacent face will require some modification in order to form a miter. In Fig. 396 let A be the normal profile of the molding placed in the gable of the side elevation. Before the miter patterns can be developed it will first be necessary to obtain the miter line or joint between the moldings of the adjacent gables as it will appear in the elevation, to accomplish which proceed as fol- lows : Draw a duplicate of A, placing it in a vertical position directly below or above the point at which the two moldings are to meet, as shown by A 1 . Divide both of these profiles into the same number of parts, as indicated by the small figures, and through these points draw lines intersecting in the points from H to K, as shown. Then a line traced through these intersections will be the miter line in elevation. For the pattern of the molding of the side gable lay off at right angles to H M a stretchout of the profile A, as shown by B C, through the points of which draw the usual measuring lines. Place the T-square at right angles to the lines of the molding, or, what is the same, parallel to the stretchout line, and, bringing it against the several points in the miter line H K, cut corresponding meas- uring lines. Then a line traced through these points, as shown by D E, will be the shape of the cut at the foot of the side gable to miter against the adjacent gable. The next step is to obtain the correct profile of the molding on the adjacent gable. H K having been established as the correct elevation of the miter, its 208 Hie New Metal Worker Pattern Book. outline may now be transferred, with its points, to the end elevation of the pinnacle, as shown at H' K 1 , Fig. 397, reversing it, because it appears here at the right side of the gable, whereas it appeared at the left of the other. Draw a duplicate of the normal profile, as shown at A\ placing its vertical lines at right angles to the lines of the gable, and divide it into the same spaces as in the first operation. From these points draw lines at rio-ht angles across the molding, which intersect with DO ^ lines drawn parallel to the molding from the points in the miter line H 1 K 1 . Then a line traced through these points of intersection will form the required modi- fied profile, as shown by W X. For the pattern of the molding of the end gable proceed as follows : At right angles to the lines of the raking cornice lay off a stretchout of the profile "W X, as shown by P E, through the points in which draw measuring lines in the usual manner. With the T-square at right angles to the lines of the raking cornice, bringing it successively against the points in K' H 1 , cut corresponding measuring lines. Then aline traced through these points of intersection, as shown from S tp T, will be the pattern required. Fig. 397.— End Elevation of Rectangular Pinnacle, Showing Same Miter as in Fig. 396. PROBLEM 98. The Miter Between the Moldings of Adjacent Gables of Different Pitches upon an Octagon Pinnacle. This problem differs from the preceding one in that the angle of the plan is octagonal instead of square, but like it requires a change of profile in one of the gables in order to effect a miter. In Figs. 398 and 399 are shown a quarter plan of pinnacle and the elevations of two adjacent gables of different widths but of similar bights. Let A 1 B 1 F 1 G 1 D' of Fig. 398 be a correct elevation and A B C G be a quarter plan of the structure. In that portion of the plan cor- responding to the part of the elevation shown to the front draw the normal profile E, placing its vertical side parallel to the lines of the plan. Divide it into any convenient number of spaces, and through these points draw lines parallel to the lines of the plan, cut- ting C O 1 , the miter line in plan, as shown. In like manner place a duplicate of the normal profile, as shown by E 1 in the elevation. Divide it into the same num- ber of equal parts, and through the points draw lines parallel to the lines of the raking cornice, which pro- duce in the direction of X indefinitely. Bring the T-square against the points in C O 1 , and with it erect vertical lines, cutting the lines drawn from E 1 , as shown from X to 0. Then a line, X 0, traced through these points of intersection will be the miter line in elevation. For the pattern of the miter at the foot of the wide gable or gable shown in elevation proceed as fol- lows : At right angles to the lines of the gable cornice lay off a stretchout of the profile E 1 , as shown by H K, through the points in which draw the usual measuring lines. Placing the T-square at right angles to the lines of the cornice, or, what is the same, parallel to the stretchout line, and bringing it against the several points in X 0, cut corresponding measuring lines. Then a line traced through the points of intersection thus obtained, as shown from L to M, will be the pat- Pattern Problems. 209 tern of tne miter at the foot of the gable shown in ele- vation. For the modified profile of the gable molding Fig. 398.— Quarter Plan and Elevation of Octagon Pinnacle, Show- ing Miter Between Moldings of Adjacent Gables of Different Pitches. upon the narrow side proceed as follows : Draw a cor- rect elevation of the narrow side, reproducing therein the miter line 1ST from Fig. 398 (reversing tne same), as shown by R P in Fig. 399, and through the points, also reproduced from N" 0, cany lines parallel to the lines of the gable cornice indefinitely, as shown. Draw a duplicate of the normal profile at any convenient point outside of the gable cornice, as shown by E% placing its vertical side at right angles to A 2 R, or the lines of the cornice. Divide E 2 into the same number of parts as used in the other profiles, and through the points draw lines at right angles to the lines of the cor- nice, intersecting the lines drawn from P R. Through Fig. 399. — Elevation of Narroiv Side of Octagon Pinnacle, Showing Same Miter as in Fig. 398. these points trace a line, as indicated by E 3 , which will be the modified profile. To lay out the pattern take the stretchout of E 3 and lay it off on any straight line drawn at right angles to the lines of the cornice, as S T, and through the points in it draw the usual measuring lines. Place the T-square at right angles to the lines of the gable cornice, and, bringing it against the points in P R, cut the measuring lines, as indicated by the dotted lines. Then a line traced through these points of intersection, as shown by IT T, will be the pattern for the molding at the foot of the gable on narrow side. 210 Tlie New Metal Worker Pattern Book. PROBLEM 99. The Patterns for a Cold Air Box in which the Inclined Portion Joins the Level Portion Obliquely in Plan. The conditions of the problem are clearly shown in the plan and side elevation of Fig. 400, in which Z B C is the elevation and X C D' Y is the plan of the level portion of a cold air passage joining a furnace just above the floor line. The inclined portion of the air passage or box is required to join the level portion at the angle Z A E of the side elevation, and at the angle Y A' E' when viewed in plan. These conditions are in many respects similar to those given in Problem 95, with the difference, however, that in this case the joint or miter between the level and the inclined por- tions does not appear as a straight line in the plan. It may be here remarked that the solution of this prob- lem is more a matter of drawing than of pattern cutting, as nothing can be more simple than the cutting of a miter between two pieces of rectangular pipe when the required angle between them is known. This problem is capable of two solutions, both of which will be given, leaving the reader to choose which is the more adaptable to his requirements. First Solution. — As above intimated, before the pattern can be developed it will be necessary to 'make careful drawings, in the preparation of which a knowl- edge of the principles of orthographic projection is necessary. (See Chapter III). To proceed, then, with the drawings, first draw a plan and elevation of as much of the furnace as is necessary to show its connection with the cold air box, placing each part of the plan directly under its corre- sponding part in the elevation, so that as soon as any new point is determined in either of the views its posi- tion can be located in the other by means of a perpen- dicular line dropped from one view to the other. Upon the plan set off the width of the box b and draw parallel lines from the side of the furnace body to the right indefinitely, and upon the elevation set off its hight, a, from the floor line up, and draw A Z. A vertical line from the point X of the plan will give the point Z upon the elevation, or, in other words, show how far the curve of the furnace body cuts into the top and bottom surfaces of the cold air box. Next, upon the elevation locate the point A the required distance from the side of the body according to specification and find its position in the plan by means of a vertical line, as shown. From the point A in both views lines must be drawn to represent the angle or deflection of the pipe as it would appear in those views. Thus the ele- vation would show the slant, which is determined by the two dimensions c and d. Therefore from the point A of the elevation erect a perpendicular line equal to the required hight e, from the top of which draw a horizontal line to the right of a length equal to the amount of slant d, thus locating the point E, which connect by a straight line with A. Then will A E represent the angle of the inclined portion of the pipe as it appears in the elevation. But according to the requirements the pipe is also to have an offset a dis- tance equal to e — that is, the point E of the elevation is nearer the observer than the point A. Therefore from A' of the plan draw a line forward the amount of the offset, from the end of which draw a line to the right, in length equal to d, or in other words till it comes directly under the point E of the elevation, thus locating that point in the plan, and draw A' E', which will show the apparent angle in the plan. The depth and width of the oblique portion of the box will next demand attention. At right angles to the line A E of the elevation set off the depth of the box a and draw a line to represent the lower near cor- ner of the box, which continue downward until it cuts the floor line, as shown at D ; then draw A D, which represents the miter cut for the side of the box. At right angles to A' E' of the plan set off the width /;, as shown, and draw a line parallel to A' E' intersecting the line from X at B', as shown, and draw A' B', which gives the plan of the miter cut across the top of the box. As the point D of the elevation is in the same vertical plane as A it may now be dropped into the plan, intersecting with the line showing the front side of the box in that view, as shown at D' ; and the point B' of the plan, being on a level with A', may be pro- jected into the elevation, where it would intersect with the line showing the top of the box at B. A line drawn from D' of the plan parallel to A' E' (shown dotted) will then show the position of the lower near angle of the inclined portion of the box, and a line from B of the elevation parallel to A E will show the position in that view of the further top corner of the box. The position in the two views of the remaining angle of the inclined portion of the box may be ascer- tained in several ways : The width b may be set off Pattern Proocems. 211 from T)' of the plan and a line drawn which will inter- sect with X B' continued, as shown at C ; thence it may be projected into the elevation at C, as shown; or the width a may be set off from B of the elevation, thus locating the line which intersects with the floor at C, which point may be dropped into the plan, thus locating the point C ; or, again, B C may be drawn parallel to A D, or D' C may be drawn parallel to A' B', all producing the same result. In the case in Problem 95, above referred to, it was noted that if the normal profile is adhered to in the level arm, the profile of the gable mold must be changed or "raked" before a perfect miter joint can be ob- tained. What is true in the case of the gable miter is equally true in the case of the furnace pipe — a correct profile or cross section of the box must be developed in order that a correct stretchout may be obtained for use in cutting the miter of the inclined arm of the pipe. As neither the plan nor the elevation, which have been correctly obtained, gives the true length of the inclined piece — that is, the true distance from A to E — it will be necessary to obtain still another elevation, in which such distance is correctly shown. As A' E' of the plan gives the horizontal distance between the points A and E, and c represents the vertical distance between them, if a right angled triangle be constructed with A' E' as a base and the bight c as the perpendic- ular, itshypothenuse will then give the desired measurement. Such a triangle properly forms part of an oblique eleva- tion which may be pro- jected from the plan in the following manner : Parallel to A' E', at any convenient distance away, draw a line to rep- resent the level of the floor, as shown; above which, at a distance equal to a, draw another paral- lel line, X 2 A 2 , represent- ing the hight of the hori- zontal arm of the pipe. Above the line X 2 A 2 , at a hight equal to c, draw still another line, upon which the point E is sub- sequently to be located. Fig. 400.- -Plan and Elevations of a Cold Air Box in. Which the Inclined Pcrtion Joins the Portion Obliquely in Plan. — First Solution. Level 212 Tlie New Metal Worker Pattern Booh. Now drop lines from all the points of the plan at right angles to A' E', intersecting each with its corresponding line of the new elevation, thus locating each point of the miter in that view As points D' and C are upon the floor, their position will be found at D 2 and C 2 . Like- wise lines from A' and B' will locate those points in the upper surface of the horizontal pipe, as shown at A 2 and B 2 , where they are also shown to be in the side elevation. A line dropped from E' will also locate that point at its proper hight, as shown at E 2 . A line con- necting A 2 and E 2 will then be the hypothenuse above alluded to and be the correct length sought. As all edges or corners of the pipe are necessarily parallel, lines drawn from B 2 C 2 and D 2 parallel to A 2 E 2 will complete this part of the elevation as far as necessary. In these, as in all geometrical drawings, lines showing parts concealed from view by other parts are always shown dotted. Lines from X and Y locate those points in the new elevation and show that, while a correct elevation of the inclined arm of the pipe has been ob- tained, the view of the horizontal portion is oblique, the space between X 2 and Y 2 showing the open end to fit against the furnace body. Having now obtained a correct oblique elevation, the next step is to obtain a correct profile upon any line, as F H, drawn at right angles across the pipe, which may be accomplished in the following manner: From each point upon the line of the section F, G, J and H project lines' parallel with the direction of the pipe to a convenient point outside the elevation, as shown at the left, across which draw a line, x y, at right angles to them as a base from which to measure distances from front to back. Assuming its crossing with the line from G (point 1) to represent the near angle of the pipe, set off from x on the line from F the horizontal breadth of the pipe b, thus locating point 4, which corresponds to the point F in the elevation. In like manner on the line from H set off from y the distance o of the plan, locat- ing the point 2, which corresponds to point H of eleva- tion, and draw the lines 1 4 and 1 2. The distance of point 3 from line x y is equal to distance b plus the distance o, or in other words, draw the line 2 3 par- allel to 1 4 and the line 4 3 parallel to 1 2, thus locating the point 3. Having now a profile and a correct elevation of the miter, nothing remains but to lay off a stretchout, as shown, upon the line H K and drop the points in the usual manner from the profile to the miter line A a B 2 C 2 D 2 , thence into the measuring lines of the stretchout, all as clearly shown in the drawing. As the plan shows all the dimensions of the hori- zontal arm of the pipe, the pattern for that can be de- veloped in the usual manner. To avoid confusion a duplicate of that part of the plan has been transferred to Fig. 401, where a stretchout of the normal profile is laid off at right angles to the lines of the pipe, into which the points are dropped from the miter line A B C D. In the normal profile of course the distances 1 4 and 2 3 are equal to b and the distances 1 2 and 4 3 equal to a of Fig. 400. D 12 PLAN Fig. 401.— Plan and Patte7ii of Level Arm of Cold Air Box. It may be noted here that, as is the case in all raked profiles, the dimensions and shape of the profile obtained from the oblique elevation differ somewhat from those of the normal profile shown in Fig. 401, and that their stretchouts are therefore necessarily dif- ferent. Second Solution.— It may be asked naturally, is there no way of producing a miter without a change of profile, just as a carpenter would saw off the ends of two square sticks of timber of the same section and produce a perfect miter at an oblique angle ? There is, but the method of doing it is not so apparent as the Pattern Problems. 213 one just described. To accomplish this a drawing or view must be obtained, in which the surface of the paper represents a plane common to both arms of the shown in Fig. 402, in which the plan shown in Fig. 400 has been reproduced, but turned around in such a manner as to facilitate the projection from it of an end Fig. 402.— Patterns of Cold Air Box. —Second Solution. pipe. As three points determine the position of a plane, it will be seen at once that such a plane passes through the points Z, A and E of the side elevation, Fig. 400. The best means of obtaining this view is elevation, all of which is clearly shown in the drawing. This view shows the offset e and the rise c of the oblique portion of the pipe. The new view, which will give the required conditions, is obtained by look- ing at the pipe in a direction at right angles to A E of the end elevation, and is obtained as follows : Parallel to A E at any convenient distance away draw A' E', which make equal to A E by means of the lines drawn at right angles to A E, as shown. Upon the line E' E set off from E' the slant d as given in the side eleva- tion and plan, Fig. 400, locating the point E 2 , and draw the line E 2 A'. From all points of the profile or end view of the horizontal pipe, 1. 2, 3 and 4, project lines also at right angles to A E, continuing them across the line A' E', and make A' Y 2 equal to A Y of the plan. Then A' Y 2 will be the length of the horizontal arm in the new view and A' E 2 will be the length of the inclined arm, both lying in the same plane, and the angle E 2 A' Y 2 will be the angle at which the two arms meet. Under the above conditions, then, a line which bisects that angle, as A' C, will be the 214 Tlte New Metal Worker Pattern Book. miter line between the two arms. As the two arms of the miter are symmetrical, the view can be completed, if desired, by drawing lines parallel with A' E 2 from the points of intersection with the lines from the end view with the miter line A' C. As 1 2 3 4 is the profile from which the short arm was projected in the new view, a stretchout may now be taken from it and laid off on any line at right angles to C W and the points dropped in the usual manner, all as shown. If desired, the stretchout may also be laid off at right angles to the inclined arm and the pattern for this piece thus developed from the same miter line, although the miter cut A B D A is the same in both pieces, one simply being the reverse of the other. PROBLEM ioo. The Patterns for the Inclined Portion of a Cold Air Box to Meet the Horizontal Portion Obliquely in Plan. This problem is here introduced on account of the similarity of its conditions with those of the one immediately preceding, although, as its patterns are obtained entirely without the use of profiles, it does not properly belong in this connection. Its solution will serve to show what widely different means may be employed to obtain the same ends. In the preceding case the miter cut was obtained without refer- ence to the miter at the upper end of the oblique arm. In this case the oblique portion is required to join, at its upper end, with another arm like and exactly parallel with the arm join- ing its lower termination. Under such conditions it follows that the planes of the upper and lower miters must be parallel, and, therefore, that miter cut at the upper end of either of the faces of the oblique por- tion must be parallel with that at the lower end of the same. Advantage may be taken of these conditions to obtain a very simple solution of the problem, as will be seen below. The first requisite is, of course, a correctly drawn elevation and plan in which all the points in each are duly projected from corresponding points in the other view. In Fig. 403 is shown a plan and elevation of the box, with the lines of projection connecting cor- responding points in each, all of which may be con- structed very much as described in the preceding problem. The inclined arm is required to have a rise equal to a of the elevation and a forward projection equal to b of the plan. Corresponding points in the two views are lettered alike. Thus the elevation shows clearly that it is an elevation of the front A B F E of the plan, with the back CDHG dotted behind, while the plan shows clearly A B D C of the elevation with the bottom EFH6 dotted below. ELEVATION A SECTION Fig. JflS.- Patterns for the Inclined Portion of a Cold Portion Obliquely in Plan. Air Box to Meet the Level The first important information to be derived from the correctly drawn views is that the front and back are the same, likewise the top and bottom are alike. The patterns of the top and front are given separately, upon the supposition that joints will be made at all of Pattern Problems. 215 the angles; should they be wanted in one piece they could readily be connected. As all the surfaces of the inclined portion of the pipe are oblique to the given view, only some of their dimensions will be correct as they appear on the paper. An inspection of both elevation and plan will show that the lines A C and B D are both horizontal and parallel, and, therefore, correct as they appear in the plan, and may be used as given in the construction of a pattern of the top piece. The shortest distance between these two lines will be represented by a line at right angles to both, as M N. Since the point N in the line B D is higher than the point M of the line A G, by the distance a of the elevation, it will be necessary to construct the diagram J L K in order to get the correct distance be- tween the points M and 1ST. J K is made equal to the distance M N, as indicated by the dotted lines. K L is equal to the rise given in the elevation; hence the distance J L represents the true distance between the points M and 1ST. Upon the continuation of the line M N of the plan set off the distance J L, as shown at J' L'. Through each of these points lines are drawn parallel to A C and B D of the plan. The line A' C is made equal to A C, and B' D' is made equal to B D by means of the dotted lines drawn parallel to M N. This pattern is completed by connecting the point A' with B' and C with D'. In developing the pattern of the side A B F E the same course might be pursued, beginning with the lines A E and B F, whose lengths are correctly given in the elevation, but for the sake of diversity another method has been employed. Beginning with the known fact that the point B is higher than the point A, as shown by a in the elevation, con- struct a diagram, P R, making P equal to and parallel with A B of the plan, and R equa to a, thus giving R P as the correct length of th line represented by A B of the plan. From the points E and F draw, at right angles to E F, the lines E S and F T indefinitely. Since the distances A E and B F are the same and are correctly given in the elevation, take that distance between the feet of the dividers, and placing one foot at the point R describe a small arc, cutting the line E S in the point S. By repeating this operation from the point P, the point T is established in the line F and T. Lines connecting the points R S, S T and T P will complete the pat- tern of the front and back. PROBLEM ioi. The Pattern of a Hip Molding: upon a Right Angle in a Mansard Roof, Mitering Against the Planceer of a Deck Cornice. Let Z X Y Y in Fig. 404 be the elevation of a deck cornice, against the planceer of which a hip mold- ing, shown in elevation by U W Y T, is required to miter. Let the angle of the roof be a right angle, as shown by the plan Q ~D A 1 , Fig. 405, D N represent- ing the plan of the angle over which the hip molding is to be placed. This angle is also shown by B A of the elevation. As the only view which will show the correct angle at which the hip molding meets the plan- ceer is a view at right angles to the line D 1ST, the first step in the development of the patterns will be to con- struct such a diagonal elevation. Assume any point, as A, in the elevation on any line representing a plain surface in the profile of the roof, as B A. Through A draw a horizontal line indefinitely, as shown by L A C. From B, the point in which the line A B meets the planceer, drop a vertical line, cutting the horizontal line drawn through A at the point C, all as shown by B C. Produce the line of planceer W Y, as shown by W Y'. Draw a duplicate of the plan, Q D A 1 in Fig. 405, in such a manner that the diagonal line D N shall lie parallel to the horizontal line drawn through A, al' as shown by Q 1 D 1 A 3 . At right angles to the line D A 2 , at any convenient point, as A 2 , draw the line A 3 C, in length equal to the distance A C in elevation, and through C draw a line parallel to D 1 A 2 , as shown by I ISP, cutting the diagonal line D 1 ISP in the point 1ST 1 . Then D 1 ISP represents the diagonal plan of that part of the hip from B to A in the elevation. From ISP erect a perpendicular, ISP M, which produce until it 216 Tlie New Metal Worker Pattern Book. meets the line carried horizontally from the planceer in the point B'. In like manner from D 1 erect a per- pendicular, which produce until it meets the horizontal line L C in the point L. Connect L and B 1 , as shown, which will constitute the desired oblique projection of A B. The next step will be to construct a section of the hip molding upon a line at right angles with it, as G the side D' A', from which erect a line perpendicular to D' N l , as shown by E F, which produce until it meets the horizontal line L C in the point L', and thence carry it upward parallel to L B 1 , cutting G H in the point F\ On either side of F 1 lay off a space equal to F E of the diagonal plan, as shown by F 1 E 1 and F' E'. Through these points E 1 and E 3 draw lines to K, the intersection of the lines L B 1 and G H. From Fig. 404. — The Pattern of a Hip Molding in a Mansard Roof, Mitering Against the Planceer of a Deck Cornice. H, assumed at any convenient point. It might be supposed that in such a section the two fascias of the hip molding would be at right angles to each other, as they undoubtedly would appear in the plan Q D A 1 of Fig. 405 or in a section on any horizontal line, as L M. The object of this part of the demonstration is to show exactly what that angle would be and how to obtain it. Assume any point in the diagonal plan, as E, in K as a center describe the curve of the roll of the re- quired diameter. Upon the lines K E 1 and K E 2 set off from K a distance sufficient to make the desired width of fascia, thus completing the profile of the hip molding in the diagonal elevation. Space one-half of this profile, as G E', in the usual manner, through the points in which carry lines par- allel to L B 1 , cutting the line of planceer W Y', which Pattern Problems. 217 is the miter line of the roll. The edges of the fascia will of course miter with the lower edge of the fascia Fig. 405. — Plan of the Fascias and Angle of the Mansard Shown in Fig. 404. at the top of the mansard, shown in profile at B E 3 , all as shown by the dotted lines projected from E\ At right angles to the line L B 1 draw the straight line S R, upon which lay off a stretchout of the profile in the usual manner, and through the points draw measuring lines. "With the T-square parallel to this stretchout line, or, what is the same, at right angles to the lines of the molding in the diagonal elevation, and, bringing it successively against the points in W Y 1 , cut corre- sponding measuring lines drawn through the stretchout. The measuring lines 7 and 8 are cut from the inter- section of the fascia of the hip with lines projected from E 3 as above explained. Then a line traced thi*ough these points, as shown in the engraving, as shown by J 1 P J, will be the pattern of the hip molding mitering against the horizontal planceer. PROBLEM 102. The Pattern for a Hip Molding upon a Right Angle in a Mansard Roof, Mitering Against a Bed Molding at the Top. Let A C B, in Fig. 406, be the section of a por- tion of a mansard roof, the elevation of which is shown to the left, and let P E be any bed molding whose profile does not correspond to or member with the molding used to cover the hips, a section of the hip molding being shown at Z Y C. The solution of this problem will be accomplished by means of a "true face" of the roof, rather than by means of a diagonal elevation as in the problem immediately preceding this. Therefore, supposing the section A C B to give the correct pitch of the roof, the first step will be to obtain the true face, or elevation of the roof as it would appear if tipped or swung into a vertical position, for the purpose of get- ting the correct angle at A 1 B 1 F 1 . To do this reproduce the section of mansard and bed molding as a whole at a convenient point below, but so turned as to bring the faces of the roof into a vertical position, maintaining the same distance be- tween the points A and B as shown by A 2 and B\ Project lines horizontally to the left from this section for the true face, marking the lines from the points A 2 andB 2 . From A of the original section carry a line across intersecting the line A' B 1 at the point A 1 . Next drop line from A 1 and B 1 vertically intersecting lines of corresponding letter, as shown by the dotted lines. Then A" B 9 F' will be the correct angle upon which to construct the corner piece and develop the miter line between the hip molding and the bed mold- ing of the deck cornice. The next step will be to obtain a correct section of the hip molding upon a line at right angles to the line of the hip. To do this it is necessary to first construct a diagonal section through the hip. At any convenient place lay off a plan of the angle of the roof, as shown by D 1 F D 2 in Fig. 407, and through this angle draw a plan of the hip, as shown by F K. From D 1 erect a line perpendicular to F D', as D' C 2 , in length equal to D C of the section. Through C 2 , parallel to D 1 F, draw C 2 K, producing it until it cuts the line repre- senting the plan of the hip. From the points F and K in the lines representing the plan of the hip erect per- pendiculars, as shown by F L and K C 3 . Draw L s parallel to F K, as shown at the base line of a diag- onal section. From C 3 erect a perpendicular, C 3 E', in length equal to C E of the original section. Connect E 1 L. Then L C 3 E 1 will be a diagonal section of a portion of the roof, and L E 1 will be the length of the hip through that portion. At right angles to L E 1 draw M H 1 , upon which to construct a correct section of the hip molding. Take any point, as G in the line F D 1 , at convenience, and from it erect a perpendicular 218 The New Metal Worker Pattern Book. to F K, cutting F K in the point H, and produce it also until it cuts the base line of the diagonal section L C 3 , as shown, and from this point carry it parallel to the line L E', representing the pitch of the hip, until it will be obtained by which the angle contained between the facias of the hip molding may be determined. Therefore from H 1 on either side set off the distance H G of the plan, as shown by G 1 and G\ Through Fig. 406.— The Pattern of a Sip Molding Upon a Right Angle in a Mansard Roof, Mitering Against a Bed Molding. crosses the line M H 1 , cutting it in the point II'. Since D 1 F D a represents the angle in plan over which the hip molding is to fit, and since H G is the meas- urement across that angle, if the distance H G be set off from H 1 either way in the diagonal section, points these points draw lines representing the fascias of the hip molding, as shown by O G 1 and G\ Add the fillets and draw the roll according to given dimensions, all as shown. In the true face, Fig. 406, draw a half section of Pattern Problems. 219 the hip molding as derived from Fig. 407, as shown. M 3 H 3 corresponds to M H' of the diagonal section. Fig. 407. — Method of Obtaining Correct Gross Section of Hip in Fig. 406. Space this profile into any convenient number of parts in the usual manner, and through the points draw lines parallel to the lines of the hip molding indefinitely. Place a corresponding portion of the profile of the hip molding in the vertical section, as shown, in which M' H 3 also corresponds to H 1 M in the diagonal section. Divide this section into the same number of equal parts, and through the points draw lines upward until they intersect with the profile of the bed molding, as shown between P 3 and B\ From the points in P 3 B 3 carry lines horizontally, intersecting the lines drawn from the profile in the true face. Then a line traced through these points of intersection will be the miter line between the hip molding and the bed molding, as seen near B 3 in elevation. For the pattern proceed as follows: At right angles to the line of the hip molding, as shown in the true face, lay off a stretchout of the hip molding, as shown by S R, through the points in which draw the usual measuring lines. Place the T-square at right angles to the lines of the hip molding, and, bringing it successively against the several points in the miter line, as shown in elevation, cut corresponding measur- ing lines, which will give the pattern for the roll and fillets, as shown from TJ to V. In like manner place the T-square against the point X in the true face, which is the point of junction between the flange of the hip molding and the apron of the bed molding corresponding to points 9 and 10 of the profile, and cut the corresponding measuring lines. The pattern is then completed by drawing a line from W to V and T toU. PROBLEM 103. Patterns for the Top and Bottom of the Hip Bar in a Skylight. In the upper part of Fig. 408 is shown the trans- verse section of a skylight in which A B represents a portion of the ventilator or finish at the top, and C D the curb or finish at the bottom. The section also shows the side elevation of a " common " bar whose profile is at F. The plan immediately below shows a corner of the skylight with one of the hip bars, H K, the patterns for which are required. It will be neces- sary first to see that the plan is correctly projected from the elevation, and afterward that a diagonal ele- vation of the hip bar be obtained from this plan, be- fore the correct or raked profile of the hip bar can be obtained. Draw a duplicate of normal profile F with its cen- ter line on the center line of the hip, as shown at F 1 , as a means of obtaining the lateral projection of all its points, numbering corresponding points in both profiles the same. Number the intersections of all the points in the normal profile F with the top and bottom of the skylight finish, as shown by the small figures in A B and C G. From each of the points in the profile F 1 carry lines parallel to the center line of the hip in either direction, intersecting lines of corresponding number dropped vertically from both the miters of the trans- verse section to the plan. Lines traced through these points of intersection will give the miter lines at top and bottom as they appear in plan. At right angles to the lines of the hip carry lines, as shown, by means of which to construct the diagonal elevation. Assume any line, as E 1 G 1 , as the base 01 220 Tlie Neio Metal Worker Pattern Booh. horizontal line of the diagonal elevation representing E G of the section. At E 1 erect a perpendicular upon the horizontal molding at the top whose profile is shown at A B, it will be found most convenient to Fig. 408. — Plan and Section of a Skylight and Patterns for the Hip Bar. which to obtain the hights of the various points in the upper miter. As the hip bar is required to miter with carry all the points of the upper profile to the vertical line A B, as shown by 1, 2, 3 1 , 4, 5 and 6', and after- Pattern Problems. 221 ward to transfer them, as shown, to the line A 1 B', keeping the perpendicular hight from E 1 to B 1 equal to E B. From all the points in A 1 B 1 carry lines hori- zontally — that is, parallel to E 1 G' — to the right indefi- nitely, as shown. These lines will then represent a partial elevation of the top molding A B in the diagonal elevation. Lines from each of the points in the plan of the upper miter at H may now be carried parallel to H E 1 until they intersect with lines of cor- responding number drawn from A 1 B 1 . Lines connect- ing the points of intersection will give the required miter line at the top of the hip bar. From each of the points obtained in this miter line carry lines parallel to B 1 G', or the rake of the hip bar, and intersect them with lines projected parallel to II E 1 from the lower miter in plan at K. Lines con- necting these points of intersection will give the re- quired miter line at the bottom of the hip bar. It now remains only to obtain the correct profile of the hip bar before a stretchout can be obtained. To accomplish this, draw any line cutting the lines of the hip bar in the diagonal elevation at right angles, as shown at R. Upon this line, and above or below the hip bar, as shown at F 2 , draw a duplicate of the normal profile F, from the points in which carry lines at right angles to the hip bar, cutting lines of corresponding number in the same. Then lines connecting the points of intersection will give the raked profile, as shown at R. On account of limited space the important details in Fig. 408 are necessarily small, but great care has been taken in the preparation of the drawing, and all the points in the several views of both miters have been carefully numbered, so that the reader will have no difficulty in following out the various intersections from start to finish. The profile and the two miter lines now being in readiness, the pattern may be de- veloped in the usual manner, as follows : Upon any line drawn at right angles to the hip bar, as L M, lay off a stretchout of the profile R, as shown by the small figures, through which draw the measuring lines. Keeping the blade of the -square parallel with L M, bring it successively against the points of intersection previously obtained in the upper and lower miters and cut corresponding measuring lines. Then lines traced through the various points of intersection, as shown by N and P Q, will constitute the required patterns. It may be noticed that while most of the points from the normal profile F come squarely against the inner beveled surface of the curb G, the points 1 and 2, representing the vertical portion of the bar, pass over the curl) to a point bej^ond. The line from point 2, therefore, intersects at both 2 and 2 1 , which points are duly carried through the views of this miter at K and G' and finally into the pattern, as shown ; from which it may be seen that the miter pattern may be cut as shown by the solid line from P to Q, or that portion from point 2 to 3 may be cut as shown by the dotted line. PROBLEM 104. Pattern for the Top of a Jack Bar in a Skylight. The jack bar in a skylight is the same as the bar in respect to its profile, and the miter at its lower end with the curb. At its upper end, however, it is required to miter against the side of the hip bar instead of against the upper finish of the sky- light. As the hip bar occupies an oblique position with reference to the jack bar, it is evident that a perfect miter between the two could not be effected without a modification or raking of the profile of the hip bar, all of which has been demonstrated in the preceding problem. It may be here remarked that the raking of the profile of the hip bar is done not so much to affect a perfect joint with the top finish as to make a perfect miter with the jack bar, or what is the same thing, that the surfaces indicated by 2 3 of the profile of the . hip bar in Fig. 408 shall lie in the same plane with that portion of the profile of the jack bar. However, as the raked hip bar presents exactly the same appear- ance when viewed in plan as a bar of normal profile, it will not be really necessary, so far as the miter cut on the jack bar is concerned, to perform the raking operation. In Fig. 409 is shown a sectional and a plan view of a portion of a skylight containing the miter above referred to. The normal profile of the jack bar shown at F and F 1 is not exactly the same in its proportions as that of the preceding problem, but possesses the 222 Tlie New Metal Worker Pattern Booh. same general features. The view of the bar given in the section from A to B represents an oblique eleva- tion of that side of the hip bar which is toward the jack bar. From B to D the view shows the side of the jack bar, while beyond D is shown a continuation of the full hip bar with its profile correctly placed in po- sition at F 3 . The first step before the pattern can be laid out is to obtain a correct intersection of the points in the plan, as at B', and afterward an elevation of the same, as shown at B. Draw a normal profile of the jack bar in correct position in the plan, as shown at F 1 . Also place a profile of the hip bar in the plan of the same, as shown at F 2 . As only the lateral projection of the points are here made use of a normal profile will answer as well as the raked profile shown, as above intimated. Number all the points in both profiles correspondingly, and from the points in each carry lines respectively parallel to their plans, intersecting as shown at B 1 . From the points of intersection of like numbers erect lines vertically into the sectional view, cutting lines of corresponding number drawn from the points in the profile F parallel to the lines of the rake, as shown near B. It will be seen that both sides of the profile F 1 intersect with one side of the profile F 2 , both sets of intersection being numbered alike, as l 1 , 2 1 , 3', etc. This gives rise to two miter lines at B in the sectional view. The line correspond- ing to the intersections on the upper side of the jack bar are here numbered l 2 , 2 2 , 3 2 , etc., while those points belonging exclusively to the lower intersection are numbered 3 3 , 5 s and 6 s . A stretchout of the normal profile F may now be laid off on any line, as G H, drawn at right angles to the elevation of the jack bar, through which the usual measuring lines are drawn. Now place the blade of the T-square parallel to G H, aud, bringing it against the various points in the two miter lines above de- scribed, cut corresponding measuring lines, carrying the points from the upper miter line into one side of the pattern and those from the lower one into the other side ; then lines connecting the points of intersection, as shown from K to L, will constitute the required miter cut. As it is desirable to cut the miter on the jack bar so as to fit over the hip bar (that is, so as not to cut the hip bar at all) and m order to prevent the surface from 4 to 5 of the jack bar from lapping on to a like por- tion of the hip bar, as shown between the points 4 1 , 5 1 and x in the plan, the line from point 4 of F 1 is al- lowed to intersect with the line from 5 of F 2 , as shown at x, which point is carried into the sectional view and thence into the pattern, where it intersects with lines 4, as shown by x, so that the cut in the pattern is from a; to 5 instead of from 4 to 5. For the same reason, / '-Ju-U j //hi V Ml/,' //K J ' j Fig. 409. — Section and Plan of Miter at the Top of the Jack Bar in a Skylight and Pattern of the Same. if it is desired to prevent the surfaces 2 3 from over- lapping the line from 2 of F 1 may be intersected with 3 from F 2 , as shown at y, and carried into the pattern, as shown, producing the cuts in the pattern shown by the dotted lines 3 y in the place of those shown from 3 to 2. Pattern Problems. 223 PROBLEM 105. The Pattern of a Hip Mold Upon an Octagon Angle in a Mansard Roof, Mitering Against a Bed Molding of Corresponding Profile. This problem, like many others pertaining to man- sard roofs, may reach the pattern cutter in drawings either more or less accurate, and in different stages of completion. Certain facts, however — viz. , the profiles of the moldings, the pitch of the roof and the angle in plan — must be known before the work can be accom- plished; but with these given the pattern cutter will have no difficulty in drawing such elevations as are necessary to produce the required patterns. In Fig. 410, let A B C D be the given section of the mansard trimming shown, A C the profile of the bed molding and apron, and B D E the pitch of the roof. According to the statement of the problem above the angle of the plan is octagonal ; it might be a special angle either greater or less than that of an octagon, but the principle involved and the operation of cutting the patterns would be the same. As in all other problems connected with mansard trimmings, the first requisite is an elevation of the " true face," in order to obtain the correct angle between the bed mold- ing and the hip molding. A normal elevation, such as is likely to be met with in the architect's drawings, is shown in the engraving at the left of the section, merely for purposes of design. In obtaining the true face, shown below, it is best to use the section and plan only. Therefore, redraw the section as shown im- mediately below it, placing the line of the roof in a ver- tical position, all as shown. From all the points of this section lines may now be projected horizontally to the left, as the first step in developing the required true face. Immediately above the space allotted to the elevation draw a plan of the horizontal angle, as shown by I E 1 K. As it will be impracticable to include the entire profile of the roof in the drawings, some point must be assumed at a convenient distance below the bed mold, as D, from which to measure hight and pro- jection, which locate also in the section below, as shown at D 1 , making B' D 1 equal to B D. From A draw a line at right angles to the line of the roof, meeting it at B, which point may be assumed for convenience as the upper limit of that part of the roof under consider- ation. Now, from the point B drop a vertical line, which intersect with one drawn horizontally from D, as shown at E ; then D E will represent the projection. From the lines I E 1 and E 1 K, upon lines at right angles to each, set off the projection D E, as shown at I F and K H ; through the points F and H draw lines parallel to the first lines, meeting in G ; then a line from G to H will represent the plan of the angle or hip of that portion of the roof of which B D is the profile. Now, to complete the true face of that part of the roof drop a line from the point E 1 intersecting the line from B' at L, and one from G intersecting the one from D 1 at M ; then the angle B" L M will be the correct angle of the miter between the bed mold and the hip mold. As in Problems 101 and 102 preceding, it will next be necessary to obtain a correct section of the hip mold on a line at right angles to the line of the hip. To avoid confusion of lines, this operation is shown in i^o-. 411 in which E 2 G 1 , the base line, is made equal to E 1 G of the plan in the previous figure. At the point E 2 erect a perpendicular, making it equal in hight to B E of the sectional view. Connect B 2 with G 1 , which will give the correct angle of the hip of the roof. As a means of constructing a correct section at right angles to this line, assume any two points on the original plan, as N and 0, equidistant, from G and connect them by a straight line, cutting the angle or hip line in P. Set off from G 1 on the line G 1 E 2 of Fig. 411 a distance equal to G P of the plan, as shown at P', from which draw a line parallel to the hip G 1 B\ Next intersect these two lines by another at right angles at any convenient point, as shown by P 2 Q. From the point P 2 set off the distances P 2 O 1 and P 2 N 1 , making them equal to P and P N. Connect the points O 1 and N 1 with E, which is the intersection of P 2 Q with the hip line ; then the angle 0' E N 1 will be a correct section of the roof upon the line P 2 Q or upon any line cutting the hip at rio-ht angles, upon which the finished profile of the hip mold may now be constructed as follows : Set off the pro- jections of the fascia and fillet as given in the sectional view, Fig. 410, from the lines E O 1 and E N 1 , contin- uing their lines to the center line P 2 Q. From the inter- section S as a center, with a radius of the bed mold describe the roll. As stipulated in the statement of this problem the profiles of the bed mold and hip mold are to cor- 224 Tlie New Metal Worker Pattern Book. tKq. 410.— The Pattern of a Hip Molding Upon an Octagon Angle, Mitering Against a Bed Molding of Corresponding Profile, Pattern Problems. 225 respond. By this it is understood that the curves of their molded surfaces are alike and struck with the same radius, and so placed as to member or miter. As the curve of the bed mold is only a quarter circle, while that of the hip mold is nearly three- quarters of a circle, it will be seen that the quarter circles in each half of the hip mold next adjacent to the fascias and fillets will miter with the arms of the bed mold on either side of the miter, and that a small space in the middle of the roll will remain between them, which must be mitered against the planceer, and the object of the operation shown in Fig. 411 is to deter- mine exactly what this space is. The dotted lines from S to the points 10 drawn at right angles to R ! and R X' show the limit of the quarter circles or the parts that must miter with the bed mold, while the space between them (10 to 10) shows the part that must miter against the planceer. It might be supposed that the angle between the fascias of the hip mold, to fit over the angle of a mansard which is octag- onal in plan, would be octagonal, but the demonstra- tion shows that while the angle N G of the plan, Fig. 410, is that of an octagon, the angle X 1 R O 1 , Fig. 411, is greater, because the distance N' O 1 is equal to X 0, while the distance R P 2 is less than G P, B P' being at right angles to the line of the hip and G 1 P' being oblique to it. The true face, Fig. 410, may now be completed, as follows : Upon any line, as S 1 T, drawn at right angles to L M, representing the face-of the roof, draw a duplicate of one-half the profile of the hip mold obtained in Fig. 411, placing the point S upon the line L M, as shown. Lines drawn through the angles of this profile parallel to L M will intersect with lines from corresponding points from the profile A' C, pre- viously drawn, giving the miter line J X and com- pleting the elevation of the true face. Upon any line at right angles to the line L M, as U V, lay off a stretchout of the complete hip mold as obtained from the half profile. S 1 T, through which draw measuring lines as usual. Drop lines from the points from 1 to 10 of the profile, parallel to L M, cut- ting the miter line; then, with the T-square placed at right angles to L M and brought successively against tho points in J X, intersect them with lines of corresponding number in the stretchout; then lines traced through the points of intersection, shown by cl b and a c, will give the pattern for that part of the profile from 1 up to the point 10. The pattern of that portion of the roll which miters against the planceer must; be obtained from the diagonal section of the hip. From points 10, 11 and 12 in Fig. 411 carry lines parallel to G 1 B a intersecting the line of the planceer, as shown at ~W. It is only necessary to ascertain how much shorter the lines 11 and 12 are than the line 10, and then to transfer these distances to the pattern. This can be done by drop- ping lines from the intersection of points 11 and 12 with the planceer, in Fig. 411, at right angles to G 1 B% cutting line 10. These distances can then be trans- ferred to line 10 of the pattern, Fig. 410, measuring down from the point 10 of pattern already obtained,, after which they may be carried parallel to U V into the measuring lines 11 and 12, thus completing the pattern. This portion of the work is necessarily very minute in the drawing, but it will be easily seen, in applying the principle to other similar cases, that if the angle of the plan I E' K were less than that shown, for instance, if it were a right or an acute angle, a greater distance or more points would occur between the points 10 and 10, and further, that if the angle of the roof were less steep a greater curve or dip would occur between those points (a to b) of the pattern. PROBLEM 106. The Pattern of a Hip Molding: Upon an Octag-on Angle of a Mansard Roof, Mitering- Upon an Inclined Wash at the Bottom. In Fig. 412, let D B of the section represent the wash surmounting the base molding at the foot of a mansard roof, the inclination of the roof being shown by B A. The plan of the angle of the roof B 2 K B 2 , as specified, is that of an octagon, but so far as prin- ciple and method are concerned, it may be any angle whatever. The profile of the hip mold as giver, in the original drawings will most likely be drawn as fitting over an octagonal angle — that is, over the angle as given in the plan of the building. As explained in the problem preceding this, a section through the angle of the roof at right angles to the line of the hip must be 226 The New Metal Worker Pattern Book. .C 1 G 1 ' H 2 D'\ Fig. 412.— The Pattern of a Hip Molding Upon an Octagon Angle, Mitering Upon an Inclined Wash at the Bottom. Pattern Problems. 227 obtained, to which the profile of the hip mold must be adjusted before going ahead. The difference between such a section and the angle in plan may seem trifling, but will be found to increase as the pitch of the roof decreases, and in a low hip roof will be found to be considerable. Hence the original detail of the hip mold must be accepted only so far as it gives width and depth of fascias and fillets, and diameter or radius of the roll, while the angle between the fascias must be adjusted to the true section across the hip as above stated. The method of doing this is shown in Fig. 413, and the principles involved therein are explained in the previous problem in connection with Fig. 411, and need not, therefore, be repeated here. The first operation will consist in obtaining the "true face" of the roof in the usual manner, viz.: Assume any point upon the section of the roof, as A, at a convenient distance above the base, as a point from which to measure hight and projection. Eedraw the section of the roof immediately below the first one, placing it in a vertical position and locating thereon the point A, as shown by A'. From the points A", B 1 and D 1 project lines horizontally to the left, thus ob- taining all the bights in the true face. It will be necessary next to complete the plan, to do which first obtain the projection of the points in the section upon any horizontal line, as the one drawn through B, which can be done by dropping vertical lines from the points A and D, cutting it as shown at I and C. Assuming the line B 2 K B 2 of the plan to represent- the point B of the section, set off upon any lines at right angles to the lines B 2 K these projections — that is, make B 2 I' equal to B I, and B 2 C 1 equal to B C. Through these points draw lines parallel to B 2 K, intersecting and forming the line P G, whicn is the plan of the angle over which the hip mold is required to fit. From the points P, K and G, which represent upon the angle of the roof the points A, B and D of the section, drop lines vertically into the true face intersecting the horizontal lines previously drawn from A 1 , B 1 and D', as shown; then P 1 K' T will be the correct angle at which to construct the miter of the half of the hip mold belonging to this face of the roof, and K 1 G" IF P will represent a corresponding elevation of the wash. The elevation of the true face may now be com- pleted by placing one-half the profile of the hip in correct position — that is, with its base line or fascia at right angles to the hip line P 1 K 1 , the point K coming on the line. Through the points Y, S and T project lines parallel to the hip line. To show the intersection of the hip mold with the wash, first place a duplicate of the half profile of hip mold in the sectional view, as shown by Y 1 R 1 T 1 ; then divide the curved portion of both profiles into the same number of equal spaces and number all the points correspondingly, as shown. From these points drop lines downward parallel with the lines of the respective views, those in the sectional view cutting the line of the wash B 1 B 1 . From these points of intersection carry lines horizontally, intersect- ing the lines dropped from the profile Y S T. Then a line traced through these points of intersection, as shown by Y 2 S 2 T 2 , will be the miter line formed by the junction of the hip molding with the wash. At right angles to the line of the hip molding in the true face lay off a complete stretchout of the hip molding, as shown by U V. Through the points in it draw measuring lines in the usual manner. Place the T- square parallel to this stretchout, or, what is the same, at right angles to the line of the hip molding, as shown in true face, and, bringing it successively against the points in the miter line Y" S 2 T 2 , cut the corresponding measuring lines. Then a line traced through these points of intersection, as shown from W to Z, will be the cut to fit the bottom of the hip molding. The normal elevation may be completed, if desired by means of projections from the plan and the section, as shown. PROBLEM 107. Pattern for a Hip Molding Mitering Against the Planceer of a Deck Cornice on a Mansard Roof Which is Square at the Eaves and Octagon at the Top. In Fig. 414 is shown the method of obtaining the miter against the planceer of a deck cornice formed by the molding covering a hip, which occurs between the main roof and that part which forms the transition from a square at the base to an octagon shape at the top. The roof is of the character sometimes employed 228 Tlie New Metal Worker Pattern Book. upon towers which are square in a portion of their hight and octagon in another portion, the transition from square to octagon occurring in the roof. The hip molding in question covers what may be called a transi- tion hip, being a diagonal line starting from one of the corners of the square part and ending at one of the corners of the octagon above. A carefully drawn plan, together with a section through one of the sides of the roof, giving the pitch, will be the first requisites to solving the problem, both of which are shown in the engraving. The first operation will be the construc- tion of a section upon the line of the hip, which may be done as follows : Assume any point, as A, in the section of the roof from which to measure hight and projection. If a horizontal line from A and a vertical line from the top of the roof surface B be intersected in C, then B C will represent the hight and A C the projection of the part of the roof assumed. Set off the projection C A at right angles to the top line of the plan C E, as shown by C A 1 , and carry a line through A 1 parallel to C E till it cuts the plan of hip E Q at D; then D E will form the base and B C the hight of the required sec- tion, which may be obtained for convenience by lines projected from D E at right angles, all as shown. The line B' D~ then represents the real angle at which the hip mold meets the planceer or level line at the top The next operation will consist in obtaining a cor- rect section of the hip mold from the data given and in placing it in correct position in the diagonal section. Take any point, G, in the plan at a convenient distance from the angle W D A 1 . Set off G 1 at the same dis- tance from the angle on the opposite side. From the points G and G 1 carry lines at right angles to and cut- ting D~ C in the points H 2 and 0'', and from these points carry them parallel with the line D~ B l indefi- nitely. At right angles to D 2 B' draw a line, as shown by Z H 1 , intersecting with the lines last drawn in the points H 1 and 0. From H 1 , along the line II 1 H a , set off a distance equal to PI G of the plan, and from O, in the line Z H 1 , set off a distance equal toO 1 G 1 of the plan, as shown by G 3 . Connect the intersection of Z IT and I) 2 B' with the points G 3 and G 2 , which will give the correct section through the angle of the roof. Having thus determined the angle of the hip molding finish, a representation of it is indicated in the drawing by adding the flanges and the roll. Since the miter required is the junction between the hip molding, the profile of which has just been drawn, and a horizontal planceer, the remaining step in the develojunent of the pattern consists simply in dividing the profile into any convenient number of parts, and carrying points against the line of the planceer, as shown near B', and thence carrying them across to the stretchout, as indicated. It is evident, however, upon inspection of the eleva- tion, that the apron or fascia strips in connection with the planceer which miter with the flanges of the hip molding will form a different joint upon the side cor- responding to the transition piece of the roof than upon the side corresponding to the normal pitch of the roof, owing to the difference in pitch of these two sides. To obtain the lines for this miter an additional section must be constructed, corresponding to a center line through the transition piece, as shown by W L in plan. Prolong C D 2 , as indicated, in the direction of W, and lay off W L', equal to W L of the plan. From L' erect a perpendicular, as shown by L' B', equal to C B of the original section. Connect W and B 2 , against the face of which draw a section of the apron or fascia strip belonging to the planceer, as shown, and from the points in it carry lines parallel to B 2 B' until they intersect lines drawn from the flange of the hip molding lying against that side of the roof, all as indicated by U X. From these points carry lines, cutting corre- sponding lines in the stretchout. The lines of the fascia behonging to' the other side are the same as if projected from the normal section at B, or as they appear in the elevation. Having obtained these points proceed as follows : At right angles to the lines of the molding in the diagonal section lay off the stretchout of the hip molding S T, and through the points draw the usual measuring lines, as shown. Place the T-square at right angles to the lines of the molding, or, what is the same, parallel to the stretchout line, and, bringing it success- ively against the points formed by the intersection of the lines drawn from the hip molding and the planceer lineB 1 , cut the corresponding measuring lines, as shown. In like manner bring the T-square against the points U and X, above described, and Y and V, points corre- sponding with the opposite side of the hip molding, and cut corresponding lines. Then a line traced through these several points of intersection, as shown by U 1 X' Y' V, will be the pattern sought. Pattern Problems. 229 Fig. 4U.— The Pattern for a Hip Molding Mitering Against the Planceer of a Deck Cornice on a Mansard Roof Which is Square at the Eaves and Octagon at the Top. 230 Tlie New Metal Worker Pattern Book. PROBLEM 108. Patterns for a Hip Molding: Mitering Against the Bed Molding- of a Deck Cornice on a Mansard Roof which is Square at the Base and Octag-onal at the Top. The problem presented in Fig. 415 is similar to that described in the previous problem, with the dif- ference that a bed molding is introduced in connection with the planceer against which the hip molding is to be mitered. MEM' represents a plan of the roof at the top, while LDM' represents a horizontal line at the point A of the section, assumed at convenience somewhere between the top and the bottom for the purpose of measurement. The intersection of the lines M L and E D prolonged would indicate the cor- ner of the building at the bottom of the roof, the structure being square at the base and octagonal at the top. The first step in the development of the pattern is to obtain a correct section of the roof on the line of one of the hips. Therefore, at any convenient point lay off E 3 D 3 of Fig. 416 equal to'D E of the plan. From the point E 3 erect a perpendicular, E 3 B\ in length equal to C B of the section of the roof. Con- nect B 2 and D 3 , which will be the pitch of the hip corresponding to the line D E of the plan. Since the section D s E 3 B 2 has been constructed away from and out of line with the plan, it will be necessary to re- produce a portion of the plan in immediate connection with the section, as shown by I 1 H A 3 C 2 . This can be done by tracing, or any means most convenient. From the point H in this plan lay off on either arm the points I and I', equally distant from it and con- veniently located for use in constructing the profile of the hip molding. From the points I and I 1 erect per- pendiculars to H C 2 , cutting it in the points K and 0, which prolong until they meet the base D 3 E 3 of the diagonal section, from which points carry them paral- lel to the inclined line D 3 B 2 indefinitely. At right angles to the inclined line D 3 B 2 draw a straight line, O 1 K 1 , cutting the lines last described in the points K 1 and 0'. From K 1 , measuring back on the line I s K 1 , set off the point F, making the distance from K 1 to F the same as from K to I of the plan. From l in the line I 1 F set off the distance O 1 F, equal to I 1 of the plan. From these points I 3 and F draw lines meeting the line 1 K 1 at the point of its inter- section with the line D 3 B 2 . Complete the profile of the hijD molding, as indicated, laying off the width of the fascias on these lines, adding the roll and edges. The next step in the development of the pattern is to draw a " true face " of the roof. In performing this operation it matters not whether the actual sur- face of the roof be used or the surface of the fascias. In this case the points A and B of Fig. 415, by which the depth and projections of the pitch are measured, are taken on the surface of the fascia. For the true face transfer the section A B to a vertical position, as indicated by A 2 B', Fig. 415, in connection with which the bed molding against which the hip mold- ing is to miter is also drawn, as shown. From the several points in this vertical section draw horizontal lines, which intersect by vertical lines dropped from cor- responding points in plan. Then D 2 E 2 X is the true face of that part of the roof corresponding to D E M' M 2 of the plan. In connection with the vertical section just described, place a half profile of the hip molding, a true section of which has been obtained by the process already explained in Fig. 416, and also place a dupli- cate of this portion of the profile in connection with the true face. Space both of these profiles into the same number of parts, and from the several points in each cany lines upward parallel respectively to the lines of the views in which they appear; the lines from the profile in the vertical section cutting the bed molding, and the lines from the profile in the true face being continued indefinitely. From the points of in- tersection in the bed molding carry lines horizontally, intersecting those, drawn from the profile in connection with the true face, producing the miter line, as shown by E 2 . By inspection of the plan where a portion of the bed mold is shown it will be seen that the miter of the bed molding around the octagon at E is regular — that is, its miter line does not coincide with the line of the hip D E. If the profile of the bed molding in the vertical section, and also the profile of the bed mold- ing as shown in the plan, be divided into any equal umber of parts, points may be dropped from the Pattern Problems. 231 Fig. 415.— Plan, Elevation, True Face and Part of Pattern. Fig. 417.— True Face of Octagonal Side and Part of Pattern. Patterns for a Hip Molding Mitering Against the Bed Molding of a Deck Cornice on a Mansard Roof which is Square at the Base and Octagonal at the Top. 232 Tlic New Metal Worker Pattern Book. profile of the plan on to the miter line E, and thence carried downward and intersected with horizontal lines from the corresponding points of the bed molding in section, also shown at E 2 , thus giving the appearance of the miter between the two arms of the bed mold behind their intersection with the hip roll. The vertical lines from the miter E of the plan have not been car- ried, in the engraving, further than E 1 , where they are intersected with lines from corresponding points from the profile at B of the elevation, thus showing how the operation is performed. This has been done to avoid a confusion of lines at E\ Having obtained this line in the true face, the point where it crosses the miter line between the hip mold and bed mold previously obtained at E 2 must be noted. A line from this point of intersection must then be carried parallel to the line of the molding in the true face, back to the profile of the hip, and there marked, as shown by the figure 7£. The position of the point 7-J should now be marked upon the section of the hip molding previ- ously obtained at O 1 in Fig. 416. So much of the profile as exists between 1 and 7% in the true face is used in obtaining the stretchout of this part of the pattern. The remaining portion of the stay — namely, from 7£ to 14 — is afterward used for the true face of the octagonal side for the remainder of the pattern. At right angles to the line of the molding in the true face lay off a stretchout equal to that portion of the profile thus used, as shown by P 1ST, through the points in which draw measuring lines in the usual manner. Place the T-square at right angles to the lines of the molding in the true face, and, bringing it against the several points in the miter line between the hip and bed molding at E 2 , cut corresponding measuring lines drawn through the stretchout. Then a line traced through these points, as shown by S T, will be the miter line for that portion of the pattern corresponding to the part of the profile thus used. For the other half of the hip molding, being that portion which lies on the face of the transition piece, another operation must be gone through. Construct a section of the roof corresponding to the line F G in the plan. At any convenient point lay off F 1 C 1 in Fig. 415, equal in length to F G. From the point C erect a perpendicular, C B 3 , in length equal to C B of the section. Connect F' and B 3 . Then F 1 B 3 is the length of the transition side of the roof through that portion corresponding to F G of the plan. It will be well to add to this at B 3 a section of the bed mold as it appears in the section below, thus establishing the true relation between it and the transition side of the roof. By means of this section and the plan, construct a true face of one-half the transition side of the roof, by means of which to obtain the miter of the re- maining portion of the roll. To do this first redraw the section B 3 F', jnacing the line of the roof in a ver- tical position, as shown by B 4 F 2 , Fig. 417, from the points in which project horizontal lines, as shown to the right, upon each of which set off from an assumed vertical line the width of the roof as given in the plan. Thus make G' E 4 equal to G E of the plan, and F 3 D 4 equal to F D. Connect D 4 and E 4 . Then G' E 4 D 4 F 3 is the true face of that portion of the roof repre- sented by G E D F in the plan. In connection with the vertical section just de- scribed place so much of the stay as was not used for the pattern already delineated, and in the elevation of the transitional face of the roof place a corresponding portion of the profile, as shown, each of which divide into the same number of spaces. From the points thus obtained carry lines parallel to the lines of the respective views of the part, those in the vertical sec- tion cutting the bed molding, and those in the eleva- tion being produced indefinitely. From the points in the bed molding of the vertical section carry lines horizontally, intersecting those drawn from the profile in the elevation, thus establishing the miter line, as indicated at E 4 . At right angles to the line D 4 E 4 set off a stretchout of the profile, as shown by B P 2 , through the points in which draw the usual measuring lines. With the T-square placed parallel to this stretchout line, or, what is the same, at right angles to the line D 4 E 4 , and being brought successively against the points in the miter line at E 4 , cut corresponding measuring lines, as shown. Points also are to be car- ried across, in the same manner as described, corre- sponding to the bottom of the apron or fascia strip in connection with the bed molding. Then a line traced through these points, as indicated by the line drawn from U to T 1 , will be the pattern of the other half of the hip molding. By joining the two patterns thus obtained upon the dividing line of the stay, correspond- ing to P T of the first piece or P 2 T 1 of the second piece, the pattern will be contained in one piece. Pattern Problems. 233 B 3 (DUPLICATE OF PAGE 231.) Fig. 415.— Plan, Elevation, True Ftce and Part of Pattern. Fig. 417.— True Face of Octagonal Si le and Part of Pattern. Patterns for a Hip Molding Mitering Against the Bed Molding of a Deck Cornice on a Mansard Roof which is Square at the Base and Octagonal at the Top. 234 Tlie New Metal Worker Pattern Book. Fig. 418. — The Patterns for the Miter at the Bottom of a Hip Molding on a Mansard Roof Which is Octagon at the Top and Squart, at the Bottom. Pattern Problems. 234a PROBLEM 109. The Patterns for the Miter at the Bottom of a Hip Molding: on a Mansard Roof which is Octagon at the Top and Square at the Bottom. Let LDB' in Fig. 418 be the plan of the roof at the base, and Pi C G 1 the plan at the top of the portion here made use of for the purpose of demonstration. The section A B P in Fig. 419 shows the pitch of the roof and of the wash at the bottom upon which the hip molds miter. The pattern then required will be the shape of the hip molding to miter against this wash. Since the roof is square at the base and octagonal at the top, the moldings covering the two converging hips, represented by R D and C D, of Fig. 418, will unite and become a single profile at D. But, since the two hip moldings join before the wash is reached, the pattern will be modified to the extent of fitting the inner edge of one against the corresponding edge of the other. This condition of things is shown in the elevation, Fig. 419, which is here introduced not for any use it may be in the operation of cutting the pat- terns, but for more clearly showing the nature of the problem. The elevation is drawn by means of inter- secting points from the section and the plan, viz. : D 5 H' B 3 corresponds to I) H B' in the plan, and horizontal lines from the points A B in the section aie drawn, intersecting lines corresponding to the points already named. Let M L of the section represent one-half of the profile of the molding which is required to be fitted to the converging hips. The first step in the develop- ment of the patterns is in the construction of a section upon the line of one of the hips. Therefore, lay off D' C 2 equal to D C of the plan, and from C 2 erect a perpendicular, C 2 A 1 , in length equal to C A of the original section. Connect A 1 D 1 . Then A' C 2 D 1 is a section of the roof as it would appear if cut through on the line D C 1 of the plan, and A 1 D 1 is the pitch of the hip. In order to locate the profile of the hip mold- ing upon this section in correct position take any two points, as G and GF, on either side of the angle and equidistant from it. From Gr and G' carry lines paral- lel to C A 1 , producing them until they cut the hori- zontal line drawn through A 1 at the top of the section, as shown by the point K 1 and F'. From K 1 and F 1 draw lines parallel to the pitch line A 1 D'. At any convenient place in A 1 D' establish the point 0, through which draw a line at right angles to A 1 D', of conven- ient length. From the intersection of the line just drawn through with the line from K 1 set off the distance K G in the plan, locating the point G 2 . From F 2 , on a continuation of the line F 1 F 2 , set off a dis- tance equal to F G 1 in the plan, as shown at G 3 . Con- nect the point with G 2 and G 3 . Then the point of the newly constructed profile will represent the corner of the hip, to which the fascias and roll may be added according to the requirements of the original designs. The nexL step will be the construction of a "true face" of one of the normal sides so as to obtain the correct angle of the hip with the base line. To do this, transfer the section A B P of Fig. 419 to a con- venient place below the plan, bringing the line A B to a vertical position, keeping the angle between the sur- face of the roof and the wash the same, as shown at A 3 B 2 P 2 . From the points in this section project lines horizontally to the left, intersecting them with lines from the plan corresponding with the points used in the section. Then B 3 D 3 P 3 Z will represent a true face of the roof with an elevation of the wash to cor- respond. Place a portion of the stay in this true face, locating it so that the point O 1 , which corre- sponds to of the hip section, shall fall upon the angle of the roof. Divide it into any convenient number of spaces, numbering them in the usual manner. , From these points drop lines parallel to B 3 D 3 indefinitely through the face of the wash. Place also a part of the profile of the hip molding (greater than one-half) in proper position in the vertical section. From the points in this profile drop lines cutting the wash P 2 B 2 . From the points thus obtained carry lines horizontally, Crossing the true face, intersecting them with lines of corresponding numbers previously drawn. A line traced through the intersection of these points will give the elevation of the miter in the true face, all as shown by S T U. Note the point where this miter line crosses the miter line of the wash P 3 D 3 , which intersection carry back upon the profile L 2 M 2 , which in this case will 2?Ab New Metal Worker Pattern Book. (DUPLICATE OF PAGE 234.) Fig. 4I8. — The Patterns for the Miter at the Bottom of a Hip Molding on a Mansard Roof Which is Octagon at the Top and Square at the Bottom. Pattern Problems. 235 correspond to the point 8. Locate the point S on the first section of the hip obtained near 0, as shown, and use the remainder of profile 8 to 14 for another opera- tion. Lay off a stretchout of the entire profile of the hip molding, as shown by W V, through the points in which draw the usual measuring Hues. With the Fig. 419.— Section and Elevation of the Miter at the Bottom of a Hip Molding on a Mansard Roof Which is Octagon at the Top and Square at the Bottom. True Face of Octagon Fig. 420.— Miter between the Inner Edges of the Hip Moldings at the Bottom. hip mold it will be necessary first to construct a true face of the octagon side of the roof. To do this, obtain a diagonal section of the roof corresponding to the line D E in the plan, viz. : Lay off D 2 E 1 equal to D E of the plan, and from E 1 erect a perpendicular, E 1 A 2 , equal to C A of the section in Fig. 419. Con- nect A 2 and D\ Then A 2 D 2 is the length of the diagonal face of the roof measured on the line D E of the plan. Upon any convenient straight line lay off D 4 A 4 in Fig. 420, in length equal to D 1 A 2 , and from A 4 set off, at right angles to it, A' C\ in length equal to EC of the plan. Then D 4 A* C 3 shows in the flat one- half of the diagonal face of the roof, or what is represented by D E C 1 in the plan. At right angles to D 4 C 3 draw the remain- ing portion of the stay not used in con- nection with the true face, placing it in such a manner that the point O 3 , corre- sponding to of the hip section, shall fall upon the line D 4 C 3 , which represents the angle of the hip. Through the point 8 of the section L 5 M 7 , corresponding to 8 of the section L 2 M 2 of Fig. 418, draw a line parallel to D' C 3 , as shown by S 2 Y'. Then S 2 Y 1 corresponds to S Y of the true face in Fig. -118. Space the profile L B M' into the same parts as used in laying off the stretchout W V, and through the points draw lines parallel to D 4 C 3 , cutting the line S 2 A', which, being the center line of the octag- onal side of the roof, is also the miter line between the two arms of the hip mold- ing. From the points of intersection in the line D 4 A 4 , at right T-square placed at right angles to the lines of the hip, as shown in the true face, and brought against the points in the miter line S T IT, cut so many of the measuring lines drawn through the stretchout W V as correspond to those points. By this means that por- tion of the pattern shown by S 1 T 1 U' will be obtained. For the portion of the pattern corresponding to the part of the profile which miters against the other jles to S 2 Y', draw lines cutting S 2 Y', giving the points marked 8, 9, 10, 11, 12, 13 and 14. For con- venience in using one stretchout for the entire pat- tern, transfer these points to the line S Y of the true face in Fig. 418, from which, at right angles to S Y, draw lines cutting the corresponding measuring lines of the stretchout. Then a line traced through these points of intersection, as shown from S 1 to X, will com- plete the pattern. 236 Tlie New Metal Worker Pattern Book. PROBLEM no. Patterns for the Fascias of a Hip Molding: Finishing: a Curved Mansard Roof which is Square at tht Base and Octag-onal at the Top. The conditions involved in this problem do not differ greatly from those given in Problems 80, 81 and 82, near which it should properly be classed. In this case, however, the profile of an entire roof is under consideration instead of that of a simple molding or vase, but the problem is here introduced as being closely related in feature to several of the foregoing- problems. C D E F of Fig. 421 represents the plan of the roof at its base, while V G II W represents the plan at the top. It will be seen that the roof is nearly square at the foot of the rafters and octagonal at the top. The same conditions may arise where the corners of the roof are chamfered, starting at nothing at the bottom and increasing to a considerable space at the top, with- out reference to forming an octagon. D G H E in the plan represents a chamfer or transition piece in the con- struction of a roof which, as above described, is square at the base and octagonal at the top. This part is rep- resented m elevation by D 2 G" FT E\ The elevation is introduced here not for any use in pattern cutting, but simply to show the relation of parts. In the sectional view of the roof A B the outer line B represents the surface of the fascias of which the patterns are re- quired, the inner curve showing the line of the roof boards and the depth of the sink strips. As it is in the plan that the miter lines are shown it will be necessary to develop the pattern from the plan. Assuming then that one of the square sides, as E F W H, is to be done first, it will be necessary to place a profile so that its projection A shall lie across this part of the roof, all as shown by O 1 A 1 B'. Divide the profile 0' B 1 into any convenient num- ber of equal spaces, and from the points of division drorj lines parallel to E F, the side of the roof, cutting the miter line E H. Upon any line at right angles to this side of the roof, as O 2 B', lay off a stretchout through the points, in which draw the usual measuring lines. Cut these measuring lines by lines drawn verti- cally from the points in E H. Then a line traced through these points of intersection, as shown by E 3 FT, will be the line of the pattern corresponding to the line E II in the plan. The width of the flange or fascia forming the hip finish may be obtained as described in Problem 6, and the corner piece drawn in to agree with the original design, as shown by S' T 1 If it is desirable to produce an elevation of this angle of the roof it can be done by dividing the profile B by the same points as were used in dividing O 1 B 1 , from which horizontal lines can be drawn to the left intersecting with the lines of corresponding number previously erected from the miter line EH. A line, E a IP, drawn through the points of intersection will with D 2 Gr s give the correct elevation of the transition side. For the pattern of this side it will be necessary to first construct a section upon its center line, P R of the plan. At any convenient place outside of the plan draw a duplicate of P R parallel to it, as shown by P 1 A 1 , and from the point A 1 erect a perpendicular, A 1 B', in length equal to A B of the original section. In A' B 1 set off points corresponding to the points in A B, and through them draw horizontal lines, as shown. Place the T-square parallel to A 1 B 1 , and, bringing it against the points in E II previously obtained from the profile O l B 1 , cut corresponding measuring lines. Then a line traced through these points of intersection, as shown by B' P 1 , will complete the diagonal section corresponding to P R in the plan. From this diagonal section take a stretchout, which lay off on the straight line corresponding to P R produced, all as shown by P 2 B 3 . Through the points in P 2 B 3 draw the usual measuring lines. With the T-square placed parallel to this stretchout line, and brought successively against the points in E II, cut the measuring lines, as shown. Then a line traced through these points of intersection, as shown by E 1 to FT, will be one side of the required pattern. In like manner, having transferred points from E H across to the corresponding line D G, cut the measuring lines from it, which will give the other side of the required pattern. The width of fascias (whose intersection forms a panel in this case) may be obtained as suggested above and as given in Problem 6. In locating the points IT 1 and M 1 of this pattern it, Pattern Problems, 237 Fig. 4S1-— Patterns for the Fascias of a Hip Molding Finishing a Curved Mansard Roof Which is Square at the Eaves and Octagonal at the Top. 238 TJie New Metal Worker Pattern Book. is desirable for the sake of design that they be, when finished and in position, at the same vertical distance below the cornice as are the points S and T on the square sides of the roof. To accomplish this it will be necessary to go back to the points S 1 and T', in the first pattern obtained, and from them carry lines back into the dtretchout line 0" B 1 , where they are numbered 10-J- and 11^-. Their positions may now be transferred by means of the dividers to the normal profile B, where their vertical hights can be measured on the line A B, as shown, and transferred again to the vertical line A 1 B 1 of the diagonal section. It is only neces- sary now to carry them across, as shown, to the profile P 1 B', where their distances from adjacent points may be measured by the dividers and placed upon the stretch- out line P 2 B 3 . By similar means the appearance of this panel bof h in the plan and in the elevation may be completed if so desired, all of which will be made clear by inspection of the drawing. In the case of very large roofs, where the develop- ment of a profile or a pattern to the full size would be impracticable, it is possible to perform the work to a scale of 1-J- or 3 inches to the foot; after which full size patterns of parts of convenient size may be ob- tained by multiplying their various dimensions by 8 or 4. As the patterns for the roll, usually finishing the hip, are properly included under the head of Flaring Work, which subject is treated in the fol- lowing section of this chapter, they will not be given here. The radii from which they can be ob- tained, however, may be derived from the diagonal section in the manner described in the following problem. PROBLEM in. To Obtain the Curves for a Molding; Covering- the Hip of a Curved Mansard Roof. The method of obtaining the pattern of the fascias of a molding covering a curved hip has been given in Problem 6. As it is necessary in obtaining the pat- terns of the molded portion or roll, that the curve of the hip should be established, this problem really consists of developing from the normal profile of the roof a profile through the hip, or, in other words, a diagonal section of the mansard. Let A E B in Fig. 422 represent the plan of a mansard roof or tower, the elevation of which is shown by H K, over the hip of which a molding of any given profile is to be fitted, in this case a three-quarter bead, the diagonal line E F in the plan representing the angle, of the hip as it would appear if viewed from the top. At any convenient point parallel to E F, and equal to it, draw E 1 F 1 , and from F 1 erect a perpendicu- lar, F 1 K 1 , in length equal to the vertical line in eleva- tion Gr K. Divide Gr K and F 1 K 1 into the same num- ber of equal spaces. From the points in G K draw lines cutting the profile H K, as shown, and from the points thus obtained in H K drop lines vertically, pro- ducing them until they cut the diagonal line E F of the plan, as shown. Through the points in F 1 K 1 draw measuring lines in the usual manner, and intersect them by lines erected perpendicularly to E F from the points therein. Then a line traced through these points of intersection, as shown by E' K 1 , will be the profile to which the molding covering the hip is to be raised. Inasmuch as in the usual process of mold raising all curves must be considered as segments of circles, to accommodate both the adjustment of the machine used and the describing of the patterns, the curved line E 1 K 1 just obtained must be so divided that each section or segment will approach as nearly as possible an arc of a circle. In this case the section from E 1 to L will be found to correspond to an arc struck from a center, M, while the section from L to K' corresponds to an arc struck from a center not shown in the engrav- ing, but which will be found by the intersection of the lines L N" and K 1 N 1 produced. In the lower part of Fig. 423 is shown an enlarged section of the hip molding, including the fascias, as it would appear at the bottom of the hip, and above it another section taken at the top, which has been de- rived from the normal section or section at the bottom by the method used and explained in Problems 105, Pattern Problems. 239 106 and 107, previously demonstrated. A dotted reproduction of the lines of the upper section is the roll require trimming after being raised so that the roll may have an equal projection throughout its course. SECTION AT TOP Fig. 423.— Enlarged Sections Through Hip Finish at Top and Bottom, Showing Change in Flare of Fascias. A F ft ' V Fig. 422.— Diagonal Section of a Curved Mansard Roof Obtained for the Purpose of Mold Raising. placed here to show the change in the flare that takes place between fascias in going from the bottom to the top of the hip, thus showing that the outer edges of Methods of obtaining the patterns of curved mold- ings will be found in the following section of this chapter. 240 Tlie New Metal Worker Pattern Book. SECTION 2. Regular Tapering; Forums (FLARING WORK.) It will be well to place before the reader here a clear statement of the class of problems he may ex- pect to meet with under this head. It will include only the envelopes of such solid figures as have for a base the circle, or any figure of equal or unequal sides which may be inscribed within a circle, and which terminate in an apex located directly over the center of the base. According to the definition of an inscribed poly- gon (Def. 66), its angles must all lie in the circum- ference of the same circle. So the angles or hips of a pyramid whose base can be inscribed in a circle must lie in the surface of a cone whose base circumscribes its base and whose altitude is equal to that of the pyramid. Therefore the circle which describes the pattern of the base of the envelope of such a cone will also circumscribe the pattern of the base of the pyra- mid contained within it. The envelopes of such solids, therefore, as scalene cones, scalene pyramids and pyramids whose bases cannot be inscribed within a circle are not adapted to treatment by the methods employed in this section. Even the envelope of an elliptical cone cannot be included with this class of problems because it possesses no circular section upon which its circumference at any fixed distance from the apex can be measured. In this connection it is proper to call attention to the difference between a scalene cone and a right cone whose base is oblique to its axis. According to Defi- nition 96, a scalene cone is one whose axis is inclined to the plane of its base, and according to Definition 94 the base of a cone is a circle. As any section of a cone taken parallel to its base is the same shape as its base, any section of a scalene cone taken parallel to its base must be a circle, and any section taken at right angles to its axis could not, therefore, be a circle, but would be elliptical. Again, as any section of a right cone (Def. 95) at right angles to its axis is a circle, if its base be cut off obliquely, such base would, according to Definition 113, be an ellipse. There- fore, since its horizontal section is a circle, its envelope may be obtained by methods employed in this section. (See Problem 136.) And since the sec- tion of a scalene cone taken at right angles to its axis is an ellipse, the scalene cone becomes virtually an elliptical cone with an oblique base — that is, with a base cut off at such an angle as to produce a circle — and, as stated above, cannot be included in this section. The principles governing the problems of this section are given in Chapter V, beginning on page 79, which the reader will find a great help in explaining anything which he may fail to understand. PROBLEM H2. The Envelope of a Triangular Pyramid. Let A B C of Fig. 424 be the elevation of the pyramid, and E F Gr of Fig. 425 the plan. From the the point K erect K H, perpendicular to F K and equal in length to the hight of the pyramid, as shown by Fir. 424.— Elevation. Fig. 435.— Plan. The Envelope of a Triangular Pyramid. Fig. 436.— Pattern. center K draw the lines E K, F K and Gr K in the plan, representing the angles or hips of the pyramid. From A D of the elevation. Draw the hypothenuse F H, which then represents the length of the corner lines. Pattern Problems. 241 From any point, as L of Fig. 426, for center, with radius equal to F H, describe the arc M N I indef- initely, and draw L M. From M set off the chord M N, in length equal to the side F G of the plan. In like manner set off N and I respectively, equal to G E and E F of the plan. Connect I and L, as shown, and draw L and L ST. Then L I N M is the pattern sought. PROBLEM 113. The Envelope of a Square Pyramid. Let E A C of Fig. 427 be the elevation of the pyramid, and F H K L of Fig. 428 the plan. The diagonal lines F K and L II represent the plan of the angles or hips, and G a point corresponding to the apex A of the elevation. From the apex A drop the or circumscribe the pattern, as shown in the diagram From any center, as M, Fig. 429, with a radius equal to A D, describe an arc, as P E O S N, indefinitely and draw M P. From P, on the arc drawn, set off a chord, P R, in length equal to one of the sides of Fig. 437.— Elevation. Fig. 428.— Plan. The Envelope of a Square Pyramid. line A B perpendicular to the base E C. Prolong E C in the direction of D, making B D equal to G F, one of the angles of the plan. Connect D and A. Then A D will be the slant hight of the article on one of the corners, and the radius of an arc which will contain the pyramid shown in the plan. From R set off another chord, R 0, in like manner, and repeat the same operation, obtaining S and S X. Draw the lines M N, M S, M and M R. Then MNSOEP will be the required pattern. PROBLEM 114. The Envelope of a Hexagonal Pyramid. Let H G I of Fig. 430 represent the elevation of a hexagonal pyramid, of which DFCL B E of Fig. 431 is the plan. The first step is to construct a section on a line drawn from the center of the figure through one of its angles in the plan, as A B. From the center A erect A X perpendicular to A B, making it equal to the straight hight of the article, as shown in the eleva- tion by G K. Draw the hypothenuse B X. Then X represents the apex and XB the side of a right cone, the plan of the base of which, if drawn, would circum- scribe the plan of the hexagonal pyramid. From any convenient center, as X' of Fig. 432, with X B of 242 The New Metal Worker Pattern Book. Fig. 431 as radius, describe an arc indefinitely, as shown by the dotted line. Through one extremity of the arc to the center draw a line, as shown by D' X ! . B 1 L 1 in the arc thus obtained draw lines to the center, as shown by E' X', B' X 1 , etc., which will represent the angles of the completed shape, and serve to locate l\ \ 1 1 1 w 1 \\ / \\ / II E 1 \\ B' ^^; V Fig. 430— Elevation. Fig. 431.— Plan. Fig. 432.— Pattern. The Envelope of a Hexagonal Pyramid. With the dividers set to a space equal to any side of the plan, as D E, commencing at D 1 , setoff this distance on the bends to be made in process of forming up. Then X 1 D 1 E' B 1 L' C* F 1 D 2 will be the complete the arc six times, as shown. From the several points E 1 | pattern. PROBLEM 115. The Envelope of the Frustum of a Square Pyramid. In Fig. 433, let G H K I be the elevation of the article, C A E D the plan of the larger end and L M Construct a diagonal section on the line A P as fol- lows : Erect the perpendicular P F, making it equal \ M / V 1 K. / \ \ K. \ \ Fig. 433— Plan and Elevation. Fig. 434.— Pattern. The Envelope of the Frustum of a Square Pyramid. 1ST the plan of the smaller end. Produce the hip lines C L, A M, etc., in the plan to the center P. to the straight hight of the article, as shown by E K of the elevation. Likewise erect the perpendicular Pattern Problems. 243 M B of the same length. Draw F B and A B. Then P A B F is the diagonal section of the article upon the line P A. Produce A B indefinitely in the direc- tion of X, and also produce P F until it meets A B extended in the point X. Then X is the apex of a right cone and X A the side of the same, the base of which, if drawn, would circumscribe the plan C A E D. Therefore, from any convenient center, as X 1 of Fig. 434, with X A as radius, describe the arc C D' E' A 1 C 2 , and from the same center, with radius X B, draw the arc L' X' : M' L 2 , both indefinitely. Draw C X 1 , cutting the smaller arc in the point L 1 . Make the chord C D 1 equal in length to one side, U D, of the plan, and D 1 E 1 to another side, D E, of the plan, and so on, until the four sides of the base have been setoff. Draw D' X', E' X', etc., cutting the arc L 1 L 2 'in the points N 1 , 1 , etc. Then D 1 N 1 , E 1 O 1 and A' M 1 will represent the lines of the bends in forming up the pattern. Draw the chords L' N 1 , X : O 1 , etc., thus completing the pattern. PROBLEM 116. The Envelope of the Frustum of an Octagonal Pyramid. H N O' p. 5 Fig. 437.— Pattern. The Envelope of the Frustum of an Octagonal Pyramid. Fig. 435 shows the elevation and Fig. 43G the plan of the frustum of an octagonal pyramid. The first step in developing the pattern is to construct a diagonal section, the base of which shall correspond to one of the lines drawn from the center of the plan through one of the angles of the figure, as shown by Gr B. Erect the perpendicular G- C equal to the straight hight of the frustum, as shown by X M of the elevation, and at b erect a perpendicular, b A, of like length. Draw B A and A C. Then G B A C is a section of the article as it would appear if cut on the line Gr B. Produce B A indefinitely in the direction of X, and likewise prolong Gr C until it intersects B A produced in X. Then X is the apex and X B the side of a right cone, the plan of which, if drawn, would circumscribe the base of the frustum. From any convenient center, as X', Fig. 437, with radius X B, describe an arc indefinitely, as shown by the dotted line E' E 2 of the pattern, and from the same center, with X A for radius, describe the arc e' e 2 of the pattern. Through one extremity of the arc E 1 Ej to the center draw a straight line, as shown by E 1 X 1 cutting the smaller arc in the point e'. Set off on the arc E 1 E 2 spaces equal to the sides of the plan of the base of the article and connect the points by chords. Thus make E 1 P 1 of the pattern equal to E P of the plan, and so on. Also from these points in the arc draw lines to the center, cutting the arc e 1 e 2 , as shown. Connect the points thus obtained in this arc by chords, as shown by e 1 p\ p l d\ d 1 o\ etc. Then e' E' E 2 e 2 will be the pattern sought. 244 Tlte New Metal Worker Pattern Book. PROBLEM 117. The Envelope of the Frustum of an Octagonal Pyramid Having: Alternate Long- and Short Sides. In Fig. 438, let IMBNOPKLbe the plan of the article of which G H F E is the elevation. The first thing to do in describing the pattern is to construct a section corresponding to a line drawn from the center Produce S R and B A until they meet in the point X. Then X is the apex and X B is the side of a cone, the base of which, if drawn, would circumscribe the plan • of the article. From any convenient center, as X 1 , Fig. 439, with radius equal to X B, describe an arc. as shown by M 1 M 2 . Draw X 1 M 1 as one side of the pattern. Then, starting from M 1 , set off chords to the arc, as shown by M 1 B 1 , B 1 X 1 , etc., equal to and corre- sponding with the several sides of the article, as shown by M B, B N, etc., in the plan. From these points, B 1 , N 1 , etc., in the arc, draw lines to the center X 1 . o' p' D f Fig. 438.— Plan and Elevation. Fig. 439— Pattern. The Envelope of the Frustum of an Octagonal Pyramid Having Alternate Long and Slwrt Sides. to one of the angles in the plan, as S B. At S erect the perpendicular S R, in length equal to the straight hight of the article, as shown by C D of the elevation. Upon the point b erect a corresponding perpendicular, as shown by b A. Draw R A and A B. Then B A R S is a section of the article taken upon the line S B. From X 1 , with X A as radius, describe an arc cutting these lines, as shown by to 1 m\ Connect the points of intersection by straight lines, as shown by m l b 1 , b 1 n', n l o 1 , etc. Then m l m 2 M 2 M 1 will be the pattern sought, and the lines B 1 V, X 1 n\ etc., will represent the lines of bends to be made in forming up the article. PROBLEM 118. The Pattern of a Square Spire Miteringf Upon Four Gables. In Fig. 440, let B F H C be the elevation of a square spire which is required to miter over four equal gables in a pinnacle, the plan of which is also square. Produce F B and H C until they meet in A, which will be the apex of the pyramid of which the spire is a section. Draw the axis A G, and at right angles to it, Pattern Problems. 245 from the lowest point of contact between the spire and the gable, as F, draw F G. Then F G will represent the half width of one of the sides of the pyramid at the base, and A F will represent the length of a side through its center. From any convenient point, as A 1 spaces of the extent of Gr' Gr 2 , as shown by G 2 g, g g' and g 2 0. Draw g 1 A 1 , g A 1 and A 1 . Make A 1 B' equal to A B of the elevation, and through B 1 draw a perpendicu- lar to A' F 1 , as shown. Draw lines corresponding to it through the other sections of the pattern. Make A 1 D 1 Fig. 440.— Elevation of Spire. Fig. 441.— Pattern. The Pattern of a Square Spire Mitering Upon Four Gables. in Fig. 441, draw A 1 F 1 , in length equal to A F. From F 1 set off, perpendicular to A' F 1 , on each side a space equal to F G of the elevation, as shown by F 1 Gr' and F' Gr 2 . From Gr 1 and G a draw lines to A 1 , as shown. From A 1 as center, and with A' G 2 as radius, describe an arc, as shown by G 2 0, in length equal to three equal to A D, and draw D 1 G 1 and D 1 G 2 . Set the compasses to G 2 D', and from G 2 and g as centers describe arcs intersecting at d. Draw d g and d G 2 , as shown. Repeat the same operation in the other sections of the pattern, thus completing the required shape. PROBLEM 119. The Pattern of an Octagon Spire Mitering Upon Eight Gables. Let A G L in Fig. 442 be the elevation of the spire, and MOP the half plan. From the point G, which represents the lowest point of the angle or valley between the gables, to H, which represents the meet- ing of the valleys and ridges at T in the plan, draw the line G H, cutting the side A C extended in the point D. Draw any line, as A 1 D 1 in Fig. 443, upon which to construct the pattern. Make A 1 C 1 equal to 240 Tlie New Metal Worker Pattern Book. A C of the elevation, and A 1 D 1 equal to A D of the elevation. Through D 1 draw the horizontal line 1 0, as Draw A 1 and A 1 1. Set the dividers to A 1 1 as radius, and from A 1 as center describe the arc 1 8 in- definitely. Set the dividers to 1 0, and step off as many spaces on the arc as there are sides in the spire. Draw the lines A 1 2, A' 3, etc., to A 1 8, which represent the angles of the spire and the bends in the pattern. Draw C and C 1 1 in the first section of the pattern. Set the dividers to C 1 1, and from 1 and 2 as' centers describe intersecting arcs, as shown by C. In like manner describe similar intersecting arcs at the points Fig. 443.— Plan and Elevation of Spire. Fig. 413— Pattern. The Pattern of an Octagon Spire Mitering Upon Eight, Gables. shown. From D 1 set off D' 0, equal to E F of the ele- vation, and likewise set off D 1 1, of the same length. C 3 , C 4 , etc. Draw lines from these points to the points 1, 2, 3,4, etc., as shown, thus completing the pattern. PROBLEM 120. The Pattern of an Octagon Spire Mitering Upon Four Gables. In Fig. 444, let B E Z U be the elevation of an octa- gon spire, mitering down upon four gables occurring upon a square pinnacle. Continue the side lines until they intersect in the apex A. Draw the center line A H, and from the point Gdraw G H perpendicular to the center line, showing half the width of one of the sides at the point Gr. By inspection of the elevation it will be seen that one-half the sides will be notched at the bottom to fit over the gables, while the others will be pointed to reach down into the angles or valleys be- tween the gables. To ascertain the correct length upon the center line of one of the pointed sides it will be necessary to construct a section through one of the valleys, for in- Pattern Problems. 247 stance, upon the line M' N' of the plan. Through the point J of the elevation draw the line J M at right angles to the center line, extending it to the left in- definitely, and from the point M set off upon this line the distance M N, equal to M 1 N 1 of the plan. Draw equal to A E of the elevation, etc. Through E 1 draw a perpendicular equal in length to the width of a side at the point E, or to twice Gr H, as shown in the ele- vation, placing one-half on each side from E', all as shown by L K. From L and K draw lines to A 1 . Erom A' as center, with A 1 L as radius, describe an arc, as shown by L U, indefinite in length. Set the dividers to the space L K, and step off spaces from L, as L Y, Y X, etc., until as many sides are set off as are required in the spire — in this case eight. Draw the lines A' Y, A 1 X, etc. From the point D', which, as will be seen by D in the elevation, corresponds to the top of the gable, draw lines to the points L and K, which gives the pattern for the notch in the first section. Set the dividers to L D' as radius, and from X and Y as centers describe arcs intersecting at W. Draw W X and W Y, and repeat this upon all the alternate sides throughout the pattern, as shown, locating the Fig. 444— Plan and Elevation of Spire. Tig. 445.— Pattern. The Pattern of an Octagon Spire Mitering Upon Four Gables. N P, and extend the side A E until it intersects this line at F. Then A F will be the correct length through the center line of one of the long sides. To describe the pattern first draw A 1 F 1 in Fig. 445, equal to' A F of the elevation, and set off points on it corresponding to points in A F. Thus make A' B 1 equal to A B, A 1 D 1 equal to A D, and A 1 E 1 points and P. For the pattern of the point, take a space between the points of the dividers equal to L F 1 , and from L and Y as centers describe small arcs intersecting at M, and draw M L and M Y. With the same radius repeat the operation upon the inter- mediate sides, establishing the points V, H and I, thus completing the pattern. 248 Tlie New Metal Worker Pattern Book. PROBLEM 121. Pattern for an Octagon Spire Mitering upon a Roof at the Junction of the Ridge and Hips. In Fig. 446, let A B C represent the front eleva- i vation let W N M K J II represent the octagon tion of the roof and A' a c C the corresponding plan. | spire and II' J' K' M' N' 0' the corresponding plan. PLAN. c ' c " PLAN Fig-. 446. — Plana and Elevations of Spire. C° Y° Fig. 447.— Section of Spire on Line of Hip. Pattern for an Octagon Spire Mitering Upon a Roof at the Junction of the Ridge and Hips. Also let D E F Gr be the side elevation of roof, and In the side elevation the spire is represented by P X A" a c' C" the corresponding plan. In the front ele- UTBQ, and in plan by P' Q' R' T' U' V. Only Pattern Problems. 249 the points in plans are designated by letters which represent similar points in the elevation. In order to draw the plans and elevations, including the miter lines, it may be found convenient to first construct the entire octagons, as indicated in the plans, and from these to project the elevations above, as shown. From the point u in front elevation, which represents the intersection of one of the rear angles of the spire with the roof, carry a line parallel with B F, cutting X p. From the point U draw the miter line U T, and from the points V U drop jaerpendiculars to plan, cutting X' V and X' U', from which points can be drawn the miter lines V U' T' of the plan. To obtain the miter line P' Q' R' of plan, from which is obtained the miter line Q R of side elevation, a diagram has been constructed in Fig. 447 which shows a section of spire and roof on the line C" X' of plan. To construct the diagram proceed as follows : Draw any line, as X° Y°. From X° set off the dis- tance X E of side elevation or W B of front elevation. The point E° represents the junction of hip and ridge. From X° set off the distance X S, and erect the perpendicular S° L°, making it in length equal to S P, and connect L° X°. Then X° S° L° is a duplicate of X S P. From X° set off the distance X Y and erect the perpendicular Y° C°, in length equal to X' C" of plan, and connect C° E°. Then L° X° repre- sents one side of spire, and C° E° the hip of the roof, and the point Q° the point of junction between the two. As the spire is a perfect octagon, the profile of - the side just constructed is in nowise different from either of those shown in the elevations. It simply has in addition the profile of one of the hips by means of which the correct hi°'ht of its intersection with the same (the point Q°) is determined. Draw Q° Z° paral- lel with C° Y°, and from the point X' of plan set off the distance Z° Q° of diagram, as shown by X' Q'. Connect R' Q' and Q' P'. From the point Q' in plan carry a line parallel with the center line X X', cutting the hip line D E at Q. Draw Q R, which shows the miter line in side elevation. From the point Q can be drawn the line Q J, cutting the hip lines A B and B C in front elevation at the points J and X, and the miter lines J K and M N drawn. The points K M in front elevation correspond with the points K' M' of plan. For the pattern proceed as follows : Draw I x of Fig. 448, equal to P X of side elevation, and from I erect the perpendiculars I p and I p', equal in length to L' P' of plan or L M of front elevation. From p and p draw lines to x, as shown. From x as center, with x p as radius, describe an arc, as shown by p' e, indefinite in length. Set the dividers to the distance p p and step off spaces from p, as p r, r t, etc., un- til as many sides are set off- -as are desired to be shown in one part of the pattern. For convenience in de- scribing the pattern draw the lines x r, x t, x c. Con- nect c and e and make c d equal to p I and draw x d. Bisect p r and draw x a, and from x, onxa, set off the distance X° Q° of Fig. 447, locating the point q. Draw p q and q r. From x, on x d, set off the distances X V and X U of side elevation, locating the points v and i. Through i draw a perpendicular cutting x c and x e in the points u and u', then draw u' v v u and u t. Then x p p q r t u v u' is the pattern for part of spire shown on plan by X' I P' Q' R' T' U' V P. Fig. 448 shows a little more than half the full pattern, which will be readily understood by a com- parison of reference letters. PROBLEM 122. The Envelope of a Right Cone. In Fig. 449 let A B C be the elevation of the cone and D E F the plan of the same. To obtain the envelope set the compasses to the space B A, or the slant hight of the cone, as a radius, and from any convenient point as center, as B 1 of Fig. 450, strike an arc indefinitely. Connect one end of the arc with the center, as shown by A 1 B 1 . With the dividers, using as small a space as i; 250 Tlie New Metal Worker Pattern Booh. convenient, step off the circumference of the plan D E F, counting the spaces until the whole, or exactly Fig. 449.— Plan and Blevation. B 1 A 1 C will be the pattern for the envelope of the cone ABC. It is not necessary that all of the spaces used in measuring the circumference of the plan should be equal. It frequently happens that when the space assumed between the points of the dividers has been stepped off upon the circumference of the base, a space will remain at the finish smaller than that originally Fig. 450.— Pattern. The Envelope of a Right Cone. one half, is completed, as shown in the upper half of the plan. Then set off on the arc A 1 C l of the pattern, commencing at A 1 , the same number of spaces as is contained in the entire circumference of the plan. Connect the last point C 1 with the center B 1 . Then assumed. In that case the required number of full spaces can be stepped off upon the arc of the pattern, after which the remaining small space may be added, thus completing the correct measurement of the pattern. PROBLEM 123. The Envelope of a Frustum of a Right Cone. The principle involved in cutting the pattern for the frustum of a cone is precisely the same as that for cutting the envelope of the cone itself. The frustum of a right cone is a shape which enters so extensively into articles of tinware that an ordinary flaring pan, an elevation and plan of which are shown in Fig. 451, has been engraved for the purpose of illustration. An in- spection of the engraving will show that C D, the top of the pan, is the base of an inverted cone, its apex B being at the intersection of the lines D and C A forming the sides of the pan ; and that A D is the top of the frustum or the base of another cone, A B, which remains after cutting the frustum from the orig- inal cone. For the pattern then proceed as follows : Pattern Problems. 251 Through the elevation draw a center line, K B, indef- initely. Extend one of the sides of the pan, as, for example, D 0, until it meets the center line in the point B. Still greater accuracy will be insured "by ex- tending the opposite side of the pan also, as shown — the three lines meeting in the point B — which deter- mines the apex of the cone to a certainty. Then B and B D, respectively, are the radii of the arcs which contain the pattern. From B or any other convenient point as center, with B as radius, strike the arc P Q indefinitely, and likewise from the same center, with B D as radius, strike the arc E F indef- initely. From the center B draw a line across these arcs near one end, as P E, which will be an end of the pattern. By inspection and measurement of the plan determine in how many pieces the pan is to be constructed and divide the circumference of the pan into a corresponding number of equal parts, in this case three, as shown by K, M and L. With the dividers or spacers step off the length of one of these parts, as shown from M to L, and set off a corresponding num- ber of spaces on the arc E F, as shown. Through the last division draw a line across the arcs toward the center B, as shown by F Q. Then P Q F E will be the pattern of one of the sections of the pan, as shown in the plan. Fig. 451. — The Envelope of the Frustum of a Right Cone. PROBLEM 124. To Construct a Ball in any Number of Pieces, of the Shape of Zones. In Fig. 452, let A I G H be the elevation of a ball which it is required to construct in thirteen pieces. Divide the profile into the required sections, as shown by 0, 1, 2, 3, 4, etc., and through the points thus ob- tained draw parallel horizontal lines, as shown. The divisions in the profile are to be obtained by the fol- lowing general rule, applicable in all such cases : Divide the whole circumference of the ball into a num- ber of parts equal to two times one less than the num- ber of pieces of which it is to be composed. In convenient proximity to the elevation, the center being located in the same vertical line A 1ST, draw a plan of the ball, as shown by K M L 1ST. Draw the diameter K. L parallel to the lines of division in the elevation. With the J-square placed at right angles to this diameter, and brought successively against the points in the elevation, drop corresponding points upon it, as shown by 1, 2, 3, 4, etc. Through each of these points describe circles from the center by which the plan is drawn. Each of these circles becomes the plan of one edge of the belt in the elevation to which it corresponds in number, and is to be used in estab- lishing the length of the arc forming the pattern of the zone of which it is the base. Extend the center line NA in the direction of indefinitely. Draw chords to the several arcs into which the profile ha3 been divided, which produce until they cut G A 0, as shown by 1 2 E, 2 3 D, 3 4 C, 4 5 B and 5 6 A. Then E 2 and E 1 are the radii of parallel arcs which will describe the pattern of the first division above the cen- 252 Tlie New Metal Worker Pattern Book. ter zone, and D 3 and D 2 are the radii describing the pattern of the second zone, and so on. From E' in Fig. 453 as center, with E 2 and E 1 as radii, strike the arcs 2 2 and 1 1 indefinitely. Step the centers D', Fig. 454; C, Fig. 455; B', Fig. 456, and A 1 , Fig. 457. The pattern for the smallest section, as indicated by F in the plan, may be struck by a radius equal to F 6 in the plan. The center belt or "Pig. 453— Pattern of Zone 1 2. Fig. 455.— Pattern of Zone 3 4. Fig. 456— Pattern of Zone 4 5, Fig. 457.— Pattern of Zoup R * Fig. 452.— Plan and Elevation Fig. 454.— Pattern of Zone 2 3. Fig. 458.— Pattern of Middle Zone. To Construct a Ball in any Number of Zones. off the length on the corresponding plan line, and make 1 1 equal to the whole of it, or a part, as may be de- sired — in this case a half. In like manner describe patterns for the other pieces, as shown, struck from zone, shown in the profile by 1 0, is a flat band, and is therefore bounded by straight parallel lines, the width being 1 in the elevation, and the length meas- ured upon line 1 of the plan, all as shown in Fig. 458. Pattern Problems. PROBLEM 125. The Patterns for a Semicircular Pipe with Longitudinal Seams. 253 By the nature of the problem the pipe resolves it- self, with respect to its section, or profile, into some regular polygon. In the illustration presented in Fig. 4-59 an octagonal form is employed, but any other reg- the profile ABCDFHGE and project the points B and C back upon N R and complete the elevation by drawing the semicircles U and P T. By inspection of the diagram it is svident that the pattern for the sections corresponding to O U T P in the elevation may be pricked directly from the drawing as it is now constructed, and that the pat- terms for the sections represented by B A and D F of the profile will be plain straight strips of the width of one side of the figure, as shown by either E A or D F, and in length corresponding to the length of the sweep of the elevation on the lines NLV and RXS, respectively. By virtue of the bevel or flare of the pieces N L V U T and R X S T P, as shown by A B and C D of Ft£. 459.— Elevation and Section Fig. 460.— Pattern. A Semicircular Pipe with Longitudinal Seams. ular shape may be used, and the patterns for it will be cut by the same rule as here explained. Let NLYbe any semicircle around which an octagonal pipe is to be carried. Draw N V, passing through the center W. Through W draw the perpendicular L K indefinitely. Let N R be the required diameter of the octagon. Immediately below and in line with N R construct the profile, each becomes one-half of the frustum of a right cone, with its apex above or below the point W. Therefore prolong C D of the profile until it cuts the center line L K of the elevation in the point M. Then M D and M G are the radii of the pieces corresponding to P T S R of the elevation. Also prolong the side A B, or, for greater convenience, its equivalent, E G, until it 254 The New Metal Worker Pattern Book. cuts the center line in the point M 1 . Then M' G and M 1 E are the radii of the pieces corresponding toNLV U of the elevation. From M 2 in Fig. 460 as center, using each of the several radii in turn, strike arcs in- definitely, as shown by N' V, O 1 U\ P 1 T 1 and B* S 1 . Step off the length NLYin the elevation, Fig. 457, and make N 1 V 1 of Fig. 458 equal to it. Draw N' O 1 and V U' radial to M\ Then N 1 V IP O 1 will con- stitute the pattern for the pieces N L V U of the elevation. In like manner establish the length of P 1 T', and draw P 1 R 1 and T 1 S 1 , also radial to the center, as shown. Then P' T' S 1 R 1 will be the pattern for the pieces P T S X R of the elevation. This rule may be employed for carrying any polyg- onal shape around any curve which is the segment of a circle. The essential points to be observed are the placing of the profile in correct relationship to the ele- vation and to the central line L K, after which prolong the oblique sides until they cut the central line, thus establishing the radii by which their patterns may be struck. In the case of elliptical curves, by resolving them into segments of circles and applying this rule to each segment, as though it were to be constructed alone and distinct from the others, no difficulty will be met in describing patterns by the principles here set forth. The several sections may be united so as to produce a pattern in one piece by joining them upon their radial lines. This principle is further explained in the pattern for the curved molding in an elliptical window cap in Problem 128. PROBLEM 126. The Blank for a Curved Molding:. As curved moldings necessitate a stretching of the metal in order to accommodate them to both the curve oi the elevation or plan and the curve of the profile at machinery designed for that purpose, care being taken to make the width of the flaring strip suffi- cient to include the stretchout of the curve of the pro- M,\ s Fig. 461. — Obtaining the Blank for a Curved Cove or Ovolo Molding. Fig. 462.— Obtaining the Blank for a Curved Ogee Molding. the same time, the patterns for their blanks can only be considered as flaring strips of metal in which the curve of the elevation or plan only is considered. The curve of the profile requires to be forced into them by file. Blanks for curved moldings thus become frus- tums of cones and are cut according to the principles of regular flaring articles, as explained in the preceding problems. The method of determining the exact flare Pattern Problems. 255 necessary to produce a certain mold with the greatest facility is a matter to be determined by the nature of the profile and the kind of machinery to be used in forming the same. Usually a line is drawn through the extremities of the profile, as shown at A D in either of the two illustrations here given, Figs. 461 and 462, and is continued until it meets the center line, for length of radius, as shown at F. Therefore, to describe the pattern of the blank from which to make a curved molding corresponding to the elevation A C E D, proceed in the same manner as though the side E C were to be straight. Through the center of the article draw the line B F indefinitely, and draw a line through the points C and E of one of the sides, which produce until it meets B F in the point F. Then F E will be the radius of the inside of the pattern. The radius of the outside is to be ob- tained by increasing F G an amount equal to the excess of the curved line E C over the straight line E C, as shown by the distance C S. Then F S is the radius of the outside of the pattern. The length of the pattern can be obtained as in previous problems. PROBLEM 127. The Patterns for Simple Curved Moldings in a Window Cap. In Fig. 463 is shown the elevation of a window cap, in the construction of which two curved moldings are required of the same profile, but curved in opposite essary for joining it to the face and roof pieces will be obtained in one piece. The method of developing the pattern for the blank is the same for both curves. The Fig. 463.— Elevation of Window Cap. Fig. 464.— Blank for Center Pieoe. e 1 /-\_ 1 jL_ 8 *■--—-. "* 9 Fig. 465.— Blank for Side Piece. The Patterns for Simple Curved Moldings in a Window Cap. directions. It is advisable to include as much in one piece as can be raised conveniently with the means at hand ; therefore, the curved part of the profile with its fillets or straight parts adjacent and the two edges nec- two pieces will raise to the form by the same dies or rolls, it being necessary only to reverse them in the machine. Before the blank for the middle piece can be developed it will be necessary to first construct a 256 The New Metal Worker Pattern Book. section upon the center line, as shown at S K ; from all points in the mold and the center of the curve upon the center line project horizontal lines to the right. Draw any vertical line, as H K, to represent the face of the cap in the section and at S draw the profile of the mold, as shown. The principle to be employed in strik- ing the pattern is simply that which would be used in obtaining the envelope of the frustum of a cone of which A D is the axis. The general average of the profile is to be taken in establishing the taper of the cone, or, in other words, a line is passed through its extreme points. Draw a line through the profile in this manner and pro- long it until it intersects A D in the point A, all as shown by C A. Then A is the apex of the cone, of which A C is the side and H D the top of the frustum. Divide the profile S, as in ordinary practice for stretch- outs, into any number of spaces, all as shown by the small figures. Transfer the stretchout of the profile S on to the line A C, commencing at the point 1, as shown, letting the extra width extend in the direction of C. From any convenient center, as A in Fig. 464, with radius A C, describe the pattern, making the length of the arc equal to the length of the correspond- ing arc in the elevation, all as shown by the spaces and numbers. From the same center draw arcs correspond- ing to points 9, 10 and 11 of the stretchout, thus com- pleting this pattern. For the pattern of the curved molding forming the end portion of the cap proceed in the same general manner. Upon any line drawn through the center N of the curve, as L M, construct a section of the mold, as shown at R. From N draw the perpendicular N B indefinitely. Through the average of the profile R, as before explained, draw the line to B, cutting N Bin the point B, as shown. Lay off the stretchout of the profile upon this line, commencing at the point 1, in the same manner as explained in the previous operation. From any convenient point, as B' in Fig. 465, as center, with radius B 1, describe the inner curve of the pat- tern, as shown, which in length make equal to the eleva- tion, measuring upon the arc 1, all as shown by the small figures, after which add the outer curves, as shown by E 1 E\ The straight portion forming the end of this mold- ing, as shown in the elevation, is added by drawing, at right angles to the line E 5 B 1 , a continuation of the lines of the molding of the required length, as shown in the pattern. Upon this end of the pattern a square miter is to be cut by the ordinary rule for such purposes, to join to the return at the end of the cap. PROBLEM 128. The Pattern for the Curved Molding in an Elliptical Window Cap. In Fig. 466 is shown the elevation and vertical sec- tion of a window cap elliptical in shape, the face of which is molded. In drawing the elevation such centers have been employed as will produce the nearest approach to a true ellipse after the manner described in Problem 76 of Geometrical Problems, page 65. The centers B, D and F, from which the respective segments of the elevation have been described, may then be used in obtaining pat- terns as follows : Through the center F, from which the arc forming the middle part of the cap is drawn, and at right angles to the center line of the cap Gr H, draw the line I K indefinitely. Project a section on the center line of the cap, as shown by P K at the right, the line P K being used as a common basis of measurement upon which to set off the semi-diameters of the various cones of which the blanks for the moldings form a part. Through the average of the profile, as indicated, draw S R, producing the line until it meets I K. Divide the profile of the molding in the usual manner and lay off the stretchout, as indicated by the small figures. Then R S is the radius of the pattern of the middle segment of the cap. With the dividers, measuring down from the pro- file, lay off on P K distances equal to the length of the radius A B, as shown by the point 0, and of C D, as shown by the point M. Through these points and M, at right angles to P K, draw lines cutting S R in the points T and U. Then U S is the radius for the pattern of the segment C E of the elevation, and T S the radius of the pattern for the segment A C. In order to obtain the correct length of the pattern, not only as regards the whole piece, but also as regards the length of each arc constituting the curve, step off the length of the curved molding with the dividers upon any line of the elevation most convenient, as shown, numbering the spaces as indicated, and setting off a like number of spaces upon a corresponding line of the pattern. As a matter both of convenience and Pattern Problems. 257 accuracy, the spaces used in measuring the arcs are greater in the one of longest radius and are diminished in those of shorter radii, as will be noticed by examina- tion of the diagram. To lay off the pattern after the radii are obtained as above described, proceed as follows : Draw any straight line, as G' H 1 in Fig. 467, from any point in which, as F', with radius equal to R S, as shown by F 1 E 1 , describe an arc, as shown by E 1 G 1 ; and likewise, from the same center, describe other arcs cor- responding to other points in the stretchout of the pro- file. Make the length of the arc E' G 1 equal to the length of the corresponding arc in the elevation, as de- scribed above. From E 1 to the center F', by which this arc was struck, draw E 1 F 1 . Set the dividers to the distance U S as radius, with which, measuring from E length of the corresponding arc in the elevation, all as shown by the small figures. From C draw the line C 1 D 1 to the center by which this arc was struck. Fig. 467.— Blank for the Curved Molding. Fig. 466.— Elevation and Section of Window Cap.' The Pattern for the Curved Molding in an Elliptical Window Cap. along the line E 1 F", establish D' as center, from which describe arcs corresponding to the points in the profile, as shown from E 1 to C. Make E 1 C equal to the Set the dividers to the distance T S in the section, and, measuring from C along the line C D 1 , establish the point B 1 , from which as a center strike arcs cor- 258 Hie New Metal Worker Pattern Book. responding to those already described in the other section of the pattern. Make the length equal to the length of the corresponding segments in the elevation, and draw the line A 1 B 1 . Then A 1 C E 1 G l is the half pattern corresponding to A C E G of the elevation. PROBLEM 129. The Pattern of an Oblong: Raised Cover with Semicircular Ends. In Fig. 468 let A B C D represent a side eleva- tion of the cover of which E G F H is the plan or shape of the vessel it is to fit. Various constructions may be employed in making such a cover as this; that is, the joints, at the option of the mechanic, may be placed at other points than shown here ; the prin- ciple used in obtaining the shape, however, is the same, whatever may be the location of the joints. By inspection of the elevation and plan it will be seen that the shape consists of the two halves of the en- velope of a right cone, joined by a staiight piece. Therefore, for the pattern proceed as follows : At any convenient point lay off B 2 C 2 , in length equal to B 1 C 1 of the plan. From B 2 and C 2 as centers, with radius equal to A B or C D of the elevation, describe arcs, as shown by N and P M. Upon these arcs, measured from and P, respectively, set off the stretchout of the semicircular ends, as shown in plan, thus obtaining the points M and N. From N draw N B', and from M draw M C\ From B 2 and C 2 , at right angles to the line B 2 C 2 , draw B 2 K and C 3 L, in length equal to A B of the elevation, which represents e C ^^ ^\ G ! V^ ~^~\ j Y \| E'\ B ' J V ' Xn^ ^y • ■ H 6 P i^y* -~f J 2 B lc* ' N. / -v Fig. 468. — Elevation, Plan and Pattern of an Oblong Raised Cover with Semicircular Ends. the slant hight of the article. Connect K and L, as shown. Then N K L M P will be the required pattern. PROBLEM 130. The Pattern of a Regular Flaring- Article which Is Oblong- with Semicircular Ends. In Fig. 469, let A B D C be the side elevation of the required article. Below it and in line with it draw a plan, as shown by E c d F H G. From D in the elevation erect the perpendicular D L. Then L C represents the flare of the article and C D is the width of the pattern throughout. Across the plan, at the point where the curved end joins the straight sides, draw the line d H at right angles to the sides of the article. As the plan may be drawn at any distance from the elevation, this line must be prolonged, if necessary, to meet C D extended. Produce C D until it meets d H, as shown by g. Then g D and g C are radii of the curved parts of the pattern. Lay off on a straight line M in Fig. 470, the length of the straight part of the article, as shown in the plan by c d. At right angles to M draw M S and B, indefinitely. Upon these lines set off from M and the distance g C, locating the points S and R, Pattern Problems. 259 the centers for the curved portions of the pattern. From S with the radius g C strike the arc M U indef- initely. In like manner, with same radius, from E as center describe the arc V. From the same centers, with radius equal to g D, describe the arcs N T and P "W. Step off the length of the curved part of the article upon either the inner or outer line of the plan, and make the corresponding arc of the pattern equal to it, as shown by the spaces in N T and P W. Through the points T and "W draw lines from the centers S and E, producing them until they cut the outer arcs at IT and V. At right angles to the line STUorEW V, as the case may be, set off V X Y W, equal to M P N, which will be the other straight side of the pattern. Then U M V X Y W P N T will be the complete pattern in one piece. If it were desired to locate the seam midway in end, instead of all at one end, as shown. In like man- ner such changes may be made as are necessarv for Fig. 469.— Plan and Elevation. Pig-. 470.— Pattern. The Pattern of a Regular Flaring Article Which is Oblong with Semicircular Ends. one of the straight sections, in adding the last member as above described, one-half would be placed at each locating the seam at any other point, or for cutting the pattern in as many pieces as desired. PROBLEM 131. The Pattern of a Regular Flaring Oblong Article with Round Corners. In Fig. 471, A C D B is the side elevation of the article and EFGMNOPEthe plan. The corners are arcs of circles, being struck by centers H, L, T and S, as shown. Draw the plan in line with the ele- vation, so that the same parts in the different views shall correspond. Through the centers H and L of the plan by which the corners F Gr and M N are struck, draw F N indefinitely. Prolong the side line of the elevation C D until it cuts F 1ST in the point K, as shown. Then K D is the radius of the inside line of 260 TJie New Metal Worker Pattern Book. the pattern of the curved part, and K C is the radius of the outside line. Draw the straight line E 1 F of Fig. 472, in length equal to the straight part of one side of the article, or E F of the plan. Through the points E 1 and F 1 , at right angles to the line E' F 1 , draw lines indefinitely, as shown by E 1 U and F 1 K 1 . Upon these lines set off, from F 1 and E', the distance K C, locating the points K 1 and U, the centers for the curved parts. From K 1 , with the radius K C, strike the arc F 1 G 1 , which in length make equal to F G of the plan. From G 1 draw a line to the center K', at right angles to which erect G' M 1 , in length equal to G M of the plan. In like manner, with like radius, describe the arc E 1 R 1 . Draw R 1 U, at right F / «U N Fig. 471.— Plan and Elevation. right angles to it lay of! 0' N 1 , equal to N of the elevation. Draw 1ST 1 W, and draw the arc N 1 M* in the Fig. 473.— Pattern. The Pattern of a Regular Flaring Oblong Article With Round Corners. angles to which erect R 1 P 1 , equal to R P of the plan. At right angles to R' P 1 draw P 1 V indefinitely. In the manner above described establish the center V, and from it describe the third arc P l 0'. Draw 1 V. At same manner as already described. In the same man- ner lay off the inner line of the pattern, as shown by mgferpon m l . Join the ends M 1 m and M 3 m 1 , thus completing the pattern sought. PROBLEM 132. The Envelope of the Frustum of a Cone, the Base of Which Is an Elliptical Figure. This shape is very frequently used in pans and plates, and therefore in Fig. 473 is shown an elevation and plan of what is familiarly termed an oval flaring pan. Let that part of the plan lying between H and L be an arc whose center is at U, and let those por- tions between V and H and L and W be arcs whose Pattern Problems . 261 centers are, respectively, R and S. A C D B represents an elevation of the vessel, and is so connected with the plan as to show the relationship of corresponding points. The first step is to construct a diagram, shown in Tig. 474, by means of which the lengths of the radii to be used in describing the pattern are to be obtained. Draw the horizontal line H U indefinitely, and at right angles to it draw H A, indefinitely also. Make II U equal to H U of the plan, Fig. 473. Make H C equal to the vertical hight of the vessel, as shown in the N 0. From the points H and L of the arc first drawn draw lines to A, thus intercepting the arc N and determining its length. In the diagram, Fig. 474, set off from H, on the line H U, the distance R H, making it equal to E H of the plan, Fig. 473. Also, upon the line C G, from the point C, set off C I, equal to E N of the plan. Then, through the points R and I thus established, draw the line R B, which produce until it intersects A II. Then R B will be the radius for those portions of the pattern lying between V and H and L and W of Fig. 473.— Plan and Elevation. R U Fig. 474.— Diagram of Radii. Fig. 475.— Pattern of One Half. The Envelope of the Frustum of a Cone, the Base of Which is an Elliptical Figure. elevation by D X. Draw the line C G parallel to H U, making C G in length equal to U N of the plan. Through the points U and G thus established draw the line U G, which continue until it meets H A in the point A. Then A U will be the radius by which to describe that portion of the pattern which is included between the points H and L of the plan. With A U as radius, and from any convenient point as center — as A, Fig. 475 — draw the arc H L, which in length make equal to H L of the plan, Fig. 473, as shown by the points 1, 2, 3, etc. From the same center, and with f,he radius A G of Fig. 474, describe the parallel arc the plan. From the point H, on the line H A, Fig. 475, set off the distance H B, equal to R B of Fig. 474. Then, with B as center, describe the arc E H, and from a corresponding center, C, at the opposite end on pattern, describe the arc L K. From the same centers, with B I as radius, describe the arcs N M and P, all as shown. Make H E and L K in length equal to H E and L K of the plan. From E and K, respectively, draw lines to the centers B and C, inter- cepting the arcs 1ST M and P in the points M and P. Then E K P M will be one-half of the complete pat- terns of the vessel. PROBLEM 133. The Pattern of a Heart-Shaped Flaring: Tray. Let E C G 1 F G C of Fig. 476 be the plan of the article, and INOK the elevation. By inspection of the plan it will be seen that each half of it consists of two arcs, one being struck from D or D 1 as center, and the other from C or C as center, the junction between the two arcs being at G and G 1 , respectively. From G 262 The New Metal Worker Pattern Book. draw C F, and likewise draw C G. Upon the point D : erect the perpendicular D 1 C 1 . To obtain the radii of the pattern construct a dia- Lay off the perpendiculars X U and P S indefinitely. Upon P S, from P, set off P E, equal to D 1 C of the plan, and on X U, from X, set off X "W, equal to D 1 c of Pig. *76.— Plan and iteration. Fig. 178— Pattern. Fig. 477.— Diagram of Kadi! The Pattern of a Heart-Shaped Flarin? Tray. gram, shown in Fig. 477, which is in reality a section upon the line C G of the plan. Draw X P in Fig. 477, in length equal to the straight hight of the article. the plan. In like manner make P S equal to C G of the plan, and X U equal to C g of the plan. Connect U S and W R. Produce P X indefinitely in the direc- Pattern Problems. 263 tion of Z. Also produce E "W until it meets P X in the point Y, and in like manner produce S U until it meets P Z in the point Z. Then Z U and Z S are the radii for that portion of the article contained between G and F of the plan, and Y "W and Y E are the radii of that portion shown from G to E of the plan. To lay out the pattern after the radii are estab- lished, draw any straight line, as Z" G 2 in Fig. 478, in length equal to Z S of the diagram. From Z 1 as cen- ter, with Z S as radius, describe the arc G 2 F 1 , in length equal to G F of the plan. In like manner, with radius Z U, from the same center, describe the arc g 1 /', in length equal to g/ol the elevation. Draw/ 1 F 1 . Set off from G 2 , upon the line G 2 Z", the distance E Y of Fig. 477, as shown at Y 1 , and from Y 1 as center, with the radius E Y, describe the arc G 2 E 1 , which in length make equal to G E of the plan. In like manner, from the same center, with radius Y ~W, describe the arc g l e\ equal to the arc g e of the plan. Draw e' E 1 , thus completing the required pattern. PROBLEM 134. The Pattern of an Oval or Egg-Shaped Flaring Pan. Let A B C D in Fig. 479 represent the elevation of the article, of which A 1 K L B 1 M I is the plan. The plan is constructed by means of the centers 0, P, F and F 1 , as indicated. The patterns, therefore, are construct a section of the article as it would appear if cut on the line A 1 P of the plan. Therefore set off, at right angles to it, A 2 P 2 , equal to A 1 P. Make P 2 D 3 equal to the straight bight of the article, as At-— 1— ;P Fig. 480.— Diagram of Small Cone. &-- B' k Fig. 479.— Plan and Elevation. Fig. 481.— Diagram of Middle Cone. An Oval or Egg-Shaped Flaring Pan. Fig. 482.— Diagram of Large Cone struck by radii obtained from sections of the several cones of which the article is composed. At any con- venient place draw the line P 2 P 1 , Fig. 480, indefi- nitely, corresponding to P of the plan, and upon it shown by E D of the elevation. Make D 2 A 3 of the diagram equal to D 1 P of the plan. Draw A 2 A 3 , which will correspond to A D of the elevation, pro- longing it until it meets P 2 P 1 in the point P 1 . Then 264 T/ie New Metal Worker Pattern Book. P' A 3 is the radius of the outside line of the pattern of the portion between K and I of the plan, and P 1 A 3 is the radius of the line inside of the same part. In like manner draw the line 1 2 , Fig. 481, corresponding to of the plan, and construct a section taken on the line B 1 , as shown by 2 B 2 C 2 C 3 . Produce B" C 2 until it meets 2 1 in the point 1 . Then 1 C 2 and O 1 B 2 are the radii of the pattern of that portion of the article contained between L and M of the plan. Draw the line F 3 F 2 , Fig. 482, which shall corre- spond to F or F 1 of the plan. Make F 3 E equal to the straight hight of the article, and lay off F' L 3 at right angles to it, equal to F 1 L of the plan, and E F equal to F 1 I of the plan. Draw L 9 Z 2 , which produce until it meets F 3 F 2 in the point F 3 . Then F 2 I and F 2 L 3 , respectively, are the radii of the pattern of those parts shown by K L and I M of the plan. To lay off the pattern after the several radii are obtained, as described above, draw any straight line, in length equal to F 2 L 3 , as shown by F 4 K in Fig. 483, and from F 4 as center, with F 2 P and F 2 L 3 , Fig. 482, as radii, strike arcs, as shown by k' V and K L 1 , which in length make equal to the corresponding arcs of the plan K L and k I, as shown. Draw L 1 F 4 , and upon it set off from t toward F 4 , a distance equal to O' C 2 of Fig. 481, establishing the point 3 , from which strike the arc T m\ in length equal to I m of the plan. In like manner, from the same center, with radius 0' B 2 , of Fig. 481, strike the arc L' M 1 , equal in length to L M of the plan. Draw M' 3 , which produce in the direction of F' making M' F b equal to K F 4 , from which center continue the inner line of the pattern, as shown by m 1 i\ which in length must equal m i of the plan. In like manner, from the same center, with radius F 3 L 3 of Fig 4S2, describe the arc M 1 1 1 and draw I 1 F 5 . Set off on this line from i' a distance equal to P 1 A 3 of Fig. 480, thus estab- lishing the center P 3 . Describe the arc i l k, in length equal to i k of the plan. In like manner, from the same center, with the radius P 1 A 3 of Fig. 480 describe the arc I' K\ in the length equal to I K of the plan. Place the straight edge against the points P 3 and K 2 and draw K 3 k, thus completing the pattern. From inspection it is evident that the pattern might have been commenced at any other point as well as at K k of the plan. If the joint is desired upon any of the other divisions between the arcs, as L /, M m, or I i, the method of obtaining it will be so nearly the same as above narrated as not to require special description. If the joint is wanted at some point in one of the arcs of the plan, as, for example, Fig. 488. — The Pattern of an Oval or Egg-Shaped Flaring Pan. at X x, draw the line X x across the plan, producing it until it meets the center by which that arc of the plan is struck. In laying off the pattern, commence with a line corresponding to X F', in place of F 4 K 1 , and from it lay off an arc corresponding to the portion of the arc in the plan intercepted by X x, as shown by XL';c. Proceed in other respects the same as above described until the line k K 2 is obtained, against which there must be added an arc corresponding to the amount cut from the first part of the plan by X x, as above described, or, in other words, equal to X K k x of the plan. Pattern Problems. PROBLEM 135. The Envelope of the Frustum of a Right Cone, the Upper Plane of Which Is Oblique to Its Axis. 265 In Fig. 484, let C B D E be the elevation of the required shape. Produce the sides C B and E D un- til they intersect at A. Then A will be the apex of Fig. 434- — The Envelope of the Frustum of a Right Cone Whose Upper Plane is Oblique to its Aotis. the cone of which C B D E is a frustum. Draw the axis A G, which produce below the figure, and from a center lying in it draw a half plan of the article, as shown by FGH. Divide this plan into any number of equal parts, and from the points carry lines parallel to the axis until they cut the base line, and from there extend them in the direction of the apex until they cut the upper plane B D. Place the T-square at right angles to the axis, and, bringing it against the several points in the line B D, cut the side A E, as shown. From A as center, with A E as radius, describe the arc C 1 E', on which lay off a stretchout of either a half or the whole of the plan, as may be desired, in this case a half, as shown. From the extremities of this stretchout, C and E', draw lines to the center, as C A and E 1 A. Through the several points in the stretchout draw similar lines to the center A, as shown. With the point of the compasses set at A, bring the pencil to the point D in the side A E, and with that radius describe an arc, which produce until it cuts the corresponding line in the stretchout, as shown at D 1 . In like manner, bringing the pencil against, the several points between D and E. in the elevation, describe arcs cut- ting the corresponding measuring lines of the stretchout. Then a line traced through these intersections will form the upper line of the pattern, the pattern of the entire half being con- tained in 0" B 1 D 1 E 1 . PROBLEM 136. The Envelope of a Right Cone Whose Base Is Oblique to Its Axis. In Fig. 485, let G D H be the elevation of a right I which is required. It will be necessary first to assum- cone whose base is oblique to its axis, the pattern of ( any section of the cone at right angles to its axis as a 266 TJie New Metal Worker Pattern Book. base upon which to measure its circumference. This can be taken at any point above or below the oblique base according to convenience. Therefore at right angles to the axis D 0, and through the point G, draw the line G F. Extend the axis, as shown by D B, and upon it draw a plan of the cone as it would appear when cut upon the line G F, as shown by ABC. Divide the plan into any convenient number of equal parts, and from the points thus ob- tained drop lines on to G F. From the apex D, through the points in G F, draw lines to the base G II. From D as center, with D G as radius, describe an arc indefinitely, on which lay off a stretchout taken from the plan ABC, all as shown by I M K. From the center D, by which the arc was struck, through the points in the stretchout, draw radial lines indefi- nitely, as shown. Place the blade of the T-square parallel to the line G F, and, bringing it against the several points in the base line, cut the side D H, as shown, from F to H. With one point of the com- passes in D, bring the other successively to the points 1, 2, 3, i, etc., iu F H, and describe arcs, which pro- duce until they cut the corresponding lines drawn through the stretchout, as indicated by the dotted lines. Then a line, I L K, traced through these points of intersection, as shown, will complete the re- quired pattern. Pattern Elevation Fig. 485. — The Envelope of a Cone whose Base is Oblique to its Axis PROBLEM 137. A Conical Flange to Fit Around a Pipe and Against a Roof of One Inclination. In Fig. 486 is shown, by means of elevation and plan, the general requirements of the problem. A B represents the pitch of the roof, G H K I represents the pipe passing through it, and C D F E the required flange fitting around the pipe at the line C D and against the roof at the line E F. The flange, as thus drawn, becomes a portion of the envelope of a right cone. At any convenient distance below the elevation assume a horizontal line as a base of the cone upon whioh to measure its diameter, and continue the sides downward till they intersect this base line, all as shown at L M. Also continue the sides upward till they in- tersect at W, the apex. Below the elevation is shown a plan, and similar points in both views are connected by the lines of projection. S T represents the pipe and N the flange. While the pipe is made to pass through the center of the cone, as may be seen by ex- amining the base line L M in the elevation, and also P R of the plan, it does not pass through the center of the oblique cut E F in the elevation, or, what is the same, N of the plan. For the pattern of the flange proceed as shown in Fig. 4S7, which in the lettering of its parts is made to correspond with Fig. 4S6, just described. Divide the half plan PXE into any convenient number of parts — in this case twelve — and from each of the points thus established erect perpendiculars to the base of the cone, obtaining the points 1', 2 1 , 3 1 , etc. From these points draw lines to the apex of the cone W, cutting the oblique line E F and the top of the flange C D, as shown. Inasmuch as C D cuts the cone at right angles to its axis, the line in the pattern corresponding to it will be an arc of a circle ; but with E F, which cuts the cone obliquely to its axis, the case is different, each point in it being at a different distance from the apex. Accordingly, the several points in E F, obtained by Pattern Problems. 267 the lines from the plan drawn to the apex W, must be transferred to one of the sides of the cone, where their distances from W can be accurately measured. There- fore from the points 3 , l 3 , 2 3 , 3 3 , in E F, draw lines at right angles to the axis of the cone W X, cutting the side W M, as shown. With W as center, and with W M as radius, strike the arc P' B 1 indefinitely, and, in the plan P X B, all as shown by 2 , P, 2 2 , 3", etc. From these points draw lines to the center W, as shown. With one point of the dividers set at W and the other brought successively to the points obtained in W M by the horizontal lines drawn from E F, cut the correspond- ing lines in the stretchout of the pattern, as indicated by the curved dotted lines. A line traced through Fig. 4S6.— Plnn and Elevation. . 487.— Pattern. A Conical Flange to Fit Around a Pipe and Against a Roof of One Inclination. with the same center and with W D as radius, strike the arc C D 1 indefinitely, which will form the bound- ary of the pattern at the top. At any convenient dis- tance from M draw W P 1 , a portion of the length of which will form the boundary of one end of the pat- tern. On P 1 E', commencing with P 1 , set off spaces equal in length and the same in number as the divisions these points, as E 1 F', will represent the lower side of the pattern. As but one-half of the plan has been used in laying out the stretchout, the pattern C E'_ F 1 D 1 thus obtained is but one-half of the piece required. It can be doubled so that the seam can be made to come through the short side at C E, or through the long side at D F, at pleasure. PROBLEM 138. The Pattern for a Cracker Boat. Let E F H Gr, in Fig. 48S, be the side elevation, ABODE the end, and I K J L the plan of a dish sometimes called a cracker boat or bread tray. The sides of the dish are parts of the frustum of a right cone. To the plan have been added the circles show- ing the complete frustums of which the sides are a part, 268 The New Metal Worker Pattern Booh. L and K being the centers, all of which will appear clear from an inspection of the drawing, and below is further shown a side view of this frustum. While in pleted cone. Before the pattern can be described it will be necessary to draw a half elevation of the cone U V Z, showing the end view of the tray in its relation to the same, as in Fig. 489. Draw any center line, as K' Z'. From the point L', as center, strike the arc K' T', being one-fourth of the plan of top, as shown by K T in Fig. 48S. Below the plan of top draw one-half of frustum of cone, as shown by v! T'X' w', in which draw the end elevation of boat A' B' C X' E', letting V X' be one of its sides, and extend the line V B' through the arc K' T' at B". Divide the part of plan B" T" into any convenient number of parts, and from the points carry lines parallel to the center line or axis until they cut the top line v! V, and from there extend them in the direction of Z' until they cut the line B' C Place the T-square at right angles to the axis, and, bringing it against the several points in the line B' C, which represents the shape shown by E C F in eleva- tion of side, cut the side V X', as shown. From Z' as center, with Z' V as radius, describe the arc I' J', upon which lay off a stretchout of plan. As the part of the plan B" T' corresponds to B' C, which shows one-half of one side of boat, and as Fig. 4SS.— Plan and Elevations. Pig-. 489.— Pattern. The Pattern for a Cracker Boat. the plan the top and bottom of the sides have been shown parallel, in the side view the top appears curved at C, the cut producing which curve being shown by B C of the end view. Extend the sides IT W and V X of the frustum until they meet at Z, which is the apex of the com- this part of plan is divided into three parts, six of these parts are spaced off on the arc I' J and num- bered from 1 to 4, and 4 to 1, 4 being the center line. Through these points in the stretchout draw measuring lines to the cen- ter Z', as shown. With one point of the compasses set at Z', bring the pencil point up to the several points between V and C in the elevation, and describe arcs cuttingmeasuringlines of corresponding numbers in the stretchout; then a line traced through these points of intersection will form the line I' K' J', show- ing the upper line of the pattern for one side of the boat. To obtain the bottom line of the pattern, with Z' as center and radius Z' X', describe the arc M' X'. Divide the plan of bottom of boat, as M T N in Fig. 48S, into any convenient number of equal parts, in this case six, three on each side of the center T, and start- ing from the center line 4 of pattern, space off three spaces each way on the arc M' N', thus establish- Pattern Problems. 269 mg rae points M' and 1ST' of pattern, corresponding to the points M and X of plan. By drawing the lines M' I' and N' J' the pattern for one side of the boat, shown by E F H Gr in elevation, is completed. PROBLEM 139. Pattern for the Frustum of a Cone Fitting Against a Surface of Two Inclinations. In Fig. 490, let A B C D represent the frustum of a cone, the base of which is to be so cut as to make it fit against a roof of two inclinations, as indicated by PED. Continue the lines of the sides of the cone A B and D C upward until they meet in the point X, which is the apex of the complete cone. Through the apex of the cone draw the line X B, representing the axis of the cone, meeting the ridge of the roof in the point R, and continuing downward in the direction of Y, as shown. At any convenient distance below A D draw a horizontal line, G H, as a base, and immediately below it draw apian of the same, as shown by E SFY. Subdivide this plan into any convenient number of spaces, as indicated by the small figures 0, 1, 2, 3, etc. From the points thus established carry lines vertically until they cut the base of the cone Gr H, and from this line carry them in the direction of the apex X until they cut the line of the given roof. From the points established in the roof line A R draw lines at right angles to the axis of the cone X Y, continuing them until they strike the side of the cone A B. From X as center, with X G as radius, describe the arc GrK, upon which lay off a stretchout of the plan. As the pattern really consists of four equal parts or quarters, the divisions of the plan have been num- bered from to 4 and from i to alternating, the points representing the lowest and the points 4 the highest points of each quarter. Therefore in number- ing the points of the stretchout Gr K, any point can be assumed as a beginning which is deemed the best place for the joint (in this case 4), numbering from 4 to and reversing each time, all as shown. From these points established in the arc G K draw lines to the apex X. Then, with X as center, and with radii corresponding to the points already established in the side B G of the cone, strike arcs as shown by the dotted lines, cutting meas- Fig. 490. — Pattern for the Frustum of a Cone Fitting Against a Surface of Two Inclinations. uring lines of corresponding number. Then a line traced through the points of intersection, as shown by L, will 270 Tlie New Metal Worker Pattern Book. be the shape or the pattern at the bottom and O N M L I cone adapted to set over the ridge of a roof, as indi- will constitute the entire pattern of the frustum of a I cated in the elevation. PROBLEM 140. The Pattern of a Frustum of a Cone Intersected at its Lower End by a Cylinder, Their Axes Intersecting: at Right Angles. Let S P E T in Fig. 491 be the elevation of the cylinder, and a&KHJ the elevation of the frustum. Draw the axis of the cylinder, A B, which prolong, as shown by C D, on which construct a profile of the cylinder, as shown by C E D F. Produce the sides of the frustum, as shown in the elevation, until they meet in the point L, which is the apex of the cone. Draw the axis L K, which produce in the direction of O, and at any convenient point upon the same con- struct a plan of the frustum at its top, a b. In connection with the profile of the cylinder draw a correspond- ing elevation of the cone, as shown by K 1 a 1 b 1 K 2 . Produce the sides K 1 «' and K s V until they intersect, thus obtaining the point L', the apex corresponding to L of the elevation. Draw the axis L 1 E, as shown, which produce in the direc- tion of N 1 , and upon it draw a second plan of the frustum at a b, as shown by M' O 1 N 1 . Divide the plans M N and M 1 O 1 N 1 into the same number of equal parts, com- duced merely to show how it may be done, should it be desired under similar circumstances in any other case. The development of the pattern in this case could be most easily accomplished by using L 1 as a center from which to strike arcs from the various points on the line a 1 K\ The same result is accom- s at corresponding points in mencmg each, as shown. With the T-square set parallel to the axis of the cones, and brought successively against the points in the plans, drop lines to the lines a b and a' b\ as shown. From L' draw lines through the points in a 1 b\ cut- ting the profile of the cylinder, as shown in K 1 E K\ and in like manner from the apex L draw lines indefi- nitely through the points in a b. Place the T-square parallel to the sides of the cylinder, and, bringing it against the points in the profile K 1 E K s just described, cut corresponding lines in the elevation, as shown at H K G. A line traced through these points of inter- section, as shown by H K G, will form the miter line between the two pieces as it appears in elevation. This miter line is not necessary in obtaining the pattern, but the method of obtaining it is here intro- Fig. 491. — The Pattern of a Frustum of a Cone Intersected at Its Lower End by a Cylinder, Their Axes Intersecting at Eight Angles. plished, however, by continuing the lines drawn from K 1 E K 2 until they meet the side a G of the cone pro- longed, as shown from G to Z. Thus a Z becomes in all respects the same as a 1 K 1 . From L as center, and with radius L a, describe the arc b~ 0?, upon which lay off a stretchout of the plan M O N of the frustum. Through each of the points in this stretchout draw lines indefinitely, radiat- ing from L, as shown. Number the points in the Pattern Problems. 271 stretchout a' b' corresponding to the numbers in the profile, commencing with the point occurring where it is desired to have the seam. Set the compasses to L Z as radius, and, with L as center, describe an arc cutting the corresponding lines drawn through the stretchout, as shown by 1, 5 and 1. In like manner reduce the radius to the second point in G Z, and de- scribe an arc cutting 2 4, 4 and 2. Also bring the pencil to the third point and cut the lines correspond- ing to it in the same way. Then a line traced through the points thus obtained, as shown by H 1 K 3 G 1 , will be the pattern of the frustum. PROBLEM 141. The Pattern for a Conical Boss. The principles and conditions in this problem are exactly the same as those in the one immediately pre- ceding (that is, the frustum of a cone mitering against Fig. 492. — The Pattern for a Conical Boss. a cylinder, their axis being at right angles), but its pro- portions are so different that it is here introduced as showing that the same application of principles often produces results so widely differing in appearance as to be scarcely recognizable. Let A B C D of Fig. 492 represent the elevation of the boss that is required to fit against the cylindrical can, a portion of the plan of which is shown by the arc A B. The plan at the smaller end of the boss is represented by E F G H. Continue the lines A T> and B C until they intersect at K, which is the apex of the cone of which the boss is a frustum. An in- spection of the elevation will show that it is only necessary to describe one- fourth of the pattern, the remaining parts being duplicates. Divide one-quarter of the plan into any convenient number of parts, in the present instance four, as shown by the points in H E. Drop lines from these points to the base D C, as shown. Draw lines from K through the points in the base until they intersect the arc at A B. which represents the body of the can. These points can- be numbered to correspond with the points in the plan from which they are derived. At right angles to the line F K draw lines from the points on A B until they strike the line A K, where their true distances from K can be measured. With K as a center, and K D as radius, strike the arc L M N, equal in length to the circumference of plan. If the whole pattern of boss is to be described from measurements derived ' from elevation it will be necessary to reverse the order of the numbers for each quarter, as shown. From K draw lines extending outwardly through these points, as indicated by the small figures. With K as center, draw an arc from the point 1' until it inter- sects radial lines 1 drawn from K, as shown at 0, Z and R. In the same manner draw an arc from 2' to lines 2, &c, as shown. A line traced through these points will produce the desired patterns, as shown by LOSZVEN. 272 The New Metal Worker Pattern Booh. PROBLEM 142. Pattern for the Lip of a Sheet Metal Pitcher. Let A B C D of Fig. 493 represent the side ele- vation of a pitcher top having the same flare all around, and E F G H the plan at the base. By producing the lines A D and B C until they intersect in the point K, tlic apex of the cone of which the pitcher top is a sec- tion -will be obtained. Divide one-half of the plan into any convenient number of equal spaces, as shown by the points in G H E. From these points drop lines to the base D C, as indicated. Then draw radial lines from K, cutting the points in D C, and producing them until they intersect the curved line representing the top of the pitcher, otherwise an irregular cut through the cone, as shown by A B. For convenience in subsequent operations, number these points to cor- respond with the numbering of the points in the plan from which they are derived. Place the T-square at right angles to the axial line of the cone H K, and, bringing it against the several points in A B, cut the line D A, as shown in the diagram. By this means there will be obtained in the line K A the length of radii which will describe arcs corresponding to points in the top line of the lip A B. With K as center and K D as radius, describe the arc L M N, which in length make equal to the circumfer- ence of the plan by stepping off on it spaces equal to the spaces originally established in the plan, all as in- dicated by the small figures. From K through each of the points inLMN thus established draw radial lines, extending outwardly indefinitely, as shown. Then with K as center and K", K, 1 K", etc., as radii, strike arcs, which produce until they intersect radial lines of corresponding number just drawn, all as shown in the diagram. Then a line traced through the points thus obtained will be the required pattern, all as shown by L P R N M. The method above described is a strictly mathe- matical rule for obtaining such shapes when a design embodying the necessary curve at the top is at hand. As by the nature of the problem, this part of the pat- tern does not require to be fitted or joined to any other piece, it would be much easier to obtain, by the foregoing method, the principal points in the outside curve of the pattern and finish by drawing the re- mainder to suit the taste of the designer. In other words, after the arc L M N has been drawn and stepped off into spaces, draw radial lines from K through the points representing the highest and the lowest parts required in the top curve, as 0.5 and 12, upon which lines the required lengths can be set off. Then these points can be connected by any curve suitable for the purpose. The principle involved in the foregoing is exactly the same as that of a hip or sitz bath given in the fol- ~i Fig. 49S.— Pattern for the Lip of a Sheet Metal Pitcher. lowing problem, the difference in the finished article being a matter of size and shape and not of principle. Thus the sides could be made less flaring by placing the point K much further away from the base line, the hight A D could be increased and the curve A B could be altered to one more desirable ; but the various steps necessary to perform the task would remain exactly the same. Pattern Problems. PROBLEM 143. Pattern for a Hip Bath of Regular Flare. 273 Let C B D E, in Fig. 494, be the elevation of the body of a hip bath having an equal amount of flare on all sides, the plan of which is a circle. In describing At any convenient distance above D draw J K parallel to G E to be used as a regular base upon which to measure the circumference of the cone. Parallel to J K draw F H, and from a center obtained on F II by prolonging the axis A X draw a half -plan of the f rustum ? as shown by F & H. Divide this half -plan into any convenient number of equal parts, and from the points thus obtained carry lines parallel to the axis until they cut the line J K, and from there extend them in the direction of the apex A, thus cutting the curved line B D. Place the ["-square parallel with J K, and bring- ing it against the several points in the curved line B D, cut the side E D, as shown. From A as center, with Firj. 494.— Pattern for a Hip Bath of Regular Flare. the pattern for the body it will be considered as a sec- tion of a right cone, the plane C E being at right angles to the axis and the base being represented by the curved line B D, as shown. The sides E D and C B can be extended until they meet at A. Then A will be the apex of a cone of which C B D E is a frus turn having an irregular base B D. A K as radius, describe the arc K 1 K", on which lay off a stretchout of either one-half or the whole of the plan, as may be desired. In this case a half is shown. From the extremities of this stretchout, as K 1 and K' 2 , draw lines to the center, as K' A and K7 A, and from the several points in the stretchout draw similar lines, as shown by 1, 2, etc. With one point of the dividers 274 The New Metal Worker Pattern Book. set at A bring the pencil point to the point D in the side A K, and with that radius describe an arc, which produce until it cuts the corresponding line 12 in the stretchout, as shown at D 1 . In like manner, bringing the pencil point up to the several points between D and E in the elevation, describe arcs cutting lines of corresponding numbers in the stretchout. Then a line traced through these intersections will form the upper line of the pattern. From A as center, with A E as radius, describe the arc C E 1 , cutting A K 1 and A K", as shown by C 1 and E 1 , forming the lower line of pattern. Then C B 1 D l E 1 will be half the pattern for the side of the hip bath. As a feature of design, the form produced in the pattern by a curved line B D drawn arbitrarily may not be entirely satisfactory. If, for instance, that part of the pattern lying between lines 9 and 12 should not appear as desired, it can be modified upon the pattern at will, as this edge of the pattern is not required to fit any other form. Such a modification is shown by the dotted lines a 1 K? of the pattern and a K of the eleva- tion. The foot of the tub is a simple frustum of a right cone, the pattern for which is obtained in the manner described in Problem 123. Different forms of bathtubs in which the flare is irregular will be found in Section 3 of this chapter. PROBLEM 144. The Envelope of a Frustum of a Right Cone Contained Between Planes Oblique to It? Axis. In Fig. 495, let F L M K represent the section of the cone the pattern for which is required. Produce the sides F L and K M until they meet in the point N, which is the apex of the cone of which F L M K is a frustum. Through 1ST draw N E. bisecting the angle LNM and constituting the axis of the cone, which pro- duce in the direction of D indefinitely. From K draw K II at right angles to the axis. At any convenient distance above the cone construct a plan or profile as it would appear when cut on the line K H, letting the center of the profile fall upon the axis produced, all as shown by ADC B. Divide the profile into any num- ber of equal parts, and from the points thus obtained draw lines parallel to the axis, cutting K H. From the apex N, through the points in K H, draw lines cutting the top L M and the base F K. Place the blade of the T-square at right angles to the axis of the cone, and, bringing it successively against the points in L M and F K, cut the side N F, as shown above L, and from H to F. From 1ST as center, with radius N II, strike the arc T S indefinitely, upon which lay off a stretchout from the plan, as shown, and through the points of which, from the center 1ST, draw lines in- definitely, as shown. "With the point of the conrpasses still at N, and the pencil brought successively against the points in the side from H to F, describe arcs, which produce until they eut corresponding lines drawn through the stretchout. Then a line traced through Fig ' 495 - The f T^* °J " *?£*" °f v */* C °"" Contained 5 between Planes Oblique to its Axis. these points of intersection, as shown by T TJ S, will form the lower line of pattern. In like manner draw ing lines drawn through the stretchout. A line traced arcs by radii corresponding to the points in the side at through these points, as E P 0, will be the upper line L, which produce also until they intersect correspond- of the pattern sought. Pattern Problems. 275 PROBLEM 145. The Pattern of a Cone Intersected by a Cylinder at Its Upper End, Their Axes Crossing at Right Angles. In the plan, Fig. 496, let A B C D F represent a frustum of the cone B C G, B H C being the half profile of cone at its base and A D J the plan of the cylinder. In line with the cylinder in plan draw the elevation, as shown by R S T U. With the T-square placed parallel to the sides of the cylinder, carry a line from the point G in plan to any convenient point, as G' of elevation. At right angles to G G' draw G' Q indefinitely, and extend B C through Q G', cutting same at 0. With O as center, and E C of plan as radius, describe the semicircle L Q M, rep- resenting one-half of the profile of the cone at the larger end. Divide LQM into any convenient num- ber of equal parts, as indicated by the small figures. From the points thus obtained carry lines at right angles to L M, cutting that line as indicated. From the points thus obtained in L M carry lines to the apex G', as indicated by the dotted lines in the engraving. Divide BHC into the same number of equal parts as was LQM, numbering them to correspond with the elevation, as shown, and from the points thus obtained carry lines at right angles to B C, cutting that line as indicated. From the points in B C carry lines to the apex G, cutting the plan of cylinder as shown. With the blade of the T-square placed parallel with G G', and brought successively against the points thus es- tablished in the plan of the cylinder, cut lines of corre- sponding number drawn from the points in L M to the apex G', as indicated from K to 1ST, and extend these lines to the line M G'. A line traced through these points of intersection, as shown by K P 1ST, rep- resents the intersection of cone with cylinder in eleva- tion, as shown by A F D in plan. For the pattern proceed as follows : From G' as center, with G' M as radius, describe an arc, as indi- cated by I m, and, starting from I, step off the stretch- out of the half profile LQM, as indicated by the small figures. If the entire pattern is required in one piece extend the arc I o m, and from m set off a du- plicate of I m, numbering the points in inverse order. From the points thus obtained draw radial lines to G', as indicated. Then with G' as center, and with radii corresponding to the distance from G' to the points established in M G', describe arcs, producing them until they cut lines of corresponding number drawn from G'. A line traced through these points of intersection, as shown by k p n, will with I m give Fig. 496. — Pattern of a Cone Intersected by a Cylinder at its Upper End. the pattern of part of article shown in elevation by L M N P K. It will be easily seen that the pattern might have 276 The New Metal Worker Pattern Book. been obtained directly from the plan without the trouble of drawing the elevation, as in Problems 141, 142 and 143. Should it be desirable, however, to cut an opening in the side of the cylinder to fit the frus- tum of the cone, the hights of all points in the perim- eter of such opening must be obtained from the line NP K of the elevation, while width of the opening upon lines corresponding to these points must be measured from F toward Dor A upon the circumfer- ence of the cylinder. PROBLEM 146. Pattern of a Tapering: Article with Equal Flare Throughout, which Corresponds to the Frustum of a Cone Whose Base Is an Approximate Ellipse Struck from Centers, the Upper Plane of the Frustum Being: Oblique to the Axis. In Fig. 497, let H F G A be the shape of the article as seen in side elevation. The plan is shown by I L N 0. In order to indicate the principle in- volved in J±e development of this shape, it will be necessary first to analyze the figure and ascertain the shape of the solid of which this frustum is a part. Since by the conditions of the problem the base is drawn from centers and the sides have equal flare, it follows that each arc used in the plan of the base is a part of the base of a complete cone whose diameter can be found by completing the circle and whose altitude can be found by continuing the slant of its sides till they meet at the apex, all of which can be seen by an inspection of the engraving. Thus those parts of the figure shown in plan by K U T M and E IT T P may be considered as segments cut from a right cone, the radius of whose base is either O K or L R, and whose apex E is to be ascertained by continuing the slant of the side L 2 C 1 till it meets a vertical line erected from O 1 of the plan, which is the center of the arc of the base, all as shown in the end view. Also those parts of the plan shown by K U R and M T P are segments of a right cone whose radius is U I or T ]ST and whose altitude is found, as in the previous case, by continuing the slant of its side Gr A (which is par- allel to C 1 L 2 ) till it meets a vertical line erected from its center T, as shown in the side view. To complete the solid, then, of which F G A H is a frustum, it will only be necessary to take such parts of the complete cones just described as are included between the lines of the plan and place them together, each in its proper place upon the plan. The resulting figure would then have the appearance shown by H D CB A when seen from the side, and that of O a C L a when seen from the end. The lines of projection con- necting the various views together with the similarity of letters used will show the correspondence of parts. This figure is made use of in the second part of Chapter V, Principles of Pattern Cutting, to which the reader is referred for a further explanation of prin- ciples. Divide one-half of the plan into any convenient number of equal parts, as shown by the small figures, and from the points thus established carry lines verti- cally, cutting the base line H A, and thence carry them toward the apexes of the various cones from the bases of which they are derived. That is, from the points upon the base line H A derived from the arc K M draw lines toward the apex E, and from the points de- rived from the arc I K carry lines toward the apex D, and in like manner from the points derived from the arc M N carry lines in the direction of the apex B, all of which produce until they cut the top line F Gr of the article. From the points in F G thus established carry lines to the right, cutting the slant lines of the cones to which they correspond. Thus, from the points occurring between F and f draw lines cutting B A, being the slant of the small cone, as shown by the points immediately below W. In like manner, from the points between g and G- carry lines cutting the same line, as shown at G. The slant line of the large cone is shown only in end elevation, and there- fore the lines corresponding to the points between / and g must be earned across until they meet the line B 1 IA Commence the pattern by taking any convenient point, as E 1 , for center, and E 1 1/ as radius, and strike the arc L ! S indefinitely. Upon this arc. commencing Pattern Problems. 277 at any convenient point, as K 4 , set off that part of the stretchout of the plan corresponding to the base of the larger cone, as shown by the points 5 to 13 in the plan, and as indicated by corresponding points from K 4 to M 2 in the arc. From the points thus established draw- lines indefinitely in the direction of the center E', as as shown by/ 1 g\ Next take A B of the side eleva- tion as radius, and, setting one foot of the compasses in the point K' of the arc, establish the point D 1 in the line K 4 E 1 , and in like manner, from M 2 , with the same radius, establish the point B 2 in the line M* E', which will be the centers from which to describe those parts of the patterns derived from the smaller cones. From D 1 and B 1 as centers, with radius B A, strike arcs from K 4 and M 2 , respectively, as shown by K 4 F and M 2 N"', upon which set Off those parts of the stretchout cor- responding to the smaller cones, as shown by the arcs K I and M N of the plan. From the points thus estab- lished, being 5 to 1 and 13 to 17, inclusive, draw radial lines to the centers D 1 and B 2 , as shown. Fig. 497.— Pattern of the Frustum of a Cone, the Base of which is an Approximate Ellipse Struck from Centers, the Upper Plane of the Frustum being Oblique to the Axis. shown. From E 1 as center, with radii corresponding to the distance from E 1 to points 5 to 13 inclusive, established in the line B 1 L 5 already described, cut cor- responding radial lines just drawn, and through the points of intersection thus established draw a line, all For that part of the pattern shown from F 1 to /', set the dividers to radii, measuring from B, corre- sponding to the several points immediately below W of the side elevation, and from D 1 as center cut the cor- responding radial lines drawn from the arc. In like manner, for that part of the pattern shown from G- 1 to g\ set the dividers to radii measured from B, corre- sponding to the points in the line B A at G, with which, from B 2 as center, strike arcs cutting the correspond- ing measuring lines, as shown. Then F 1 Gr 1 W F will be one-half of the pattern sought — in other words, the part corresponding to I K L M N of the plan. The whole pattern may be completed by adding to it a du- plicate of itself. 278 The New Metal Worker Pattern Book. PROBLEM 147. The Envelope of a Right Cone, Cut by a Plane Parallel to Its Axis. Let B A F in Fig. 49S be a right cone, from which a section is to be cut, as shown by the line C D in the elevation. Let GLHK be the. plan of the cone in which the line of the cut is shown by D 1 D\ For the pattern proceed as follows : Divide that portion of the plan corresponding to the section to be cut off, as shown by D 1 G D 2 , into as many spaces as are nec- essary to give accuracy to the pattern, and divide the remainder of the plan into spaces convenient for laying off the stretchout. From A as center, with radius A B, describe an arc, as M N, which make equal to the stretchout of the plan G L II K, dividing it into the same spaces as employed in the plan, taking care that its middle portion, D 3 T>% is divided to correspond with D 1 D 5 of the plan. From the points in M N correspond- ing to that portion of the plan indicated by D' G D" — namely, 8 to 16 inclusive — draw lines to the center A, as shown. From points of the same number in the plan carry lines vertically, cutting the base of the cone, as shown from B to D, and thence continue them toward the apex A, cutting C D, as shown. From the points in C D carry lines at right angles to the axis A E cutting the side of the cone, as shown by the points between C and B. From A as center, with radii corresponding to the distances from A to the several points between C and B, cut lines drawn from points of corresponding number in the stretchout, to A, and through the points of intersection thus obtained trace a line, as shown by D 3 C 2 ~D*. Then the space indicated by D 3 C 2 D* is the shape to be cut from the envelope MAN of the cone to produce the shape to fit against the line C D in the elevation. To obtain the pattern of a piece to fill the open- ing D 3 C 2 D 4 in the envelope, shown in profile by C D of the elevation, first draw radial lines from the center P of the plan to points 9 to 15 inclusive on the cir- cumference, cutting D 1 D\ Upon B F of the elevation extended, erect any perpendicular as D 6 C", as shown Fig. 498.— The Envelope of a Right Cone Cut by a Plane Parallel to its Axis. at the left, which cross with horizontal lines projected indefinitely from the points on C D. The width of the piece upon each of these lines may be found by measuring upon D 1 D 2 of the plan the distances be- tween the intersections of radial lines of corresponding number, as between lines 11 and 13, 10 and 14, etc. A line traced through the points so obtained, as shown by D 6 C b D 7 , will give the desired pattern. PROBLEM 148. The Pattern for a Scale Scoop, Having: Both Ends Alike. In Fig. 499, let A B C D represent the side ele- vation of a scale scoop, of a style in quite general use, and E F II G a section of the same as it would appear cut upon the line B D, or, what is the same, Pattern Problems. 279 so far as concerns the development of the patterns, an end elevation of the scoop. The curved line ABC, representing the top of the article, may be drawn at will, being, in this case, a free-hand curve. For the patterns proceed as follows : From the center K, by which the profile of the section or end elevation is Fig. $99. — The Pattern for a Scale Scoop. drawn, draw a horizontal line, which produce until it meets the center line of the scoop in the point 0. Produce the line of the side ~D until it meets the line just drawn in the point X. Then X is the apex and X the axis of a cone, a portion of the envelope of which each half of the scoop may be supposed to be. Divide one-half of the profile, as shown in end elevation by E Gr, into any convenient number of spaces, and from the points thus obtained carry lines horizontally, cutting the line B D, as shown, and thence carry lines to the point X, cutting the top B C, as shown. With X D as radius, and from X as center, describe an arc, as shown by L 1ST, upon which lay off the stretchout of the scoop, as shown in end elevation. From the points in L X thus obtained draw lines to the center X, as shown. From the points in B C drop lines at right angles to X, cutting the side D C, as shown. With X as center, and radii corresponding to each of the several points between D and C, describe arcs, which produce until they cut radial lines of correspond- ing numbers drawn from points in the arc L N to the center X. Then a line traced through the points thus obtained, as shown by L M N, will be the profile of the pattern of one-half of the re- quired article. PROBLEM 149. The Patterns for a Scale Scoop, One End of Which Is Funnel Shaped. In Fig. 500 is shown a side view of a scale scoop by which it will be seen that the portion A B Gr H of the funnel-shaped end is a simple cylinder and, there- fore, need not be further noticed here. In Fig. 501 are shown a side and an end elevation of the tapering portions. It will also be seen that the part ~D E F of the side view is similar in all respects to the article treated in the preceding problem, and the pattern shown in connection with the same is obtained by exactly the same method as that there described and need not, therefore, be repeated. An inspection of the side elevation will show that the part G B C D F is a section of a cone of which I is the apex, H F the base and H' C" F' the plan of the base, and that this cone is cut by the lines B Gr and C D. To obtain the pattern of this part, first divide F' C" and C" H' of end elevation into any con- venient number of parts, and from the points thus ob- Fio. 500. — Scale Scoop, One End of which is Funnel Shaped, tainea carry lines cutting the miter line H F, as shown. From the points in H F carry lines to the 280 Tlie New Metal Worker Pattern Book. apex I, cutting the curved line C D, as shown. From the points in C D drop perpendiculars cutting the sides the same as in Fig. 501. "With I of Fig. 502 as cen- ter, and I Gr and I F as radii, describe the arcs E, S Fig. 502— Pattern of Piece B C D F G of Fig. 500. G F, as shown. For convenience in describing the pattern a duplicate of the side view of this part is shown in Fig. 502, in which similar parts are lettered P Q. Upon P Q lay out twice stretchout of H' C" F' of Fig. if the pattern is desired in one piece. Thus the stretchout of H' C" is represented by P IT and Q "W, from the points in which draw lines to the center I. From I as center, and radii corresponding to the dis- tance from I to each of the various points in G F, describe arcs cutting lines of similar numbers. Trace lines through the points thus obtained, as shown by T TJ, V W. The ETUWVS is the pattern for part of scoop shown in side elevation by BCDFG. PROBLEM 150. The Pattern of a Conical Spire Mitering upon Four Gables. Let E I B in Fig. 503 be the elevation of a pin- nacle having four equal gables, down upon which a conical spire is required to be mitered, as shown. Produce the sides of the spire until they meet in the apex D. Also continue the side E F downward to any convenient point below the junction between the spire Pattern Problems. 281 and the gables, as shown by H, which point may be considered the base of a cone of which the spire is a part. Let YKLM be the plan of the gables. The diagonal lines V L and M K represent the angles or valleys between the gables, while R S and T U repre- sent the ridges of the gables over which the spire is to be fitted. Through the point H in the elevation draw a line to the center of the cone and at right angles to its axis, as shown by H 0. This will represent the half diameter or radius of the cone at its base. With radius C H, and from center A 2 of the plan, describe a circle, as shown, which will represent the plan of the cone at its base. At any convenient distance from the elevation, and to one side, project a diagonal section correspond- ing to the line M A 2 in the plan, as follows : From all the points in the side of the pinnacle draw horizon- tal lines indefinitely to the left, which will establish the bights of the corresponding points in the section. From any vertical line, as D' A', as a center line set off upon the horizontal lines the distances as measured upon the line M A 2 of the plan. Thus make B 1 A 1 of the crossing of the two ridges of the gables, there- fore a line drawn from F 1 to B 1 will represent one of the valleys between the gables. Draw H 1 D 1 , the side of the cone. Its intersection with the line of the val- ley at G will then represent the hight of the lowest points of the spire between the gables, and a line pro- Fig. 504.— Pattern. M U L Fig. 503.— Plan, Elevation and Diagonal Section. The Pattern of a Conical Spire Mitering Upon Four Gables. equal to M A 2 and C B? equal to A 2 5, the radius of the cone at its base. The point F 1 represents the hight jected from this point back into the elevation, as shown, will locate those points in that view. 282 The New Metal Worker Pattern Book. To describe the pattern, first divide one-eighth of the plan of the cone, choosing the one which miters with the gable shown in the elevation, into any num- ber of equal spaces, as shown by the small figures. From these points carry lines vertically cutting the base of the cone H C, as shown, and thence toward the apex D, cutting the line B J of the gable, against which this part of the cone is to miter. As the true distance of any one of the points just obtained upon the line B J from the apex D can only be measured on a drawing when that point is shown in profile, proceed to drop these points horizontally to the profile line D H, where they are marked l 1 , 2 1 , etc., and where their distances from D can be measured accurately. Next draw any straight line, as D 2 H 2 of Fig. 504, upon which set off all the distances upon the line D II of the elevation, all as shown, each point being lettered or numbered the same as in the elevation. With D 2 of Fig. 504 as a center, from each of these points draw arcs indefi- nitely to the left, as shown. Upon the arc drawn from I!" set off spaces corresponding to those used in spac- ing the plan, beginning with IF, as shown by the small figures, and from each poiut draw a line toward the center D 2 cutting arcs of corresponding number drawn from the line F 2 H 2 . A line traced through the points of intersection (g to F 2 ) will give the shape of the bottom of the cone to fit against the side of one of the gables, or one-eighth of the complete pattern. By repeating the space 1 5 upon the arc drawn from H 2 seven times additional, as marked by the points 1 and 5, the point V will be reached, from which a line drawn to D 2 will complete the envelope of the cone. From the points marked 1 and 5 draw lines toward D* intersecting the arcs of corresponding number. This will locate all of the highest and lowest points of the pattern, after which the miter cut from g to F 2 can be transferred by any convenient means, as shown from g to /, and so on, reversing it each time, as shown. In the case of a spire of very tall and slender proportions it will be sufficiently accurate for practical purposes to draw the lines g F 2 and g f straight. But the broader the cone becomes at its base the more curved will the line g F 2 become. With a radius equal to D E of Fig. 503 describe the arc E 2 F, as shown, which will com- plete the pattern. PROBLEM 151. The Pattern of a Conical Spire Mitering Upon Eight Gables. In Fig. 505 is shown the elevation of a pinnacle having eight equal gables, upon which the conical spire E F P I is to be fitted. Produce the sides F E and P I until they meet in the point D, which is the apex of the spire. Let A IF S K M N'TU represent the plan of the pinnacle drawn in line just below the elevation. To ascertain the length of the cone forming the spire at its longest points, where it terminates in the valleys between the gables, it will be necessary to construct a section on the line A B representing one of the valleys in plan, which can be done as follows : From the points D, F and H in the elevation project lines horizontally to the left, which intersect with any vertical line, as D 1 B 1 , representing the center line of spire in the section. Upon the line drawn from H set off from B 1 a distance equal to A B of the plan and draw A 1 F 1 . From D' draw a line parallel to D F cut- ting A 1 F 1 in B 1 ; then D 1 R 1 Avill be the length or slant hight of the cone at its longest points, and a line from R 1 projected back into the elevation will locate the base of the cone in that view, as shown at R. From B as a center, with a radius equal to R 3 R 1 , describe a circle in the plan, which will represent the base or plan of the cone. Divide an eighth of this circle into any number of equal parts, as shown by 1, 2, 3, 4 and 5, which spaces are to be used in measur- ing off the arc circumscribing the pattern. Draw any line, as D R in Fig. 506, upon which set off the sev- eral points in the line D R, as shown by the letters, and from D as center describe arcs indefinitely from each point, as shown. On the arc drawn from R step off spaces corresponding to one-eighth of the plan, as Pattern Problems. 283 shown by 1, 2, 3, 4 and 5. Draw the line D 5, as shown, cutting the arc from F, as indicated by/. By Fig. SOS. — Elevation and Plan of Conical Spire Mitering upon Eight Gables. inspection of the elevation it will be seen that the arc F represents the line of the top of the gables, and that the arc R represents the line of points in the base of the cone to fit down between the gables. Therefore from F to the middle point 3 draw F g, and from / draw/ g. Then ~D f g F will be one-eighth of the re- quired pattern. Set the dividers to 1 3 on the arc R and step off a sufficient number of additional spaces to complete the pattern, as shown by 3, 5, 3, 5, etc., to W. Draw W D. Also from the points 3 draw the lines f'g and gf, thus completing the pattern. In case the work is of large dimensions it will be advisable to miter the cone from F to g, g to/, etc., in the manner shown in the preceding problem, but in 6 rvrr Fig. 506.— Pattern of Spire Shown in Fig. 505, case the work is small it will be sufficiently accurate to make the lines fg straight, as shown. z$i The New Metal Worker Pattern Book. PROBLEM 152. Patterns for a Two-Piece Elbow in a Tapering: Pipe. In the solution of this problem two conditions may arise ; in the first, the two pieces of the elbow have the same flare or taper, while in the second case one of the both would present to view two perfect ellipses of ex- actly the same proportions and dimensions ; and, there- fore, that if the two parts be placed together again, Fig. 507.— A Two-Ptece Elboiv in a Tapering Pipe. pieces may have more flare than the other. It has been shown in the chapter on geometrical problems that an oblique section through the opposite sides of a cone is a perfect ellipse. Keeping this in mind, it is evident that if the cone shown by A B C in Fig. 507 were made of some solid material and cut obliquely by the plane D E and the severed parts placed side by side, turning the upper piece half way around, as shown by D E A 1 , the edges of the two pieces from D to E would exactly coincide. Taking advantage of this fact, then, it only becomes necessary to ascertain the angle of the line D E, neces- sary to produce the required angle between the two pieces of an elbow, both of which have equal flare. Pattern Problems. 285 Therefore, at any convenient point upon the axis A H, as I, draw I J at the angle which the axis of the upper piece is required to make with that of the lower, then bisect the angle J I H, as shown by the line I K. Draw D E parallel to I K at the required hight of the lower piece, which will be the miter line sought. Before completing the elevation of the elbow it will be necessary to notice a peculiarity of the oblique section of a cone — viz., that although the line A H bisects the cone and its base it does not bisect the oblique line D E, as by measurement the center of D E is found to be at x. Therefore, through the point b, which is as far to the right of x as point a is to the left of it, draw any line, as b A 1 , parallel to I J and make b A 1 equal in length to a A, and draw A' D and A 1 E. Next draw G 1 F 1 at right angles to A 1 b, representing the upper end of the elbow. Make D F equal to E F', and E G equal to D G 1 . Then B F G C will be the elevation of a frustum of a cone, which, when cut in two upon the line D E, will, when the upper section is turned half-way around upon the lower part, form the elbow BDG'FEC. At any convenient distance below the base of cone B C draw half the plan, as shown by L H M, which divide into any convenient number of equal spaces. From the points of division erect lines vertically, cut- ting the base of the cone B C, and thence carry them toward the point A, cutting the miter line J) E. Plac- ing the T-square parallel to the base line B C bring it successively against the points in D E, cutting the side of the cone, as shown below D. From A as center, with radii A B and A F, draw arcs, as shown. Upon the arc drawn from B, begin- ning at any convenient point, as N, step off a stretch- out of L H M, as shown by the small figures. From each of the points thus obtained draw measuring lines toward the point A, and from the last point one cutting the arc drawn from F at Q. Placing one point of the compasses at the point A, bring the pencil point in turn to each of the points in the side of the cone below D and cut measuring lines of corresponding number. Then a line traced through the points of in- tersection, as shown from S to R, will be the miter cut between the two parts of the pattern of the frustum 1ST P Q necessary to form the patterns of the required elbow. As but half the plan of the cone was used in ob- taining a stretchout, the drawing shows but halves ol the patterns. In duplicating the halves to form the complete patterns the upper piece can be doubled upon the line Q S and the lower part upon the line R N, thus bringing the joints on the short sides. If, according to the second condition stated at the beginning of this problem, the upper section of this elbow is required to have more or less flare than the lower section, thereby placing the apex A 1 nearer to or farther away from the line D E, a different course will have to be pursued in obtaining the pattern. If, for instance, the hight of the cone A H be reduced, the base B G remaining the same, the proportions — that is, the comparative length and width — of the ellipse derived from the cut D E would be different from those derived from the same cut were the proportions of the cone to remain unchanged. Therefore, since the shape of the lower piece at the line D E is a fixed factor, if the circle at G 1 F 1 be shifted up or down the axis, or, re- maining where it is, its diameter be changed, the piece D G 1 F' E becomes an irregular tapering article, in which case its pattern can most easily be obtained by triangulation. Patterns for pieces embodying those conditions can be found in Section 3 of this chapter, to which the reader is referred. PROBLEM 153. Patterns for a Three-Piece Elbow in a Tapering Pipe. In Fig. 508 is shown a three-piece elbow occur- ring in taper pipe, in which the flare is uniform throughout the three sections. In solving this problem the simplest method will be to construct the elevation of the elbow and an elevation of an entire cone, from which several sections may be cut to form the re- quired elbow, at one and the same time. Therefore in the elevation of the cone E F G let L 1 M 1 be drawn at a distance from E F equal to the total length of the three pieces measured upon their center lines, and also let its length be equal to the diameter of the elbow at its smaller end ; then through E and L 1 and 286 Hie New Metal Worker Pattern Book. through F and M 1 draw the sides of the cone, inter- secting in G. At any convenient point, asB, draw the line B A at the angle which the axis of the middle piece is required to make with that of the lower (in this case 45 degrees), and bisect the angle A B G, as shown, by the line B D. Parallel with B I) draw P B at any re- upper piece is required to make with that of the middle piece (in this case also 45 degrees, or hori- zontal), and bisect the angle S U I, as shown, by U T. Then the miter line 1ST can be drawn parallel with U T at any required distance from I, upon which locate the point i, making 1ST i equal to j. From i draw the axis of the upper piece of the elbow paral- K . — -""" L— -"Vx \ / Fig. 508. — A Three-Piece Elbow in a Tapering Pipe. quired hight, upon which locate the point I, making P I equal to B J. (The reason for this is explained in the previous problem.) From the point I draw the axis of the second section of the elbow parallel with A B, making it (I H) equal to J G, and draw P H and R H. From any convenient point upon this axis, as 17, draw US at the required angle which the axis of the lei with 17 S, making i K equal to j H. Next locate the line N upon the original cone, making N 1 P equal to R and 1 R equal to P N. Now make N L equal to N 1 L and M equal to M' O 1 and draw ML. It may be remarked here that on account of the shifting of the positions of the axes of the several Pattern Problems. 287 pieces upon the miter lines by turning them, as shown by I J and i j, it will be impossible to ascertain with extreme accuracy the lengths of the various pieces upon their axes until the elevation EPNLMORF is drawn, and therefore to obtain the position which the line M L will occupy. This method of solving the problem is given upon the supposition that its simplicity will compensate for this slight inaccuracy, as usually differences of length can be made up in the parts with which the elbow may be connected. If the lines M L and E F are to be assumed at the outset as fixed factors between which a tapering elbow is to be constructed, it will be some- what difficult to ascertain the exact dimensions of a cone, E F G, which can be cut and its parts turned so as to constitute the required elbow. Hence, while two of the pieces (say the two lower ones) can easily be cut from an entire cone assumed at the outset, the third piece will have to be drawn arbitrarily to fit be- tween the last miter line N and the small end M L, and will very likely be of different flare from that of the other two pieces. This will necessitate the last section being cut by the method of triangulation, problems in which are demonstrated in Section 3 of this chapter, to which the reader is referred. Having, as explained above, obtained the lines of cut through the cone, the patterns may be described as follows : Draw the plan V W Y, its center X fall- ing upon the axis of the cone produced, which divide in the usual manner into any convenient number of equal parts. Through the points thus obtained erect, perpendiculars to the base E F, and thence carry lines toward the apex G, cutting the miter lines P E and N' 0'. With the T-square at right angles to the axis G C, and brought successively against the points in N' 1 and P K, cut the side G F of the cone, as shown by the points above O 1 and below K. From G as center,, with radius G F, describe the arc E 1 F', upon which lay off the stretchout of the plan V W Y, as shown by the small figures 1, 2, 3, etc., and from these points draw measuring lines to the center G. From G as center describe arcs corresponding to the distance from G to the several points established in G F, which produce until they intersect lines of corresponding numbers drawn from the center G to the arc E 1 F'. Through these points of intersection trace lines, as shown by s N s and P' R 1 . From G as center, with radius G M 1 , describe the arc 1/ M 1 . Then L 2 M" N 2 O 2 is the half pattern of the upper section, O 2 N 3 E, 1 P 1 that of the- middle section, and P' E, 1 F 1 E 1 that of the lower section. PROBLEM 154. The Patterns for a Regular Tapering; Elbow in Five Pieces. b c Fin. 509.— Diagram of Angles for a Five-Piece Elbow. In this problem, as in the two immediately preced- ing, the various pieces necessary to form the elbow may be cut from one cone, whose dimensions must be- determined from the dimensions of required elbow. The first essential will be to determine the angle of the- cutting lines, which may be done the same as if the elbow were of the same diameter throughout. Such an elbow of five pieces would consist of three whole pieces and two halves ; therefore, if it is to be a right angle elbow, divide any right angle, as A' B C in Fig. 509, into four equal parts, as shown by the points 1, 2, 3. Bisect the part A' B 3 by the line A B and. transfer the portion A' B A to the opposite side of the figure, as shown by C B C. This gives the right angle ABC divided into the- same number of pieces and half-pieces as would be em- ployed in constructing an ordinary five-piece elbow. 288 The New Metal Worker Pattern .Book. Fig. BIO. — A Five-Piece Elbow in a Tapering Pipe. Pattern Problems. 289 The division lines in this diagram are of the correct angle for the miter lines in the elbow pattern, and there- fore can be used npon the diagram of the cone, out of which are to be obtained the pieces to compose the re- quired elbow. It is assumed that the amount of rise and projec- tion are not specified, therefore after having got the line of the angle or miter it becomes a matter of judg- ment upon the part of the pattern cutter what length Fig. 511. — Elevation of Five-Piece Tapering Elbow. the shall be given to each of the pieces composing elbow. In Fig. 510, let A B represent the diameter of the large end of the elbow. From the middle point in the line A B, as 0, erect a perpendicular line, as indicated by ON, producing it indefinitely. On the line N, proceeding upon judgment, as already mentioned, set off G X to represent the length of the first section of the elbow measured upon its center line. With X thus determined, draw through it the line D E, giving it the same ansrle with A B as exists between B C of Fis<-. 509 and the horizontal B C. This, in all probability, can most readily be done by extending B A indefinitely beyond A and letting E D intersect with B A extended, producing at their intersection an angle equivalent to CBC'of Fig. 509. From the point X set off the dis- tance X Y, also established by judgment, thus deter- mining the position across the cone of the miter line of the next section. Through Y draw G F at the same angle as D E, already drawn, but inclined in the oppo- site direction. In like manner locate the two other miter lines shown in the diagram, finally obtaining the point Z. From Z set off the width toward N of the last section of the pattern, and through the point N thus obtained draw the line M at right angles to C N, making it in length equal to the diameter of the small end of the elbow and placing its central point at JN . Through the points A M and B of the figure thus constructed draw lines, which produce indefinitely until they intersect the axis in the point P. Then P will be the apex of the required cone. Construct a plan of the base of the cone or large end of the elbow below and in line with the diagram, as shown in the drawing, which divide into any con- venient number of spaces, as indicated by the small figures, and from the points thus obtained carry lines vertically, cutting the base of the cone A B. From A B continue them toward the apex of the cone, cut- ting the several miter lines drawn. "With the apex P of the cone for center, and with P B as radius, describe the arc T U, upon which set off a stretchout of one- half the plan, all as indicated by the small figures. From the points thus established in T U carry lines to the center P. With the T-square placed at right angles to the axis N C of the cone, and brought against the points of intersection in the several miter lines made by the lines drawn from points in the base of the cone to the apex, cut the side B of the cone, as shown Then from P as center, with radii corresponding to the distance from P to the several points on B, as men- tioned, strike arcs cutting the lines of corresponding numbers in the pattern diagram, as shown. Then lines traced through the points thus obtained, as indicated by I) 1 E', F 1 G 1 , etc., will cut the pattern OWU T of the frustum in such a manner that the sections will consti- tute the half patterns of the pieces necessary to form the required elbow. In Fig. 511 is shown an elevation of the elbow resulting from the preceding operation. 290 Tlie New Metal Worker Pattern Book. PROBLEM 155. The Frustum of a Cone Intersecting; a Cylinder of Greater Diameter than Itself at Other than Right Angles. In Fig. 512, E Gr H F represents an elevation of the cylinder, and M N L K an elevation of the frustum of a cone intersecting it. FZQ represents the profile or plan of the cylinder, to which it will be necessary to add a correctly drawn plan of the frustum before the miter line in elevation cau be obtained. At any con- obtained drop points parallel with the side G H of the cylinder and continue them indefinitely, cutting the line F 1 O 1 , which is drawn through the center of the plan of the cylinder at right angles to the elevation, all as shown in the engraving. Make Y 1 W equal to Y W of the first section constructed. In like manner measure Fig. 512.— The Frustum of a Cone Intersecting a Cylinder of Greater Diameter than Itself at Other than Right Angles. venient point on the axial line T of the cone construct the profile V Y X W, which represents a section through the cone on the line M 1ST. Divide the section TYX AY into any convenient number of equal spaces in the usual manner, as shown by the small figures 1, 2, 3, 4, etc. From each of the points thus established drop lines parallel with the axis of the cone cutting the line M N. From the intersections in M N thus distances from the center line V X of the first section to the points 2, 3, 4, etc., and set off corresponding spaces in the plan view, measuring from M 1 N 1 , upon lines of corresponding numbers dropped from the in- tersections in M N", already described. Then a line traced through these points will represent a view of the upper end of the frustum as it would appear when looked at from a point directly above it. Produce the Pattern Problems. 291 sides of the frustum K M and L N" until they meet in the point 0. From drop a line parallel to the side G H of the cylinder, cutting the line F' 0' in the point O', thus establishing the position of the apex of the cone in the plan. From the point O 1 thus established draw lines through the several points in the section M 1 Y 1 N 1 W, which produce until they intersect the plan of the cylinder in points between Z and Q, as shown in the engraving. From 0, the apex of the cone in the elevation, draw lines through the several points in M 1ST already determined, which produce until they cross G H, the side of the cylinder, and continue them inward indefinitely. Intersect these lines by lines drawn vertically from the points of corresponding number be- tween Z and Q of the plan just determined. Then a line traced through these intersections, as indicated by K T L, will represent the miter between the frustum and cylinder, as seen in elevation. To lay off the pattern proceed as follows : From O as center, with X as radius, describe the arc P R, on which set off a stretchout of the section YV¥X in the usual manner. From 0, through the several points in P R thus obtained, draw radial lines indefi- nitely. From the several points in the miter line K T L draw lines at right angles to the axis T of the cone, producing them until they cut the side N L. From O as center, with radii corresponding to the distance from to the several points in N L just obtained, describe arcs, which produce until they intersect radial lines of corre- sponding number drawn through the stretchout P R. Then a line traced through these points of intersection, as indicated by S 1/ U, will be the lower line of the pat- tern sought, and PSL'UE will be the complete pattern. The pattern for the cylinder and the opening in the same to fit the intersection of the cone is really a problem in parallel forms, with which problems (Section 1) it should properly be classed. F 1 Z Q is the pro- file of the cylinder, and L T K is the miter line. The stretchout B D is drawn at right angles to E F, the direction of the mold or cylinder. The points between Z~ and Q ! of the stretchout are duplicates of those be- tween Z and Q of the plan. Place the T-square at right angles to the cylinder, and, bringing it successively against the points in the miter line K T L, cut lines of corresponding numbers. A line traced through the points of intersection thus formed, as shown by Z 1 K 1 Q 1 L', will be the shape of the required opening in the cylinder. PROBLEM 156. The Patterns of the Frustum of a Cone Joining: a Cylinder of Greater Diameter than Itself at Other than Right Angles, the Axis of the Frustum Passing - to One Side of That of the Cylinder. Let EJHG in Fig. 513 be the elevation of a cylinder, which is to be intersected by a cone or frus- tum, D AJC, at the angle F D A in elevation, and which is to be set to one side of the center, all as shown by S P L M R of the plan. Opposite the end of the frustum, in both elevation and plan, draw a sec- tion of it, as shown by TUTW in the elevation and T 1 U' V W in the plan. Divide both of these sec- tions into the same .number of equal parts, commenc- ing at corresponding points in each, and number them as shown by the small figures in the diagram. From the points in T II V ¥ carry lines parallel to the axis of the cone, cutting the line A J, and thence drop them vertically across the plan. From the points in the section T 1 II 1 V 1 W draw lines parallel to the axis of the cone, as seen in plan, intersecting the lines of cor- responding number dropped from A J just described. Through these points of intersection trace a line, as shown by L M. Then L M will show the end of the frustum A J as it appears in plan. From X, the apex of the cone in elevation, drop a line vertically, cutting the axis of the cone in plan as shown at X 1 . From X draw lines through the points in A J and extend them through the side of the cylinder indefi- nitely. From X 1 through the points in L M draw lines cutting the plan of the cylinder, as shown from P to R, and from these points carry lines vertically, intersecting those of corresponding number in the elevation drawn from the apex X. Tnen a line traced through these points, as shown by D K N, will be the miter line in elevation. For the pattern of the frustum, from X as center, with radius X A, describe the arc A 1 J 1 , upon which lay off a stretchout of the section T IT V W, through the points in which, from X, draw radial lines indefi- nitely. From the points in D K G 1ST carry lines at right angles to the axis of the cone, cutting the side A D extended, as shown from D to B. From X as 292 Tlte New Metal Worker Pattern Book. center, with radii corresponding to the distance from X to the various points in the line D B, describe arcs cutting radial lines of corresponding number in the pattern. Through the points of intersection in the tern of the frustum D A J C, inhering with the cylin- der at the angle described. The method of obtaining the pattern of the cyl- inder is analogous to that described in the preceding Fig. 513.— The Patterns of the Frustum of a Cone Joining a Cylinder of Greater Diameter than Itself at Other than Right Angles, the Axis of the Frustum Passing to One Side of that of the Cylinder. pattern thus obtained trace a line, as shown by C K 1 N 1 D'. Then D 1 N 1 K' C A' J 1 will be the pat- problem, and is clearly shown at the left in the drawing. PROBLEM 157. The Patterns of a Cone Intersected by a Cylinder of Less Diameter than Itself, Their Axes Crossing; at Right Angles. In Fig. 514, let B G B D F A C be the elevation of the required article. Draw the plan in line with the elevation, making like points correspond in the two views, as shown by M S T U P K Let D M E be a half section of the cylinder in the elevation and D 1 M 1 E 1 a corresponding section in the plan. Pattern Problems. 293 Divide these sections into any convenient number of equal parts, commencing at the same point in each, as shown by the small figures, and draw the center line of the cylinder in plan D 1 R. From each of the points in the section shown in elevation carry lines parallel to D H Fig. 514. — A Cone Intersected by a Cylinder of Less Diameter than Itself at Right Angles to Its Axis. F cutting the side of the cone, and extend them some distance into the figure for further use. From the several points of intersection with the side of the cone, as shown by a, b, c, d and e, drop lines parallel to the axis of the cone cutting the line D 1 R of the plan, giving the points a l ,b l ,c l ,d x and e', and through each of these points, from R as center, describe an arc, as indicated in the en- graving. From the points in the profile D 1 M' E 1 of the plan draw lines parallel to the sides of the cylinder, producing them until they meet the arcs drawn through corresponding points, giving the points indicated by l 1 , 2', 3 1 , 4 1 and 5'. From these points carry lines vertically to the elevation, producing them until they meet the lines drawn from points of corresponding numbers in the profile of the cylinder in the elevation, giving the points l a , 2% 3', 4" and 5". A line traced through these points, as shown from Gr to F, will be the miter line in elevation formed by the junction of the cvlinder and the cone. Fig. 515.— Half Pattern of the Cone Shown in Fig. 514. To obtain the envelope of the cone with the open- ing to fit the intersecting cylinder proceed as follows : From any convenient point, as A 1 , Fig. 515, draw A 1 B 1 , in length equal to A B of the elevation. Set off points e", d', c", b" and a~ in it, corresponding to e, d, c, b and a of A B, Fig. 514. From A' as center, with radius A 1 B 1 , describe the arc B' V, upon which lay off the stretchout of the plan of the cone, as indicated by the small figures outside of the pattern. (But one-half of the envelope of the cone is shown in the engraving.) From the same center A 1 describe arcs from the points e% d 2 , c 2 , V and a". From the center R of the plan draw lines to the circumference through the points 2 1 , 3 1 , 4', etc. , giving the points in the circumference marked 2 s , 3 3 , 4 3 , etc. Set off by measurement corresponding points in the arc B' V, as showu by 3 4 , 2 4 , 4 4 , 5 4 , etc. From these points draw lines to the center A 1 , inter- secting the arcs of corresponding number drawn from 294 Tlie New Metal Worker Pattern Book. a?, b\ (?, etc. A line traced through these points of intersection, as shown by F 1 0' (x P', will be the shape of the opening to be cut in the side of the cone to fit the mitered end of the cylinder. The pattern for the cylindrical part is shown above the elevation, and is obtained in accordance with the principles demonstrated in the first section of this chap- ter, which need not be here repeated. PROBLEM 158. The Patterns of a Cone Intersected by a Cylinder of Less Diameter than Itself at Right Angles to its Base, the Axis of the Cylinder Being to one Side of that of the Cone. N 4 N 3 PATTERN OF CYLINDER In Fig. 516, let B A C represent the elevation of the cone, DE GrH the elevation of the cylinder, which joins the cone at right angles to the base BC. J K L M N P Q is the plan of the articles, which is to be drawn in line and under the elevation, making like points correspond in the two views, as shown. Draw a section of the cylinder in line with the elevation, as shown by E F G E. Divide the section of the cylinder into any convenient number of equal parts, as shown by the small figures. From the apex A drop a line through the plan, as shown by A M. Through the center of the section of the pipe, as shown in plan, draw a straight line to the center of plan of cone, as shown by J P. This line will also be at right angles to K M. From each of the points in the section of the pipe in elevation drop lines parallel to the sides of the pipe cutting the side of the cone, extending them to the line J P in plan, as shown by 1ST a b c, etc. Through each of these points, from P as center, describe circles, PLAN Fig. 516.— Plan and Elevation of Cone Intersected by a Cylinder at Right Angles to its Base. Pattern Problems. 295 as shown, cutting the sides of the plan of cylinder. From each of the points of intersection with the side of the cone (A B) draw lines parallel with the base, and extend them inward. If it is desired to show the miter line in elevation formed by the junction of pipe and cone, from the points d ef in the plan of cylinder carry lines vertically to the elevation, producing them until they meet the horizontal lines having similar letters drawn through the side of the cone A B, giving the points g h j. A line traced through these points, as shown by D g hj H, will be the miter line. H f e d D of elevation, as shown by H c b a D. From the center A of pattern describe arcs cutting the points HckD. It is only necessary now to make each of these arcs equal in length to the one to which it corresponds in the plan by any method most convenient. Thus make a d and a d l equal to a d of the plan, b e and b e 1 equal to b e of the plan and c/and cf equal to cfoi the plan. A line traced through these points, as shown by H Q D 0, will be the shape of the opening. Another method of making the measurements of the arcs is shown by Fig. 617. — Half Pattern of Cone Shown in Fig. 516. Fig. 51S.— Perspective View of Cone and Cylinder Sliown in Fig. 516. The half pattern of the cone, with the opening to fit the cylinder, is shown in Fig. 517, to describe which proceed as follows : From any convenient point, as A in Fig. 517, with A B of Fig. 516 as radius, strike an arc indefinitely, as shown. From B of pattern set off each way the stretchout of J M and J K of plan and connect K and M with A. Then K A M B is the half pattern of the cone, or as much as shown on plan by K J M. To obtain the shape of opening to be cut in cone to correspond with the shape of pipe, on A B, the center line of pattern, set off points corresponding to the radial dotted lines of the plan and pattern in the man- ner explained in the problem immediately preceding. The pattern for the cylinder is obtained in the manner usual with all parallel forms, its only pecul- iarity in this case being that its stretchout is taken from the irregular spaces upon the profile NOPQ oi the plan, which are transferred to the line P' P", as shown. A pictorial representation of the finished article is shown in Fig. 518, upon which some of the lines oi measurement shown in Fi°\ 516 have been traced. 296 Tlie New Metal Worker Pattern Book. PROBLEM 159. Patterns of a Cylinder Joining: a Cone of Greater Diameter than itself at Right Angles to the Side of the Cone. Let B A K in Fig. 519 be the elevation of a right cone, perpendicular to the side of which a cylinder, L S T M, is to be joined. The first operation -will be to describe the miter line as it would appear in elevation. Draw the section TJ V of the cylinder, which divide into auy convenient number of equal parts, as indicated by the small figures, and from these points drop lines parallel to L S, cutting the side A K of the cone in the points H, F and D, producing them until they cut the axis A X in the points G, E and C. In order to ascer- tain at what point each of these lines will cut the en- velope of the cone it will be necessary to construct sections of the cone as it would appear if cut on the lines G H, E F and C D. Draw a second elevation of the cone, as shown by B 1 A 1 K', representing the cone turned quarter way round ; the first may be regarded as a side elevation and this as an end elevation. Draw a plan under the side elevation of the cone, as shown by NEPO, which divide into any convenient number of equal parts, and in like manner draw a corresponding plan or half plan under the end elevation, as shown by K 1 P 1 O 1 . Divide this second plan into the same spaces, numbering them to correspond with the other plan. From the points 1 to 5 in plan NEPO carry lines vertically to the base B K and thence toward the apex A, cutting the lines C D, E F and G H. In like man- ner, from the same points (1 to 5 inclusive) in the plan R' P 1 O 1 carry vertical lines to the base B 1 K 1 and thence toward the apex A 1 . Place the T-square at right angles to the axes of the two cones, and, bringing it against the points of intersection of the lines from X to K with C D, cut corresponding lines in the second ele- vation, and through the points of intersection thus es- tablished trace a line, as shown by C 3 C 4 . Produce the axis X 1 A 1 to any convenient distance, upon which set off C D 1 , in length equal to C D, in which set off the points corresponding to the points in C D, and through these points draw lines at right angles to C D 1 . Place the T-square parallel to the axis X 1 A 1 , and, bringing it against the several points in C 3 C 4 , cut the lines of corresponding number drawn through C 1 D', as shown, and through the intersections thus established trace a line, as shown. Then C D 1 is a section of the cone as it would appear if cut on the line C D. In like manner carry lines from the points upon E F across to the end elevation, intersecting them with lines of corresponding number, as shown from E 3 to E 4 , and thence carry them parallel to the axis, cutting lines drawn through E 1 F 1 , which with its points has been Fig. 519.— A Cylinder Joining a Cone of Greater Diameter than Itself at Right Angles to the Side of the Cone. made equal to E F. The resulting profile E 1 F' is a section of the cone as it would appear if cut on the line E F. Also use the points in G H in like manner, es- Pattern Problems. 297 tablishing the profile G' H 1 , which represents a section of the cone as it would appear if cut on the line G H. (Some of the lines indicating the operation in connec- tion with sections E 1 F 1 and G 1 H 1 are omitted in the engraving to avoid confusion.) Having thus obtained sections of the cone corre- sponding to the several lines C D, E F, G H, it will next be necessary to project a plan of the cone, with its intersecting cylinder, at right angles to L S, or as viewed in the direction of A K, which plan shall in- clude all of these sections. To do this extend the line Fig. 520. — Envelope of Cone Shown in Fig. 519. A K to a convenient distance above the elevation, and project lines from all other important points parallel to the same, as shown. At right angles to A K draw any line, as C~ V, as a center line of the new plan. As the points D 1 , F' and H 1 of the oblique sections of the cone are all in the line A K, transfer these sections to the new plan, so placing them that their center lines shall coincide with the center line of the new plan, and the points D', F 1 and H 1 shall be at the intersection of A K with the center line of the plan, all as shown. Op- posite the end of the cylinder draw a section, as indi- cated by U 1 V, which divide into the same number of equal parts as used in the divisions of U V, commenc- ing the division at corresponding points in each. As both halves of the cylinder and of the cone, when di- vided by a vertical plane passing through the axis of each, are the same, only one-half of the section of the cylinder has been numbered. From the points in U 1 V drop lines parallel to C 2 V, each line cutting its corresponding section, as shown from x toy, and then carry them parallel to A K back to the elevation, cut- ting lines of corresponding number in that view. That is, from the intersection of the line drawn from point 4 in U 1 V with the profile C 2 L 3 cut the line C D, which in the elevation corresponds to the point 4 in the profile U V, and from the intersection of e line drawn from 3 with E 2 L 3 cut the line E F, and so on, all as indicated by the dotted lines. Then a line traced through these points of intersection, as shown by L M r will be the miter line in elevation, from which the pat- terns may readily be obtained. The intersections in the plan above give all that is necessary to obtain the pattern of the cylinder, which can be done as follows : Lay off a stretchout of the profile U 1 V opposite the end S 2 T 2 , through the point- in which draw the usual measuring lines. Place the T-square at right angles to the same, and, bringing it against the points in the miter line L M (or the points of intersection in x y in the plan from which L M was obtained), cut the corresponding measuring lines. Then a line traced through these points, as shown from L' to M 1 , will be the shape of the pattern of the cylinder to fit against the cone. For the pattern of the cone proceed as follows -. From each of the points in the miter line L M carry lines horizontally across, cutting the side A B of the cone, by means of which their distance from the apex A may be accurately measured; also through these points draw lines from the apex A cutting the base B K, continuing them vertically into the plan N B P O,. as shown. It may be noted that the line from point 4 on L M falls at point 2 in the plan of the cone \ likewise that the line from 3 on L M falls at 3 in the plan of the cone, while the line from 2 falls upon the plan of the cone at a point marked a. From any convenient point, as A 2 of Fig. 520, with a radius equal to A B, describe the arc B 2 K 2 B 3 , which in length make equal to the circumference of the plan of the cone, setting off in the same all the points of the plan, as indicated by the figures and letters, and from these points draw lines toward the center A 2 , all as shown. From A 2 as center, with radii corresponding to the dis- tances A L, A 2, A 3, A 4 and A M of the elevation, strike arcs intersecting corresponding lines just drawn. Then a line traced through the intersections thus ob- tained will be the shape of the opening to be cut in the envelope of the cone to fit the end of the cylinder. ^98 The Neiv Metal Worker Pattern Book. PROBLEM 160. The Patterns of a Cylinder Joining the Frustum of a Cone in which the Axis of the Cylinder is Neither at Right Angles to the Axis Nor to the Side of the Cone. The principles involved in the solution of this problem are exactly the same as those of the problem immediately preceding, to which the reader is referred for a more full explanation of the operation. The de- section of the cylinder, which divide into any con- venient number of equal parts, as indicated by the small figures, and from these points carry lines parallel with N X cutting the side B L of the cone in the Fig. 521. — A Cylinder Joining the Frustum of a Cone at an Oblique Angle. tails or conditions differ only in the angle at which the cylinder joins the side of the cone. In Fig. 521, let C B L be the elevation of a right cone of which C c I L is a frustum, and let M T U N represent the cylinder which is to join the frustum., making the angle TJ E" L greater than a right angle. The first operation will be to determine the shape of miter line M N of side elevation. Draw V W X, the points A, G and E, producing them until they cut the axis B Y in the points H, F and D. Draw a plan un- der the side elevation of cone, as shown by S Q P, which divide into any convenient number of equal parts. From points 1 to 4 in S Q P carry lines verti- cally to the base C L, and thence toward the apex B, cutting the lines D E, F Gr and H A Draw a second elevation of the cone, as shown by Pattern Problems. 2J9 C B 2 L 1 , which represents the cone as turned quarter way round. Draw a corresponding plan under the end elevation, as shown by S 1 Q 1 P 1 O 1 . Divide this plan into the same number of equal parts, commencing to number them at the same point as in the other plan — that is, at the point Q. From the points 1 to 4 in- clusive in S 1 Q 1 P' of plan carry vertical lines to the base C 1 L', and thence to the apex B 2 . The next step is to construct sections of the cone as "it would appear if cut upon the planes represented by the lines Ii A, F G and D E. For this purpose place the J-square at right angles to the axes of the two cones, and, bringing it against the points of in- tersection of the lines from the base G L with D E, cut corresponding lines in the second elevation, and Fig. 522. — Envelope of Cone Shown in Fig. 521. through the points of intersection thus established trace a line, as shown by N 1 E 3 X 2 . Continue the axis Y 1 B 2 as may be convenient, upon which set off spaces equal to those between the points in D E, and through these points draw lines at right angles to D 1 E 1 . Place the T-square parallel to the axis Y 1 B 2 , and, bringing it against the several points in N 1 E 3 N 2 , cut the lines drawn through D 1 E 1 , as shown, and through these points of intersection trace a line, as shown by W E 1 N 3 . Then W E 1 N 3 is a section of the cone as it would appear if cut on the line D E. Sections corresponding to F Gr and H A can be obtained in a similar manner. Having obtained sections of the cone correspond- ing to the several lines D E, F G and H A, it will next be necessary to project a plan at right angles to the axis of the cylinder, in which each of these sections shall find its place. Therefore, from all the points of the cylinder and of its intersections with the sides and axis of the cone project lines at right angles to N X indefinitely, through which at any convenient point draw a line, as D 2 X', parallel to X X. Upon this line, as a center of the plan about to be constructed, place the oblique sections just obtained so that each may be in line with the line in the elevation which it repre- sents, and their center lines shall all coincide with D 2 X 1 , all as shown. Make T 2 IF equal to T U and complete the plan of the cylinder, opposite the end of wliich draw a profile, as indicated by V W X', commencing the divisions at the point V. From the several points in the profile V 1 AY X 1 drop lines paral- lel with the center line D 2 X' against the several profiles d E 2 d\f G Q /' and h A 2 A 1 , and thence drop the points back on the elevation, cutting correspond- ing lines in it. Thus, from the intersection of the line drawn from point W (3) with G 2 / 1 of section cut the line F G, which in the elevation corresponds to the point 3 in the profile Y W X. From the intersec- tion of a line drawn from point 2 in V 1 W with A 2 h 1 of section cut the line H A, and so on, as indicated by the dotted lines. A line traced through these points of intersection, as shown by the curved line M N, will be the miter line in elevation, from which the patterns can be obtained as follows : For the pattern of cylinder shown in elevation by M T U X, on T U extended lay off a stretchout of profile V W X, through the points in which draw the usual measuring lines. Place the J-square parallel with T U, and, bringing it against the points in the miter line M X, cut measuring lines of corresponding number. Trace a line through the points thus ob- tained, as shown from m to m'. Then m t t' w! is the pattern of the cylinder to fit against the cone, as shown in elevation by MTUN. To obtain the pattern of the frustum carry lines from each of the points in the miter line M N horizon- tally across the elevation, cutting the side of the frus- tum c C. as shown by a\ b' and d 1 ; also through the same points draw lines from the apex B, cutting the base line C L, and thence drop them on the plan, as shown by 1, 2, a and b. From any convenient point, as B 2 in Fig. 522, as a center, with radii equal to B c and B C, describe arcs, as shown by Q 1 and c 1 V. Make OQO' equal in length to the plan of cone S Q P and upon it set off each way from the point Q 500 Tlie New Metal Worker Pattern Book. spaces equal to those upon the plan between Q and S. From these points draw lines indefinitely toward the center B 2 . With B 2 as center describe arcs whose radii correspond to B M, B a\ B b\ B d 1 andB 1ST, cutting lines of corresponding number or letter. Then a line traced through the intersections thus obtained will be the shape of opening to cut in the envelope of frustum where it joins the cylinder, and lines drawn from O and O 1 toward B 2 till they cut the arc c 1 1 1 in the points c 1 and V will complete the pattern of the frustum. PROBLEM 161. The Patterns of Two Cones of Unequal Diameter Intersecting: at Rig-lit Angles to their Axes. Let U T V in Fig. 523 be the elevation of a cone, at right angles to the axis of which another cone or frustum of a cone, F G P, is to miter. Lex L K 1ST M be a section of the frustum on the line F G. Let U 2 W V s be a half plan of the larger cone at the base. The first step in describing the patterns is to obtain the miter line in the elevation, as shown by the curved line from to P. With this obtained the development of the pattern is a comparatively simple operation. To obtain the miter line P proceed as follows : Divide the profile L K N M into any convenient num- ber of equal parts, as shown by the small figures. In- asmuch as the divisions of this profile are used in the construction of the sections — or, in other words, since sections through the cone must be constructed to cor- respond to certain lines through this profile — it is de- sirable that each half be divided into the same number of equal parts, as shown in the diagrams. Thus 2 and 2, 3 and 3, 4 and 4 of the opposite sides correspond, and sections, shown in the upper part of the diagram, are taken upon the planes which they represent. From the points in the profile LKN M draw lines parallel to B E cutting the end F G of the frustum. Produce the sides F and P G until they meet in E, which is the apex of the cone. Through the points in F G draw lines from E, producing them until they cut the axis of the cone, as shown at A, A 1 , A 2 . Next construct sections of the cone as it would appear if cut through upon the lines A C, A 1 B, A 2 D. Divide the plan U 2 W V 2 into any convenient number of parts. From the points thus established carry lines vertically to the base line TJ V, and thence carry them toward the apex T, cutting the lines A C, A 1 B, A 2 D, all as shown. Through each of the several points of intersection in these lines draw horizontal lines from the axis of the cone to the side, all as shown. At right angles to the lines A C, A 1 B, A 2 D project lines to any convenient point at which to construct the re- quired sections. Upon the lines drawn from the points A, A 1 , A 2 locate at convenience the points A 3 , A 1 , A 6 . Inasmuch as A 1 B is at right angles to the axis of the cone, the section corresponding to it will be a semicircle whose radius will be equal to A 1 B. There- fore, from A 3 as center, with radius A 1 B, describe the semicircle S B 1 P. For the section corresponding to A 2 D lay off from A 6 the distances A" S 2 and A 6 K'' 3 in a line drawn at right angles to A 2 D of the elevation, each in length equal to the horizontal line drawn through the point A 2 from the axis to the side of the cone. At right angles to S 2 R 2 draw A 6 D 1 , in length equal to A 2 D of the elevation. Set. off in it points 5, 4 and 2, corresponding to similar points in A'" D of the elevation. Through these points 5, 4 and 2, at right angles to A 6 D 1 , draw lines indefinitely. From A 6 as center, with radius equal to the length of horizontal line passed through point 5 in A 2 D of the elevation, describe an arc cutting line 5 of the section. From the same center, with a radius equal to the length of the horizontal line drawn through point 4 in the line A 2 D of the elevation, strike an arc cutting the line 4, etc. Then a line traced through these points, as shown by S 2 D 1 R 2 , will be the section of the cone as it would appear if cut on the line A 2 D of the elevation. In like manner obtain the section S 1 C B. : , corresponding to A C of the elevation. These sections may, if preferred, be obtained in the manner described in connection with Problems 159 and 160. As these sections are obtained solely for the pur- pose of determining at what point in their perimeters — that is, at what distance from points C, B 1 and D' — they will be intersected by the lines representing the points 2, 3 and 4 of the profile L K M N", it is not necessary that the complete half sections should be developed. In the engraving, the small intersecting cone has so little flare that the lines A C and A 2 D cross the large cone so nearly at right angles to its axis that sections 2 2 and 4 4 could be constructed with sufficient accu- Pattern Problems. 30} Pig. 525.— The Patterns of Two Unequal Cones Intersecting at Right Angles to their Axes. 302 77ie New Metal Worker Pattern Book. racy for practical purposes, as in the case of section 3 3, by small arcs of circles with radii respectively equal to A C and A 2 D, and of only sufficient length to include the points c c and d d. Prolong A 5 D 1 , as shown by E 3 , making A s E 3 in length equal to A' E of the elevation. In like manner make A 4 E 2 and A 3 E' equal to A E and A" E of the elevation respectively. At right angles to these lines in the sections set off F" G% F 9 G 3 , F 4 G 4 , in position corresponding to F G of the elevation. Make the length oi Y~ G" equal to the length across the section of the frustum marked 2 2. In like manner make F 3 G 3 equal to 3 3, and F' G 4 equal to 4 4 of the section. From E', E* and E 3 respectively, through these points in the several sections, draw lines cutting the oblique sections just obtained. From the several points of in- tersection between the lines drawn from E 1 , E 2 , E 3 and the sections of the cone, as shown by d d, c c and b b, carry lines back to the elevation, intersecting the lines A C, A 1 B, A 3 D. Then a line traced through these several intersections, as shown from to P, will be the miter line in elevation. Having thus obtained the miter line, proceed to describe the patterns, as follows : For the envelope of the small cone, from E as center, with radius E G, de- scribe the arc F 1 G 1 , upon which set off the stretchout of the section LKMK Through the points in this arc, from E, draw radial lines indefinitely. From E as center, with radii corresponding to the several points in the miter line P, but obtained from the oblique sections above, cut corresponding radial lines. Thus with the radius E 3 d cut lines 4 and 4, with the radius E 2 c cut lines 2 and 2 and with radius E 1 b cut lines 3 and 3. Then a line traced through these points of intersec- tion, as shown by P 1 0' P 3 , will be the shape of the pattern of the frustum to fit against the larger cone. For the pattern of the larger cone, from T as center, with radius T U, describe the arc V'U', in length equal to the circumference of the entire plan of the cone. From the points in the miter line P carry lines parallel to the base of the cone cutting its side T IT, as shown between O 3 and P 3 , also through the points in P draw lines from the apex cutting the base and thence carry them vertically to the plan. These points can be numbered upon the side of the cone to correspond with the plan, but entirely in- dependent of the system of numbers employed upon the smaller cone. Upon the arc V U 1 set off points corresponding to the points just obtained in the plan from the miter line, from which draw lines toward the center T. With one foot of the compasses set at the point T, bring the pencil point successively to the points between O 3 and P 3 and cut radial lines of corre- sponding number in the pattern. Then a line traced through these intersections, as shown by X Y Z Y 1 , will be the shape of the opening to be cut in the en- velope of the larger cone, over which the smaller cone will fit, and T U 1 V will be the envelope of the entire cone. PROBLEM 162. The Patterns of the Frustums of Two Cones of Unequal Diameters Intersecting: Obliquely. In Fig. 524, let M K P O be the side elevation of the larger frustum and F' G 1 S E the side elevation of the smaller, the two joining upon a line between the points E and S, which line must be obtained be- fore the patterns can be developed. Produce the sides S G 1 and E F 1 until they meet in the point E. At any convenient place on the line of the axis of the smaller frustum draw the profile H F K G, corresponding to the end F 1 G 1 . Divide this profile into any convenient number of equal parts, as shown by the small figures 1, 2, 3, etc., and from these divisions, parallel to the axis of che cone, drop points on to F 1 G 1 . From the apex E, through these points in F 1 G 1 , carry lines cutting the side F P of the larger frustum, and pro- ducing them until they meet the center line, or the base P, all as shown by B A, C A 1 and D A 3 . The next step is to construct sections of the larger frustum as it would appear if cut on each of these lines, from which to obtain points of intersection with the lines of the smaller frustum for determining the miter line from E to S in the elevation. Draw the plan of the base of the larger frustum, as shown bv T U V W, and divide one-half of it in the usual man- ner. From these points carry lines vertically to tn& base P of the frustum. Produce the sides M and P N" until they meet in the point L. From the points Pattern Problems. 303 in the base line obtained from the plan carry lines toward the apex L, cutting the section lines A B, project lines at right angles cutting A 3 B 1 , as shown, in the points 4, 3 and 2. In like manner make A* C Fig. 524- — Patterns of the Frustums of Two Unequal Cones Intersecting Obliquely. A' C and A 3 D, as shown. Parallel to A B and of the same length, at any convenient point outside of the elevation, draw A 3 B', and from the points in A B equal and parallel to A C, and from the points m A C project lines at right angles to it, cutting it as shown, giving the points 4, 3 and 2. Also make A s D 1 equal •304 The New Metal Worker Pattern Book. to the section line A" D of the elevation, and cut it by lines from the points in A 2 D, obtaining the points 3 and 2, as shown. In order to complete these sev- eral sections, the width of the frustum through each of the points indicated is to be set off on correspond- ing lines drawn through A 3 B 1 , A 4 C and A 5 D'. To obtain the width through these points first draw an end elevation of the larger frustum, as shown by M' N 1 P 1 0'. Produce the sides, obtaining the apex L'. Draw a plan and divide it into the same number of spaces as that shown in T U V W, and commence numbering at a corresponding point, all as indicated by V U' T 1 W. From the points in the plan carry lines vertically to the base O 1 P 1 , and thence toward the apex L'. Place the blade of the J-square at right angles to the axis of the cone, and, bringing it succes- sively against the points in the section line A B in the side elevation, draw lines cutting the axis of the end elevation, and cutting the lines corresponding in num- ber to the several points in A B, all as shown by a a, h h and c t. Make the length of the lines drawn through A 3 B equal to the corresponding lines thus obtained, as shown by a 1 a', b 1 b 1 , c 1 c 1 and d' d', and through these extremities trace a line, as shown by d 1 W d\ which will be the section through the cone when cut on the line A B. In like manner complete the sections i' C I 1 and /' D' /'. As remarked in the previous problem, it is only necessary that these sections should be developed far enough from the points B 1 , C and D 1 to receive the lines representing the sections of the smaller frustum. Produce A 3 B', making B 1 E 1 equal to B E of the ele- vation, and B 1 X 3 equal to B X 1 of the elevation. In like manner make C E 2 equal to C E, and C X' equal to G X. Make D 1 E 3 equal to D E, and D' X 5 equal to D X' 2 . Through X, at right angles to B 1 E", draw a line in length equal to the line 2 2 drawn across the profile FKG IT, with which this section corresponds, as shown by 2' 2'. Through X 4 draw a line equal to II K, as shown by H 1 K', and through X & draw 4' 4', in length equal to the line 4 4 drawn through the profile F K G H. From E', through the extremities of 2' 2', draw lines cutting the section. In like man- ner draw lines from E 2 through the points H 1 K 1 , and from E 3 through the points 4' 4'. From the points at which these lines meet the sections, as a 2 a~ in the first, o o in the second and m m in the third, carry lines back at right angles to and cutting the corresponding section lines in the elevation. A line traced through the points thus obtained, as shown by E S, is the miter line in elevation formed by the junction of the two frustums. Having thus obtained the miter line in elevation, proceed to develop the patterns as follows : From the. points in E S, at right angles to A 1 E, which is the axis of the smaller cone, draw lines cutting the side E S, as shown by the small figures 1, 2, 3, 4 and 5. These points are to be used in laying off the pattern of the smaller frustum. From E as center, with radius E G 1 , describe the arc F 2 G 2 , upon which step off the stretchout of the profile F K H G, numbering Fig. 525.— The Envelope of the Larger Frustum Shown in Fig. 52$. the points in the usual manner. Through the points, from the center E, draw radial lines indefinitely. From the same center, E, with radius E 1 (of the points in E S), cut the radial line numbered 1, and in like manner, with radii E2, E3, etc. , cut the correspond- ing numbers of the radial lines. A line, E 1 S 1 , traced through the several points of intersection thus formed will be the larger end of the pattern for the small frus- tum, thus completing the shape of that piece, all as shown by E 1 S' G 2 F\ Pattern Problems. 305 To avoid confusion of lines, the manner of ob- taining the envelope of the large frustum is shown in Fig. 525, which is a duplicate of the side elevation and plan shown in Fig. 524, the miter line E 1 S' and the points in it being the same. Similar letters refer to corresponding parts in the several figures. From Jj as center, with radius L" 0", describe an arc, as shown by Y Z, and from the same center, with radius L 2 M 2 , describe a second arc, as shown by y z. Draw Y y, and upon Y Z lay off the stretchout of the plan V s W T 2 , all as shown. Draw Z z. Then ZzyY will be the envelope of the large frustum. Through the points in the miter line E, 1 S 1 draw lines from the apex of the cone to the base, and from the base con- tinue them at right angles to it until they meet the circumference of the plan. Mark corresponding points in the stretchout Y Z, and insert any points which do not correspond with points already fixed therein. From each of the points thus designated draw a line across the envelope already described to the apex, as shown by 3 L", x 1/ and 1 IA Also, from the points in the miter line R 1 S' draw lines at right angles to the axis of the frustum cutting the side L" O 2 , as shown. From L 2 as center describe arcs corresponding to each, of these points and cutting the radial lines drawn across the envelope of the cone. A line traced through the points of intersection between arcs and lines of the same number, as shown by h Br A 1 S 2 , will be the shape of the opening to fit the base of the smaller frustum. ;;ik, The New Metal Worker Pattern Booh. SECTION 3. Irregoflar Forms. (TRIANGULATION.) The class of subjects treated in this section will include all irregular forms which can be constructed from sheet metal by simple bending or forming, but whose patterns cannot be developed by the regular methods employed in the two previous sections of this chapter. These problems divide themselves naturally, in regard to the arrangement of the triangles used in the development of the patterns, into two classes, viz. : First, those in which the vertices of the triangles used in constructing the envelopes all terminate at a com- mon point or apex, and, second, those in which the relative position of the base and the vertex is reversed in each succeeding triangle, or, in other words, those in which the vertices of alternate triangles point in opposite directions. In the introduction to Section 2 (page 240), at- tention is called to the difference between a scalene or oblique cone and a right cone with an oblique base. The scalene cone may be called the type or representa- tive of a large number of forms belonging to the first class above mentioned, since many rounded surfaces entering into the construction of various irregular flar- ing articles are portions of the envelope of a scalene cone. The principles involved in this particular class of forms are explained in that part of Chapter V refer- ring to Fig. 271, page 94. Inasmuch as triangulation is resorted to in all cases where regular methods are not applicable, it is not sur- prising that the forms here treated, especially those included in the second class above referred to, are more varied in character than those of any other class to be met with in pattern cutting. An explanation of methods and principles governing these will be found in the third subdivision of Chapter V, beginning on page 86. The last few problems of this class are devoted to the development of the horizontal surfaces of arches in cir- cular walls. The arrangement of problems in this section will be in accordance with the above classification although no headings will be introduced to distinguish the classes. PROBLEM 163. The Envelope of a Scalene Cone. In Figs. 526 and 527 are shown perspective rep- resentations of scalene or oblique cones. In Fig. 526 the inclination of the axis to the base is so great that a vertical line dropped from its apex would fall out- side the base, while in Fig. 527 a perpendicular from its apex would fall at a point between the center and the perimeter of its base. Supposing the circumference of the base in either case to be divided into a number of equal spaces, it is plain to be seen that lines drawn upon the surface of the cone from the points of division to the apex would be straight lines of unequal lengths, and that such lines would divide the surface of the cone into triangles whose vertices are at the apex of the cone and whose bases would be the divisions upon the base of the cone. It will be seen further that with the means at hand of determining the lengths of these lines forming the sides of the triangles, the pattern cutter possesses all that is necessary in developing their envelopes or patterns. Fig. 526. Fig. 527. Scalene Cones of Different Inclinations. In Fig. 528, D AHis an elevation of the cone shown in Fig. 526 and DGH is a half plan of the Pattern Problems. 307 same, drawn for convenience, so that D H is at once the base line of the elevation and the center line of the plan. Fig. 529 shows an elevation and plan of the cone shown in Fi°\ 527, drawn in the same manner. The principle involved in the development of the pat- terns of the two oblique cones is exactly the same and, as will be seen, letters referring to similar parts in the two drawings are the same; therefore the following demonstration will apply equally well in either case. From the apex A drop a perpendicular to the base Fig. 528.— Pattern of Cone Shown in Fig. 526. line, locating the point 1ST. Divide the base DGH into any convenient number of equal spaces, as shown by the small figures, and from the points thus ob- tained draw lines to the point N. These lines will form the bases of a series of right angled triangles of which A 1ST is the perpendicular hight, and whose hy- pothenuses when drawn will give the correct length of lines extending from the points of division in the base of the cone to the apex. The most convenient method of constructing these right angled triangles is to trans- fer the distances from N to the various points upon the circumference of the base to the line NDasa base line, measuring each time from the point 1ST, by which method the line A 1ST becomes the common perpen- dicular of all the triangles. Therefore from IS" as center, with the distances N 1, N 2, etc., as radii, de- scribe arcs as shown in the engraving, cutting the base line N D. Lines from each of these points to the apex, as A 1, A 2, etc., will be the required hypoth- enuses. The simplest method of developing the pattern is to first describe a number of arcs whose radii are re- spectively equal to the various hypothenuses just obtained; therefore place one foot of the compasses at A, and, bringing the pencil point successively to the Fig. 529.— Pattern of Cone Shown in Fig. 527. points 1, 2, 3, etc., upon the line N D, describe arcs indefinitely. From any point upon the arc drawn from point 1, as n, draw a line to A as one side of the j^at- tern. Next take between the feet of the dividers a space equal to the spaces upon the circumference of the plan, and placing one foot of the dividers at the point n, swing the other foot around till it cuts the arc drawn from point 2 ; then A n 2 will be the first triangle forming part of the envelope or pattern. With the same space between the points of the dividers, and 2 of the pattern as center, swing the dividers around again, cutting the arc drawn from point 3. Repeat this operation from 3 as center, or, in other words, continue to step from one arc to the next, until all the arcs have been reached, as at g, which in this 308 The New Metal Worker Pattern Book. case will constitute one-half the pattern ; after which, if desirable, the operation of stepping from arc to arc may be continued, as shown, finally reaching the point d. Draw d A and trace a line through the points ob- tained upon the arcs, as shown by n g d, which will complete the pattern. PROBLEM 164. The Envelope of an Elliptical Cone. In Fig. 530 is shown an elevation and plan of a cone whose base is an elliptical figure. So far as the solution of this problem is concerned the plan may be a perfect ellipse or an approximate ellipse drawn by any convenient method. Fig. 531 shows a perspective view of the cone in question, upon which lines have been drawn from points assumed in its base to the Fig. 530— Plan and Elevation of Cone with Elliptical Base. apex. From an inspection of this view it will appear that these lines, as in the case of the scalene cone, are of unequal length, and therefore that the pattern of its envelope may be developed by a method analogous to that adopted in the preceding problem. Since the cone consists of four symmetrical quar- ters, it will be necessary to obtain the envelope of only one quarter, from which the remainder of the pattern can be obtained by reduplication. Therefore draw a half side elevation, as shown by Y X G of Fig. 532, immediately below which draw a quarter plan, X C E, so that the line X C shall be common to both views, as shown. Divide E G into any convenient, number of Fig. 531. — Perspective View of C>>ne Shown in Fig. 530 with Lines Drawn upon its Surface Used in Developing Pattern. equal parts, as indicated by 1 the small figures. Lines drawn from the points in E C to X will give the base lines of a set of triangles, whose altitudes are equal to QUARTER PLAN Fig. 532.— Pattern of One-Half the Cone Shown in Fig. 530. the hight of the article X Y, and whose hypothenuses will give the true distances from the apex to the points Pattern Problems, 30& assumed in tile base line. A convenient method for drawing these triangles is as follows : With X as cen- ter strike arcs from the points in E G, cutting X C, as shown by the small figures. Lines drawn from the points thus obtained to Y, as shown, will give the hy- pothenuses of the triangles. With Y as center, and the distance from Y to the several points in X as radii, strike arcs indefinitely. From Y to any point upon the arc draw any line, as Y E, which will form the edge of pattern corresponding to X E of plan. With the dividers set to the space used in stepping off E C of plan, and starting from E of the pattern, space off the stretchout of the plan, stepping from one arc to the next, as shown. From the point 6, or C 1 , draw a line to Y. Through the points thus obtained trace a line. Then Y G E is the pattern for that part of the article shown on plan by E X 0. This quarter can he du- plicated by any means most convenient so as to obtain the pattern for one-half or for the whole envelope in one piece, as desired. PROBLEM 165. Pattern for a Raised Boiler Cover With Rounded Corners. The shape of the cover considered in this problem may perhaps be more accurately described as that of ELEVATION Fig. 533. — Plan and Elevation of Cover. an oblong pyramid with rounded corners, as shown by the plan and elevation in Fig. 533, an inspection of which will also show that the rounded corners are por- tions of a scalene cone, while the four pyramidal sides- are simply plain triangular surfaces. The plan shows one-half of cover, or as much as- would usually be made from one piece. First divide G H of plan into any convenient number of equal parts — in this case four — and connect the points thus obtained with 0, thus obtaining the base lines of a set of right angled triangles whose hypothenuses when obtained will give the true distances from the points in Gr H to the apex of the cover. To construct a diagram of triangles represented! by lines in plan, draw the right angle M N P in Fig^ Fig. 534.— Diagram of Triangles. 534, making M X equal to the hight of cover, as shown by B D of elevation. Measuring from X, set off on X P the length of lines in plan, including J O and F. From the points in X P draw lines to M, as shown. The line C' M gives the slant hight of cover as seen in the end elevation, and M J' the slant hight as would be seen in side elevation. The other lines give the hypothenuses of triangles, the bases of which are shown by the lines in O G H of plan. To describe the pattern -proceed as follows : 310 Tlie New Metal Worker Pattern Booh. Draw the line Q IT, in Fig. 535, in length equal to M J' in the diagram of triangles. Through TJ, at right angles to Q U, draw V T, making U T and U V each equal to J II or J K of Fig. 533, and draw Q T and Q V. Then Q V T will be the pattern of one of the sides of the pyramid, to which may be added on either side the envelope of the portion of a scalene cone shown by H G in Fig. 533. It should be here remarked that the method above employed of obtaining the length Q T produces the same results as that employed in the diagram of triangles as shown by the hypoth- enuse M 1, which is one side of the adjacent triangle forming part of the pattern of the rounded corner. From Q of Fig. 535 as center and M 2 of the diagram of tri- angles as radius strike a small arc, 2', which arc is to be intersected with one struck from T of pattern and the distance H 2 of plan as radius. Proceed in this manner, using the spaces in H G of plan for the dis- tances in T S of pattern, and the lengths of lines drawn from M to points 2 to 5 in diagram of triangles for the distances across the pattern from Q to the points in T S. "With S of pattern as center, and Gr F of plan as radius, describe a small arc, R, which intersect with one strack from Q of pattern as center, and M C of the triangles or B G of the elevation as radius, thus estab- lishing the point R of pattern, line through the points from S Q Draw R S, and trace a to T, as showD. The Fig. 535. — Pattern of Cover. other part of pattern, as Q V W P, can be described in the same manner, or by duplication. PROBLEM 166. Pattern for the End of an Oblong: Vessel which is Semicircular at the Top and Rectangular at the Bottom. In Fig. 536, A C D E represents the side eleva- tion of the article, F H K L the end elevation, and M NEPin Fig. 537 the plan. By inspection of these it will be seen that the portion represented upon the E D SIDE. END. Fig. 536. — Side and End Elevations of Oblong Vessel with Semicircular End. end elevation by G L K is simply a flat triangular sur- face, while the corners of the vessel, shown by B C D of the side view and N R of the plan, are quarters of the envelope of an inverted scalene cone. To obtain the patterns proceed as follows : Divide one-half of the end of the plan into any convenient Fig. 537.— Plan of Oblong Vessel with Semicircular End. number of equal spaces, all as shown by small figures 1, 2, 3, 4, etc., in N R. From each of the points thus Pattern Problems. 311 determined draw lines to the point N", the apex of the cone in plan, all as shown in the engraving. Proceed next to construct the diagram of triangles shown in Fig. 53b, of which the lines just drawn in the plan are the bases and B D is the common altitude. Draw A B, in length equal to D B of Fig. 536, and at right angles to it draw B C, which produce indefinitely. From B Fig. 5SS. — Diagram of Triangles. Fig. SS9.— Pattern of End Pieces. along B C set off spaces equal to the distances from N of the plan to the several points in the boundary line. That is, make B 5 of Fig. 53S equal to 1ST 5 of Fig. 537, and B 4 equal to IN" 4, and so on. And from each of the points in B C draw lines to A. Then the distances from A to the various points in B C will be the distances from the apex of the scalene cone to the various points assumed in its base, and will be the radii of the arcs shown between D F and E in Fig. 539. For convenience erect any perpendicular, as A 1 D of Fig. 539, upon which set off distances equal to the length of the lines in the diagram drawn from A, or, in other words, make A 1 1 equal to A 1 of the diagram, Fig. 538 ; A 1 2 equal to A 2 of the diagram, and so on. From A 1 as center, with radius A 1 D, describe the arc D E indefinitely. In like manner, from the same center, with radius A 1 2, describe a corresponding arc, and proceed in this way with each of the other points lying in the line A 1 D. From any convenient point upon arc 6, as F, draw A 1 F, which will represent the side of the pattern cor- responding to B D of the side elevation. With the dividers set to the space used in stepping off the arc N R of the plan, place one foot at the point F of the pattern and step from one arc to the next until all the arcs are reached, and draw A 1 E. Then A 1 F E will be one portion of the required pattern. From E as center, with radius E A 1 , describe the arc A 1 G in- definitely. Make the chord A' G equal to L K of the end elevation, Fig. 536, and draw E G. Then A 1 E G will be the pattern of that portion shown by L G K of the end view and 1ST R P of the plan. Duplicate the part A 1 F E, as shown by G H E, thus completing the pattern of the entire end. PROBLEM 167. Pattern of an Irregular Flaring: Article, both Top and Bottom of which are Round and Parallel, but Placed Eccentrically in Plan ; Otherwise the Envelope of the Frustum of a Scalene Cone. In Fig. 540 is shown an elevation and plan of the article, in which E F Gr H is the plan of the bottom and E J K L that of the top, the two being tangent at the point E. In Fig. 541 the elevation and a portion of the plan are drawn to a larger scale and conven- iently located for describing the pattern. Since the top and the base of the article are both circular and are parallel, the shape of which the pat- tern is required becomes a frustum of a scalene cone, and lines drawn upon its surface from any set of points assumed in the circumference of its base to its apex will divide the circumference of the top into similar and proportionate spaces. Therefore, the first step is to extend the lines of the sides B A and C D until they meet at M, the apex. Next divide the plan of the base, one-half of which, EH6, only is shown, into any convenient number of equal spaces, as shown by the small figures. As it is necessary to ascertain the distance from each of these points to the apex of the cone the simplest method of accomplishing this is as follows : From E, the position of the apex in plan, as a center, with E 6, E 5, E 4, etc., as radii, describe arcs cutting E G. Carry lines vertically from each of the points in E G, cutting the base line A D ; thence 312 The New Metal Worker Pattern Book. carry them toward the apes M, cutting the line of the top B C, all as shown. With M as center describe arcs from each of the points in the base line A D, and extend them indefi- nitely in the direction of 0. In the same manner draw arcs from the points of intersection in B C, as shown. From the apex M draw any line to intersect the arc from A or 7 of the base line, as M N, which will form one side of the pattern, corresponding to B A of the elevation. Set the dividers to the space Fig. 640.— Plan and Elevation of Frustum of a Scalene Cone. E 6, used in dividing the plan of the base, ana starting from N step from one arc to the next, thus laying out the stretchout of the base E II G, and at the same time locating each point at its proper distance from the apex M. A line traced through these points, as N Q 0, will be the bottom of one-half of the pattern. From the points in the line NQO draw lines to M, cutting the arcs of corresponding number previously drawn from B C ; then a line traced through these points of intersection, as shown by B P, will be the top Fig. 541. — Method of Obtaining Pattern of a Scalene Cone. of the pattern, and P B N Q O will thus be one-half the required pattern. PROBLEM 168. Pattern of a Flaring; Article, the Top of which is Round and the Bottom Oblong- with Semicircular Ends.— Two Cases. First Case. — In Fig. 542 is shown the elevation and plan of the article drawn in proper relation to each other, as shown by the lines of projection. In this case the top of the article is located centrally with reference to the bottom, as shown in the plan. From 0, the center of the top, erect tne perpendicular 0, cutting Pattern Problems. 313 the line of the top in elevation, and from P erect the perpendicular P p, cutting the line of the base. Since LMK and FHGof the plan are semicircles lying in parallel planes, that part of the pattern of the article shown by L F H G X M must be one-half the envelope of the frustum of a scalene cone. Fig. 54S.— Plan, Elevation and Pattern of Flaring Article with Round Top and Oblong Base, the Top being Centrally Located, To ascertain the apex of the cone, prolong the side line C D of the elevation indefinitely in the direction of X. Through the points p and draw p 0, which produce until it meets C D prolonged in the point X. Then X is the apex required. From X drop a per- pendicular, cutting the center line of the plan at X 1 , thus locating the apex in plan. Divide FHG into any convenient number of equal spaces, as shown by the small figures. Should lines be drawn from each of the points thus obtained to X', they would represent the bases of a set of right angled triangles, of which Y X is the common altitude, and whose hypothenuses will give correct distances from the apex of the cone to the various points assumed in the base. The simplest method of obtaining these hypothe- nuses is as follows: From X 1 as center draw arcs from each of the points in F H G, cutting the center line E H of the plan. From each point in P H erect a per- pendicular to p C, as shown. From the points thus obtained in p C carry lines toward the apex X, cutting o D, as shown. From X as center strike arcs from each of the points in p C indefinitely. Assume any point, as G', upon the arc struck from point 1 as the first point in the pattern of the base, from which draw a line to X. Set the dividers to the space used in stepping off the plan, and, commencing at G 1 , step to the second arc, and from that point to the third arc, and so on, as shown in the engraving. A line traced through these points will be the boundary of a lower side of the semi- circular end. From each of these points just obtained draw a line toward the center X. Place one foot of the dividers at X, and, bringing the pencil point suc- cessively to the points in D, cut radial lines of cor- responding number just drawn. A line traced through these points of intersection, as shown by X* L 1 , wit. form the upper edge of the pattern of the end piece. From the point L 1 , which corresponds to L of the plan, as center, with L 1 F 1 as radius, describe the arc F' R', and from F 1 as center, with radius equal to F R of the plan, intersect it at R 1 , as shown. Draw L 1 R'. Then L 1 R 1 F" is the pattern of one of the sides. To L 1 R 1 add a duplicate of the end piece already ob- tained, all as shown by L 1 R 1 S 1 W, and to S' X 2 add a duplicate of the side just obtained, as shown by S 1 X a G\ thus completing the pattern. Second Case. — This case differs from the first only in the fact that the top of the article, being located near one end, is drawn concentric with the semicircle of the near end. As the result of this condition, that portion of its pattern shown by S E R L K X in the plan, Fig. 513, becomes one-half the envelope of the frustum of a right cone, the method of developing which is given in Problem 123 of the previous section of this chapter. In that portion of the article shown by R F H G S X the conditions are exactly the same as in the first case. In Fig. 543 corresponding parts have been let- tered the same as in Fig. 512, so that the demonstra- 314 The New Metal Worker Pattern Book. tion given above is equally applicable to either figure. In the final make up of the various parts of which the a duplicate of L 1 F 1 G 1 N 1 , all as clearly shown in the engraving. The seam in this case has been located Fig. 543. — Plan, Elevation and Pattern of Flaring Article with Round Top and Oblong Base, the Top being Located near One End. complete pattern is composed, the part R 1 S 1 N 3 L 1 is upon the line N S of the plan instead of upon N G as of course obtained as in Problem 123 instead of being before. PROBLEM 169. The Patterns of a Flarinj Tub with Tapering: Sides and Semicircular Head, the Head having: More Flare than the Sides. In Fig. 544, A B C D shows a side elevation of the tub, LMNOP the plan at the top, and E F G H K the plan at the bottom, an inspection of which will show that the head, as shown by H or C D, has more flare than the sides, whose flare is shown by A J or A B, the flare of the sides and foot being the same. Inasmuch as the article is tapering in plan, the conical part of the pattern will include a little more than a semicircle, as shown. The points showing the junction between the straight sides and the conical part are to be determined by lines drawn from the cen- ters by which the top and bottom were struck, per- pendicular to the sides of the article. Therefore lay off in the plan T N and T P, drawn from the center T of the curved part of the plan of the top of the article, perpendicular to the sides M N and L P respectively. Pattern Problems. 31, And in like manner from S, the center by which the curved part of the bottom of the article is struck, draw S G and S K. Since the top and bottom of the tub are parallel, as shown by the side elevation, and their circles are not concentric in xhe plan, it follows that the part P Fig. 544. — Plan, Elevation and Pattern of Flaring Tub with Tapering Sides and Semicircidar Head. N G H K is part of the envelope of a scalene cone. To find the apex of this cone, first drop lines from the points T and S vertically, cutting respectively the top and bottom lines of the elevation, as shown at T 1 and S 1 . A line connecting T 1 and S' will give the inclina- tion of the axis of the cone in that view, which con- tinue indefinitely in the direction of R 1 until it inter- sects the side G D continued, as shown at R 1 . Then R 1 is the apex of the cone. From R 1 draw R' R verti- cally, cutting the center line of the plan at R. Then R shows the position of the apex of the cone in the plan. As the pattern of the curved portion consists of two symmetrical halves when divided by the center line of the plan, divide the curve N into any con- venient number of equal spaces, as shown by the small figures. Lines drawn from each of these points to R would represent the bases of a series of right angled triangles whose common altitude is V R 1 , and whose hypothenuses when drawn will represent the correct distances from the apex to the vari- ous points assumed in the base of the cone. The simplest method, however, of meas- uring these bases is to place one foot of the compasses at the point R, and, bringing the pencil point successively to the points in N O, draw arcs cutting the center line, as shown between T and 0. Now place the blade of the T-square parallel to R R' and drop lines from each of these points, cutting the line A D as shown. From the points obtained upon A D draw lines toward the apex R', cutting the bottom line of the tub B C. These lines drawn from the points in A D to R 1 will be the desired hypothenuses and may be used in connection with the spaces of the plan in developing the envelope of the scalene cone. Therefore from R 1 as center, and radii corresponding to the distance from R 1 to the several points in T : D, describe a set of arcs indefinitely, as shown. Assume any point upon the arc 0, as 1ST', as a starting point, from which draw a line to R 1 . With the dividers set to the space used in divid- ing the plan 1ST 0, place one foot at the point- N 1 and swing the other foot around, cutting the arc 1. Repeat this operation, cutting the arc 2, and so continue to step from arc to arc until all the arcs have been reached, which will complete the outline of one-half the pattern. The operation of stepping from arc to arc can be con- tinued, stepping back from arc 5 till arc is reached at P 1 , thus completing the top line of the pattern of the entire curved portion of the tub. From each of the points thus obtained draw lines toward the apex R', as shown. Place one foot of the compasses at R 1 , and, bringing the pencil point successively to the points in 316 The New Metal Worker Pattern Booh. the line S' previously obtained, cut radial lines of corresponding number in the pattern, as shown from G 1 to K'. Lines traced through the several points in the two outlines, as shown by G' H' K 1 and N 1 0' P 1 , will complete the pattern of the conical part of the tub. The patterns of the sides and foot may be obtained as described in Problem 74 and as indicated in the upper part of the engraving. PROBLEM 170. The Pattern of a Flaring 1 Article which is Rectangular with Rounded Corners, Having More Flare at the Ends than at the Sides. In Fig. 545, ABCDEF represents the plan at the top of a portion of the flaring article, whose general shape is rectangular with rounded corners. GHI J K L represents the plan of the bottom of the same, showing that the flare at the ends, represented by I C or J D, is greater than that of the sides, represented by A G. The arc E D of the plan of the top is struck from as center, while the arc J K of the bottom is struck from N. Since the top and bottom are parallel, as shown by P Q and P S of the side elevation, the corner JDEK is a portion of the envelope of the frustum of a scalene cone. To find the apex of the cone, drop lines from O and N at right angles to P Q, cutting respectively the top and bottom lines in the side view, as shown at T and IT, and draw T U and continue the same indefinitely in the direction of X. Also continue Q S until it in- tersects T U at the point X. Then X will be the apex of the cone. From X erect a line vertically, cutting the line D M of the plan at M ; then M will show the posi- tion of the ajDex of the cone in plan. Divide the arc E D into any convenient number of equal spaces, and from the points thus obtained draw arcs from M as center, cutting D, as shown. From the points in Ddrop lines vertically, cutting T Q, the top line of the side, otherwise the base of the cone. From the points thus obtained in T Q draw lines toward the apex, cut- ting U S. "With one foot of the compasses set atX, bring the pencil point successively to the points in T Q and draw arcs indefinitely, as shown. From any convenient point upon the arc 0, as E', draw a line to X, forming one side of the pattern. Take between the points of the dividers a space equal to that used in stepping off the plan of cone E D, and, placing one foot at the point E', swing the other foot around, cutting the arc 1, from which intersection step to the next arc, and so continue until all the arcs have been reached at D 1 , from which point draw a line to the apex X. Likewise from each of the points between E 1 and D 1 draw lines toward the apex indefinitely. Finally, with one foot of the compasses at X, bring the pencil point to each of the points in U S Fig. 54a. — Plan, Elevation and Pattern of Rounded Corner for an Article whose Sides and Ends Flare Unequally. and draw arcs, cutting radial lines of corresponding number in the pattern. Lines traced through the points between the points K 1 and J' and E 1 and D 1 will complete the pattern of the curved corner. The pat- tern for the plain sides can easily be obtained after the manner described in Problem 74 and added to that of the corner as may be found practicable. Pattern Problems. 317 PROBLEM 171. The Pattern of a Flaring: Article which Corresponds to the Frustum of a Cone whose Base is a True Ellipse. In Fig;. 546, let G H F E be the elevation of one side of the article, L M IT E. the elevation of an end, E' R 1 F 1 U' the plan of the article at the base, and T V S P the plan at the top. Produce E G and F II of the side elevation until they meet in the point I, the apex of the cone. Divide one-quarter of the plan E 1 R 1 into any con- Fig. 546. — Plan, Side and End Elevations of the Frustum of an Elliptical Cone. venient number of equal parts, as indicated by the small figures. From the points thus determined draw lines to the center C. These lines will form the bases of a series of right angled triangles whose common alti- tude is the hight of the cone, and whose hypothenuses when drawn will give the true distances from the apex to the several points assumed in the base of the cone. Therefore at any convenient place draw the straight line D A of Fig. 547, in length equal to I E\ Make D B equal to I G'. From A and B of Fig. 547 draw perpendiculars to D A indefinitely, as shown by A and B N". Take the distances C 5, C 4, C 3, etc., of the plan and set off corresponding distances from A on A 0, as shown by A 5, A 4, A 3, etc. From these points in A draw lines to D, cutting B 1ST. These lines are also shown in the elevation, but are not necessary in that view in obtaining the pattern. From D as center describe arcs whose radii are equal to the lengths of the several lines just drawn from D to the points in A 0. From any convenient point in the first arc draw a Fig. 547. — Diagram of Triangles and Pattern of Frustum Shown in Fig. 546. straight line to D, as shown by W D. This will form one side of the pattern. From W, as a starting point, lay off the stretchout of the plan E' B,' F 1 , etc., using the same length of spaces as employed in dividing it, stepping from one arc to the next each time, as shown'. A line traced through these points will be the outline of the base of the pattern, one-half of the entire en- velope being shown in the pattern from W to Z, From the points in W Z draw lines to D, which intersect by arcs drawn with D as center and starting from points of corresponding number in B 1ST. A line traced through the points of intersection will form the upper line of the pattern, as shown. Then WXYZ will constitute the pattern of one-half of the envelope, to which add a duplicate of itself for the complete pattern. 318 The New Metal Worker Pattern Booh PROBLEM 172. The Patterns for a Hip Bath. In Fig. 548, let H A L ]S T be the elevation of the bath, of which D 1 G E 1 B' is a plan on the line D E. Let the half section A ! M C B 3 represent the flare which the bath is required to have through its sides on a line indicated by A B in elevation. By inspec- tion of the elevation it will be seen that three patterns are required, which, for the sake of convenience, have been numbered in the various representations 1, 2 and 3. Since the plan of piece No. 1 on the line I) B, Fig. B4S. — Plan, Elevation and Section of a Hip Bath. which is at right angles to its axis A F, is a semicircle, as shown by G D 1 B', and since its flare at the side, as shown by C B 2 A°, is the same as at B D LT, its pat- tern will be a portion of the envelope ^ a right cone. Patterns of this class have been treated in the previous section of this chapter — to which the reader is re- ferred — where, in Problem 143, an exactly similar subject has been treated. The operation of obtaining this pattern is fully shown in Fig. 549, and, therefore, need not be here described. Piece No. 2, as shown in Fig. 548, is so drawn as to form one-half of the frustum of an elliptical cone. As its section at A B (shown at the right) must neces- sarily be the same as that of piece No. 1, against which it fits, the point F is assumed as the apex of the elliptical cone, and consequently the flare at the foot, E L, is determined by a continuation of the line drawn from the apex through E. Should it be decided to have more flare at the foot than that shown by E L, the point L may be located at pleasure, and the plan of the top, K L l A 1 , be drawn arbitrarily; after which its pattern may be developed by means of the alter- nating triangles alluded to in the introduction of this Fig. 549.— Pattern of Piece No. 1 of Hip Bath. section (page 306), examples of which will be found further on in this section. The plan G E 1 B', from which the dimensions of the pattern are to be determined, may be a true ellipse, or may be composed of arcs of circles, as shown, ac- cording to convenience. Divide one-half the plan G E 1 into any convenient number of equal spaces, as shown by the small figures, and from each point thus obtained draw lines to the center C. To avoid con- fusion of lines a separate diagram of triangles is con- structed in Fig. 550, in which M G is the hight of the Pattern Probleins. 319 tub or frustum and M F the hight of the cone. Draw M L and C E, each at right angles to M F. Upon C E set off from C the lengths of the several lines C 1, 1534 s it Fig. 550.— Pattern of Piece No. 2 of Hip Bath. C 2, etc., of the plan. Through each of the points in C E draw lines from F, cutting the line M L. From Fig. 551. — Diagram of Radii for Pattern of Foot. F as center draw arcs indefinitely from each of the points in C E and also from the points in M L. Through any point upon arc 1 of the lower set, as G, draw a line from F and extend it till it cuts arc 1 of the upper set at K ; then K G will be one side of the pattern. With the dividers set to the space used in dividing the plan G E', place one foot at the point G of the pattern and step to arc 2, and so continue step- ping from one arc to the next till all are reached, as at E, and repeat the operation in the reverse order, finally reaching B and completing the lower line of the pattern. From each of the points in G E B draw lines radially from F, cutting arcs of corresponding Fig. 552.— Pattern of Foot of Hip Bath. number drawn from M L. Lines traced through these points of intersection will complete the upper line of the pattern. Then G E B A L K will be the required pattern of piece No. 2. As the plan D 1 G E 1 B 1 has been drawn entirely from centers (C, P, S and P 1 ), the pattern of piece No. 3 is exactly similar to that described in Problem 134 of the previous section of this chapter, to which the reader is referred. In Fig. 551 is shown a diagram for obtaining the radii taken from dimensions given in Fig. 54S, while Fig. 552 shows the pattern described by means of the radii given in Fig. 551. 320 The New Metal Worker Pattern Book. PROBLEM 173. The Patterns for a Soapmaker's Float. In Fig. 553 is shown a perspective view of a soap- maker's float. In general characteristics it is very similar to piece No. 2 of the hip bath treated in the preceding problem. It also resembles the bathtub in that its bottom is bulged or raised with the hammer, and is therefore not included in the field of accurate pattern cutting. The sides are to be considered as parts of two cones having elliptical bases, the short diameters of which are alike, but the long diameters of which vary. In Fig. 554 is shown a plan and an inverted eleva- tion of the flaring sides, showing in dotted lines the completed cones of which the sides form a part. Thus L D' M represents one-half the base of an elliptical cone of which L M is the short diameter and D 1 K' one-half the long diameter. As all sections of a cir- J^ig. 553.— Perspective View of Soapmaker's Float. cular cone taken parallel to its base are perfect circles, so all sections of an elliptical cone parallel to its base must be ellipses of like proportions with the base. Therefore the plan of the upper base of the frustum A' P must be so drawn that a straight line from A' to P will be parallel to a straight line joining D 1 and L. For the pattern of the portion shown by D A E F of the elevation, first produce the line F B of the ele- vation in the direction of K indefinitely. In like man- ner produce D A of the elevation until it reaches F E produced in the point K. Then D K F may be re- garded as the elevation of a half cone, of which that part of the vessel is a portion, and K F its perpendicular hight. Next, divide one-half the plan LD'M into any number of equal parts, as shown by the small figures 1, 2, 3, etc. Construct the diagram of trian- gles, shown in Fig. 555, by drawing the line D K 1 of indefinite length, and the line K 1 K at right angles ta it, making K 1 K in length equal to F K, Fig. 554. Establish the point K a by making the distance K 1 K 3 equal to E F of Fig. 554. Draw K 2 A parallel to K 1 D. From each of the points 2, 3, 4, etc., of the plan draw lines to the center K', and set off distances equal to these lines upon the line K 1 D of Fig. 555, measuring from K 1 toward D. From each of the points thus ob- tained draw lines to the point K, cutting A K 3 . "With one foot of the compasses in the point K, and the other -Oil Fig. 554.— Plan and Inverted Elevation of Soapmaker's Float. brought successively to the points 1, 2, 3, etc., in the line D K' and also to the points in the line A K 2 , de- scribe arcs indefinitely. Take in the dividers a space equal to the divisions in D 1 L of Fig. 554, and, commencing at the point a in arc 7 (Fig. 555), step to arc 6 and thence to arc 5, and thus continue stepping from one arc to the next until the entire stretchout of the half plan has been laid off, as shown in Fig. 555. From each of the points thus obtained in a d draw lines to K, cutting arcs of corresponding number drawn from A K\ Then Pattern Problems. 321 a line traced through the several points of intersection thus obtained, as shown by b c and a d, will be the boundary lines of the pattern. The pattern for the other end of the article is to be, in the main, developed in the same manner as above described. One additional condition, however, exists in connection with this piece, viz. : To determine the dimensions of the cone of which this piece (EBCF, Fig. 554) is a part, since the flare at B C is much greater than A D, while the flare of both pieces at the side is the same as shown by P L of the plan. The quarter ellipse P B 1 of the plan being given, and also the point C, it becomes necessary to draw from C a quarter ellipse which shall be of like proportions with 01 23 J SU7 Fig. 555. — Diagram of Triangles and Pattern of Piece LD*M of Fig. 554 P B 1 , which, as remarked above, is a necessary condi- tion, both beins: horizontal sections of the same cone. To do this proceed as follows : Connect the points P and B 1 by means of a straight line. From the point C 1 draw a line parallel to P B 1 , and produce it until it cuts the line L G 1 , which is a straight line drawn at right angles to L M. Then G 1 becomes a point in the lower base of the cone corresponding to the point P in the upper base. Draw the line G 1 P, and continue it until it intersects the long diameter in H 1 . Drop the point G 1 vertical from the plan on to the base line D of the elevation, as indicated by the point G. Draw a line through the points G and E, which produce in- definitely in the direction of H. In like manner pro- duce the side C B of the cone until it intersects G E produced in the point H. Then it will be found that the jwint H of the elevation and the point H 1 of the plan coincide, as indicated by the line H H 1 . H G of the elevation thus represents the axis and H C one side of the cone of which the piece E B C G is a part, from which it will be seen that this cone is at once elliptical and scalene. The operation of developing the pattern from this stage forward is the same as in the previous case, all as clearly shown in Fig. 556, save only in the addition of the triangular piece indicated by G E F of the elevation. After completing the other I? 'G 5 i 3 2 1^ Fig. 556. — Diagram of Triangles and Pattern of Piece L&M of Fig. 554. portions of the pattern, this triangular piece is added as follows : The distance H 1 L in Fig. 556 is to be set off on the line H 1 C in the same manner as the distances to the other points — i.e., H 1 L is equal to H 1 L of Fig. 554. ■ Then L is to be treated in the same manner' as the other points, an arc being struck from it, as indi- cated in the engraving, by which to determine the corresponding point 1/ in the outline of the pattern. L 2 G 2 is made equal to L G 1 of the plan, Fig. 554. From If draw a line to E. Then E L 2 G 2 will be the pattern of the triangular piece indicated in Fig. 554 by E F G. It is to be added upon the opposite end of the pattern in like manner, as indicated by E 1 G' L 1 . 322 Tlie New Metal Worker Pattern Book. PROBLEM 174. The Envelope of a Frustum of an Elliptical Cone Having: an Irregular Base. The form E F K L J shown in Fig. 557, the lower line of which is an irregular section through an elliptical cone, is introduced here, not as representing any particular article or class of forms, but because it embodies a principle somewhat different from other sections of cones previously given, which may be use- ful to the pattern cutter. B A C is the side elevation of a cone having an elliptical base, one-half of which is shown by B 1 H C Divide one quarter of the plan, as H C, into any convenient number of equal parts, as shown by the small figures. From each of the points of division draw lines to the cen- ter D 2 , and also erect lines cutting the base of the cone B C, from which carry them toward the apex, cutting the lines E F and J L K. The first operation will be that of obtaining the envelope of the complete cone in the same manner as described in pre- vious problems. Construct a diagram of triangles, as shown at the right, in which A 1 D 1 is equal in hight to A D, and at right angles to G 1 W and D 1 V, ex- tensions respectively of E F and B C. Upon D 1 V, measur- ing from D 1 , set off the dis- tances from jy to the several points in H C, as shown. From each of the points thus obtained draw lines toward A 1 , cutting G' W. Also from each of these points, with A' as center, describe arcs indefi- nitely. Take between the points of the dividers a space equal to that used in dividing the plan H C, and placing one foot upon the arc drawn from point 1 in the line D' V, step to arc 2, thence to arc 3 and so continue till one quarter of the stretchout is completed at 7, and, if desirable, continue the operation, taking the arcs in reverse order, thus completing the outline of one-half the envelope of the cone, as shown in the From each of the points in this outline or stretchout draw measuring lines toward the center A 1 . Place one point of the compasses at point A 1 , and, bringing the pencil point successively to the several points of intersection on the line G 1 W, cut measuring lines of corresponding number, as shown from G 1 to G\ Place the T-square parallel to the base B 0, and, bringing it successively to the several points of inter- im';/. 557. — Patterns for the Frustum of an Elliptical Cone Having an Irregular Base. section previously obtained in the curved line L K, cut lines of corresponding number drawn from the points in D 1 V to A 1 , as shown from X to Y. Finally, with one foot of the compasses at A 1 , bring the pencil point to each of the points of intersection last obtained and cut corresponding measuring lines in the pattern. Then lines traced through the points of intersection, aa shown from L 1 to L° and from G 1 to G 3 , will complete the pattern of one-half the frustum E F K L J. Should it be desirable to cut a pattern to fill the end J L K of the frustum, as for a bottom in the same, it will first be necessary to obtain a correct plan Pattern Problems. 323 of the line J K L. To accomplish this, set off on the lines D 2 7, D" 6, etc., of the plan the lengths of the several lines of corresponding number drawn from the line G 1 D 1 to the intersections between X and Y, thus obtaining the desired line L 3 K 2 . Extend the center line B 1 C 1 of the plan, as shown at the right, upon which lay off a stretchout of the line L K, taking each of the spaces separately as they occur, all as shown by Z K 3 , through which draw measuring lines at right angles. Place the T-square parallel to B 1 C, and, bring- ing it to the several points in the line L 3 K 3 , cut corre- sponding measuring lines. Then a line traced through the points of intersection, as shown by L 4 K 3 , will be the pattern of one-quarter of +he desired piece, which may be duplicated as necessary for a half or for the entire pattern in one piece. PROBLEM 175. The Patterns of the Frustum of a Scalene Cone Intersected Obliquely by a Cylinder, their Axes Not Lying: in the Same Plane. In Fig. 558, let A B C D represent the frustum I A D and B C are the outlines of the slanting sides. of an oblique cone, and T S E V U the cylinder that , In Fig. 559 E F G H shows the plan of the frustum Fig. 558. — Front Elevation of the Frustum of a Scalene Cone Intersected Obliquely by a Cylinder. joins the same at the angle indicated. The view here given of the frustum is that of its vertical side, so that SECTIONS Fig. 559.— Elevation, Plan and Sections of the Frustum of a Scalene Cone Intersected Obliquely by a Cylinder. at its base and K I J G the plan of the top, from which the side elevation is projected at the left, D C 324: Tlie New Metal Worker Pattern Book. being the base and A D the vertical side. The inter- secting cylinder is indicated by F L M G, and its pro- file by NOPQ. The diameter of cylinder is the same as that of top of frustum. Divide the profile NOPQ into any convenient number of equal parts, and from the points thus ob- tained carry lines parallel with G M, cutting I J G and F G of plan, as shown. As the points in the profile of the cylinder lie in four vertical planes, indi- shown "With b" and d" as centers, strike the arcs G b' and G d', thus forming sections of the cone in plan corresponding with a b and c d of elevation. The four vertical sections above referred to are shown below the plan by I' F', e f, J' g' and h' i'. To avoid a confusion of lines, the method of obtaining the shapes is shown separately in Figs. 560 to 563, in which the reference letters are the same as in Fig. 559. To obtain the shape of section on line I F in b I . I \ I D' ¥' D' /' Fig. 560. Fig. 561. Fig. 562. 1 Sections of the Frustum of Scalene Cone Corresponding to Divisions in Profile of Cylinder in Fig. 559. cated by the lines 7, 8 6, 1 5, and 2 4-, it will be nec- essary, before their intersection can be obtained, to construct four vertical sections through the cone upon the lines I F, e /, J g, and h i. The point 3 requires no section; it being flush with the vertical side of the cone, must intersect somewhere on the line A D. To obtain the desired sections divide A D of elevation into any convenient number of equal parts, and from the points thus obtained erect lines parallel to the base D C, cutting B C. From the points in B C carry lines parallel with A G, cutting the center line E G, as Fig. 560, extend E G, as indicated by I' D', which make equal to A D of the elevation, with its points of division a and c. From the points in I' D' erect the perpendiculars a b, c d and D' F'. With the T square placed parallel with I' D', drop lines from the points in I F, cutting similar lines drawn from I' D'. A line traced through the points of intersection, as shown by I' F', will give the required shape. The sections shown in Figs. 561, 562 and 563 are obtained in a similar manner. Having obtained these sections of the cone by the Pattern Problems. 325 above method, arrange them as shown below the plan m Fig. 559. An inspection of the plan and profile will show that a line drawn from of profile will cut section I F, line S 6 of profile will cut section ef, line 1ST P of profile will cut section J g, line 2 4 will cut section h i, and a line from Q of profile will cut the vertical side represented by Gr. In connection with the sections in Fig. 559 draw an elevation of cylinder, as shown by S R V TJ, oppo- site the end of which draw a profile, as indicated by Fig. 564. — Method of Obtaining Pattern of Cylinder Shown in Figs. 553 and 559. N' Q' P' 0', commencing the divisions at the point N'. From the several points in the profile N' 0' P' Q' carry lines parallel with TJ V against the several pro- files I' F', e' f, J' g' and li i' as described above and as indicated by the small figures 1 to 8. A line traced through these points of intersection will give the miter line. A duplicate of this part of Fig. 559 is presented in Fig. 564: for the purpose of avoiding a confusion of lines. The miter line drawn through the intersecting lines is indicated by S T TJ. Having now the profile of the cylinder and the miter line, all as shown, the pattern of the cylinder is obtained in accordance with the principles given in numerous examples in Section 1 of this Chapter, and as clearly shown in Fig. 564. The method of obtaining the envelope of the frustum, and the opening in the side of the same to fit against the end of the cylinder just obtained, is shown in Fig. 565. The simple envelope of the frustum is obtained exactly as described in Problem 167, as will be seen by a comparison of Figs. 565 and 541. To obtain the opening in its side, however, involves an operation similar to that given in the problem immedi- ately preceding. ABCD of Fig. 565 represents a side elevation of the frustum, as shown by the same letters in Fig. 559, and the vertical lines drawn through the same, designated by the small figures at the bottom, are the lines of the vertical sections ob- tained in Figs. 560—563, and correspond in numbers to the divisions in the profile in Fig. 559. To obtain the elevation of the opening, set off on each of these section lines the hights of the points of intersection occurring on corresponding sections as they appear in Fig. 564. Thus upon line designated at the bottom by 2 4, set off the vertical hights of points 2 and 4 on section h' i\ Fig. 564, which section corresponds to line 2 4 of the profile, as shown in Fig. 559. In the same manner set off online 1 5 the verti- cal hights of the points 1 and 5 on section J' g . Obtain also points 8 and 6 from section e f and point 7 from section I' F', all as shown by the small figures. A line traced through these points will give the elevation of the opening. The out- line of the opening has been shown in the plan, but its development is not necessary to the subsequent work of obtaining the pattern. Divide the plan of the base of the frustum GrFE into any convenient number of equal spaces, as indicated by the small letters. As an accu- rate elevation of the opening has now been obtained, this operation can be conducted without reference to any of the points previously used in obtaining the line of the opening. Therefore letters have been used in the divis- ions of Gr F E instead of figures so that no confusion may arise. From each of these points of division draw lines to Gr, which represents the plan of the apex of the cone. Also from so many of these points from which lines will cut the line of the opening, as a to /, erect 326 'Hie New Metal Worker Pattern Book. lines verticany, cutting the base line D C, as shown by corresponding letters. From these points draw lines toward the apex of the cone X, cutting the line of the opening in the elevation, as shown but not lettered. Proceed now to construct the diagram of triangles shown at the right, in which X 1 D 1 is equal to and parallel with X D, and in which A 1 B 1 and D 1 C are drawn in continuation of A B and D C, as shown. dividers at D 2 , step to arc b, thence to arc c, etc., till arc i is reached at C\ A line traced through these points will give the lower outline of the half of the envelope of the frustum which is pierced by the cylin- der. From each of these points also draw lines toward X 1 , which intersect by arcs of corresponding number drawn with X 1 as center from the line A 1 B 1 , thus ob- taining the upper line of the envelope. Fig. 565.— Method of Obtaining Opening in Side of Cone to Fit End of Cylinder. Upon D" C, measuring from D', set off the several lengths G 5, G c, etc., of the plan, as shown by cor- responding letters, and from the points thus obtained draw lines to X', cutting the line A 1 B 1 . From X 1 as center draw arcs indefinitely from each of the points in D 1 C 1 . Zrom any convenient point upon arc a, as D 2 , draw a line to X 1 , which will form one side of the pattern of the desired envelope. Take between the points of the dividers a space equal to that used in dividing the plan G F E, and, placing one foot of the From each of the points where the lines b b, c c, d d, etc., of the elevation cross the line of the opening project lines horizontally, cutting hypothenuses of corresponding letter in the diagram of triangles, all as shown by a\ b' b\ c 1 c\ etc. "With one foot of the com- passes at X 1 , bring the pencil point successively to the points a 1 , 5', b% etc., and draw arcs cutting radial lines in the pattern of corresponding letter. Then a line traced through the points thus obtained will be the re- quired shape of the opening in the pattern. Pattern Problems. PROBLEM 176. The Pattern for a Chimney Top. 327 In Fig. 566 are shown the side and end elevations and the plan of a chimney top. A B C I> of the plan represents the size of the article at the bottom to fit the chimney, and E F G H is the size of the opening from the points thus obtained draw lines to C. The next step is to construct a diagram of triangles of which the lines just drawn are the bases and of which the hight of the article is the altitude. Assuming G as the base line of this diagram, place one foot of the compasses at C, and, bringing the pencil point to the vari- ous points in F G, strike arcs cut- ting C, as shown. At right angles to C erect C Q, equal in hight to J H' of Fig. 566, and from Q draw lines to the several points in C. These hypothenuses will then repre- sent the true distances from C to the points in F G. From Q as center, and radii equal to the several hy- pothenuses, strike arcs indefinitely, as shown to the left. From any con- venient point on arc 0, as G', draw a line to Q, which will form one side of the pattern of the rounded corner. Set the dividers to the space used in stepping off the arc F G, and, com- PLAN Fig, 566. — Plan and Elevations of Chimney Top. in the top to fit a pipe or extension. An inspection of the drawings will show that the article consists of two flat triangular sides, of which AHD is the plan and A 1 H 1 D 1 the elevation, two similar triangles, D G C, forming the ends, and four corner pieces, of which F C G is a plan, which are portions of an oblique cone. Further inspection of the plan will also show that the 2ntire article consists of four symmetrical quarters, therefore in Fig. 567 is shown a quarter plan of the same in which corresponding points are lettered the same as -in Fig. 566, from which the pattern for one- quarter of the article is obtained. The quarter circle F G is the quarter plan of an oblique cone, of which C is the apex ; therefore divide F G into any convenient number of equal parts, and Fig. 567.— One-Quarter Plan and Pattern of Chimney Top. mencing at the point G 1 , step to arc 1 and from that point to arc 2 and so on, reaching the last arc in the 32a lite New Metal Worker Pattern Booh; point F 1 . Trace a line through these points, as shown from F 1 to G 1 , and draw F 1 Q, which will complete the pattern of the corner piece. From C set off on C the distances F and L G, as shown by M and N. Draw lines from these points to Q, then M Q and N Q will represent the true distances shown by F and G L of the plan or J H 1 and L G 2 of the elevations in Fig. 566. "With Q as center, and C L as radius, describe an arc, L 1 , and from G 1 as center, with radius equal to N Q, intersect the arc, as shown, thus establishing the point L 1 . Draw G" L' and L 1 Q. In a similar manner, with F 1 as center, and Q M as radius, describe the arc 0', and from Q as center, with a radius equal to C O of the plan, intersect the arc at the point O 1 . Draw Q 0' and 0" F 1 ; then F' O' Q L 1 G" will form the pattern for one complete quarter of the chimney top. A du- plicate of this pattern may be added to it if desired, Fig. 568.— One-Half Pattern of Chimney Top. joining the two upon the line F 1 0, thus forming a pattern for one half, as shown in Fig. 568. PROBLEM 177. The Pattern of an Article with Rectangular Base and Round Top. In Fig. 569 are shown the plan and elevations of an article in which the conditions are exactly the same as in the preceding problem. The article here shown differs from that shown in Fig. 566 only in the fact that the diameter of the round end or top is greater than the width of the base, while in Fig. 566 it is less, but the method of obtaining the pattern is exactly the same. In this case, as in the preceding one, the article consists of four flat triangular pieces (two ends and two sides) and four equal rounded corners, each of which is a quarter of an oblique cone. As the eivtire envelope consists of four symmetrical quarters, one-quarter of the plan OPN J has been reproduced in Fig. 570 from which to obtain the patterns in the simplest manner. Divide J I of plan into any convenient number of equal parts, and from the points thus obtained draw lines to N, which represents the apex of an inverted oblique cone. The object is to construct triangles whose altitudes will be equal to the straight hight of the article, and whose bases will be equal to the length of lines in I J N of plan, and whose hypothenuses will give the distance from points in I J of top to N in the base. To construct this diagram, proceed as follows: From 1ST of Fig. 570 as center, and radii equal to the lengths of the several lines drawn to 1ST, describe arcs, cutting any straight line, as N W. From N draw N n at right angles to N W, which make equal to the straight hight of the article, and from the points inN¥ draw lines to n. With n as center, and the distances from 1ST to points in N W as radii, strike arcs as shown. From any point, as i, on arc 1, draw a line to n. Set the dividers to the space used in stepping off I J of plan, and, commencing at i, step from arc to arc, as indicated by the small figures, reaching the last in the point 7 or/. Draw/n, thus completing the pattern for part of article indicated in plan by I 1ST J. From NodN W set off the distances Q J and I P, as shown by the points q' and f. Then n q' and n f will represent re- spectively the altitudes of the flat triangular pieces forming the sides and the ends of the article. With N Q of plan as radius, and n of pattern as center, strike a small arc (f), which intersect with one struck from / of pattern as center, and n q' of diagram as radius, thus- establishing the point q of pattern. Draw n q and qj„ Pattern Problems. 820 "With PNof plan as radius, and n of pattern as center, strike a small arc, which intersect with one struck from i of pattern as center, and n t' of the diagram as radius, B E' B' In Fig. 571 ipqjls, a duplicate of the pattern indicated by the same letters in Fig. 570. Below this the pattern is duplicated once, and above twice, each E" N' M Fig. 569.— Plan and Elevations of an Article with Rectangular Base and Round Top. Fig. 570. — One-Quarter Plan and Pattern of Article Shown in Fig. 569. Fig. 571. — The Entire Pattern of Article shown in Fig. 569 in One Piece. thus establishing point p of pattern. Draw ip&ndpn, as shown, thus completing the quarter pattern. alternate pattern being reversed, thus completing the entire pattern in one piece. 330 Tl\e New Metal Worker Pattern Book. PROBLEM 178. Pattern for an Article Forming: a Transition from a Rectangular Base to an Elliptical Top. In Fig. 572, ABB'A' of the plan shows the rectangular base and CEDF the elliptical top of an article, the sides of which are required to form a tran- sition between the two outlines. A" C D' B" is an obtaining the pattern has, however, been employed, not because it is better but for the sake of variety, leaving the reader to judge which method is the more available in any given case. Divide E D into any convenient number o f equal spaces, as shown by the small figures, and from the points thus obtained draw lines to B. These lines will form the bases of a series of triangles whose common altitude is equal to the hight of the article, X Y, and whose hypothenuses when ob- tained will be the real dis- tances from B in the base Fig. 57S. — Plan and Elevation of Transition Piece. end elevation of the same, showing its vertical hight X Y. An inspection of the plan will show that the arti- cle consists of four symmetrical quarters, and that that part of either quarter lying between the curved outline of the top and the extreme angle of the base, as the part E D B, is a portion of the envelope of an oblique elliptical cone, of which E D is the base and B the apex. The conditions here given are exactly the same as in the two preceding problems; a different method of Fig. 573.— Pattern for One-Quarter of Article Shown in Fig. 572. to the points assumed in the curve of the top. To con- struct such a diagram of triangles, first draw any line, as L M, and from M lay off the distances shown by solid lines in plan, thus making M 1 equal to B 1, M 2 equal to B 2, etc. At right angles to L M draw M N, in hight equal to the straight hight of the article, as shown by X Y of elevation, and connect the points in M L with N. Also setoff the distance D divom M, and draw X d. If E d was different in length from D d, this distance would be set off from M and a line drawn to N. Pattern Problems. 331 To develop the pattern first draw any line, as E B of Fig. 573, equal in length to N 1 of the diagram. With B of pattern as center, and N 2 of the diagram of triangles as radius, describe a small arc, which in- tersect with another arc struck from E of pattern as center and E 2 of plan as radius, thus establishing point 2 of pattern. Proceed in this manner, using the distance between points in plan for the distance be- tween similar points in pattern, and the hypothenuses of the triangles in the diagram in Fig. 572 for the dis- tances to be set off from B of pattern on lines of simi- lar number. Through the points thus obtained trace a line, as shown by E D. With B of pattern as center, and B d of plan as radius, strike a small arc, which in- tersect with another struck from D of patterns as cen- ter, and N" d of diagram as radius, thus establishing the point d of the pattern. Draw D d and d B. With B of the pattern as center, and B e of the plan as radius, strike a small arc, which intersect with another struck from E as center, with a radius equal to N d of the diagram of triangles. Draw E e and e B ; then E e B d D will be the pattern for one-quarter of the article. In performing the work of development of the pat- tern it will be found convenient as well as more accu- rate to use two pairs of compasses, one of which should remain set to the space used in dividing the curve E D of the plan, while the other may be changed to the varying lengths of the hypothenuses in the diagram of triangles. PROBLEM 179. Pattern for an Article Forming: a Transition from a Rectangular Base to a Round Top, the Top Not Being Centrally Placed Over the Base. In Fig. 574, F G H J of the plan represents the bottom of the article and A B D E the top. Below J' FRONT ELEVATION Fig. 574. — Elevations and Plan of an Irregular Transition Piece. the plan is projected a front elevation and at the right a side elevation, like points in all the views being lettered the same. An inspection of the drawing will show that each side of the article consists of a triangular piece whose base is a side of the rect- angle and whose vertex lies at a point in the circle of the top, the four vertices marking the division of the circle into quarters, and four quarters of inverted oblique cones whose bases are the quarter circles of the top and whose apices lie at the corners of the rectangle. A comparison between this figure and the one shown in Problem 177 will show that the con- ditions existing in either one of the corner pieces in this case are exactly the same as in the former problem, but that while in Problem 177 the four corners are alike, in the present instance the four corners are all differ- ent, and that therefore the pattern for each corner piece, as well as that for each of the flat sides, must be ob- tained at a separate operation, all being finally united into one pattern. Divide the plan of the top A B D E into any convenient number of equal spaces in such a manner that 532 Tlie New Metal Worker Pattern Book. each quarter of the circle shall contain the same number of spaces and from the points of division in each quarter draw lines to the adjacent corner of the rectangle of the base, all as shown in Fig. 575. Thus lines from the points in E D are drawn to H and lines from points in D B are drawn to G, etc. The next operation will be to construct the four diagrams of triangles (one for each corner piece) shown in Fig. 576, of which these lines are the bases. Accordingly lay off at any convenient place the line H L, Fig. 576, equal to the straight hight of article, as shown by J' X in Fig. 574. From the point H, and at right angles to L H, draw the line H M, and, measuring from H, set off the length of lines in E D IB" 12 / / \ i/Y \ w / / / F A l\ 14 1 / X- 16 C D 5 f \ \ PLAN 4 X | X ^ Fig. 575. — Plan of Irregular Transition Piece with Surface Divided into Triangles. H of the plan, Fig. 575. Thus H 1 is made equal to II E of the plan, H 2 is made equal to the distance H 2 of the plan, and H 3 is equal to distance H 3 of the plan, etc. From the points thus established in M H draw lines to L, as shown. Then the hypoth- enuses L 1, L 2, L 3, etc., will correspond to the width of the pattern, measured between points in E D of top and H in the base. The triangles for the corner piece D Gr B are con- structed in the same general manner. N Gr corre- sponds to the hight J' X of the elevation. Gr is drawn at right angles to N Gr, on O Gr are set off the lengths of lines in D Gr B of the plan, and from the points thus obtained lines are drawn to N. Thus Gr 5 of the diagram is equal to Gr 5 of the plan, Gr 6 of the diagram is equal to Gr 6 of the plan, etc. The tri- angles in P Q F correspond with the lines in A F B of the plan, as do those in S B J with the lines A J E in the plan. Before commencing to desmbe the pattern the seam or joint may, for convenience, be located at K E of the plan. The real length of the line K E of the plan is given by H" E" in the side eleva- tion, Fig. 574, or the distance E K can be set off, as shown by II K in Fig. 576. The dotted line K L will then be the distance from K in the base to E in the top. As it is necessary in obtaining the pattern for the entire envelope that the patterns of the parts shall sue- L M// /, ^7/ 1 /// i // i 5 1 4 2 3 10 11 ,3.2 'f ,3 ,41 ;| Fig. 576. — Diagrams of Triangles Obtained from Fig. 575. ceed one another in the order in which they occur in the plan, the method of development here adopted is that of constructing separately each small triangle, as in the preceding problem, instead of by means of a number of arcs, as in Problem 177 and others preced- ing it. To begin, then, with the pattern of the part corresponding to F B Gr of the plan. ' The length F Gr of the pattern, in Fig. 577, is established by the length F Gr of the plan in Fig. 575. With F of pattern as center, and P 9 of Fig. 576 as radius, describe an arc, B, -which intersect with one struck from Gr of the pat- tern as center, and 1ST 9 of Fig. 576 as radius, thus es- tablishing the point B of the pattern. Then F B Gr ie Pattern Problems. 333 the pattern for that part of the article shown by F B G of the plan. From G of pattern as center, with radii corresponding to the hypothenuses of the tri- angles shown in N" G of Fig. 576, strike the arcs shown. Thus G S of the pattern is equal to N 8, G 7 of the pattern is equal to 1ST 7, etc. With the dividers set to the same space used in stepping off the plan, with B or 9 of the pattern as center, strike a small arc intersecting arc S previously drawn, thus locating the point 8. From S as center intersect arc 7, and so continue, locating the points 6 and 5. Through the points thus obtained can be traced the line B D. Then With the dividers set to the same space as was used in stepping off the plan, and commencing at 5, intersect each succeeding arc from the point obtained in the one before it, as shown by the figures 4, 3, 2, 1. Trace a line through the points thus obtained, and connect W H, as shown. Then E' D H is the pattern for that part of the article shown on plan by E D H. With II of pattern as center, and H K of plan as radius, describe a small arc, which intersect with one struck from E' of pattern as center, and L K of Fig. 576, or what is the same, E" H" of Fig. 574, as radius, thus establish- ing the point K' of the pattern. Connect H K' and Fig. 577.— Pattern tf Transition Piece Shoivn in Fig. 574. GBDis the pattern for that part of the article shown on the plan by G B D. With G of pattern as center, and G H of plan as radius, strike a small arc, H, which intersect with one struck from D of pattern as center and L M of Fig. 576 as radius, thus establishing the point H of pattern. Connect G H and H D, as shown. Then G E D is the pattern for that part of the article shown in plan by G H D. With H of pattern as center, and the hypoth- enuses of triangles in M L H of Fig. 576 as radii, strike arcs, as shown, making H 4, H 3, H 2, H 1 of pattern equal to L 4, L 3. L 2, L 1 of the diagram of triangles. K' E', as shown, which gives the pattern for that part of the article shown on plan by H K E. The radii for striking the arcs in A F B of the pattern are found in P F of Fig. 576. The length F J of pattern is established by the length F J of the plan. The radii for striking the arcs in A J E of pat- tern are found in S R J of Fig. 576. J K of the pat- tern corresponds with J K of the plan, and E K of the pattern corresponds with L K of Fig. 576. Thus E A BDE' of the pattern is the stretchout of E A B D of the plan of the top, as K J F G H K' of the pattern is the stretchout of K J F G H of the plan of the base. PROBLEM 180. The Pattern for a Collar Round at the Top and Square at the Bottom, to Fit Around a Pipe Passing; through an Inclined Roof. Let A B D C of Fig. 578 represent the side eleva- tion of the pipe and C D E F the side view of the col- lar, fitting against the pitch of the roof shown by G H. Construct a plan below the elevation, as shown, making J K M L the plan view of the pipe and NOPE the plan view of the collar on a horizontal line, giving the 334 Tfte New Metal Worker Pattern Book. collar an equal projection at the bottom on the four sides, as shown. Through the center point X in plan draw a line parallel to N E, intersecting the circle at K and L ; likewise through the center X, and parallel to N, intersect the circle at J and M. From J and K draw lines to the corner N ; likewise from J and L, L and M, and M and K, draw lines to the cor- ners R, P and 0. It will be seen that by this opera- the bases of a series of right angled triangles, whose hypothenuses will give the correct distances across the pattern of the collar. To construct these triangles proceed as follows : Upon C Y extended assume any point, as S, at which erect the perpendicular ST, equal in hight to the cone CYF, as shown by the dotted line from F. From S on S C set off the lengths of the several lines in K N J of the plan, as shown by 1', 2', Fig. 578. — Plan and Side Elevation of a Collar to Fit Around a Pipe Passing through an Inclined Roof. tion the collar has been divided in such a manner that the four corner pieces are portions of oblique cones whose apices lay at the corners of the collar, while the side pieces between are simply flat triangular pieces of metal. The dotted lines connecting the plan with the elevation show corresponding points in the two views. Divide the quarter circles K J and J L into any convenient number of equal spaces, as shown by the small figures, and from points on each draw lines to the corners N and R. Then will these lines represent 3', etc., and from these points draw lines to T. In the same manner construct the diagram of triangles shown at the right. At U upon the line Y D extended erect the perpendicular U V, equal in hight to the cone Y D E, as shown by the dotted line E V. From U on U D set off the lengths of the lines in J R L and draw the hypothenuses, as shown. To develop the pattern, first draw any horizontal line, as A A 1 of Fig. 579, equal in length to P R in plan of Fig. 578. With A and A 1 as centers, and the Pattern Problems. 33; hypothenuse V 9' of Fig. 578 as radius, describe arcs intersecting each other at 9. Now, with 9 of the pat- tern as center, and 9 8 of the plan as radius, describe A A Fig. 579.— Pattern of Collar Shown in Fig. 578. the arc 8 ; then with V 8' of Fig. 578 as radius, and A of the pattern as center, describe an arc, intersecting the arc previously drawn, thus establishing the point 8. Proceed in this manner, using alternately first the divisions on the quarter circle L J in plan, then the hypothenuses of the triangles whose bases are shown by the lines in JLK, until the point 5 in pattern has been obtained. Draw a line from 5 to A in Fig. 579. Then with A as center, and E F in side elevation, Fig. 578, as radius, describe an arc, shown at C of Fig. 579, and with 5 of the pat- tern as center, and the hypotlie- nuse T 5' of Fig. 578 as radius,' describe an arc intersecting the previous arc at C. Draw a line from 5 to C. Now proceed as above described, using alternately first the spaces on the quarter circle in J K in plan, then the hypothenuses of the triangles whose bases are shown in J K N in plan, until the point 1 in pat- tern has been obtained. Then with C of the pattern as center, and W N of the plan as radius, describe an arc, as shown at D, and with F C in side elevation as radius, and 1 of the pattern as center, describe an arc, inter- secting the arc previously de- scribed at D. Draw the lines 1 D, D C, C A, and through the intersections of the arcs trace a line, shown from 1 to 9 on pattern. This will complete one-half the pattern. The entire pattern may be completed by duplicating the part 1 5 9 A C D and adding the same to that already obtained in such a manner that the side 9 A will coincide with 9 A', as shown by 9 5' 1' D' C" A 1 . PROBLEM 181. The Pattern for a Flaring: Article Round at the Base and Square at the Top. The shape shown in Fig. 580 differs from that treated in Problem 176 principally in the fact that the round end is larger than the rectangular end instead of smaller as in Fig. 56G ; the conditions involved are, however, exactly the same as in the other problem and consequently the method of obtaining the pattern must be similar. F G H J, in Fig. 580, represents the plan of the base, K L M N that of the top, and A B C E the elevation of a side of the article. Through 0, the center of the circle of the base, draw the diameters G J and F H parallel to the sides of the top. From the four points thus obtained in the cir- cumference of the base draw lines to the angles of the top, as shown by G M and HM,HN and J N, etc. It will be seen from this that the envelope of the ar- ticle consists of four flat triangles, of which L6M is a plan and B D C the elevation, and four rounded corners, either one of which, as J N H, is a portion of The Nexv Metal Worker Pattern Booh. an oblique cone of which J H is the base and N the apex. g ELEVATION Q PLAN Fig. 580.— Plan and Elevation of a Flaring Article, Round at the Base and Square at the Top. To obtain the pattern first divide the quarter plan of base J H into any convenient number of parts, as indicated by the small figures, and con- nect these points with 1ST, as shown. To obtain the distance from points in J H of base to N of top it will be necessary to construct the diagram of triangles shown in Fig. 581. Draw any line, as E P, in length equal to the hight of the article, as shown by S C in Fig. 580. At right angles to R P draw P Q, and on P Q lay off the lengths of lines in J H N. Thus make P 1 equal to N 1 of the plan, P 2 equal to N 2, etc. Connect the points in P Q with R. The hypothenuses thus obtained give the true distances from the points in the base to N in the top. From any convenient point, as N in Fig. 582, as center, with radius R 1 of Fig. 581, describe an arc, as shown by 1 7. In like manner, with radii R 2, R 3 and R 4 of Fig. 581, describe arcs, as shown. Draw a straight line from 1ST to any convenient point upon the arc 1 7, as shown by 1ST H. Set the dividers to the space used in stepping off the plan of the base and, starting with H, lay off the stretchout, Fig. 581. — Diagram of Triangles Used in Obtaining Pattern of Article Shown in Fig. 580. stepping from arc to arc, as shown. A line traced through these points will form the pattern for as much of the article as shown by J 1ST H of the plan. With N" of pattern as center, and 1ST K of plan or B C of ele- vation as radius, describe a small arc, K, which inter- sect with an arc struck from J of pattern as center and J 1ST as radius. Connect J K and K N, which com- pletes the pattern for J K N of the plan. J K F of pattern is the same as J N H, and can be obtained in the same manner, or by any convenient means of du- plication. With N as center, and N W of plan as radius, describe a small arc, which intersect with one Fig. 582.— One-Half of Pattern of Article Shown in Fig. 580. Pattern Problems. 337 struck from H as center, and E C of elevation as F K V of pattern is obtained in a similar manner, radius. Connect H W and W N, thus producing the Then TKNWHJF is the pattern for one-half of part of pattern corresponding to N W H of the plan. article. PROBLEM 182. Pattern for an Article Rectangular at One End and Round at the Other, the Plane of the Round End Not Being: Parallel to that of the Rectangular End. In Fig. 583 are shown front and side views and plan of an article forming a transition between a rect- angular pipe at one end and a round pipe at the other, and forming; at the same time an angle between the Fig. 58S. — Front and Side Views and Plan of an Article Forming a Transition Between a Rectangular Pipe and a Round Pipe, at an Angle. two pipes. A E F C of the front view shows the size of the rectangular pipe, while 6 B II D shows the opening to receive the round pipe. In the side view a c shows the vertical rectangular end, and b d shows the angle at which the round end is placed, bid being a half profile of the round end. As will be seen by an inspection of the front view, each quarter of the circu- lar opening is treated as the base of a portion of a scalene cone whose apex is in the adjacent angle of the rectangle, the intermediate surfaces being flat triangu- lar pieces. Thus B & and G D are the quarter bases of scalene cones whose apices are respectively at A and C ; A B E and CDF are triangles whose altitudes or profiles are shown respectively by a b and e d of the side view ; and A G C is a triangle whose profile appears at u in the plan. Divide each quarter of the pro- file I I and I d of Fig. 583 into any number of equal spaces, as shown by the small figures ; also draw a duplicate of this half profile in proper relation to the plan, as shown by m g x, which divide as before, numbering the points in each to correspond, as shown. From the points in lip drop lines at right angles to b d, cutting the same. From the points in m g x carry lines indefinitely to the left parallel to the center line g f, and intersect them by lines of corresponding number erected vertically from the points in b d. A line traced through the points of intersection will give a correct jDlan view of the opening in the round end. To avoid con- fusion of lines the intersections from the points between b and h or the upper half of the opening are shown only in the near or lower half of the plan from t to u, while the points belong- ing to the lower half (/* to d) are shown only in the further half of the plan from p to q. From each of the points in p q of the plan draw lines to 5, which is the projection of e of the side view or apex of the cone in the lower half, and from the points in t u draw lines to o, the apex of the cone of the upper half of the article. These lines represent only the horizontal distances from s and o to the points in the opening t u q p of the plan or B Gr D of the front 338 The New Metal Worker Pattern Book. view. To ascertain the real distances between these points it will be necessary to first ascertain their ver- tical hights from an assumed horizontal plane and then to construct from these measurements a series of right angled triangles whose hypothenuses will give the de- sired distances. From the points in b h of the side view drop lines vertically, cutting a horizontal line drawn from a, as shown between v and j ; and from the points in h d drop lines to to z drawn horizontally from e. To construct the triangles required in the top part, first draw the right angle R O K, as shown in Fig. 584, and from on E set off the length of lines in b hjv of side view, as indicated by the small figures. From on K set off the length of lines in o t u of plan of top, also as indicated by the small figures. Connect the points in R with those of similar number in K, as shown. To obtain the triangles required for the bottom part, proceed in a similar manner. Draw the right angle W S L, as shown in Fig. 585. From SonSW set off the length of lines in h d z to of side view, as indicated by the small figures. From S on S L set off the length of lines in s p q oi plan of top, also as indicated by the small figures. Connect the points in S W with those of similar number in S L, as shown. For the pattern proceed as shown in Fig. 586. Draw the line 0', in length equal to A B of front view or o k of plan. Bisect 0' in C, and erect the D of pattern as center, and b 2 in b I of profile as radius / thus establishing point 2 of pattern. Proceed in this Fig. 584. — Diagram of Triangles in Top Half. manner, using the length of lines in R K for dis- tances from of pattern, and the stretchout between points in b I of profile of side view for +he distance be- 777T5' Fig. 585. — Diagram of Triangles in Bottom Half. tween points in D G of pattern ; then draw D G and G: 0. With point G of pattern as center, and 5 5' in Fig. 5S6. — Pattern for Transition Piece Shoivn in Fig. 58S. perpendicular C D, in length equal to a & of side view, and draw D, D 0'. These lines are equal in length to R K of first diagram of triangles. With of lDat- tern as center, and 2 2' in R K as radius, describe a small arc, 2, which intersect with one struck from point W S L of triangles as radius, strike a small arc, E, which intersect with one struck from point of pat- tern as center and a e of side view as radius, thus estab- lishing point E of pattern. Draw Gr E and E 0. With point E of pattern as center, and 6 6' of triangle in Pattern Prohl ems. 339 W S L as radius, strike a small arc, 6, which intersect with one struck from point G of pattern as center, and I 6 of profile as radius, thus establishing point 6 of pat- tern. Proceed in this manner, using the length of lines in W S L as distance from E of pattern, and the stretchout between points in I d of profile of side view for the distance between points in G H of pattern, and draw G H and H E. With point H of pattern as cen- ter, and e d of side view as radius, strike a small arc, C, which intersect with one struck from point E of pattern as center, and ofol plan, or C of pattern, as radius, thus establishing point C of pattern ; then draw H C and C E. From E and C erect the perpendicu- lars E E and C F, in length equal to c e of side view, and draw F E. AVith of pattern as center, and a c of the side view as radius, strike a small arc, which intersect with one struck from E of pattern as center and e c of the side view as radius, thus establishing O point K of pattern, and draw K and K E. Then DGHFEEKC represents the half pattern of article. The other half can be obtained in the same manner or by duplication, as may be found convenient. PROBLEM 183. The Pattern for a Flaring Article, Round at Top and Bottom, the Top Being: Placed to One Side of the Center, as Seen in Plan. In Fig. 587, the elevation of the article is shown by A B D C, below which is drawn the plan of the A C 10' ^9 5 6 Fit,. 687. — Plan and Elevation of an Irregular Flaring Article, with Lines of Triangulation Shoivn in the Plan. dame, corresponding parts in each being connected by the vertical dotted lines. There are two methods of triangulation available in the solution of this problem only one of which is given in this connection. Divide one-half of the circle representing the base of the article into any convenient number of spaces, as indicated by the small figures, 1, 2, 3, etc. In like manner divide the inner circle, which represents the top, into the same number of spaces, as indicated by 1', 2', 3', etc. Between the points of like numbers in these two circles, as for example between 2 and 2', 3 and 3', etc., draw lines, as shown; also connect the points in the inner circle with points in the outer circle of the next higher number, as indicated by the dotted lines. Thus, connect 1' with 2, and 2' with 3, and so on, as shown. These lines just drawn across the plan are the bases of a number of right angled triangles whose altitudes are equal to the hight of the article, and whose hypothenuses, when drawn, will give the cor- rect distances across the pattern, or envelope of the article, between the points in the top and those in the bottom in the direction indicated by the lines of the plan. The triangles having the solid lines of the plan as their bases are shown in Fig. 5SS, while those con- structed iipon the dotted lines are shown in Fig. 589, and are obtained in the following manner: At any convenient point erect a jDerpendicular, E F, Fig. 58S, which in length make equal to the straight hight of the article, as shown in the elevation. From F at right angles set off a base line of indefinite length. On this line, measuring from F, set off lengths equal to the several solid lines in the plan. For example, make the space F 10 equal to the length 10 310 Tlie Neio Metal Worker Pattern Booh. 10' in the plan, and the space F 9 equal 9 9' in the plan, and so on, until F 1 is set off equal to 1 1' in the plan. From the points thus established in the base line draw lines to the point E. The triangles thus constructed will represent sections through the arti- cle on the solid lines in the plan. In other words, the several hypothenuses of the triangles shown in Fi"-. 588 are equal in length to lines measured at cor- responding points on the surface of the completed ar- ticle. In like manner construct the triangles shown in Fi°\ 589, representing measurements taken on the dotted lines shown in the plan. Draw the perpen- dicular K G, equal in length to the straight night of the article. From K lay off a horizontal base line in- definite in length, drawing it at right angles to K G. From Iv set off lengths equal to the dotted lines in the plan that is, making the distance K 10 equal to the Fig. 58S.— Diagram of Triangles Based upon the Solid Lines of the Plan in Fig. 587. A?/ '/'/ ' I III / /' / / I I ) / \ ' \ ' \ ' / < / fa 2 2 4 S 6 7 8 attern ; the spaces in E H of the plan to form the lower line E H of the pattern and the spaces in L J of the plan to form the upper line of the pattern, all as shown. The remaining parts of the pattern can be obtained by any convenient means of duplication, K F G being a duplicate of L E G and K J 1 H' F being a duplicate of L J H E. PROBLEM 191. The Patterns for a Three-Piece Elbow, the Middle Piece of which Tapers. In Fig. 623, let A B D F H G E C be the side view of a three-piece elbow, the middle piece (C D F E) of which is made tapering. The piece CDFE may also be described as an offset between two round pipes of different diameters. A half profile of the upper and smaller of the two pipes is shown by a m b, while g n h shows that of the larger pipe. * The straight por- tions ABDC and E F H G are in all respects similar to many pieces whose patterns have already been de- scribed in the first section of this chapter in Problems 38 to 45 inclusive. It will therefore be unnecessary to repeat the description in this connection. 6i> 6 TJie New Metal Worker Pattern Booh. Since an oblique section through a cylinder is an ellipse, an insjuection of the drawing will show that the sections C D and E F, the upper and lower bases of the middle piece, must be elliptical. The first opera- tion, therefore, will be to develop the ellipses, which may be done in the following manner : Divide the ■ \\ i\ — i-V \ \\ \ H \ \\ \ Fig. 623 -Elevation of a Three-Piece Elbow, the Middle Piece of which Tapers. profile a m b into any convenient number of equal spaces, as shown by the small figures. From the points thus obtained drop lines vertically to a b and continue them till they cut the line C D. From the intersec- tions on C D carry lines at right angles to the same indefinitely, as shown. Through these lines draw any line, as c d, parallel to C D. Upon each of the lines drawn from C D, and measuring from c d, set off the lengths of lines of corresponding number in the profile a m b, measuring from a b. A line traced through the points thus obtained, as shown by c k d, will be the required elliptical section. The section upon the line E F may be obtained in the same manner, all as shown by epf. In Fig. 624, C D F E is a duplicate of the middle piece of Fig. 623, below which is drawn its half plan made up of the elliptical sections just obtained, all as shown by corresponding letters. The piece thus be- Fig. 624.— The Middle Piece of Elbow in Fig. 623, with Plans of its Bases Arranged for Triangulation. comes an irregular flaring article or transition piece? the envelope or pattern of which may be obtained in exactly the same manner as described in Problems 1S4 or 186, to which the reader is referred. The eleva- tion in Fig. 623 is so drawn that C D and E F are parallel, and C E is at right angles to both. Should the elevation, however, be so drawn that C D is not parallel with E F the conditions will then become the same as in Problem 193 succeeding, which see; and should C E be drawn otherwise than vertically, the plan would then resemble that shown in Prob- lem 194. PROBLEM 192. The Patterns for a Raking: Bracket in a Curved Pediment. In Fia;. 625, let C E F D be the front elevation of o 7 a portion of a curved pediment whose center is at K, and of which E K is the center line. C A B D of the same elevation represents the face view of a bracket having vertical sides, of which E G F is the normal profile. Since the bracket sides are vertical and are necessarily at different distances from the center line, it will be easily seen that they are of different lengths or hights ; that is, the side C D, being further from E K than the side A B, is longer. The patterns for Pattern Problems 357 the two sides will therefore be different and the face piece will be really an irregular flaring piece. It will first be necessary to obtain the pattern or profiles of the two sides. To facilitate this operation the normal profile of the bracket E G F has been so line E F, as shown. Thence carry lines around the arch from the center K, from which the same is struck, cutting the sides A B and G D. Conveniently near the lower side of the bracket draw any vertical line, as E 1 B', as a base line upon which to construct the true RIGHT SIDE ELEVAT Fig. 625.— A Raking Bracket in a Curved Pediment, Showing the Patterns for Its Face and Sides. placed that its vertical line or back coincides with the , center line E K of the arch. Divide the face of this profile into any convenient number of parts, as shown by the small figures, and from these points carry lines at right angles to the back of the bracket, cutting the sides of the bracket. At any convenient position upon this line, above or below, as at Gr E 1 F 1 , draw a duplicate of the normal profile, so that its back or vertical line shall coincide with E 1 B 1 , and divide its face line into the same spaces as Gr F. Place the 358 Tlie New Metal Worker Pattern Booh. T-square at right angles to the line E 1 B 1 , and, bringing it successively against the points in the side C D, draw lines cutting E 1 B', continuing the same indefi- nitely to the left, as shown. At any convenient po- sition, as A 1 B 1 , on the line E 1 B 1 transfer the spaces from A B, as shown, and from the points thus ob- tained draw lines indefinitely to the left also at right angles to E' B'. Place the T-square parallel to E' B 1 , and, bringing it successively to the points in the normal jn'ofile G 1 F l , cut lines of corresponding number in the two sets of parallel lines just drawn. Lines traced through the points of intersection will give the re- quired patterns of the lower and upper sides, as shown respectively by C M D 1 and A 1 N B'. Some of the lines of projection in the pattern of the upper side have been omitted to avoid confusion. At the ex- treme left of the engraving is shown a side view of the bracket as seen from the right, which is made up of the two sides just obtained and which have been placed in proper relation to each other, all as shown by the dotted lines projected to the left from the points A, B, G and D of the front elevation. Having now obtained all that is necessary, it re- mains to triangulate the face of the bracket preparatory to developing the pattern of the same. With this in view first connect all points of like number in the upper and lower sides of the front view by solid lines, as shown. Also connect them in the side elevation. Since points of like number in A B and C D have the same projection from the back of the bracket, it will be seen that the solid lines just drawn connecting them represent true distances across the face of the bracket. The four-sided figures produced by draw- ing these lines must now be subdivided into triangles by means of clotted lines drawn diagonally through each. Therefore connect each point uj>on the profile of the lower side of the bracket with the point next higher in number upon the upper side, as shown in the side view. To determine the true length of these lines it will be necessary to construct a diagram of triangles, as shown by S V T in the upper part of the engraving. Draw S V and S T at right angles to each other. Make S V equal to the width of the bracket measured horizontally across the face, and upon S T, measuring from S, set off the lengths of the several dotted lines in the side view, as shown by the small figures. From each of points in S T draw lines to V. Then these lines will be the real distances between points of corresponding number on the lower side of the bracket and points of the next higher number upon the upper side. The figures in S T correspond with the figures upon the lower side of the bracket, the point V representing, in the case of each line, the next higher number ; thus 2 V is the distance from 2 to 3' across the face of the bracket, 3 V the distance 3 4', 4 V the distance 4 5', etc. The dotted lines in the side view representing the distances 1 2 and 7 8 cannot, of course, be shown in that view, because they lie in surfaces which ajnpear in profile ; but since these surfaces are parallel with the plane of the back of the bracket these distances for use in the pattern may be taken directly from the front view, as shown by the dotted lines 1 2' and 7 8' in that view. To lay out the pattern of the face piece first draw any line, as C 3 A 3 or 1 1' of the pattern, equal in length to 1 1' of the front view. From C 3 of the pattern as center, with a radius equal to 1 2' of the front view, de- scribe a small arc, which intersect with another arc drawn from A 3 as center, with a radius equal to 1' 2' of the front view, thus establishing the point 2' of the upper side of the pattern of the face. From 2' of the pattern as center, with a radius equal to 2 2' of the front view, strike a small arc, which intersect with another arc struck from 1 of the pattern as center, with a radius equal to 1 2 of the front view, thus establish- ing the position of the point 2 in the lower side of the pattern. From 2 of the pattern as center, with a radius equal to 2 V of the diagram of triangles, strike a small arc, which intersect with another arc struck from 2' of the pattern of center, with a radius equal to 2' 3' of the side view, thus establishing the point 3' of the pattern. From 3' of the pattern as center, with a radius equal to 3 3' of the front elevation, strike a small arc, which intersect with another arc struck from 2 of the pattern as center, with a radius equal to 2 3 of the side view. So continue, using the distances across the face indicated by the dotted lines as found in the diagram of triangles in connection with the spaces in the profile A 2 B 2 of the side view to form the upper side A 3 B 3 of the pattern, and the distances across the face as measured upon the solid lines of the front view in connection with the spaces upon the profile (7 D 2 to form the lower side C 3 D 3 of the pattern, until the points 13 and 13' are reached. As the lines C A and D B of the front of the bracket must be cut to fit the curves of the moldings above and below, against which the bracket fits, the corresponding lines of the pattern can be drawn with radii respectively equal to K E and K F, as shown by the curved lines C 3 A s and D 3 B 3 of the pattern. Pattern Problems. PROBLEM 193. Pattern for a Transition Piece to Join Two Round Pipes of Unequal Diameter at an Angle. 359 Iu Fig. 626, D C K L shows a portion of the larger pipe, of which M P N is the section ; HGBA a portion of the smaller pipe, of which E J F I is the section ; and ABCD the elevation of the transition piece necessary to form a connection between the two pipes at the angle HAL. The drawing also shows that the ends of the two pipes to be joined are square, Fig. 626. — Elevation of a Transition Piece Joining Two Round Pipes of Unequal Diameter at an Angle. or cut off at right angles, so that the lower base of A B C D is a perfect circle whose diameter is D C (or M N) and the upper base is a circle whose diameter is A B (or E F), and also that the side AD is vertical. In the choice of a method of dividing the surface of the piece ABCD into triangles, either the elevation or the plan can be made use of for that purpose, ac- cording to convenience. In the demonstration here given the elevation has been used by way of variety, all as shown in Fig. 627. Proceed then to divide the plan of the upper base into any convenient number of equal spaces, as shown, and drop a line from each point at right angles to A B, cutting A B, and numbering each point to correspond with the number upon the plan. In like manner divide the plan of the lower base into the same number of equal spaces, and erect a perpendicular line from each, cutting the line D G, and numbering the points of intersection in the same order, or to correspond with the points in the upper base, all as shown. Connect the points in D C with points of similar number in A B by solid lines, also Fig. 627. — Triangulation of Transition Piece Shown in Fig. 626. connect points in D C with points of the next higher number in A B by dotted lines, which will result in a ■ triangulation suitable for the purpose. The next step will be to construct sections through the piece upon all of the lines upon the elevation (both solid and dotted), which operations are shown in Figs. 628 and 629, and which may be done in the following manner : Upon any horizontal line, as T S of Fig. 628, erect a perpendicular, as T U. Upon T S set off from T the several distances of the points in the lower base from the center line I 7 of the plan, as measured upon the vertical lines (Fig. 627), all as indicated by the small figures. Upon T U set off the lengths of the 360 TIi e New Metal Worker Pattern Book. solid lines of the elevation, numbering each point thus obtained to correspond with its line in the elevation. From each of the points upon T U draw horizontal W \ \J_ -\ M— \ ,\| \3 \j x * K\ / v \ w 3 4 6 Fig. 628.— Diagram of Sections Fig. 629.— Diagram of Sections Taken on Solid Lines of Fig. Taken on Dotted Lines of Fig. 627. 6 ~?- lines to the right, making each in length equal to the distance of points of corresponding number in the plan of the upper base from the center line 1 7, as measured upon the lines at right angles to line A B, thus ob- taining the points 2', 3', 4', etc. Now connect these points with points of corresponding number in the base line T S by means of solid lines, as shown. In constructing the sections upon the dotted lines of the elevation, shown in Fig. 629, the same course is to be pursued as that employed in Fig. 628. The base line W V is a duplicate of T S. Upon the per- pendicular line erected at W set off the lengths of the Fig. 631.— Perspective View of Model. several dotted lines of the elevation, numbering each point thus obtained to correspond with the number at the top of its line in the elevation. From each point draw a horizontal line to the right as before, which make equal in length to the similar lines in Fig. 628, numbering each point as shown by the small figures 2', 3', 4', etc. Now connect each of these points with the point of next lower number in the base line V W by a dotted line. Having obtained all the necessary measurements, the pattern for one-half the envelope of A B C D may be developed in the following manner : Draw any line, as A D in Fig. 630, which make equal in length to A D of the elevation. With A as a center, and a radius equal to 1 2 of the plan of the upper base, Fig. 627, strike a small arc, which intersect with another struck from D as a center, with a radius equal to the dotted line 1 2' of the diagram, Fig. 629, thus establishing the position of the point 2 in the upper line of the pat- tern. From D as a center, with a radius equal to 1 2 of the plan of the lower base, Fig. 627, strike a small arc, which intersect with another struck from point 2, just obtained, with a radius equal to the solid line 2 2' 3 4 5 Fig. 630.— Pattern of Transition Piece Shown in Fig. 627. of the diagram, Fig. 628, thus fixing the position of point 2 in the lower line of the pattern. So continue, using the lengths of the dotted lines in the diagram, Fig. 629, in connection with the lengths of the spaces in the plan of the upper base, to develop upper line of the pattern, and the lengths of the solid lines in the diagram, Fig. 628, in connection with the lengths of the spaces in the plan of the lower base, to develop the lower line of the pattern, using each combination alter- nately until the pattern is complete. As each new point of the pattern is determined it should be num- bered, and the solid or dotted line used in obtaining the same may be drawn across the pattern if desired, merely as a means of noting progress, but these lines are not necessary, as each point is simply used as a center from which to find the next point beyond. Sometimes, in order to more thoroughly under- stand the method employed in such an operation as the foregoing, it is desirable to construct a small model, Pattern Problems. 361 which can be made from cardboard or thin metal, the details of which are clearly shown in Fig. 631. The pieces forming the upper and lower bases of it should be duplicates of the half plans of the upper and lower bases shown in Fig. 627, having the lines there shown drawn upon them, and the piece forming the back is a duplicate of the plane figure ABCD. These three parts may be cut in one piece, after which a right angle bend on the lines A B and C D will bring the two bases into correct relative position. Five quadrilateral figures corresponding to those shown in Fig. 628 may now be cut and fastened in position, according to their num- bers, between the two bases of the model. Threads or wires can be so placed as to correspond in position with the dotted lines shown in the elevation, Fig. 027, to complete the model. The model is only useful be- fore the pattern is developed to assist in showing the shapes and order or rotation of the various triangles ; and one constructed to the dimensions of any problem which may occur to the student at the outset of his study of triangulation will serve to assist his imagina- tion in all subsequent operations. PROBLEM 194. The Pattern for a Flaring; Collar the Top and Bottom of which are Round and Placed Obliquely to Each Other. In Fig. 632 EFGH shows the side elevation of a flaring collar, the profile of the small end or top being shown at ABCD, and that of the bottom at K L M JNT of the plan. The- conditions embodied in this problem are in no respect different from those of the problem immediately preceding. A slight diffei- ence in detail consists in the fact that in the former case the short side was at right angles to the larger end, while in the present case it is at right angles to the smaller end, but the pattern may be obtained by exactly the same method as that employed in the previous problem. However, as the elevation was there made use of to determine the triangulation, the plan will here be used upon which to determine the position of the triangles of which the pattern will sub- sequently be constructed. Divide A B C of the profile into any convenient number of parts, and, with the T-square at right angles to E F of the elevation, carry lines from the points in ABC, cutting E F, as shown. Extend the base line G H to the left indefinitely, and through the center of plan of base draw M, parallel with H G of elevation. Drop lines from the points in E F, extending them vertically through M With the dividers take the distance across the profile A B C D on each of the sev- eral lines drawn through it, and set the same distance off on corresponding lines drawn through M. That is, taking A C as the base of measurement in the one case, and M in the other, set off on the latter, on each side, the same length as the several lines measure on each side of A C. Through the points thus ob- tained trace a line, as shown by P Q E, thus obtain- ing. 632. — Plan and Elevation of Flaring Collar. 362 Hie New Metal Worker Pattern Book. ing the shape of the upper outline as it would appear in the plan. As both halves of the plan when divided by the line M are exactly alike, it will only be necessary to use one-half in obtaining the pattern ; therefore divide K N M of plan into the same number of parts as was the half of profile, in the present instance six, as shown by the small figures. Number the points in K N M to correspond with the points in R Q, and connect corresponding points by solid lines, as shown by 1 1', 2 2', 3 3', etc. Also connect the points in ORQ with those of the next higher number in K N M, as shown by the dotted lines 1 2'. 2 3', 3 4', etc. The solid and dotted lines thus drawn across the plan will represent the bases of a number of right angled triangles whose altitudes are equal to the vertical lines between E F and J Y of the elevation, and whose hy- V W X and on W X set off the lengths of dotted lines in plan, and from W on W V the lengths of lines in E F Y J of elevation, excepting the line E J, or No. 7, which is not used. Connect the points in W V of diagram with those of the next higher number in W X, as shown by the dotted lines in diagram and by simi- lar lines in the plan. The resulting hypothenuses will give the correct distances from points in top of article to points of next higher number in the plan of base. 2 *v A \ \\ \ \ \ \ \ \ T Fig. 63 Based Plan i 7 6 5 4 3 2 i U 3. — Diagram of Triangles upon the Solid Lines of the n Fig. 632. W \ \\ \ \ A^ \ \ \ -, 6 63A.- J± zX Fig. 634. — Diagram of Triangles Based upon the Dotted Lines of the Plan ia Fig. 632. pothenuses, when obtained, will give the real distances across the sides of the finished article in the direction indicated by the lines across the plan. To construct these triangles proceed as follows : Draw any right angle, as STU in Fig. 633. On T U, measuring from T, set off the lengths of solid lines in plan, making T U of diagram equal to QM of plan, T 2 of diagram equal to 2 2' of plan, T 3 of diagram equal to 3 3' of plan, etc. From T on T S set off the length of lines in E F Y J of elevation, making T S of diagram equal to F Y of elevation, T 2 of diagram equal to a 2 of elevation, T 3 of diagram equal to b 3 of elevation, etc. Connect points in T S with those of similar number in T U, as shown by the solid lines. The hypothenuses of the triangles thus obtained will give the distance from points in plan of base to points of similar number of top as if measured on the fin- ished article. The diagram of triangles in Fig. 634 is constructed in a similar manner. Draw the right angle i m Fig. 63S. — Pattern of Flaring Collar. Having now obtained all the necessary measure- ments, the pattern may be developed as follows : Draw any line, as q m in Fig. 635, in length equal to S U of Fig. 633, or F G of elevation. With m of pattern as center, and M 2' of plan as radius, describe a small arc (2"), which intersect with one struck from point q of pattern as center, and V X of diagram of triangles in Fig. 634 as radius, thus establishing the point 2" of pattern. With point 2" of pattern as center, and 2 2 of Fig. 633 as radius, describe a small arc (2), which Pattern Problems. 363 intersect with another struck from point q of pattern as center, and C 2 of profile as radius, thus establish- ing the point 2 of pattern. With 2 of pattern as cen- ter, and 2 3 of Fig. 634 as radius, describe a small arc (3"), which intersect with another struck from 2" of pat- tern as center, and 2' 3' of plan as radius, thus estab- lishing point 3" of pattern. With 3" of pattern as center, and 3 3 of Fig. 633 as radius, describe a small arc (3), which intersect with one struck from point 2 of pattern as center, and the distance 2 3 of profile as radius, thus establishing point 3 of the pat- tern. Proceed in this manner, using the hypothenuses of the triangles in Figs. 633 and 634 for the distances across the pattern ; the distances between the points in the plan of base for the stretchout of the bottom of pattern; and the distances between the points in the profile of top for the stretchout of the top of pattern. Lines drawn through the points of intersection, as shown by q o and m k, will, with q m and ok, constitute the pattern for half the article. The other half of the pattern q o' k' m can be obtained by any convenient means of duplication. PROBLEM 195. The Pattern for a Flaring: Flange, Round at the Bottom, the Top to Fit a Round Pipe Passing - through an Inclined Roof. In Fig. 636, let K L represent the juitch of the roof, ABCD the elevation of the flaring flange, A J D the half plan of the base, and BBC the half plan of round top through which the pipe passes. Fig. 636. — Elevation of a Flaring Flange to Fit Against an Inclined Roof. It will be seen by comparison that this problem embodies exactly the same principles as do the two immediately preceding, with the slight difference in detail that its short side is not at right angles to either upper or lower base. Also, in this case the bottom of the article appears inclined instead of the top. It will be seen at a glance that if the shape be considered as anything else than a flange against an inclined roof the drawing might be so turned upon the paper as to bring the line K L into a horizontal position, when it would present the same conditions as those of Problems 193 and 194 with the slight difference in detail above al- luded to. The method of triangulation employed in this case is exactly the same as in the problem immediately pre- jftDG v\ \ \V\ w \ \ \\ \ \ \ \ \ \ \ 6 5 3 2 Fig. 637.— Diagram of Triangles Fig. 688.— Diagram of Triangles Based upon the Solid Lines of Based upon the Dotted Lines of the Plan in Fig. 636. the Plan in Fig. 636. ceding, and the operation is so clearly indicated by the lines and figures upon the four drawings here given as scarcely to need explanation, if the previous problem has been read. The plans of both top and bottom are divided into the same number of equal parts, and a view of the top as it would appear when viewed at right angles to the base line K L, and as shown by F Gr H, is projected into the plan of base, as indicated by the lines drawn from B C at right angles to A D. 364 The New Metal Worker Pattern Book. Points of like number in the two curves FHG and A J D are joined by solid lines, and the four-sided figures thus obtained are redivided diagonally by dotted lines. These solid and dotted lines become the bases of the several right angled triangles shown in Figs. 637 and 638, whose altitudes are equal to the bights given be- tween the lines B C and F Gr, and whose hypothenuses give correct distances across the pattern between points indicated by their numbers. The pattern is developed in the usual manner by assuming any straight line, as C D in Fig. 439, equal to C D of Fig. 636, as one end of the pattern, and then adding one triangle after an- other in their numerical order; using the stretchout of B E C, Fig. 636, to form the upper line of the pattern, the stretchout of A J L to form the lower side of the nattern and the various dotted and solid hypothenuses Fig. 639. — Pattern of Flaring Flange Shown in Fig. 636. in Figs. 637 and 63S alternately to measure the dis- tances across the pattern. PROBLEM 196. Pattern for an Irregular Flaring Article, Elliptical at the Base and Round at the Top, the Top and Bottom not Being Parallel. The conditions given in this problem are essen- tially the same as those of Problem 193, but the fol- lowing solution differs from that of the former problem in the method of finding the distances from points assumed in the base to those of the top, and is intro- duced as showing varieties of method : In Fig. 640, C G H D represents the side view of the article, of which G K H is a half profile of the top and C F D a half profile of the base. For convenience in ob- taining the pattern the half profiles are so drawn that their center lines coincide with the upper and lower lines of the elevation. Divide both of the half profiles into the same number of equal parts — in the present instance eight. From the points obtained in the half profiles drop per- pendiculars cutting G H and C D. Connect the points secured in Gr H with those in C D, as a n, b m, etc. Also connect the points in Gr H witli those in C D, as indicated by the dotted lines 1 n, a m, etc. Prefer- ence to Problem 193 will show that in order to obtain the correct lengths represented by the several solid and dotted lines drawn across the elevation complete sections upon those lines were constructed, as shown in Figs. 628 and 629. In the present case these dis- tances will be derived from a series of triangles whose bases are the differences between the lengths of the lines drawn across the half profile of the top and those of the bottom. Therefore, to obtain the triangles giving the true dis- tances represented by the solid lines proceed as follows : Fig. 640. — Elevation and Profiles of an Irregular r ,uring Article, Showing Method of Triangulation. First set off from C D upon each line in the base CFD the length of the corresponding line in the top ; thus Pattern Problems. 365 make n o equal to a 2, mp equal to b 3, I q equal to c 4, etc. For the bases of the triangles represented by the dotted lines set off from C D the length of correspond- »■'«' p' 0' R »' f' FKg. 641. — Diagram of Triangles Representing Solid Lines of the Elevation. w 1 ' /, a" // I b II ll II v c" II \ \ \ 11 II •• in d 11 Hi \ \ \ \ ,','1 f" 'l N \ 1 «" J \ \ /// / in / IV \ \ /// / /// ' ■ // 1 L IV \ .. \ .. 3"a"X"Z" V 6 '7" 5 " 4 " Fig. 64S. — Diagram of Triangles Representing Dotted Lines of the Elevation. ing lines in G K H, as shown by the small figures in COD. Thus make m 2' equal to a 2, I 3' equal to b 3, h i' equal to c 4, etc. The triangles represented by solid lines in the elevation, and shown in Fig. 6-41, are obtained as follows : Draw the line P Q, and from from C to are set off to the left of R, and the lengths from O to P on R Q. Thus make R a' of diagram equal to n a of Fig. 640, R 0' of diagram equal to o 17 of half profile of base, and connect a! a'. Make R b' of diagram equal to m b of Fig. 640, R p' of diagram equal to p 16 of the base, and connect p' 6', etc. The triangles represented by clotted lines in C G H P are obtained in a similar manner. Praw the line T U in Fig. 642 and erect the perpendicular V W. From V, on V W, set off the lengths of dotted lines in C Gr H P of the elevation. Thus make VI" equal to n 1 of Fig. 640, Y a" equal to m a, V b" equal to 1 b, etc. Upon V T or V U set off the lengths of the lines in C P F of Fig. 640, as indicated by the small figures. Thus make Y X" equal to n 17 of the base in Fig. 640, and draw X" 1". Make V 2" equal to 2' 16 of the base, and draw 2" a", etc. To obtain the pattern first draw the line C G of Fig. 643, in length equal to C G of Fig. 640. From C, with radius equal to C 17 of the half profile of base, strike a small arc (0), which intersect with an- other arc struck from G as center, and 1" X'' of Fig. 642 as radius, thus establishing point in the curve of the pattern. From G of pattern as center, and G 2 of the half profile of top as radius, strike a small arc, which intersect with another arc struck from Fig. 643. — Pattern of Shape Shown in Fig. 640. a convenient point erect the perpendicular R S. From R on R S set off the lengths of solid lines in C G H P, and from R on P Q set off the lengths of correspond- ing lines in C O P F, as indicated by the small letters in C P. To avoid a confusion of lines the lengths o of pattern as center, and a' 0' of Fig. 641 as radius, thus establishing point a in the upper curve of the pattern. From of pattern as center, and 17 16 in F as radius, strike a small arc (p), which inter- sect with another arc struck from a of pattern as cen- 366 The New Metal Worker Pattern Book. ter, and a" 2" of Fig. 642 as radius, thus locating point p of the pattern. From a of the pattern as cen- ter, and 2 3 in G K as radius, strike a small arc, which intersect with another arc struck from p of pat- tern as center, and p V of Fig. 641 as radius, thus locating point b of pattern. Proceed in this manner, using in the order named the spaces in the lower pro- file, the hypothenuses of triangles in Fig. 642, the spaces in the upper profile, and the hypothenuses of triangles in Fig. 641. The points thus obtained, as indicated by the letters in Fig. 643, are the points through which the pattern lines are to be traced. Then C G H D is the required pattern for one-half the article. The other half of pattern, as shown by C G H' D', can be obtained by any convenient method of du- plication. PROBLEM 197. The Patterns for a Bathtub. In Fig. 644, let A B C D be the elevation and E F G H half the plan of a bathtub. An inspection of the drawing shows that neither the segments forming irregular in character, and the only available method by which the various dimensions and curves constitut- ing the patterns of the same can be ascertained is by 70/11 p 532 TRIANGLES IN HEAD PIECE — ^^4^ 7ig. 644. — Plan and Elevation of Bathtub, with Diagrams of Triangles, Section of Top and Pattern of Side Piece. the . head nor those of the foot of the tub are concen- tric, and that their upper and lower bases are not par- allel. Therefore the figures which they constitute are dividing their surfaces into small triangles, which can most easily be accomplished in the following manner: Divide each of the curves J I and G H, forming the Pattern Problems. iHil plan of the head piece, into the same number of equal parts, numbering each the same, as shown, and con- nect points of similar number by solid lines. Also connect each point in J I, the line of the bottom, with the point of next higher number in G H, the line of the top, by a dotted line, all as shown. The curves E F and L K, forming the plan of the foot piece, are also to be divided into spaces and the points connected by solid and dotted lines in the same manner as those of the head. The solid and dotted lines thus drawn between the points in the two curves of the plan will form the bases of a series of right-angled triangles, whose hypoth- enuses (after the altitudes are obtained) will give the real distance between the points whose number they bear upon the finished article. As, owing to the slant of the top line A B of the elevation, the triangles will Fig. 645.— Half Pattern of Head Piece. Fig. C4C.— Half Pattern of Foot Piece. be of differing bights, the simplest way of constructing them will be as follows : Upon D C of the elevation extended, as a base, erect a perpendicular line, M N From N on the base line set off the various lengths of the solid lines in the plan of the head piece, as shown toward Q. From each of the points in the curve G H erect perpendicular lines, cutting A B of the eleva- tion ; and from these points of intersection carry lines horizontally to the right, cutting the line M N, num- bering each point to correspond with the points in G H, all as shown. Lines connecting j)oints of similar num- ber at M and Q will be the hypothenuses required, or the real distances between points of similar number in the top and bottom of the finished article. In a sim- ilar manner erect another perpendicular, P, and set off from P on the base line the lengths of the several dotted lines in the plan of the head piece, as shown toward R. The bights of the points in the curve of the top can be determined upon the line P by con- tinuing the lines drawn from A B toward M till they intersect P. Each point in the base P E is now to be connected with the point of the next higher number in P by a dotted line. The various hypothenuses drawn between and R will then be the correct dis- tances between the points connected by the dotted lines of the plan. (The numbers in P B, correspond with those in I J of the plan and not with H Gr). The dia- grams from which the dimensions for the foot piece are obtained are shown at S T U and V W X at the left of the elevation and are obtained in a manner exactly similar to those just obtained for the head piece, all of which is clearly shown by the lines of the drawing. From an inspection of the drawing it will be seen that the line E F G H does not represent the true lengths or measurements taken on the top line of the tub, because A B, not being horizontal, is longer than the line E H, its equivalent in the plan, and therefore a true section on the line A B must be obtained, as shown above the elevation. This may be accomplished in the following manner : At any convenient distance above A B draw E 1 H 1 parallel to A B, and from all of the points previously obtained on A B carry lines at right angles to A B, cutting E 1 H 1 , and extend them beyond indefinitely, numbering each line to correspond with the point in E F Gr H from which it is derived. On the line 2 set off from E 1 H' a distance equal to the distance of point 2 of the plan from the line E H as measured on the vertical line; on line 3 set off as before a distance equal to the distance of point 3 of the plan from E H, and so continue until the distances from E H of all the points in E F G H have been transferred in like manner to the new section. Then a line traced through these points, as shown by E 1 F' G 1 H', will be a section or plan on the line A B, from which measurements can be taken in developing the upper edge of the pattern. Having obtained, by means of the various dia- grams constructed in connection with the elevation, the correct distances between all the points originally as- sumed in the plan, the pattern may now be developed by simply rejDroducing all of these distances or meas- urements in the order in which they occur upon the plan. For the pattern of the head piece assume any line, as I H of Fig. 645, which make equal in length to C B of the elevation, or what is the same thing, equal to 1 1 of the diagram MNQ. From H as a center, with a radius equal to 1 2 of the section of top, strike a small arc, which intersect with another arc struek 368 Tlie New Metal Worker Pattern Book. from I as a center, with a radius equal to 1 2 of the diagram of dotted lines OPE, thus establishing the point 2' of the pattern. From 2' as center, with a radius equal to 2 2 of the diagram of solid lines M N Q, strike a small arc, which intersect with another struck from point I as a center, with a radius equal to 1 2 of the line 1 -1 of the plan, thus establishing the poinl 2 of the pattern. Continue this operation, using in nu- merical order the distances taken from the top section, in connection with the distances obtained from the diagram of dotted lines P E, to form the top line of the pattern, and the distances taken from the diagram of solid lines M N 0, in connection with the distances measured upon the bottom line I J of the plan, to form the bottom line of the pattern, all as indicated by the solid and dotted lines drawn across a portion of the pattern. Then IHGJ will be one-half the pattern of the head piece. The pattern for the foot piece is de- veloped in exactly the same manner by making E L equal to A D of the elevation, and using the diagram of dotted lines V W X to measure upon the pattern the distances indicated by the dotted lines upon the plan, and the diagram of solid lines ST U to measure upon the pattern the distances indicated by the solid lines across the plan, the distances forming the top line of the pattern being taken from E 1 F' of the top section while the distances forming the bottom line of the pattern are taken from the line L K of the plan. The pattern for the flat portion of the side F G J K can be obtained as follows : Parallel to K J of the plan draw any line, as K 1 J 1 . At right angles to K J of the plan project lines from points K, J, F and G, cutting K 1 J 1 , as shown, establishing the points K 1 and J 1 , and continuing the lines from points F and G in- definitely. From K 1 of the pattern as a center, with a radius equal to 8 8 of the diagram S T U, or of Fig. 64-1, strike a small arc, cutting the line projected from point F of the plan, as shown at F 2 of the pattern. From J 1 of the pattern as a center, with a radius equal to 7 7 of the diagram M N Q, or of Fig. 644, strike a small arc, cutting the line projected from the point G of the plan, as shown at G 2 . Draw the lines K 1 F 2 , F 2 G 2 and G 2 J 1 ; then K' F 2 G 2 J 1 will be the pattern of the flat portion of the side. The patterns of the several parts can be joined together, by any convenient method of duplication, in such a manner as to produce as much of the entire pattern in one piece as it is desired. PROBLEM 198. The Pattern for a Flaring Flange to Fit a Round Pipe Passing through an Inclined Roof; the Flange to Have an Equal Projection from the Pipe on All Sides. In Fig. 647, let a b c d be the elevation of the pipe, E E' its plan, A B C D the elevation of the flange and C D the angle or pitch of the roof. Since the projection of the base of the flange is required to be equal on all sides, as shown by C 1 and D 1, the flange will appear in the plan as a perfect circle, F F'. To avoid confusion of lines another elevation of the flange G H K J is shown in Fig. 648, below which is drawn a half plan of its base, MBN, and above which is a half plan of its top, G L H, all of which will be made use of in dividing the surface of the flange into measurable triangles for the purpose of developing a correct pattern of the same. Divide the semicircle G L H into any convenient number of equal parts— in the present instance 12 — and from the points thus obtained drop perpendicular lines to G H. To obtain the shape of section on roof line J K divide the half plan of base MBN into the same number of equal parts as was G L H, and from the points thus obtained carry lines at right angles to M N, cutting J K. From the points in J K draw lines at right angles to it, as shown by a 1, b 2, c 3, etc. On these lines, measuring from J K, set off the length of corresponding lines in M N B, thus making lines a 1, b 2, c 3, etc., in JKC equal to lines al, b2, c 3, etc., in M N B. A line traced through these points, as shown by J C K, will give the shape of sec- tion on roof and furnish the stretchout of base for obtaining the pattern. In Fig. 649 is drawn a duplicate of the plan in Fig. 647, the spaces in its outer line D P being exact duplicates of the spaces in M B N of Fig. 648, Pattern Problems. 369 and the spaces in its inner line 0' D' P' being dupli- cates of those in G L H, all as shown by the small figures. Draw solid lines connecting similar points, as 1' 1, 2' 2, 3' 3, etc. In like manner connect the PLAN Fig. 647. — Plan and Elevation of Pipe and Flange. points in 0' D' P' with those of the next higher num- ber in ODP, as with 1', 1 with 2', 2 with 3', etc., with dotted lines. These solid and dotted lines will then form the bases of a series of right angled trian- gles, whose altitudes can be derived from the eleva- tion, and whose hypothenuses, when obtained, will be the correct measurements across the pattern between points of numbers corresponding with the lines across the plan. To construct the diagrams of triangles represented by solid and dotted lines in plan, extend G H of Fig. 648 indefinitely, as shown by H W. From the points in J K carry lines to the right indefinitely, parallel with G W, as shown by the lines between G W and K Y. At any convenient place, as R, and at right angles to GW, erect the line R S, cutting the base line K Y. From R set off the distance R T, equal to the length of any of the solid lines in plan, Fig. 649, as P' P, which is the horizontal distance between the pipe and lower edge of the flange. Draw T U parallel with R S, and also draw lines from the points in R S to T. For convenience the points in R S can be num- bered to correspond with the points in J C K. Then the triangle TUS will correspond to a section through Wig. 649. — Plan of Flange, Showing Triangxdation. the article on the line P' P in plan, the hypothenuse S T representing the distance between the pipe and lower edge of the flange. The diagram of triangles in V W Y X is constructed in a similar manner; draw W Y at right angles to G W, and set off the space W V equal to the length of one of the dotted lines in plan, Fig. 649, as 1', and draw lines from the points in W Y to V. In developing the pattern the stretchout of top of 370 T)ie New Metal Worker Pattern Book. can be obtained from stretchout of lower edge flange where it joins the pipe the semicircle G L H. The of flange where it joins the roof can be obtained from the section on the roof line J C K. The distance be- tween points in D P and 0' D' P' of plan, Fig. 649, length to T S of first diagram of triangles. With the dividers set to the distance K 1 in K C J of section strike a small arc (1') from the point 0' of pattern. With the dividers set to the distance Y 1 of second dia- gram of triangles strike a small arc from the point of SECOND DIAGRAM Fig. 6 J/S.— Elevation of Flange, with Plan, Sections and Diagrams of Triangles. as indicated by the solid lines, is given in the diagram of triangles T E S. The distance between points as indicated by dotted lines in plan is given in the diagram V W Y. For the pattern then proceed as follows : Draw any line, as H' K', Fig. 650, equal in pattern as center, cutting the first arc at 1' of pattern. From point 1' of pattern as center, and T 1 of first diagram of triangles as radius, describe a small arc (1), which intersect with one struck from of pattern as center, and 1 in H L G as radius. Thus the points Pattern Problems. 371 0' and 1 1' of pattern are established. Proceed in this manner, using in the order described the stretch- out obtained from the elliptical section K C J, the hy- pothenuse of triangle in second diagram corresponding to the dotted line in plan, the stretchout from the sec- tion GLH, and the hypothenuse of triangle in the other half of the pattern can be obtained by any means of duplication most convenient. Should it be required to construct such a flange to fit over the ridge of a roof, it is clear that that part of the flange shown in the plan, Fig. 649, by OO'D'D would be a duplicate of the part shown by D' P' P D, •' 12 J '2' Fig. 650.— Half Pattern of Flange Shown in Fig. 647. first diagram corresponding to the solid line drawn across the plan, until all the measurements are used. Lines traced through the points thus obtained, as shown by H' G' and K' J', will be the half pattern. The and that, therefore, that portion of the pattern, Fig. 650, shown by 6 H' K' 6' would be one-quarter of the entire pattern, which could be duplicated so as to make either one-half or the whole pattern in one piece. PROBLEM 199. Pattern for the Hood of a Portable Forge. In Fig. 651, C A B D represents the front eleva- tion of a hood such as is frequently used upon a por- table forge, K L M N its plan and EFHJ a its side view. The opening A B at the top of the hood is round, as shown by L P of the plan, while the base C D where it joins the forge is nearly semi-elliptical, as shown by K L M of the plan. In the side elevation E a shows the amount of flare and projection of the front of the hood, while the opening, shown in the front by C S D, appears as a simple straight line, a J. With these conditions given, the arch of the opening C S D of the front elevation can be determined in connection with the plan, by projection, as shown by the hori- zontal dotted lines, while if the arch of the front eleva- tion be assumed arbitrarily then its line (a J) in the side view must be obtained by projection, and will be either 372 The New Metal Worker Pattern Book. straight or curved according to the nature of the curve employed in the front elevation. Assuming the straight line a J of the side view as the true profile of the arch, its curve in either the front elevation or the plan must be determined, as a means FRJONT ELEVATION L 91011 SIDE ELEVATION Fig. 651. — Front and Side Elevations and Plan of Hood, Showing System of Triangulation. of obtaining the pattern. As the flaring portion of the hood very much resembles a conical frustum having an oblique base, probably the simplest method of ar- riving at its true shape is to first determine the plan of this irregular frustum of which it is a part. Therefore produce the oblique line E a of the side elevation until it intersects the base line H J extended in the point G. Next set off from L on the center line of the plan a distance equal to H Gr of the side elevation, thus locating the point R. Through R, from a center to be determined upon the center line, draw the curve form- ing the front of the plaD., with such length of radius as will make an easy junction with the curves of the back at K and M. It is not necessary that the curve K R M should be a perfect circle throughout; it may change as it approaches K and M so as So flow smoothly into the as- sumed curve of the back. It is simply necessary that no angle be produced at K and M, as such an angle would be con- tinued through the surface of the hood toward the opening of the top. Divide the circle of the top P L into any convenient num- ber of equal spaces, as shown by the small figures ; also divide the outer curve of the plan EML into the same number of spaces. For accu- racy and convenience it will be found advisable to make the spaces shorter as the curve increases from M toward L until the end of the curve is reached at the point 11. Connect points of similar number in the two curves by solid lines, as shown; also connect points in the plan of the top with points of the next higher number in the plan of the base by dotted lines. In order to pro- duce the curve of the opening correctly in the plan and the front elevation it will be necessary first to draw upon the side elevation lines corresponding to the solid lines just drawn across the plan. To accom- plish this place the "|"-square at right angles to L R of the plan, and, bringing it successively against the points in the plan of the base R M L, drop corresponding points on L R, as shown. Transfer the spaces thus produced to the base line H Gr of the side elevation, numbering each point to correspond with the plan. By means of the J-square placed as before, drop points from the plan of the top to the center line L P (omitted in the drawing to avoid confusion of lines) and transfer the same to the line FE of the side elevation, number- ing each point as before. Now connect points of cor- responding number in the upper and lower lines of the side elevation by solid lines, as shown ; then will these lines be the elevations of the solid lines drawn across the plan. Pattern Problems. 373 It may be here remarked that, as the pattern will be obtained from the plan, a correct front elevation of the opening, or arch, is not necessary to the work, but if it is desired it can be obtained in the following man- ner : Place the T-square parallel to L R of the plan and, bringing it against the ]3oints in the plan of the *7///'iii '// / / //iii B Ffr~. //// / ' //III ..'_ _2 L 6 9 10 II Fig. C5S. — Diagrams of Triangles. base between R and M, drop corresponding points on the base line C D of the front elevation. Also in the same manner drop points from the curve of the top L P in plan upon A B of the front elevation, and connect points of corresponding number in the two lines by solid lines, as shown. From the points of intersection of the solid lines in the side elevation with the line a J (the profile of the arch), a, b, c, etc. , carry lines horizontally across, as shown, intersecting them with lines of cor- responding number in the front elevation. A line traced through the points of intersection as shown from S to D, will be the correct elevation of the opening in the front of the hood. The correct plan of the opening may be obtained by placing the T-square parallel to L E and bringing it against the various points of intersection through which the curve S D was traced and cutting the solid lines of corresponding number in the plan, giving the points a, b, c, etc. In case the development of the curve S D has been omitted, measure the horizontal distance of each of the points a, b, c, etc., in a J of the side eleva- tion from the line F H and set off the same on the center line of the plan from L toward N". Thus the horizontal distance of point a from the line F H is set off from L on the center line of the plan, thus locating the point N or a, the extreme point of projection of the hood. In the same manner the projections of points b, c, etc., of the side elevation, or in other words, their distances from F H are set off from L of the plan, as shown between N and T. Now place the T-square at right angles to L R and, bringing it against these points last obtained, cut the corresponding solid lines of the plan, thus locating the points a, b, c, etc., of the plan, as before. A line traced through these points will be the correct plan of the curve of the opening. Before the pattern can be begun it will be neces- sary to first obtain the correct distances represented by the solid and dotted lines across the plan. This is ac- complished by means of two diagrams of triangles, shown in Fig. 652, as follows: Draw the vertical line A B, in length corresponding to the hight of the hood, as indicated by F H in the side elevation. At right angles to A B draw B C, in length corresponding to P R or 1 1 of the solid lines of the plan. From B set off also the spaces B 2, B 3, B 4, etc., corresponding in length to the lines 2 2, 3 3, I 4, etc., of the plan. Con- nect the points in B C with the point A by solid lines. Then will these lines represent the true distances between points 1 and 1, 2 and 2, etc., of the plan. The second diagram of triangles is constructed in a similar manner. The vertical line E D is drawn, equal to F H of the side elevation. E F is set off at right angles to it, in length equal to the dotted line 1 2 of the plan. From E are set off the distances E 3, E 4, etc., corresponding to the lines 2 3, 3 4, etc., of the plan. The points thus established in F E are then connected with D by means of dotted lines. Then will these lines represent the 6 --/io^s " m Fig. 653.— Pattern of Hood. true distances between points 1 and 2, 2 and 3, etc., of the plan. To develop the pattern, first draw any vertical line, as L Z of Fig. 653, representing the center of the 374 Tlie New Metal Worker Pattern Book. back, which make equal to the hight of the hood F H. As the base of the hood is perfectly straight from L to the point 11, set off on a horizontal line from the point Z, in Fig. 653, a distance equal to L 11 of the plan, and draw 11 L of the pattern. With L as center, and 11 10 of the small circle in plan as radius, describe a short arc. Then, from 11 of the base in pattern as center, and 11 D of the second diagram of triangles as radius, describe a short arc intersecting the one first drawn, thus establishing the point 10 of the ripper line of the pattern. Then from this point as center, with A 10 of the first set of triangles as radius, describe a short arc, and from 11 of the base of the triangular portion of the pattern, with 11 10 of the outer curve of the plan as radius, describe another arc intersecting it, thus establishing the point 10 in the lower line of the pattern. Proceed in this manner, using alternately the spaces in the inner line of the plan, the hypothe- nuses of the dotted triangles, the hypothenuses of the triangles indicated by solid lines, and the spaces in the outer line of the plan, obtaining the several points, as shown. Then lines traced through these points will be the pattern of the envelope of the shape indicated by F E G H of the side elevation, or in other words, of the frustum of which the hood forms a part. It now remains to cut away such a portion of this pattern as rejoresents the part G a J of the side elevation. To ac- complish this it is simply necessary to obtain the posi- tions of the points a, b, c, etc., of the plan and side elevation upon the lines 1 1, 2 2, 3 3, etc., of the pat- tern. With the blade of the T-square set parallel to the base line G H of the side elevation brine it against the points of intersection made by the line a J with the radial lines, and cut the vertical line F H, as shown by the short dashes drawn through it. Transfer the points thus obtained in F H to the vertical line A B of the first set of triangles. Then with the blade of the T- square at right angles to A B, and brought successively against the points in it, cut the hypothenuses of the several triangles corresponding in number to the lines from which the points were derived in the side eleva- tion, all as indicated by the letters a, b, c, d, e and/. The distances of these points from A may now be transferred to lines of corresponding number in the pattern, measuring from the upper line, as shown by a, b, c, etc. Then a line traced through these points, as shown from 1ST to M, will give the shape of the front or arch of the hood, and LPS M Z will be the half pattern of the hood. PROBLEM 200. The Patterns for the Hood of an Oil Tank. In Fig. 654 are shown the elevations and plan of a hood of a style which is usually hinged to the top of an oil tank, or can. The plan shows a curve of some- thing more than a semicircle, H' G F', while the curve F K H of the back view is slightly less than a half circle, the problem being to determine the shape of a piece of metal to fill the space between the two curves, as shown by A B C of the side view. Divide one-half of the plan into any number of equal parts, as shown by the small figures 1, 2, 3, etc. From the points established in the plan carry lines up- ward until they cut the base line of the required piece, as indicated by the points between A and B. From the points thus established carry lines parallel to A C until they cut the line representing the back of the hood, as shown between C and B, thence carry them horizontally until they cut the profile of the back of the hood, as shown by the points between K and F. From the points in K F drop lines vertically on to the base line F E, establishing points in it, as shown. Lay off spaces in the line F' E' of the plan corresponding to those of F E in the back, and from the points thus established draw solid lines to those of corresponding numbers laid off in the plan from G to F'. These lines represent the bases of a series of right angled triangles whose altitudes are shown by the dotted lines of the back view, and whose hypothenuses will give the correct distances between points of similar number in the plan. As the altitudes of these triangles are also shown in C B of the side elevation, that view is here made use of for the purpose of obtaining the required hy- Pattern Problems. 375 pothenuses. However, since the solid lines drawn across the plan are not parallel to Gr E', the distances 1 B, 2 B, etc., representing them in the base line of the Fig. 654. — Elevations and Plan of Hood for an Oil Tank, Shoii'ing System of Triangulation. side view will not be the correct bases of the triangles, therefore set off on A B, measuring each time from B, the correct lengths of the several solid lines of the plan, as indicated by the points near 1, 2, 3, etc., on the line Fig. 655. — Diagram of Triangles Based upon the Dotted Lines of the Plan. A B, from which points draw lines (shown dotted) to points of similar number in B C. Then the dotted lines 11, 2 2, etc., of the side view will be the correct hypothenuses of the triangles whose bases are indicated by the solid lines drawn across the plan. To com- plete the measurements necessary for obtaining the pattern connect the points in the opposite sides of the plan diagonally, as, for example, of the front and 1 of the back, and 1 of the front with 2 of the back, as shown by the dotted lines. These clotted lines represent the bases of a second set of triangles, to be constructed in the same manner as the former set, all as shown, Fig. 655. Draw A B andB C at right angles to each other and upon C B set off the several bights shown in G B of Fig. 654. Upon A B lay off B 0, corresponding in length to 1 in the plan. Make B 1 diagram equal to 2 1 of the plan, and in the make B 2 and B 3 of the diagram equal to 3 2 and 4 3 of the plan respectively. From the points thus established in the base line of the diagram same manner Q Fig. 656.— Pattern for the Top of Hood. draw lines to points of next higher number in the ver- tical line. These hypothenuses will then represent lengths of lines measured on the face of the hood corresponding to the diagonal dotted lines in the plan. To develop the pattern, first draw any line, as of Fig. 656, equal in length to A C of side, Fig. 654. From 0, at the right of the pattern, as center, with the distance between the points to 1 in the pro- file F K of the back as radius, describe a short arc. 376 Tlie New Metal Worker Pattern Book. Next take in the dividers the distance 1 of Fig. 655, and from the opposite end of the center line describe a short arc, intersecting the one already drawn at the point 1, thus establishing that point. From i as center, with dotted line 1 1 of the side view as radius, describe another short arc, which in turn intersect by an arc struck from of the left hand side of the pat- tern with 1 of the plan as radius. This will estab- lish the point 1 of the opposite side of the pattern. Continue in this way, intersecting the hypothenuse of the triangles whose bases are the dotted lines of the plan with the measurements taken from the back view, and the hypothenuse of the triangles which are shown by the solid lines of the j}lan with the measurements taken from the circumference of the plan. In this manner all points in the profile of the pattern neces- sary to its delineation will be established. A free- hand line drawn through these points will give one- half the required pattern, all as shown in Fig. 656. The other half may be obtained by any convenient method of duplication. The shape of patterns forming the back and the vertical sides of the hood are clearly shown in the engraving and need no further explanation. PROBLEM 201. Pattern for an Irregular Flaring Shape Forming: a Transition from a Round Horizontal Base to a Round Top Placed Vertically. In Fig. 657, let I D E F H represent the front elevation of the article, showing the circular opening DEFG forming its upper perim- eter or profile. The triangle A B C shows the shape of the article as it appears when viewed from the side, below which is drawn the plan, showing its circular base, J K L M. The line N P shows the plan of the opening DEFG, which opening is shown in the side view by that por- tion of the line A B from A to Q. Opposite the front side of the plan N P is drawn a duplicate of the pro- file D E F G, as shown by E' F' G', so placed that its vertical center line E' G' shall coincide with the center line of the plan, as shown. As the article consists of two symmetrical halves it will only be necessary to develop one-half the complete pat- tern. Therefore divide one-half of both profiles E F G and E' F' G' into the same number of equal parts, numberino- each in the same order, as shown by the small figures ; also divide the plan of the base into the same number of equal parts as the profile, numbering the points to correspond with the same. Drop lines from the points on the profile E' F' G' on to the line N P, at right an- gles to the same, as shown, and connect these points with those of similar number upon the plan of base by solid lines, as shown. Also connect points upon the i M Fig. 657. — Elevations and Plan of an Irregular Shape Forming a Transition from a Round Horizontal Base to a Bound Top Placed Vertically. base with those of the next higher number upon the line N P by dotted lines. It will be noticed that the point J of the plan Pattern Problems. 377 represents at once the point 1 of the base and the points 1 and 7 of the profile, shown by B, Q and A of the side elevation. The lines drawn across the plan represent the horizontal distances between the fi 5 4 3 \ -i q 2 3 4 Fig. 658. — Diagram of Triangles. points which they connect and will form the bases of a series of right angled triangles, whose altitudes can be derived from the elevations, as will be shown, and whose hypothenuses, when drawn, will give the true distances between points of corresponding number across the finished article or its pattern. To obtain the altitudes of the triangles carry lines from the points in the half profile E F G horizontally across, cutting the line A Q, as shown ; then the distances of the points in A Q from B will constitute the respective altitudes of the triangles. Therefore, to construct a diagram of all the triangles, draw any horizontal line, as D C, Fig. 658, near the center of which erect a perpendicular, B A. Upon B A set off from B the various distances from B to spaces forming the upper or shorter side of pattern can be measured from either of the profiles. To develop the pattern it is simply necessary to construct the various triangles whose dimensions have been obtained in the previous operations, beo-innina; at either end most convenient and using the dimensions in the order in which they occur until all have been used and the pattern is complete. Therefore, upon any straight line, as A C of Fig. 659, set off a distance equal to A C of Ficr. 657 or the solid line 7 7 of Fig. 658. From C as a center, with a radius equal to 7 6 of the plan, Fig. 657, describe a small arc to the left, which intersect with another small arc struck from A as a center, and with a radius equal to the dotted line 7 6 of the diagram of triangles, Fig. 658, thus establishing the position of the point 6 of the pattern. From A of Fig. 659 as center, with a radius equal to 7 6 of the profile, Fig. 657, describe a small arc, which intersect with another struck from point 6 of pattern as center, with a radius equal to the solid line 6 6 of Fig. 2, thus locating the position of the point 6' of the pattern. a r points in A Q of Fig. 657. number the same as shown by the small figures. From B set off on B C the lengths of the various solid lines drawn across the plan, Fig. 657, and connect points in B C with those of like number in B A. From B set off toward D the lengths of the various dotted lines drawn across the plan and connect them by dotted lines with points of the next higher number in the line B A, all as shown ; then these various hyjDothenuses will constitute the true distances across the finished article between points of corresponding number indicated on the plan and elevations. The distances between points in the base line forming the larger or outer curve of the pat- tern can be measured from the base line in plan, while Fig. 659. — Pattern of Shape Shown in Fig. 657. So continue to use the spaces of the plan, the lengths of the dotted lines of the diagram of triangles, the spaces in the profile and the lengths of the solid lines of the diagram of triangles in the order named until all have been used and the pattern is complete. Lines traced through the numbered points obtained, as 378 Tlie New Metal Worker Pattern Book. shown from C to B and from A to Q, will form the out- lines of the pattern for half the article. The other half, A Q' B' C, can be obtained by any means of duplica- tion most convenient. PROBLEM 202. Pattern for the Lining of the Head of a Bathtub. In Fig. 660 are shown a plan and side and end views of the head of a bathtub or the lining of a tub the body of which is constructed of wood. The end view shows the bottom corners of the tub to be rounded, as shown at C G 1 and B 1 F 1 ; the plan shows the head any convenient number of equal spaces, as shown by the small figures. In like manner divide the quarter circle B 1 F 1 of the end view into the same number of equal spaces, less one, as also indicated by the small figures. From the points thus established in B 1 F 1 carry Fig. 660. — Elevations and PUxa of Lining for a Bathtub, Showing Ti'iangulation of the Head Piece. to be semicircular, while the side view shows that the junction between the head and the sides is made on the vertical line B 2 W. It will thus be seen that the conditions here given are the same as in the previous problem — viz. , an irregular flaring piece form- ing a transition between two quarter circles (instead of complete circles as in the previous problem) lying in planes at right angles to each other. Divide the quarter circle A F of the top view into lines to the horizontal line B F in the top view and mark the intersection by small figures, as shown. The reason for using one less space in the quarter circle B' F' than in the large arc A F is because B' F 1 is not the complete profile of the end which is to be connected with A F of the top ; the line F 1 E being required to complete the same, thus constituting the remaining space. Having established these two sets of points in the plan, connect those of like numbers, as 1 with 1, 2 with 2, etc., by solid lines. Also connect the points in the line of the top with those of the next lower number in the base, as 2 with 1, 3 with 2, etc., as in- dicated by the dotted lines. These solid and dotted lines form the bases of the two sets of triangles shown in the diagrams at the right, from which the correct measurements across the pattern are to be obtained. To construct these diagrams extend A 2 E 2 of tne side indefinitely to the right, as shown. At any con- venient points, as J and M, drop the perpendiculars J K and M N. From the points established in the quarter circle B 1 F 1 carry lines horizontally to the right, cut- Pattern Problems. 379 ting the two perpendiculars, as shown by the small figures above K and N. From J, upon J H, set off the space J 1, equal to the line 1 1 of the plan or top view, and from the point 1 thus established draw the hypoth- enuse of" the triangle, terminating in the point 1 of the line J K. In like manner set off from J, upon J H, the length 2 2 of the top view, also 3 3, 4 i and 5 5, and from the points thus established draw lines to points of corresponding designation in the line J K, all as shown. By this means triangles have been constructed the hypothenuses of which represent measurements on the surface of the finished article, taken on lines cor- responding to the solid lines of the top view. In like manner construct the second diagram of triangles shown at the extreme right, setting off from Fig. 661.— Pattern of Head Piece Shown in Fig. 660. M distances equal to the length of the dotted diagonal lines in the top view, and connecting the points thus established with points of next lower number in the line M N. Then the hypothenuses of this set of tri- angles will give the lengths corresponding to measure- ments on the dotted lines of the plan or top view. Having now obtained all the necessary measure- ments, the pattern may be developed as shown in Fig. 661. The central portion of the pattern will corre- spond to A 1 C 1 B 1 of the end view, it being simply a flat triangular piece of metal. Therefore draw any horizontal line, as C B, equal in length to C B or C B 1 of Fig. 660. Take the space 1 1 of the first diagrams of the triangles as radius, and from C and B, respect- ively, as centers, strike arcs which will intersect at A. From A as center, with 1 2 of the outer line of the plan as radius, describe a small arc. From B as cen- ter, with 1 2 of the second diagrams of triangles as radius, intersect the arc as shown, thus establishing the point 2 in the upper curve of the pattern. Then from B as center, with 1 2 of the arc B 1 F 1 of the end view as radius, describe another small arc, and from 2 of the upper edge of the pattern as center, with 2 2 of the first diagram of triangles as radius, intersect it as shown, thus establishing point 2 in the lower line of the pat- tern. Proceed in this way, using alternately the stretchout of the top of the tub, as indicated by the plan view, with the hypothenuses of the second dia- gram of triangles to establish the points in the upper curve of the pattern, and the stretchout of the quarter circle shown in the end view with the hypothenuses of the first diagram of triangles to establish the points in the lower line of the pattern, until the points 6 and 5, or E and F, are reached. Connect E and F by a straight line and through the points from A to E and from B to F trace lines, as shown ; then A E F B will be the pattern for one of the corners of the head, a du- plicate of which may be reversed and transferred to the other side of the pattern, as shown by A D G C, thus completing the entire pattern of the head in one piece. PROBLEM 203. The Pattern for a Boss to Fit Around a Faucet. In Fig. 662 are shown two views of a boss such as is used for fastening a faucet into the side of a large can ; the curvature of the body of the can being rep- resented by the line A D B. For convenience in demonstration, what would be properly considered the front view of the article is here called the top view, the other view being considered as the side. Let H L and K 1ST represent its desired length and width of base or part to fit against the body of the can, and PRO the circle of the top to fit around the neck of the faucet. Also let D E be its required projection from the can. Through E draw Y Z parallel to H L, 380 Tae New Metal Worker Pattern Booh. the long diameter of the base. From P and drop lines at right angles to H L, cutting Y Z in the points Y and Z, also from H and L drop lines cutting A D B, and connect the points thus obtained with Y and Z, as shown, thus completing the side view. Commence by dividing one-quarter of the plan of the base K H into any convenient number of spaces, as shown by points 1, 2, 3, etc. For greater accuracy these spaces may be made shorter as they approach the ends of the base, where the line has more curve than near the middle. Having established the points 0, 1, 2, 3, etc., in K H, draw a line from each of them to the center of the plan M. By this means the quarter of the circle representing the top of the article, measurements, as shown at the right of C B, the hypothenuses of which will represent the real distances between the required points. Therefore from the points established in H K drop lines vertically cutting the section line* ADB, as indicated, then carry lines from the points on A D horizontally till they cut the line C E and continue them indefinitely to the right. The points at which these lines cross the center line E C will represent the bights of the several triangles. On these horizontal lines, measuring from the center line C E, which is assumed as the common perpendicular for all the tri- angles, set off the bases of the several triangles, trans- ferring the distances from the plan. From the points Fig. 662.— Top and Side View of Boss, Showing System of Triangulation. and shown in the diagram by P R, will be divided in the same manner or proportionately to the plan of the base, all as shown by points l 1 , 2 1 , 3', etc. It will be seen that these lines divide the surface of the boss into a number of four-sided figures, each of which must now be redivided diagonally so as to form trian- gles. Therefore connect with 1', 1 with 2 1 , etc., by means of dotted lines, as shown. These solid and dotted lines drawn across the top view represent the horizontal distances between the points given, while the vertical distances between the same can be measured on lines parallel to C E ; hence it will be necessary to construct a series of triangles from these thus established draw lines to E, which will give the hypothenuses of the several triangles. For example, on the line drawn from the point 5 2 , in A D B, meas- uring from C, set off a distance equal to 5 1 5 and also a distance equal to 6' 5 in the top view. The difference between these two is so small as to be im- perceptible in a drawing to so small a scale as this. In like manner, on the line drawn from 4 3 set off a distance equal to the length of the diagonal lines i 5 1 and 4 4 1 in the top view, and in the same manner on the line drawn through 3 2 set off the distance equal to 3 -i 1 in the top view and also 3 3\ Then, as before remarked, lines drawn from the points thus established Pattern Problems. 381 in the horizontal lines toward E will be the hypoth- enuses of the several triangles corresponding to sections represented by the diagonal lines in the top view. In view of the fact that the base of the boss is curved as shown by A D it will be noticed that the measurements from K to H in the top view do not represent the real distances, because the distance H M is less than the distance A D. In case extreme ac- curacy is required it will therefore be necessary to develop an extended section on the base line A D, which may be done as follows : Extend the line M H required width of the pattern on one end, as shown by Y 6' in Fig. 662. With these two points established proceed to obtain other points in both lines of the pattern by striking arcs with radii equal to the spaces established in the plan of both base and top of the article and to the hypothenuses of the triangles already described. Thus, from S as center, with radius equal to the distance 6 3 5 4 of the stretchout of the base, de- scribe a short arc, as shown at 5 in the pattern. Then from T as center, with radius equal to E 6' of the tri- angles, intersect it by a second arc, as shown. From T as center, with radius equal to 6 1 5' of the plan of T ' u Fig. 663.— Pattern for Boss. of the top view, as shown at the left, upon which place a correct stretchout of A D ; that is, make D 1 l 3 equal to D 1 J , I s 2 3 equal to V 2% etc., and through each of the points thus obtained draw measuring lines at right angles to D 1 M. Place the T-square parallel to H M, and, bringing it successively against the points in the line K H, drop lines into the measuring lines of cor- responding number, as shown by 4 , l 4 , 2 4 , etc. Then will the distances 0* l 4 , l 4 2 4 , etc., be the correct dis- tances to be used in developing the pattern instead of the distances 1, 1 2, etc. The pattern may now be developed as shown in Fig. 663. Lay off the line S T, in length equal to the the top of the article, describe a small arc, as shown, and from 5 of pattern as center, and radius equal to E 5' of the triangles, intersect it by another arc, thus deter- mining the second point in the top. Proceed in this manner, adding one triangle after another in the order in which they occur in the top view, using the spaces of the plan of top and of the stretchout of the bottom and the hypotheneuses of the triangles as above described. Lines traced through the points thus obtained, as shown from S to N and from T to M, will give the pat- tern of one-quarter. This can be duplicated as often as is necessary to make the entire pattern in one piece, or to produce it in halves, as shown. PROBLEM 204. Patterns for a Ship Ventilator Having; a Round Base and an Elliptical Mouth. In Fig. 664 are presented the front and side ele- vations of a ship ventilator of a style in common use. A 1 B : shows the section or plan of its lower piece A E F B, as well as of the pipe to which it is joined, while EOSP is the shape of its mouth, or a section upon the line C D. The curves E C and F D connecting the two ends of the ventilator and forming the general outlines of the same may be drawn at the discretion of the designer. As the ventilator is constructed after the manner of an elbow, it may be divided into as 382 Tlie New Metal Worker Pattern Booh. many sections or pieces as desired. Therefore divide the curved lines E and F D into the same number of spaces, and connect opposite points by straight lines, as shown hj G II, K L and M 1ST. These lines should be so drawn as to produce a general equality in the appearance of the different pieces without refer- ence to equality in the spaces in either outline. The next step is to establish a profile or section upon each one of these lines. These profiles can be drawn arbitrarily, but each should be so proportioned that the series will form a gradual transition from the circle A 1 B' to the ellipse E S P. All the profiles will, therefore, be elliptical, those nearer the mouth being more elon- gated than those nearer the base or neck. Since the lower piece is cylindrical and is cut obliquely by E F, the section at E F must neces- sarily be a true ellipse and can be developed by a method frequently explained in connection with various problems in the first section of this chapter, and as also explained in Geometrical Problem 68 on page 61. Of the remaining sections, their major axes are, of course, equal to the lengths of the lines G II, K L and M N, and their minor axes may be determined by any method most convenient, or in the following man- ner: Draw R U and S V, repre- senting a front view of the curved lines passing through the points n, m, Jc, g and e of the side view. From the points g, Jc and m project lines horizontally across to the front view, cutting the lines R U and S V and the center line T. Then f 1, do and b c will be respectively one-half the minor axes of the sections above referred to. With the major and minor axes of the several sections given, they may be drawn by any method producing a true ellipse, or in case the mouth has been drawn by means of arcs of circles the other sections may be drawn in the same manner. Each of the several pieces of which the ventilator is composed (except the lower piece) becomes, as will be seen, a transition piece between two elliptical curves not lying in the same plane, and in that respect is the same as the form shown in Problem 191. The pat- tern for each piece must, therefore, be obtained at a separate operation, that for the piece MNDC only being given. To avoid confusion of lines a duplicate of it is transferred to the opposite side of the front elevation, as shown by W Y Z X. Drop points from Y and Z perpendicular to the center line T of the elevation, thus locating the points M ! and N\ Make the distance tf c equal to b c. Then draw the ellipse Mr V W, which will be a front view of the sec- tion M 1ST of the side elevation. On a line parallel with Y Z construct the section M 1 Y N 1 , as follows : Let M' N 1 be equal to and opposite Y Z. Let the distance c' b' be equal to the distance c b of the see- ing!. 664. — Elevations and Sections of a Ship Ventilator. tion. With these points determined, draw through them the semi-ellipse M 1 5 1 N 1 . Divide the sec- tions M 1 S 1 N 1 and O S P into the same number of equal parts, as indicated by the small figures in the engraving. Drop the points 1, 2, 3, 4, etc., on to and perpendicular to the line Y Z ; thence carry them per- pendicular to the center line P of the front eleva- tion, cutting the section M" V W in the points l 2 , 2 3 , 3 2 , etc., thus dividing it into the same number of spaces as were given to the original section M 1 b 1 N 1 . Next connect the points of like numbers in the two sections of the front elevation by solid lines, thus: Connect 2 1 with 2% 3' with 3 s , 4 1 with 4 2 , etc. ; also connect the points 2 1 with V, 3 1 with 2% 4 1 with 3\ Pattern Problems. 383 etc., by dotted lines, all as shown in the engraving. These lines represent the bases of right angled tri- angles, whose altitudes may be measured on the hori- zontal lines cutting the lines W X and Y Z. The next step, therefore, is to construct diagrams of these triangles, as shown at A and B of Fig. 665. Draw any two horizontal lines as bases of the triangles, and erect the perpendiculars E C and F D. On both E C and F D set off the various bights of the tri- angles, measured as above stated and as indicated by the points 1, 2, 3, 4, etc. Next set off the length of the. bases of the triangles as follows: In diagram A, let C 1 equal the distance l 1 1~ of Fig. 664; make C 2 equal to 2 1 2 2 and C 3 equal to 3' o", etc. Connect the points in the vertical line with the points in the horizontal line of the same number, thus obtaining Fig. 665.— Diagrams of Triangles. hypothenuses of the triangles, or the true distance between the points l 1 1% 2 1 2 2 , etc., of the elevation. In diagram B, let the distances D 2, D 3, D 4, etc., represent the distances V 2 1 , 2 a 3 1 , etc., of the eleva- tion. Having located these points, connect 1 in the vertical line with 2 in the base ; also 2 in the vertical line with 3 in the base, and proceed in this manner for the other points. This will give the hypothenuses of the triangles, whose bases are l 2 2 1 , 2"- 3 1 , etc., in the elevation. Having thus obtained the dimensions of the vari- ous triangles composing the envelope of the first section of the ventilator, proceed to develop the pattern for it, as shown in Fig. 666. On any straight line, as C M, set off a distance equal to 1 1 in diagram A. From C as center, with radius equal to l 1 2 1 of the elevation, Fig. 664, draw an arc, which cut by another arc drawn from M as center, with radius equal to 1 2 of diagram B, thus establishing the point 2. From 2 as center, with radius equal to 2 2, diagram A, draw an arc, which cut with another arc drawn from l 1 as center, with radius equal to 1 2 of the elevation, thus estab- lishing the point 2\ Proceed in this manner, next locating the point 3, then the point 3 1 ; next the point 4, and then 4', etc. It will be noticed that, after C M Fig. 666.— Pattern of First Section of Ship Ventilator. passing points 6 and 6 1 , 7 1 is obtained before 7. This is for the sake of accuracy, as it will be seen by in- spection of the elevation that the distance V 6 1 is less, and therefore more accurately measured in the eleva- tion, than the distance from 6 2 to 7\ Having thus located the points 1, 2, 3, etc., I 1 , 2', 3 1 , etc., trace the lines C D and N M, and connect D with 1ST, as in- dicated in Fig. 666. Then DNMC will be the pattern for one-half the section M N D C of the eleva- tion. The pattern of the section E A B F will be the same as that for the corresponding piece in an ordinary elbow, and, therefore, need not be specially explained here. 384 Tlie New Metal Worker Pattern Book. PROBLEM 205. Patterns tor the Junction of a Large Pipe with the Elbows of Two Smaller Pipes of the Same Diameter. The elbows of the smaller pipes in the problem here presented are such as would, if each were com- pleted independently of the other, form six-piece elbows. The junction between the two elbows occurs between the fifth pieces, which pieces unite to form the transition from the smaller diameters of the elbows to the diameter of the larger pipe, or sixth piece. A pictorial representation of the finished work is. shown in Fig. 667, in which, however, the upper section, or larger pipe, is omitted to more fully show the shape and junction of the transition pieces. A front view or elevation of the various parts is shown in Fig. 668. The side view given in Fig. 669 shows more fully the amount of lateral flare of the transition piece necessary to form a union between the varying diameters of the larger and smaller pipes. The drawing of that portion of the elbows in the smaller pipes from the horizontal parts up to the line a h t in Fig. 668 is exactly the same as that employed in drawing a six-piece elbow. The piece A G h a, occupying the place of what would otherwise be the fifth piece of the elbow, becomes in this case an irregular shape, the lower end or opening, ah, of which is nearly circular while its upper end, A G, is a perfect semicircle. This piece unites with its mate GD(/i on the line G h, thus form- ing the complete circle at A D, a plan of which is shown immediately below the ele- vation. The relative proportion between the diameters of the larger and smaller pipes is such that the junction between the elbows is carried somewhat below the fifth pieces, mitering the fourth pieces for a short distance, as shown from h to L. The method of cutting the lower parts of the elbow, how- ever, is the same as that employed in all elbow patterns where the pipe is of a uniform diameter throughout, numerous examples of which are given in Section 1 of this chapter, to which the reader is referred. As the section or profile of all the parts forming the elbow is a perfect circle when taken at right angles to the sides of the pipe, as at Q F or M N", it will be seen that a section on the line a h will be somewhat elliptical ; it will therefore be necessary to obtain a correct drawing of this section from which to obtain the stretchout of the lower end of the piece A G h a, with which it joins, and also a drawing of it as it will appear in plan. Therefore between two parallel lines drawn from M and N at right angles to M N construct a profile or section, as shown below at the left, which divide into any convenient number of equal spaces, as shown by the small letters «, b, c, etc. From each of these points carry lines back to M N at right angles to the same, and continue them in either direction till they cut the miter line a n of the elevation, as shown by the small letters, and the center line a n of the section. From the points in a n of the elevation draw lines at right angles to the same indefinitely, as shown above the elevation, across which at any convenient point draw a line, as B 1 C, at right angles to them. From B' C set off on the lines last drawn distances equal to the distances from the circumference to the diameter on corresponding lines in the section below, all as shown by a', h", c 2 , etc. A line traced through Fig. 667. — Perspective View of the Junction of a Large Pipe with tne Elbows of Two Smaller Pipes. these points will be the correct section on the miter line a n. It will be noticed that the section has not been carried further than the point Ji ', the balance of the curve not being required by reason of its intersec- tion with the corresponding piece in the other elbow. Below the elevation and in line with the same, as shown by the center line G T, is drawn the plan of the larger pipe ABCD. It will be necessary to add to this the plan of the curve on the line a h of the eleva- tion, in order that the horizontal distances between the points assumed in the two curves may be accurately measured. Therefore from the points on the miter line a h drop lines vertically through the plan, cutting the transverse center line X Y. From X Y set off distances on these several lines equal to the distances Pattern Problems. 386 of corresponding points from the line anoi the original section, as shown by a, b', etc., from X to S. A line traced through these points will give the correct posi- tion of the intersection of the smaller pipe as seen from above. This entire line is shown in the plan, although the part from S to Z will not be required, for the reason given above. An inspection of the plan will show that the side of the plan from V T to the right would be an exact duplicate of the left side if it were completed, and that therefore the plan consists of four symmetrical quarters, one of which, X E T, is completely shown in the plan. Hence the pattern for this quarter will suffice by duplication for the entire transition piece. Divide the quarter of the plan of the larger pipe P T, adjacent to the curve X S, into the same number of equal spaces as are found in the inner curve from X to S, as shown by the small figures 1, 2, 3, etc. Connect corre- sponding points in the two lines as shown by the solid lines h' 8, g' 7, /' 6, etc. Next sub- divide the four-sided figures thus obtained by their shortest diagonal, as shown by the dot- ted lines g' 8,/' 7, etc. These solid and dotted lines across the plan represent the bases of a series of right angled triangles whose altitudes can easily be obtained from the elevation, and whose hj^pothenuses when obtained will give correct dis- tances across the finished piece between points connected on the plan. These lines have also been drawn across the ele- vation from corresponding points in the same for illustrative purposes, but such an operation is not neces- sary to obtain the pattern. Neither is the side view shown in Fig. 669 necessary to the work, but is here introduced merely to assist the student in forming a more perfect conception of the operations described. From the points a, b, c, etc. on the miter line a h of the elevation carry lines horizontally across, cutting the vertical line Gr L, as shown by the points from s to h. The distances of these points from Gr will then represent the vertical distances of corresponding points in X S of the plan from the plane of upper base of the transition piece shown by A D of the elevation and V P T of the plan. To obtain the hypothenuses of the various tri- angles above alluded to, or in other words, the true Fig. 668.— Front Elevation, Flan and Sections, Showing Method of Triangulation. lengths of the lines dividing the surface, as shown in the two elevations and plan, it will be necessary to construct a series of diagrams, as shown in Fig. 670. Therefore draw any two lines, as A 8 and h h', at right 386 The New Metal Worker Pattern Book. angles to each other ; make h 8 equal to h' 8 of the plan, Fig. 668, and h h' equal to h 8 of the elevation, and draw h' 8. Next draw any two lines, as g 8 and g g', at right angles to each other, making g 8 equal to the Fig. 669.— Side Elevation. dotted line g' 8 of the plan and g 7 equal to the solid line g' 7 of the plan. Make g g' equal to the distance of point g from the line A D as measured by its cor- responding point on the line L G. Draw g' 8 and g 7. So continue till all the triangles have been constructed. Then the solid hypothenuses will represent the true distances across the pattern indicated by the solid lines of the plan and elevations, and the dotted hypothenuses the true distances on corresponding dotted lines in make equal to the line 1 a' of the diagram of triangles, Fig. 670. From 1 as a center, with a radius equal to 1 2 of the plan, describe a small arc, which intersect with another small arc drawn from a as center, with a radius equal to a 2 of the diagram of triangles, thus locating the point 2 of the pattern. From point 2 as a center, with a radius equal to V 2 of the diagram of triangles, describe a small arc, which intersect with an- Fig. 671. — Pattern, for One-Quarter of Connecting Piece. other small arc struck from a of the pattern as center, with a radius equal to a 2 b 2 of the section on line a h of elevation shown above, thus establishing the posi- tion of the point b of the pattern. Proceed in this manner, using the spaces in P T in the plan of the larger pipe to form the upper edge of the pattern and the spaces from the section B 1 C to form the lower edge of the pattern, measuring the distances between the same by the alternate use of the solid and dotted hypothenuses of corresponding number and letter taken from the diagram of triangles in Fig. 670. A line traced through the two series of points and a straight line from S to h will complete the pattern for one- Fig. 670. — Diagram of Triangles. those views. In describing the pattern, work can be begun at either end of the pattern most convenient. Draw any straight line, as 1 a of Fig. 671, which quarter of the transition piece required. The remain- ing three-quarters can be obtained by any means of duplication most convenient. Pattern Problems. 3S7 PROBLEM 206. The Patterns for a Right Angle, Two-Piece Elbow, One End of Which is Round and the Other Elliptical. In Fig. 672, let A G C B II D represent the eleva- tion of elbow, A F D the half profile of elliptical end and CEB the half profile of round end. The first step will be to establish a section on the miter line G H. Since the width at A D, one-half of which is shown by K F, is greater than J E, one-half the width at C B, it is proper that the width at L should be a medium between the two. Therefore from K, on K F, set off the distance J E, as indicated by K to. Bisect F m in n, and take K n as the width at L. The section at G H will then be an ellipse, of which G~ H is the major axis and K n one-half of the minor axis. Fig. 672. — Elevation of Elbow, with Half Profiles of the Two Ends. In Fig. 673, AGHD is a duplicate of the part bearing the same letters in Fig. 672. Against A D is placed a half profile, A F D, of the elliptical end, while against G H is placed one-half of the elliptical section, constructed as above described and as shown by G L H. Divide G L H into any convenient num- ber of equal parts, and from the points thus obtained drop perpendiculars cutting G H, as shown. Also divide A F D into the same number of parts, and from the points thus obtained drop perpendiculars cutting A D. Connect the points in A D with those in G H, as indicated by the solid and dotted lines. The next step is to construct sections on each of the solid and dotted lines drawn across the elevation by means of which to obtain the true distances between the points in A D and those in G H as though meas- ured upon the finished article. In Fig. 674 is shown a diagram containing sections upon the solid lines, which is constructed in the followina; manner : Draw any two lines, as M N* and M P, at right angles to each other. Upon M 1ST set off the hights of the several points in the profile A F D; thus make M 13, M 12, M 11, etc., respectively equal to k 13, j 12, h 11, etc., of Fig. 673. Upon M P set off from M the lengths Fig. 67S. — Elevation of Lower Piece of Elbow, Shoioing Method of Triangulation. of the several solid lines of the elevation ; thus make M a, M b, etc., respectively equal to / a, g b, etc., of Fig. 673, and at the points a, b, c, etc., thus obtained, erect perpendiculars, each equal in hight to the hight of the corresponding point in the profile G L H of Fig. 673 from the line G H. Thus make a 2, b 3, etc., of the diagram respectively equal to 5 3, etc., of Fig. 673, and from the points 2, 3, 4, etc., thus obtained, draw solid lines to points 9, 10, 11, etc., in the lino M N, all as shown. Then the dis- tances 9 2, 10 3, 11 4, etc., will be the true lengths represented by corresponding solid lines drawn across the elevation. 388 Tlie New Metal Worker Pattern Book. The true distances represented by the dotted lines drawn across the elevation are obtained in the same manner by means of the diagram shown in Fig. 675. E S is drawn at right angles to R T and upon it are set off the hights of the points in A F D the same as in M N of Fig. 674. Upon R T set off from R the lengths of the several dotted lines drawn across the 11 t ! : J io, ix; 2 6 8,13 M a b c d e Fig. 674.— Diagram of Sections Upon Solid Lines of Fig. 673. elevation, as shown by corresponding letters, and from the points thus obtained erect perpendiculars also as in Fig. 674. Finally connect by dotted lines such points as correspond with those connected by dotted lines in the elevation. Thus from 9 in R S draw a line to point 1 in the base line, corresponding to the line / 1 of the elevation, Fig. 673. Lines from 10 to 2 and from 11 to 3 of the diagram will correspond respectively to g a and h b of Fig. 673. To develop the pattern from the dimensions now obtained proceed as follows : At any convenient place from H of pattern as center, describe an arc, which cut with another arc struck from point 9 of pattern as center, and 9 2 of Fig. 674 as radius, thus establish- ing point 2 of pattern. With point 2 of pattern as center, and 2 10 of Fig. 675 as radius, describe an arc, which intersect with another arc struck from point 9 of pattern as center, and 9 10 of profile as radius, u 10,12 0,13 --1 5 R lab c d e Fig. 675. — Diagram of Sections Upon Dotted Lines of Fig. 67S. thus establishing point 10 of pattern. With point 10 of pattern as center, and 1 3 of Fig. 674 as radius, describe a small arc, which intersect with one struck from point 2 of pattern as center, and 2 3 of G L H as radius, thus establishing point 3 of pattern. Continue this process, locating in turn the remaining points in pattern, as shown. Lines drawn through the points thus obtained, as indicated by G H and D A, will be one-half of the required pattern. The other half of the pattern can be obtained in a similar manner, or by tracing and transferring. The pattern for the li 13 12 11 .10 A Fig. 676. — Pattern for Lower Piece of Elbow. draw the straight line H D in Fig. 676, in length equal to H D of Fig. 673. From H of pattern as center, with radius 1 9 of Fig. 675, describe an arc, which intersect by a second arc struck from D as center, with radius D 9 of profile, thus establishing the point 9 of pattern. Then with radius H 2 of GLH, Fig. 673, other part of elbow, as shown in Fig. 672 by Gr C B H, can be obtained by the same method. The shape G L H of Fig. 673 is to be drawn to the left of the miter line G H, and the operation continued, using the same process, as shown in Figs. 674, 675 and 676. Pattern Problems. 389 PROBLEM 207. The Pattern for a Y Consisting of Two Tapering: Pipes Joining- a Larg-er Pipe at an Angle. In Fig. 677, BCDE represents the elevation of a portion of the larger pipe and 0' K D' L its profile. This pipe is cut off square at its lower end, with which the branches of the Y are to be joined. ABOHJ and G H E F are the elevations of the two similar branches joining each other from H to 0, and the larger Fig. 677.— Elevation, and Profiles of Y with Tapering Branches. pipe on the line BE. A' N J' M is the profile of one of the tapering branches at its smaller end. Since the article consists of two symmetrical halves when divided from end to end on the lines A' J' or C D' of the profiles, and since the two branches are alike, the pattern for one-half of one of the branches, as A B O H J, is all that is necessary. The dividing surface ABOHJ, lying as it were at the back of the half of the branch shown in eleva- tion by the same letters, will then form a plane or base from which the nights or projection of all points in the surface of the branch piece can be measured. As the branch piece A B H J is an irregular tapering form, its surface must be divided into a series of measurable triangles before its pattern can be ob- tained. Therefore divide the half profile C L D' into any convenient number of equal parts — in the present instance six, as shown by the small letters/^ hj k — and from these jDoints drop lines parallel with C B, cutting the line B E, as shown. In a similar manner divide the half profile A' N" J' into the same number of equal Fig. 67S. — Elevation of One Branch of Y, Showing Method of Triangulation. parts as was C L D', as shown by the small letters a b c d e. From the points thus obtained carry lines par- allel with J' J, cutting A J. Connect the points in A J with those in B E, as shown. To avoid a confusion of lines the subsequent oper- ations are shown in Fig. 678, in which A B H J is a duplicate of the piece bearing the same letters in Fig. 677. The profiles B L E and A 1ST J are also dupli- cates of those shown in Fig. 677 and are for conven- ience here placed adjacent to the lines which they rep- resent. B L of the upper profile then represents a section on the line B 0, and A 1ST J that upon the line A J, but the section on the line H, the miter be- tween the two branches, is as yet unknown- To obtain this it will be necessary to first obtain sections upoa 390 Tlie New Metal Worker Pattern Booh. the various lines drawn across the elevation from B E to A J in Fig. 678, or in other words, diagrams upon which the true lengths of those lines can be measured. In the diagram of sections shown in Fig. 679 S—— — 9 J, 1 ' f. 1 a 1 1 1 Fig. 680. Diagrams of Sections Upon Solid Lines of the Elevation. S T represents the dividing surface or base plane al- luded to above and is made equal in length to 2 2' of Fig. 67S. At either extremity of this line erect the perpendiculars Si and T/, as shown. Make T/ equal in bight to 2' /of profile B L E, and upon S b set off from S the hight S a, equal to 2 a of the profile A N J, and draw the line a f. On S T, measuring from T, set off the distance 2' 2", and erect the perpendicular 2" f", cutting af at /". Then will a f represent the true distance between the points 2 and 2' in Fig. 678, and af" will represent the true distance from 2 to 2", Fig. 681. df u T 6' 5' V Fig. 682. Diagrams of Sections Upon Dotted Lines of the Elevation. while 2" /" will be the hight of the point 2". In a similar manner set off from S, on S T, a distance equal to 3 3' of Fig. 678 and erect the perpendicular 3' g, equal in length to 3' g of profile B L E. - Make S b equal to 3 b of profile ANJ and draw b g. From S set off on S T a distance equal to 3 3" of Fig. 678 and erect the perpendicular 3" g", cutting b g at g" . Then will b g be equal to the true distance between 3 and 3' of Fig. 678, b g" will be the true distance from 3 to 3" of Fig. 67S and 3" g" will be the hight of the point 3". To construct the section on the line H, at points 3" and 2" draw 3" g' and 2"/' at right angles to O H, making them respectively equal 3" g" and 2" /" of Fig. 679. As the profile B L E is a semicircle the hight of point •i' — that is, i' h — is equal to E ; therefore through the points E, g', f and H draw the curve shown, which will be the true section on line H, from which the stretchout can be taken for that portion of the pattern. The sections on the remaining' lines (i 4', 5 5' and 6 6') of the elevation are shown in Fig. 680 and are constructed in exactly the same manner as those shown in Fig. 679, giving c h, dj and e k as the true lengths Pattern of Tapering Branch. of those lines. Before the pattern can be developed the four-sided figures into which the surface of the branch pipe has been divided by the solid lines must be subdivided into triangular spaces, as shown by the dotted lines in the elevation. Sections upon these lines must also be constructed, in order that their true lengths can be obtained. These are shown in two groups in Figs. 681 and 682 and are constructed in a manner exactly similar to that described in connection with Fig. 679. They may be easily identified by cor- respondence between the figures on the base lines U V and W X and those of the elevation. To describe the pattern proceed as follows : Draw any line, as J H in Fig. 683, in length equal to J H of Fig. 678. With J of pattern as center, and J' a of smaller profile as radius, describe a small arc (a), which Pattern Problems. 391 cut with one struck from H of pattern as center, and 1" a of Fig. 681 as radius, thus establishing the point a of pattern. With a of pattern as center, and a f" of Fig. 679 as radius, describe another small arc (/'), which intersect with one struck from H of pattern as center, and H/' of profile H E as radius, thus estab. lishing the point /of pattern. In a similar manner, a b of pattern is struck with a b of profile as radius ; /' b of pattern with/" b of Fig. 681 as radius; b g' of pat- tern with b g" of Fig. 679 as radius, and/' g' of pattern with/' g' of profile HE as radius; also, b c of pattern is struck with b c of profile as radius ; g' c of pattern with g" c of Fig. 681 as radius ; g' h of pattern with g E of profile as radius, and c h of pattern with c h of Fig. 680 as radius. Thus are the points established in O H J P of pattern. B P A of pattern corresponds with B P A of elevation and is obtained in the same manner. The points in B of pattern are derived from profile L B, as are the points in P A of pattern from N A of small profile. The lengths of solid lines in pattern are ob- tained from the diagram of sections in Fig. 680, as are those of the dotted lines from the diagram of sections in Fig. 682. Lines drawn through the points in B II J P A, Fig. 683, will be the half pattern for ABO H J of elevation. The other half of pattern, as shown by A J' H' 0' B, can be obtained in a similar manner or by duplication. PROBLEM 208. Pattern for a Three-Pronged Fork With Tapering Branches. In Fig. 684 is shown a pictorial representation of a fork, or crotch, consisting of three branches of equal size and taper; all uniting so as to form one round pipe. In the plan, Fig. 685, ABC represents the base of article or size of the large pipe and B D E C G one of the tapering branches. The other branches are partly shown in plan by A G C S T and AUYBS. Fig. 684- — Perspective View of Three-Pronged Fork with Tapering Branches. In the elevation the branch is shown by J K L M N and the half profile of small end by K E, L. An inspection of the engraving will show that the perimeter of the larger end of the branch must be di- vided into three parts, two of which form the joints or -connections with the branches on either side of it while the third part must form one -third of the base or circumference of the large pipe with which it is to be united. In the elevation P M represents the plane of the base or upper end of the round pipe of which A B C is the profile or plan, and J is assumed as the hight of the central point at which all the branches meet. From J of the elevation or G of the plan to either of the three points A, B or C any suitable curve may be chosen as the profile upon which to make a joint or miter between adjacent branches. As J is equal to G A or G C, a quarter circle is assumed as the most suitable curve ; therefore from as a center de- scribe the quarter circle P J of the elevation, corre- sponding with A G of the plan. In order to complete the elevation of the branch J K L M N, it will be necessary to obtain the elevation of the miter line G C. Therefore divide P J into any convenient number of equal parts, as shown by the small figures, and from the points thus obtained carry lines to the right paral- lel with P M. From G, on G C, set oil spaces equal to the distances from the points in P to the line O J, as shown, and from the points thus obtained in G C erect perpendiculars cutting lines of similar number drawn from P J. A line traced through these points of intersection, as shown by J N, will give the miter line in elevation corresponding with G C of the plan. Divide C H of the plan into the same number 392 Tlie New Metal Worker Pattern Book. of equal parts as P J of the elevation, and from the points thus obtained erect perpendiculars cutting N M. Divide K E L, the profile of the smaller end of the branch, into the same number of equal parts as the larger end — that is, as many as are found in J N M — and from the points of division drop lines perpen- dicular to K L, cutting the same. Connect points in K L with those in J N M by solid and dotted lines in the manner shown in the drawing. Upon all of these lines it will be necessary to construct sec- tions in order to obtain the true dis- tances as if measured upon the surface of the branch. As each of the branch pipes consists of symmetrical halves when divided by the line Gr F of the plan half sections only need be con- structed, all projections being measured from the dividing plane represented by G F in the plan and shown in eleva- tion by JKLM N. In Fig. 6SG are shown the sec- tions having for their bases the solid lines of the elevation, which are con- structed in the following manner : Upon any horizontal line, as P Q, set off from P the lengths of the several solid lines of the elevation, as indicated by the small figures corresponding with those in JN M. At P, which corre- sponds with all the points in K L of the elevation, erect a perpendicular, P H, upon which set off the bights of the points in K R L, as 2' 2, 3' 3, etc., shown by P 2, P 3, etc. At each of the points near Q erect a perpendicu- lar, which make equal in hight to the length of line drawn from the point of corresponding number in G C H of the plan to the line G H. Thus make 9' 9, 10' 10, etc., equal to 9" a, 10" b, etc., of the plan. From the points 9, 10, etc., draw solid lines to the points in H P, connect- ing points correspondingly connected by the solid lines of the elevation. The sections having for their bases the dotted lines of the elevation are shown in Fig. 687, and are constructed in exactly the same manner. Upon Y Z, set off from Y the lengths of the clotted lines of the elevation, numbering the points near Z to correspond with those in JNM of the elevation. The perpendiculars erected from these points are the same as those similarly located in Fig. 6S6, and the perpendicular X Y is a duplicate of H P of Fig. 6S6. From the points 9, 10, 12, etc., draw clotted lines to points in X Y, connecting points correspondingly con- nected b} r dotted lines of the elevation. To describe the pattern shown in Fig. 6SS pro- ELEVATION J Fig. (JS5. — Plan and Elevation of Three-Pronged Fork. ceed as follows : Draw any line, as J K, in length equal to J K of elevation, Fig. 685. With K of pat- tern as center, and K 2 of profile as radius, describe a small arc (2), which cut with one struck from J of pattern as center, and 8' 2 of Fig. 687 as radius, thus establishing point 2 of pattern. With point 2 of pat- tern as center, and 9 2 of Fig. 686 as radius, describe another small arc (9), which intersect with one struck Pattern Problems. 393 from J of pattern as center, and J 9' of elevation as radius, thus establishing the point 9 of pattern. Pro- Fig. 686. — Diagram of Sections Upon Solid Lines in J K L M N of Fig. 6S5 ceed in this manner until the remaining points are located, all as clearly indicated by the solid and dotted lines in Fig. 688. By drawing lines through the 13 35 26 8'12')13' ' 10 /u Fig. 6S7 .—Diagram of Sections Upon Dotted Lines in J K L M N of Fig. 6S5. points thus obtained the half pattern shown by K Q LMN J is the result. The other half, as shown by N li J s fr Fig. 688.— Pattern of Tapering Branch. K Q' 1/ M' 1ST J, can be obtained in a similar maDner, or by duplication. PROBLEM 209. The Pattern for an Offset to Join an Oblong Pipe With a Round One. In Fig. 6S9, B C F Gr represents the side elevation of the offset, ABGHa portion of a round pipe join- ing it below, and C D E F a portion of the oblong pipe joining it above. In the plan immediately below, JKLM shows the plan of the round pipe and 1ST P QES that of the oblong pipe, while the distance L T shows the amount of the offset. The piece forming the offset is similar in shape to that shown in Problem 189, the difference being that its bases B Gr and C F are neither horizontal nor parallel to each other and that sections on the lines of the bases are not given. Since the article required consists of symmetrical halves when divided on . the line J T of the plan, the plane surface ABCDEFGH lying as it were back of the half shown by the eleva- tion may, as in Problem 207, be regarded as a base from which to measure all bights, or projections, in obtaining the required profiles and sections necessary in developing the pattern. The first steps necessary will be to obtain true sections upon the lines C F and B Gr of the elevation. In Fig. 69 0, CDEF rep- resents a duplicate of the part bearing the same letters in the elevation. Upon D E as a base line construct a duplicate of the half section of oblong pipe NOPT of Fig. 689, as shown by D N" P E. Divide the semicircle 1ST P- into any convenient number of equal parts, as shown by the small figures. With the blade of the T-square placed at right angle? 39i Tlie New Metal Worker Pattern Book. toDE, drop lines cutting C F. With the T-square placed at right angles to G F, and brought against the points in C F, draw lines, extending them indefinitely, as shown. Measuring in each instance from C F, set off on the lines just drawn the same length as similar lines in D K P E, and through the points thus ob- Fig. 6S9.—Plan and Elevation of Offset. tained trace a line, as shown by n Op. Then CFj) O n is the half shape of cut on line C F. In Fig. 691, A B G H is a duplicate of the elevation of the round pipe, below which is drawn a half profile of same, A M H. To obtain the shape of cut on line B G, divide the half profile A M H into the same number of parts as was N P, and, with the T- sc L uare placed parallel with A B, and brought successively against the points in A M H, carry lines cutting B G. With the T-square placed at right angles to B G, and brought against the Fig. 690. — Development of Section on Line C F of Elevation. points therein contained, erect perpendiculars, as shown. Measuring in each instance from B G, set off on the lines just drawn the same length as similar lines in A 14 h Fig. 691. — Development of Section on Line B G of Elevation. M H, and through the points thus obtained trace a line, as shown by B on G. Then B in G is the half shape of cut on line B G. In order to avoid a confusion of lines a duplicate Pattern Problems. 395 of B C F G of the elevation is presented in Fig. 692, upon C F and B G of which, as base lines, are drawn duplicates of the sections obtained in Figs. 090 and 691, all as shown. From points in n 0^9 drop lines at right angles to C F, cutting the same, and from points in B m Gr drop lines at right angles to B Gr, cutting it. Connect points in these lines in consecutive order by solid lines, as shown, and subdivide the four sided figures thus obtained by dotted lines representing their shorter diagonals. The surface of the offset or transi- tion piece is thus divided into a series of very tapering- triangles, the lengths of whose bases or shortest sides Fig. 692. — Middle Piece of Offset, Showing Method of Triangulation. are given in the two sections C nOjjF and B m G. In order to obtain the correct lengths of their longer sides two diagrams or series of sections must be con- structed for that purpose, which are shown in Figs. 693 and 694. To obtain the various sections on the solid lines of the elevation proceed as follows : Draw the right angle UTW, Fig. 693. From V, on V U, set off the length of lines in B m Gr, Fig. 692. From V, on V W, set off the length of solid lines in B C F G, and from the points thus obtained erect perpendiculars, in length equal to lines of similar number in C n p F, Fig. 692. Thus make line W V of Fig. 693 equal to line C n or C 1, and draw VI', which gives the distance from point B to point n in Fig. 692 as if measured on the finished article. Connect the perpen- diculars drawn from V W with the points in V U, as shown, and corresponding with the figures in Fi°\ 692. Thus connect 1' and 8, 2' and 9, 3' and 10, etc. Then 7 6 5 4 3 2 1V/' Fig. 693.— Diagram of Sections on Solid Lines of Fig. 692. will the lengths of the oblique lines in Fig. 693 be the true lengths of the solid lines crossing the elevation. The diagram of sections shown in Fig. 694 is con- structed in the same manner, using the dotted lines of the elevation as the basis of measurements. Draw the right angle X Y Z, and from Y set off on Y Z the length of lines in G n p F. From Y, on Y X, set off the length of dotted lines in B C F G, and from the points thus obtained erect perpendiculars, in length equal to lines of similar number in B m G, as indicated by the small figures. Connect the perpen- diculars drawn from X Y with the points in Y Z, as shown, and corresponding with the figures in B C F G. Thus connect 1 and 9', 2 and 10', 3 and 11', etc. Z 4 ^«=^=^~ n lo'r — '-», 1112 j^ 13| I 14 2-6 1-7 Fig. 694. — Diagram of Sections on Dotted Lines of Fig. 692. An inspection of the plan and elevation, Fig. 689, will show that the curved surface of the offset or transi- tion piece B C F G, which has been divided into tri- angles, is shown by J M L Q R S of the plan, and that this piece is connected with its mate or equivalent in 396 Trie Neiv Metal Worker Pattern Book. the opposite half of the article by a large plain trian- gular surface, S J 1ST, on the upper side, and by another, Q L P, on its lower side, which must be added to the pattern of the curved portion after it has been de- veloped. It will also be seen that V W 1' of Fig. 693 is one-half of J N" S. Therefore to develop the pattern, first draw any line, as j x in Fig. 695. in length equal to B C of Fig. 689, or V W of Fig. 693. With j as center, and 1' V of Fig. 693 as radius, describe a small arc (near s), which intersect with another small intersect with another small arc struck from point 1 of pattern as center, and a radius equal to 1 2 of the pro- file C n p F of Fig. 692, thus establishing the position of point 2 of pattern. Proceed in this manner, using the dotted oblique lines in Fig. 694, the lengths of the spaces in B m G in Fig. 692, the lengths of the solid oblique lines in Fig. 693 and the lengths of the spaces in C n p F of Fig. 692 in the order named until the line 7 1-t is reached. Lines traced through the points of intersection from j to I and from s to t will give the Fig. 695.— Pattern of Offset. arc struck from x as center, and with a radius equal to W V of Fig. 693, thus duplicating the triangle V W 1'. From s, or point 1, as center, with a radius equal to 1 9' of Fig. 694, describe a small arc (near 9), which intersect with another small arc struck from j or 8 of pattern as center, with a radius equal to 8 9 of the pro- file B m G, Fig. 692, thus establishing the position of point 9 of pattern. From 9 as a center, with a radius equal to 9 2' of Fig. 693, describe a small arc, which shape of the curved portion of the pattern. From 14 of pattern as center, with a radius equal to G F of Fig. 692, or V 7 of Fig. 693, describe a small arc, which intersect with another small arc struck from point 7 of pattern as center, and a radius equal to 7 7' of Fig. 693, or T P of the plan. Draw 7 t and t I; then will I j x s g t he one-half the pattern required. The other half can be obtained by any means of duplication most convenient. PROBLEM 210. Pattern for an Offset to Join a Round Pipe with one of Elliptical Profile. This problem differs from the preceding one only in the shape of the pipe having the elongated profile, which profile in the preceding problem consists of two semicircles joined by a straight part, whereas in this case its curve is continuous throughout; its pattern therefore will consist throughout of a series of triangles Pattern P ruble ms. 397 having short bases instead of having; a large flat trian- gular surface uniting its curved portion as in the pre- vious case. In Fig. 696, DCB A represents the elevation of the offset, CFE B that of a portion of the round pipe with which it is required to connect at its upper end Fig. 696. — Elevation and Sections of Offset, Showing Method of Triangulation. and HDAG that of the elliptical pipe joining it be- low. MPNis the half profile of the round pipe and K J L that of the elliptical pipe. The plan or top view is not shown, and is not necessary to the work of obtaining the pattern. Since the profiles given neces- sarily represent sections on lines at right angles to the respective pipes, as at F E and H G-, it will first be necessary to derive from them sections on the joint or miter lines C B and D A, from which to obtain correct stretchouts of the two ends of the pattern of the offset piece. As the pattern required consists of symmet- rical halves, one-half only will be given, and one-half of the profiles only need be used. Therefore divide the half profile M P 1ST into any convenient number of equal spaces, as shown by the small figures, and from the points thus obtained draw lines at right angles to F E, cutting M 1ST and C B. To avoid confusion of lines a duplicate of C B is shown at the left by C 1 B 1 . From the points on C B 1 draw lines at right angles to it indefinitely, and upon each of these lines, measuring from C B', set off the lengths of tines of corresponding number in the profile M P N measured from M N. Thus make the distance of point 2' from C 1 B 1 equal to the distance of point 2 from line M N, the length of line 3' equal to that of line 3, measuring from the same base lines as before, etc. A line traced through the points of intersection, as shown by C 1 B 1 , will be the correct section on the line C B of the elevation. The method of obtaining the section on the line D A, shown at D 1 I A 1 , is exactly the same as that just described in con- nection with the round pipe, all as clearly shown in the lower part of the engraving. The next operation will consist of dividing the surface of the transition or offset piece into measurable triangles, making use of the spaces used in the profiles ; therefore connect points in C B with those of similar number in D A by solid lines, as 1 with 1', 2 with 2', etc., and connect points in C B with those of the next higher number in D A by dotted lines, as 1 with 2', 2 with 3', 3 with 4', etc. The surface of the transition piece is thus divided into a series of triangles the lengths of w T hose bases or short sides are found in the two sections C 1 B 1 and D 1 I A 1 . As the bights of corresponding points in the two sections, measuring from their center or base lines, differ very materially, it will be necessary to construct two diagrams of sections from which the lengths of the various solid and dotted lines can be obtained. In Fig. 697 is shown a diagram of sections through A B C D taken on the solid lines drawn across the eleva- tion, in which the base line P Q represents the sur- face of a plane dividing the offset into symmetrical halves. At P erect a perpendicular, P R, upon which set off the hight of the points in the profile K JLor the section D 1 I A 1 , measuring upon the straight lines joining them with the base line K L, as shown by the small figures. From P, upon P Q, set off the lengths S9S Tlie New Metal Worker Pattern Booh. of the various solid lines drawn across the elevation, also shown by small figures, and at each of the points thus obtained erect a perpendicular, which make equal in hight to the distance of point of corresponding num- ber in profile M P N from M N, measuring on the per- pendicular line. Thus, make line 2 of Fig. 697 equal Fig. 697 .—Diagram of Sections on Solid Lines of Elevation. in hight to the distance from point 2 of profile to the line M N, line 3 equal to the length of line 3 of profile M P N. Now connect points of corresponding num- ber at the two ends of the diagram by straight lines, as shown, then will these oblique lines be the correct distances between points of corresponding numbers connected by the solid lines drawn in the elevation. The diagram in Fig. 69 S is constructed in an ex- actly similar manner. The distances S 1, S 2, S 3, etc., on the base line are in this case made equal to the lengths of the dotted lines of the elevation, and the Fig. 69S. — Diagram oj Sections on Dotted Lines of Elevation. perpendiculars erected at points 2, 3, etc., are the same as those used in the previous diagram. The per- pendicular S U is also an exact duplicate of P E in Fig. 697. In drawing the oblique dotted lines, point 1 at the right end of the diagram is connected with that of the next higher number (2') on the line S U, 2 at the right with 3' on the line S U, etc., all as shown. The oblique dotted lines will then be the correct dis- tances between points of corresponding numbers con- nected by the dotted lines in the elevation. To develop the pattern, first draw any straight line, as D C in Fig. 699, which make equal in length to DC of Fig. 696. From D as center, with a radius equal to 1 2 of the section D' I A 1 , strike a small arc, which intersect with another small are struck from G as center, with a radius equal to 2' 1 of Fig. 698, thus establishing the location of point 2' of pattern. From 2' of pattern as center, with a radius equal to 2' 2 of Fig. 697, strike a small arc, which intersect with an- \0B Fig. 699.— Half Pattern of Offset Piece. other small arc struck from C of pattern as center, and a radius equal to 1 2 of section C B 1 , thus establish- ing the position of point 2 of pattern. So continue, using alternately the dotted and the solid oblique lines in Figs. 6.9S and 697 to measure the distances across the pattern, the spaces from the section D 1 I A 1 to form the stretchout of the lower end (D A) of pattern, and the spaces from the section C 1 B 1 to form the stretchout of the upper end (G B) of the pattern. Lines traced through the points of intersection, as from C to B and from D to A, will complete one-half the required pattern. Pattern Problems. PROBLEM 211. The Patterns for a Funnel Coal Hod. 399 In Fief. 700 are shown the drawings for a funnel coal hod of a style in general use. In preparing such a set of drawings it is necessary that care should be taken to have a correspondence of all the principal here constructed in two pieces, the front being in one piece joined together on the line B C of the elevation or B' 2 C 3 of the plan, and joined to the back piece on the line II D. As will be seen by an inspection of Fig. 700 — Plan, Elevation and Sections of a Funnel Coal Hod, Showing Method of Triangulation. parts in the two views, as shown by the dotted lines, leaving the final drawing of the curves to be more accurately performed as circumstances may require in subsequent parts of the work. The design is capable of any degree of modification so far as the proportions of its parts are concerned without in the least affect- ing the method of obtaining its patterns. Thus, hights, lengths, diameters or curves may be changed at the discretion of the designer. The coal hod is the elevation, the front piece consists of a flat tri- angular piece, H J D, joined to two irregular flaring pieces, A J II G and B J D C. On account of the taper or slant of the flat portion of the front piece, as shown by J 2 D = of the plan, the line D~ IF has been drawn somewhat obliquely from X, the center of the bottom, instead of at right angles to A 2 E\ The section at A B is assumed to be a perfect circle and should be drawn exactly opposite, as 400 The New Metal Worker Pattern Book. shown, its vertical centsr line A 1 B 1 being placed parallel to A B. Divide each quarter of this, as A 1 J' and J 1 B l , into any number of equal spaces, as shown by the small figures, and through the points thus ob- Q b i U u Fig. 701.— Diagram of Sections on Solid Lines in A J H G of Fig. 700. tained draw lines cutting A 1 B 1 and A B. From J, the middle point on A B, draw lines to D and to H. Also divide H' G 1 of the plan into the same number of equal spaces as A 1 J 1 , numbering the points to cor- respond. From the points thus obtained erect lines perpendicularly, cutting G H of the elevation. Con- nect points of like number on A J and G H, as 5 with. 5, 6 with 6, etc., by solid lines, as shown; also, con- nect each point on A J with that of next higher number on G II by a dotted line, as 5 with 6, 6 with 7, etc. These solid and clotted lines just drawn are the lines upon which measurements are to be taken in obtaining the pattern, and upon which sections must 5 s 6 7 8 9 ,u 7 9S 7 6 Fig. 70S.— Diagram of Sections on Dotted Lines in A J H G of Fig. 700. be constructed before their true lengths can be ob- tained. In Fig. 701 are shown the sections having the solid lines in A J II G as their bases, which are con- structed in the following manner : Draw any right angle, as P Q R. Upon P Q set off the hights of the several points in the section A' J' from the line A' B 1 , as measured upon the straight lines joining them with A 1 B 1 ; thus make Q 5 and Q 6 equal to the distance of points 5 and 6 from the line A 1 B 1 . From Q on Q B, measuring from Q, set off the lengths of the several solid lines in A J H P, as indicated by the small figures, and from the points thus obtained erect perpendiculars equal in hight to the length of lines drawn from points of corresponding number in G 1 H 1 of the plan to the line G 1 X ; thus make the perpen- diculars at points 5', 6', etc., equal to the length of the lines drawn from points 5 and 6 in G 1 H 1 to G' X. Connect the points thus obtained with points of cor- responding number in P Q. The oblique lines thus obtained will be the true distances represented by lines of corresponding number in the elevation. The diagram in Fig. 702 shows the sections upon the dotted lines in A J H G and is constructed in the same man- ner. Upon T U, measuring from T, are set off the lengths of the several dotted lines. S T is the same as P Q of Fig. 701, and the perpendiculars at U are equal to' those of corresponding number in Fig. 701. Points in S T are then connected with the perpen- diculars of next higher number by dotted lines, which L 23 4 s Fig. 70S.— Diagram of Sections on Solid Lines in J B O D of Fig. 700. give the true lengths represented by the dotted lines of the elevation. That portion of the front piece shown by J B C D of the elevation must be triangulated in exactly the same manner as the portion just described, and sec- tions constructed upon the several solid and dotted lines there drawn, as shown in Figs. 703 and 701. However, as no outline is given in either the plan or the elevation from which a correct stretchout of C D can be obtained, a section must be constructed for that purpose, which can be done in the following manner : First draw C M 1 as the vertical center line of a rear ,Y - W IS 3 4 Fig. 704.— Diagram of Sections on Dotted Lines in J B C D of Fig. 700. elevation. From points C and D project lines hori- zontally to the right, cutting C M 1 at C and M. Upon D M, measuring from M, set off half the width of the front piece at D" of the plan; that is, make M D' Pattern Problems. 401 equal to M 2 D\ Any desirable curve may then be drawn from D 1 to C, representing the rear elevation of curve represented by D G of the side elevation. As the distance from C to D is much greater than C 1 M, an extended profile, as measured upon C D, must now be developed from which to obtain a correct stretch- out of that portion of the pattern. Therefore divide the curve C 1 D 1 into the same number of parts as the quarter circle B 1 J 1 , and from the points thus obtained cany lines horizontally to the left, cutting C D. Upon C M extended, as C a M 1 , set off spaces equal to those in C D, as shown, and through Fig. 70 J. — Half Pattern of Froyit Piece of Funnel Coal Sod. the points thus obtained draw lines to the left indef- initely. From the points in C D 1 drop lines verti- cally, cutting those just drawn, all as shown. A line traced through the points of intersection, as shown from D 2 to C 2 , will give the desired stretchout. In dividing the curve C D 1 into spaces it is advisable to make those nearest to D 1 less than those near the top of the curve in oixler to compensate for the increase in the spaces in C" M 1 as they approach the bottom ; thus obtaining a set of nearly equal spaces upon the final profile D 2 (J 2 , all of which will appear clear by an inspection of the drawing. As above stated, the diagrams of sections in Figs. 703 and 704 are constructed in the same manner as those of Figs. 701 and 702. The bights in K L aud V AV are taken from J' B 1 of Fig. 700 and are the same as those in P Q and S T of Figs. 701 and 702. The distances upon L N and "W Y are those of the solid and dotted lines in J B C D of Fig. 700, and the bights of the perpendiculars near N and Y are equal to the lengths of the lines drawn from points of cor- responding number in the profile D 2 C 2 of Fig. 700 to the lines C 2 M 1 . To develop the pattern of the front piece, first draw an)- line, as A G in Fig. 705, equal in length to A G of Fig. 700. From G as a center, with a radius equal to the dotted lines 9 8 of Fig. 702, describe a short arc (near S), which intersect with another arc drawn from A as center, with a radius equal to 9 8 of the section A 1 J 1 B 1 of Fig. 700, thus establishing the position of point 8 in the upper line of the pattern. From 8 of the pattern as center, with a radius equal to 8 S of Fig. 701, describe a short arc (near 8'), which intersect with another arc drawn from G of the pat- tern as center, with a radius equal to 9 8 of the plan, Fig. 700, thus establishing the point S' in the lower line of the pattern. Continue in this manner, using the lengths of the oblique clotted lines in Fig. 702 in connection with the spaces in the section A' J 1 B' of Fig. 700 as radii to determine the points in the upper line of the pattern, or the side forming the mouth, and the lengths of the oblique solid lines of Fig. 701 in connection with the spaces in the plan of the bottom (G 1 H 1 ) as radii with which to determine the points in the lower line of the pattern or the side to fit against the bottom. Having reached the points 5 and 5', next add to the pattern the flat triangular surface shown by J II D of the elevation. From II (5') of the pattern as center, with a radius equal to 5 5 of Fig. 706, the Side of the last triangle in the pattern of the back piece, describe a short arc (near D), and intersect the same with another arc struck from J (5) of the pattern as center, with a radius equal to the oblique line 5 5 of Fig. 703, and draw II D and D J. Using D J of the jjattern as one side of the next triangle, take as radii the dis- tances 5 4 of Fig. 701 and 5 1 of the section D 2 C 2 of Fig. 700 to locate the position of point 1' of the pat- tern, as shown in Fig. 705. With 1 4 of Fig. 703, and 5 4 of the section B' J' of Fig. 700 as radii locate the point 4 of the pattern, as shown, and so continue until C D is reached. Lines traced through the points of intersection from B to A, C to D and H to G will complete the pattern of one-half the front piece. 402 Tlte New Metal Worker Pattern Book. The method of triangulating the piece forming the back of the coal hod and the development of the pattern of the same are so clearly shown in Figs. 706, 707 and 70S, in addition to the plan and elevation, Fig. 700, as to need only a brief description. Divide H 1 F 1 and D" E 2 of the plan, Fig. 700, into the same Fig. 706. — Diagram of Sections on Solid Lines in D E F H of Fig. 100. number of equal parts, and from the points thus ob- tained erect lines vertically cutting the corresponding lines H F and D E of the elevation, as shown by the dotted lines. Connect points of like number in that view by solid lines and points in D E with those of next lower number in H F by dotted lines. Since D E, being inclined, is longer than M a E 2 , its equivalent in the plan, it will be necessary to develop an ex- tended section upon the line D E of the elevation, as shown by D 5 E 3 of the plan, which may be clone in the same manner as the section on the line C D above explained. Upon M a E 2 extended, as E 2 E 3 , set off the i . 2 4 3 2 1 5' Fig. 707.— Diagram of Sections on Dotted Lines in D E F H of Fig. 700. spaces in D E, and through the points thus obtained draw lines at right angles, as shown, which intersect with lines drawn parallel with M 2 E 3 from points of corresponding number in D 2 E 2 , thus establishing the curve D 5 E 3 , from which a correct stretchout of the top of the back piece may be obtained. In Figs. 706 and 707, the hights of the various points upon the perpendiculars from X and Z are equal to the lengths of the straight lines drawn from points of corresponding number in H' F 1 of the plan, Fig. 700, to the line M 2 F'. The distances set off to the right upon the horizontal lines from X and Z are equal to the lengths of the several solid and clotted lines in D E F H of the elevation, and the hights of the per- pendiculars at the right ends of the bases are equal to the straight lines drawn from points in the section D 5 E 3 to the line E 2 E\ The several oblique solid and dotted lines are, therefore, the true distances repre- sented by the solid and dotted lines of corresponding number in the elevation. Fig. 70S. — Half Pattern of Back Piece of Funnel Coal Hod. In Fig. 70S, E F is equal to E F of Fig. 700 and is made the base of the first triangle, from which base the several triangles constituting the complete pattern may be developed in numerical order and in the usual manner from the dimensions obtained in Figs. 706 and 707 and in the plan and section in Fig. 700, all as clearly indicated. The pattern for the piece forming the foot of the coal hod is a simple frustum of an elliptical cone, the method of obtaining which is fully explained in Prob- lem 171. In Fig. 546 of that problem the lines E F and G H are drawn much further apart than the proportions of the foot in the present case would justify, but the operation of obtaining its pattern is exactly the same. Pattern Problems. PROBLEM 212. 408 Patterns for a Three-Piece Elbow to Join a Round Pipe with an Elliptical Pipe. In Fig. 709, let ABCD represent the profile of the round pipe and E F G H I J K L the elevation of the elbow. In the plan the profile of round pipe is represented by A 1 B 1 C D 1 , the elbow by P 1 M' G' W PROFILE C ELEVATION Fig. 709.— Plan and Elevation of Three-Piece Elbow, Bound at One End and Elliptical at the Other. P 2 , and the shape of elliptical end of elbow by J 1 M 1 G 1 M\ The section J G H I of elevation is without flare, and sections K F G J and EFKL are flared, as shown in plan. Through the plan draw E 1 G 1 and M 1 M 2 , and carry M 1 M 2 through the center of elevation, as shown by M N P. Perpendiculars dropped from the points K F of elevation, cutting P' M 1 , E 1 G' and P 2 M 2 , as shown by K 1 O 1 F 1 O 2 , will give the shape of miter line K F in plan. As J G H I of elevation is without flare the pat- tern for this part is procured in the ordinary manner as for a pieced elbow. Since J 1 M 1 G 1 M 2 is the profile of an elliptical cylinder, the section upon the oblique line J G of the elevation, cut- ting the same, must necessarily be an ellipse whose major axis is equal to M' M 2 and whose minor axis is equal to J G. In like manner, the section at K F of the elevation may be assumed as an ellipse whose minor axis is K F and whose major axis is equal to 0' 0\ In Fig. 710, a duplicate of K F G J of elevation is shown by T E TJ W. Bisect T E in d and erect the perpendicular d S, and make d S equal to Q 1 O 1 of plan. Through the points T, S and E trace the half ellipse, as shown. In a similar manner bisect W TJ in I, and erect the perpendicular I V, in length equal to N 1 M 1 of plan. Through the points thus obtained trace the half ellipse W V TJ. Divide T S E into any convenient num- ber of equal parts, and from the points thus obtained drop per- pendiculars cutting T E, as shown. Also divide "W V TJ into the same number of equal parts as was T S E, and from ' the points thus obtained drop perpendiculars cutting W TJ. Connect points in T E with those opposite in W TJ, as shown by the solid lines. Thus connect a with h, b with/, c with k, etc. Also connect the points in T E with those in W 0, as indi- cated by the dotted lines. Thus connect 1 with h, a withy, b with k, etc. The next step will be to construct a series of sec- tions upon the several solid and dotted lines just drawn for the purpose of obtaining the true distances which they represent. The sections represented by solid lines 401 Tlie New Metal Worker Pattern Booh. are shown in Fig. 711. To construct these sections proceed as follows : For section a, draw the line a h, Fig. 710.— Elevation of Middle Section of Elbow, Showing Method of Triangulation. d I Fig. 711.— Sections on Solid Lines of Fig. 710. in length equal to a h of Fig. 710. From a erect a perpendicular, in length equal to a 2 in T S B, as shown by a 2 1 , and from h erect a perpendicular, in length equal to h 11 in W V IT, as shown by /; ll 1 , and connect 2 1 ll 1 , as shown. For section 5, draw b /, in length equal to bj of Fig. 710. From b erect the perpendicular b 3 1 , in length equal to b 3 in T B S, and from / erect a per- pendicular, in length equal to j 12 in W V U, and con- nect 3 1 12', etc. For the sections representing the dotted lines, as shown in Fig. 712, proceed in a similar manner. For section h, draw 1 h, in length equal to 1 h of Fig. 710. From h erect a perpendicular, in length li- 9\ g is 12- ■> / 13- 8*„-' 6 2 "~n la- s' 1 15 2 C I d m Fig. 712.— Sections on Dotted Lines of Fig. 710. equal to A 11 in W V U, and connect 1 with 11 s . For section/, draw a j, in length equal to a j of Fig. 710. From a erect the perpendicular a 2 s , in length equal to a 2 in T S E, and from/ erect a perpendicular, equal in length to/ 12 in W V U, and connect 2 2 12 2 , etc. To describe the pattern for part of article repre- sented in Fig. 710 byTEU W, as shown in Fig. 713,. proceed as follows : Draw any line, as E V of pattern, in length equal to E IT of Fig. 710. With B of pat- Pattern Problems. 405 tern as center, and 1 ll 5 of the diagram of sections, Fist. 712, as radius, describe a small arc, which intersect with one struck from point V of pattern as center, and U 11 of Fig. 710 as radius, thus establishing the point 11 of pattern. With point 11 of pattern as center, and 2' 11' of diagram of sections, Fig. 711, as radius, describe a tances between points represented by numbers in Fig. 711 for the length of solid lines in pattern, and the spaces in E S T for the stretchout of B T' of pattern. Lines drawn through the points thus obtained, as indi- cated by E T 1 W V, will be one-half of the required pattern. The other half, as shown by E T "W V, can Fiij. 713. — Pattern of Middle Section of Elbow. small arc, which intersect with one struck from E of pattern as center, and E 2 of Fig. 710 as radius, ttras establishing point 2 of pattern. Proceed in this man- ner, using the dotted lines in Fig. 712 for the distances in pattern represented by dotted lines ; the spaces in W V U for the stretchout of V W of pattern ; the dis- be obtained by a repetition of the same pi-ocess or by duplication. The pattern for E V K L of elevation can be ob- tained in a similar manner, A B C of profile being one- half the shape on E L and E S T of Fig. 710 being the half section on F K. PROBLEM 213. Patterns for a Right Angle Piece Elbow to Connect a Round with a Rectangular Pipe. In Fig. 714 is shown the design of a right angle elbow of which one end is rectangular, as shown by NOPQ, and the other rcrand, as shown by A B C D. Such an elbow may be constructed in any number of pieces, the elevation for which may be drawn in the manner described in the case of an ordinary piece elbow. In the present instance the elbow consists of seven pieces. In adjusting the transition from the rectangle to the circle, it is evident that the flat sides of each of the five intermediate pieces must become shorter in each piece as the round end of the elbow is approached ; and that the quarter circles forming the corners of each of the intermediate pieces must be of shorter radius as the corners of the rectangular end are approached. This may be accomplished upon the elevation in the following manner: Through the center of the eleva- tion draw the lines c to m, and divide L V into the ' number of parts there are pieces in the elbow subjected to the change in shape, in the present instance five. From h' set off each way four spaces, as shown b} r k Je and h' k". Set off from f three spaces, as shown by j f and/'/". Continue this operation and connect the points L h j h g f and g" h" j" k" L', thus showing in side elevation the change from the rectangle NOPQ to the circle A B C D. To show a similar shape on the outer carve of elbow, draw any line, as E M, in Fig. 715. From E on E M set off the spaces E F, F G, etc., to L M of Fig. 714. As it is only necessary to show the half 406 Tlie New Metal Worker Pattern Book. shapes, from M and L erect perpendiculars, in length equal to N n of profile, and connect same, as shown by M" L\ Connect 1/ F, and from the points in E M ELEVATION Fig. 714. — Elevation and Profiles of an Elbow to Connect a Round With a Rectangular Pipe. erect perpendiculars cutting F L\ The shapes on in- ner curve of elbow, as shown in Fig. 716, are obtained in the same manner as described for Fig. 715. For the hights of section on c m of the elevation, on any line, as E M, in Fig. 717, starting from E, set off the distances cf,fg', g' h', etc., and from the points thus obtained erect perpendiculars, as shown. From E and F set oft the distance C B of profile of circular end and draw E" F" From M and L set off the dis- tance N n of profile of rectangular end and draw M 3 L'. Connect L 3 with F 3 , thus completing the section. The method for obtaining the patterns for sections E F F' E' and L M M' L' is the same as for an ordinary pieced elbow. The method for obtaining the pattern ior one of the remaining sections will be shown, which will indicate the method to be followed in the other sections. In Fig. 718, F G G-' F' is a duplicate of the sec- tion having similar letters in elevation. The shape F U F' is the half of an ellipse, because F' F of Fig. 714 is an oblique section of a cylinder of which A B C D is the plan, and can be de- scribed in any convenient manner. From G erect the perpendicular G S, equal to G G 2 of Fig. 715, and from G' erect another perpendicular, equal to G G" of Fig. 716. From points g and g' erect perpendiculars equal to G 3 G of Fig. 717, and connect T T', as shown. Connect S T and T' S' by a quarter of an ellipse. Divide S T, T' S', F U and U F' into any convenient number of equal parts, and from the points thus obtained drop perpendiculars cut- M°| M L K lA K c \ \ J H J \ H°\ gV" G ^ F E Fig. 715.— Shape of Flat Part of Outer Curve of Elbow. Fig. 'He,— Shape of Flat Part of Inner Curve of Elbow. ting G G' and F F'. Connect these points, as shown by the solid and dotted lines in G G' F' F. The next operation will consist in constructing sections upon these solid and dotted lines for the pur- Pattern Problems. 40 ', pose of ascertaining the correct distances which they represent. These sections are shown in Figs. 719 and 720. To construct the sections represented by solid Fig. 718.- ■Elevation of One of the Pieces, Shouting Method of Triangulation lines in Fig. 718, proceed as follows: Draw the line F G of Fig. 719, in length equal to F G of Fig. 718, and from point G erect a perpendicular, in length equal to G S of Fig. 718. Connect F S, which gives the distance between points F and S. For the second section draw v o, in length equal to v o of Fig. 718, M d L 3 uA. \ r B l E'l F E Fig. 717.— Extended Section on Line c m of Fig. 714. and make the perpendiculars o 6 and v 7 of the section equal to lines having similar letters in Fig. 718. The other sections are obtained in a similar manner. To construct the sections represented by dotted lines in Fig. 718, proceed as follows : Draw the line F o of Fig. 720, in length equal to F o of Fig. 718, and from o erect the perpendicular o 6, equal to o 6 of Fig. 718, and connect F 6. For the second section draw v p, in length equal to vp of Fig. 718, and from points v and p erect perpendiculars equal to v 7 and p 5 of Fig. 718. Connect points 7 5, which give the distance between corresponding points in Fig. 718. In Fig. 721, GG'F'F is the pattern of part of / 1 G 1 Fig. 719.— Sections on Solid Lines of Fig. 718. article shown by similar letters in Figs. 714 or 718, The distances represented by solid lines in pattern are obtained from the sections in Fig. 719, as indicated by corresponding figures, and the distances represented by dotted lines in pattern are obtained from the sections in Fig. 720. The stretchout of G G' of the pattern is obtained from GTT' G' of Fig, 718, as the stretchout of F U F' of the pattern is obtained from F U F' of Fig. 718. 408 Tlie New Metal Worker Pattern Booh. To develop the pattern from the sections above constructed, first draw G F of Fig. 721, in length equal to G F of Fig. 718 or 719, upon which duplicate the 10 Si- lo -\0 -i9 11' 'S 1' 'F Fig. 720. — Sections on Dotted Lines of Fig. 718. triangle G F S of Fig. 719, as shown. From S of pat- tern as center, with S 6 of Fig. 718 as radius, de- scribe an arc, 6, which intersect with one struck from F of pattern as center, with radius F 6 of Fig. 720, thus establishing point 6 of pattern. Then with radius F 7 of Fig. 718, from F of pattern as center, describe an arc, which intersect with a second arc struck from point 6 of pattern as center, and 6 7 of Fig. 719 as radius, thus establishing point 7 of pattern. Continue this process until the various points indicated in pat- tern are located. Lines drawn through the points 1 S G' Fig. 721— Half Pattern of F G G' F' of Fig. 714. thus obtained, as indicated by GSTT'S'G' and F' U F, will complete one-half of the required pattern. The other half can be obtained by duplication or by a repetition of the above process. In obtaining the pattern for any one of the re- maining pieces first draw a duplicate of its elevation as taken from Fig. 714, upon either side of which con- struct the proper section, obtaining the points in the same from Figs. 715, 716 and 717 as was done in Fig. 718, the subsequent operations being explained in Prob- lem. PROBLEM 214. Pattern for the Soffit of a Semicircular Arch in a Circular Wall, the Soffit Being: Level at the Top and the Jambs of the Opening; Being: at Rig:ht Angles to the Walls in Plan. Two Cases. First Case. — In Fig. 722, let A B C represent the outer curve of an arch in a circular wall corresponding to A' H C of plan, and let E B D represent the inner opening in the wall, as shown by E' F' D' in plan. Then A E B C D will represent the soffit of the arch m elevation and A' H C D' F' E' the same in plan. In the engraving the outer curve of the arch is a per- fect semicircle, and the inner curve is stilted, as shown, so as to make the soffit level at B. Instead of the stilted arch, the inner curve may, if desired, be drawn as a semi-ellipse of which E D is the minor axis and F B one-half of the major axis. Divide A B of elevation into any convenient num- ber of equal parts, shown by the small figures. With the T-square parallel with the center line B B', drop lines from the points in A B, cutting A' H of plan, as shown. Since that portion of the inner arch from E to 13 is drawn vertical, as above explained, divide 12 B into the same number of parts as was A B, and, with the T-square parallel with the center line B B', drop lines to E' F', as shown. Connect opposite points in A' H with those in E' F', as shown by the solid lines in plan. Also divide the four-sided figures thus produced by means of the diagonal dotted lines 6 8, 5 9, etc., as shown. The several triangles thus produced will represent in plan the triangles into which the soffit, or under side, of the arch is divided for the purpose of obtaining its pattern. In order to ascer- Pattern Problems. 409 tain the real distances across the surface of the arch which the solid and clotted lines represent, it will be necessary to construct a series of sections of which these lines are the bases, as shown in Figs. 723 and 724. In constructing the diagram shown Fig. 723, the several solid lines of the plan, though not exactly equal in length (because they are not drawn radially from the center of the curve A' II C), may be con- sidered as of the same length. Draw the right angle PQE as in Fig. 723, and from Q set off horizontally the distance H F' of plan, as shown by Q R. Draw R S parallel with Q P, and, measuring from Q, set off on QP the length of lines dropped from points in A ELEVATION B Fig. 722.— Plan and Elevation of Arch in a Circular Wall- First Case. B to A F, as shown by corresponding figures 2 to 6. Likewise set off from R on R S the length of lines dropped from points in E B to E F, as shown by the figures 12 to 7, and connect the points in P Q with those in S R, as indicated by the solid lines in plan. Thus connect 1 with 12, 2 with 11, 3 with 10, etc. To construct the diagram based upon the dotted lines of the plan, draw the right angle MNO in Fig. 724, and, measuring in each instance from N, set off on N M the same distances as in Q P of Fig. 723. Starting from N, set off on N" the lengths of dotted lines in plan, as shown by the small figures in N 0. With the T-square parallel with M N, draw lines from the points in 1ST 0, and, in each instance measuring from N" 0, make these lines of the same length as lines of similar number dropped from points in E B of eleva- tion to E F. Connect the points in these lines with points in M N, as indicated in plan by the dotted Fig. 723.— Diagram of Sections on Fig. 724.— Diagram of Sections on Solid Lines of Plan, Fig. 722. Dotted Lines of Plan, Fig. 722. lines. Thus connect 6 with 8, 5 with 9, 4 with 10, etc. The next step is to obtain the distances between points in A B of elevation as if measured on the outer opening in the curved wall. To do this, on F A ex- tended set off a stretchout of A' H of plan, as shown by the small figures 5', 4', etc., and with the T-square at right angles to the stretchout line J F, draw the usual measuring lines. With the T-square parallel with J F, carry lines from the points in A B to lines of similar number drawn from the stretchout line. A line traced through these points, as shown by J B, will give the true distances desired between the points in the outer curve of the arch. The distances between points in E B, the inner curve, are obtained in a similar manner. To avoid a confusion of lines, the stretchout of F' E' of plan is 13 12 1' Fig. 725.— One-Half Pattern of Soffit of Arch Shown in Fig. 722. set off on F C of elevation, as shown by the small figures, 7', 8', 9', etc. B D is also divided into the same parts as was E B, and from the points thus ob- tained lines are drawn to the right parallel with F C. With the T-square parallel with B F, carry lines 410 The New Metal Worker Pattern Book. from the stretchout points in F K, cutting lines of similar number drawn from the points in BD. A line traced through the points thus obtained, as shown by B K, will give the distance between points as if measured on the inner curved line of the wall. From the several sections now obtained the pat- tern may be developed in the following manner : At any convenient place draw the line a e in Fig. 725, making it in length equal to Q R of Fig. 723, or A' E' thus establishing the point 11 of pattern. Continue in this way, using the tops of the sections in Figs. 723 and 721 for measurements across the pattern, the spaces in J B for the distances along the edge a h of pattern, and the spaces in B K for the distances along the inner edge e /, establishing the several points, as shown. Through the points in a h and e f lines are to be traced, while fh is to be connected by a straight line, thus completing one-half the pattern. The other Fig. 726.— Plan and Elevation of Arch in a Circular Wall. — Second Case. of plan. At right angles to a e draw e 12, in length equal to R 12 of Fig. 723, and connect a with 12 if it is desired to show the triangle. From a as center, and J 2 of elevation as radius, describe a small arc, 2, -which intersect with one struck from point 12 of pat- tern as center, and 12 2 of Fig. 724 as radius, thus es- tablishing the point 2 of pattern. With 2 of pattern as center, and 2 11 of Fig. 723 as radius, describe another arc, 11, which intersect with one struck from 12 of pattern as center, and 12 11 of B K as radius, half of pattern can be obtained by the same method or by any convenient means of duplication. If the arch were semi-elliptical instead of semi- circular, the method of procedure would be the same as above described. Second Case. — In Fig. 726, ABC represents the outer curve of an arch in circular wall, as shown by A' H C in plan. EBD represents the inner curve in elevation, as does E' D' the same in plan. Then A E B D C represents the soffit of the arch in eleva- Pattern Problems. 411 tion and A' H C D' E' the same in plan. The con- ditions given in this case differ from those of the first case only in the fact that the inner curve of the arch in this case is straight in plan, as shown by E' D', instead of curved to the radius of the wall as in Fig. 722. The method of procedure in this case is exactly the same as before, but one less operation will be nec- essary, since measurements upon the inner curve may be taken directly from E B D of the elevation. To avoid a confusion of lines, a duplicate Fig. 727. — Diagram of Sections on Solid Lines of Plan, Fig. 726. Fig. 72S. — Diagram of Sections on Dotted Lines of Plan, Fig. 726. of EBD of elevation has been drawn in plan, as shown by E' B' D'. To obtain the divisions on plan divide A B into any convenient number of equal parts, and from the points thus obtained drop lines parallel with the center line B B' to A' H of plan, as shown. Divide E' B' in a similar manner, and from the points thus obtained drop lines to E' F' of the plan, as shown. Connect points in A' H' with those of similar number in E' F' by solid lines. Also connect points in A' H with those of next lower number in E' F' by clotted lines. These solid and dotted lines just drawn will form the bases of a series of sections, shown in Figs. 727 and 728, whose upper lines will give correct dis- tances across the pattern of the soffit. To construct the sections based upon the solid lines of the plan, first draw the right angle P Q B in Fig. 727, and set off on Q P, measuring from Q, the length of the vertical lines in A B F of elevation. Starting from Q, set off on Q R the length of solid lines in A' H F' E' of plan, as shown by the small figures in Q R. With the T-square parallel with P Q, draw lines from the points in Q R, and, measuring from Q R, set off on these lines the length of lines of corresponding number in E' F' B' of plan, and connect the points with points of similar number in P Q. The diagram of sections based upon the dotted lines of the plan, shown in Fig. 728, is constructed in the same manner, using the length of dotted lines in plan for the distances in N 0, the length of lines in E' F' B' of plan for the length of lines set off at right angles to N 0, and the length of lines in A B F of elevation for the distances in M N. Connect the points as in- dicated by the dotted lines of the plan, all as shown. The next step is to obtain the correct distances between points in A B of elevation, or A' H of plan. To do this lay off horizontally J K, on which set off a stretchout of A' H of plan, and, with the T-square at right angles with J K, draw the usual measuring lines. With the T-square parallel with J K, carry lines from the points in A B to lines of similar num- ber. A line can be traced through these points, as shown by J L, from which the correct stretchout of the outer side of the pattern can be obtained. To describe the pattern first draw any line, as a e of Fig. 729, equal to A' E' of plan. With e of pattern as center, and E' 1 of the inner curve of the arch as radius, strike a small arc, 1', which intersect with one struck from a of pattern as center, and Q 1' of Fig. 727 as radius, thus establishing the point 1' of pat- tern. With a of pattern as center, and J 2 of Fig. 726 as radius, describe a small arc, 2, which intersect with one struck from 1' of pattern as center, and V 2' of Fig. 728 as radius, thus establishing point 2 of pattern. Then from 2 as center, with 2' 2' of Fig. 727 as radius, strike a small arc, 2', which is inter- s' -y Fig. 729.— Half Pattern of Soffit Shown in Fig. 726. sected with one struck from 1' of pattern as center, and 1 2 of the inner curve of the arch as radius, thus definitely establishing the point 2' of pattern. Con- tinue in this way, using the tops of sections in Figs. 727 and 72S for measurements across the pattern, and the spaces in the inner curve E' B' and in outer curve as developed in J L, Fig. 726, for the distances about the edges of the pattern, establishing the several points, as shown. Connect points h and f with ", straight line, and through the intermediate points trace the curves, as shown. The other half of pattern can be obtained by the same method or by duplication. 4:12 Tlie New Metal Worker Pattern Book. PROBLEM 215. Pattern for a Splayed Elliptical Arch in a Circular Wall, the Opening: Being- Larg-er on the Outside of the Wall than on the Inside. In Fig. 730 is shown the elevation and plan of an elliptical window head in a circular wall. The outer curve of head is represented by A B C in elevation and by A' B' C in plan. The inner curve is repre- sented by F E D in elevation and F' E' D' in plan. A B C D E F therefore represents the splayed or beveled portion in elevation for which the pattern is required, and A' B' C D' E' F' the plan of the same. Divide A B of elevation into any convenient number of sections on A' B' of plan, as the lines dropped from F E to F G give the hight of sections on F' E' oi plan. To construct the sections shown in Fig. 731, rep- resented in plan by the solid lines, proceed as follows : Draw the right angle a a' 1, making a a' equal to E' B' of plan, and a' 1 equal to G B (a 1) of elevation. Draw a 12 parallel to a 1, making its length equal to G E (a 12) of elevation, and connect 12 with 1. The dis- L g e a b DEVELOPMENT OF INNER CURVE, Fig. 7S0. — Elevation and Plan of Splayed Elliptical Arch. of parts, in the present instance five. For convenience number the points thus obtained, as shown by the small figures. Drop perpendiculars from the points in A B, cutting A' B' of plan, as shown. Also divide F E of elevation into the same number of parts as was A B, and drop similar perpendiculars to F' E' of plan. Connect opposite points in A' B' with those in F' E', as shown by the solid lines, as 2 11, 3 10, etc. Also divide the four-sided figures thus produced into tri- angles by means of the dotted lines, as shown from 1 to 11, 2 to 10, etc. To ascertain the true distances across the face of the arch which these several solid and dotted lines of the plan represent, it will be nec- essary to construct vertical sections through the arch upon each one of these lines as a base. The lines dropped from A B to A G of elevation give the hight tance 12 1 of this section represents the actual distance between the points 1 and 12 in the elevation or plan. The second section is constructed in a similar manner; h c represents the distance 2 1 1 of plan ; b 11 is equal to b 11 of elevation and c 2 to c 2 of elevation. Con- nect 11 with 2 of section, which will give the actual distance between points 11 and 2 of elevation or plan. The remaining sections are constructed in a similar manner, each of the sections representing a vertical section through the head on the lines of corresponding numbers in the plan. The sections based upon the dotted lines of the plan, shown in Fig. 732, are con-, structed in exactly the same manner. Draw b a, in length equal to 1 11 of plan, and erect the two perpen- diculars, as shown. Make a 1 of section equal to a 1 of elevation, and also make b 11 of section equal to b fattem froblems. 413 11 of elevation, and connect 11 with 1. The remain- ing sections are constructed in the same manner. Before the pattern can be obtained it will be nec- essary to develop extended sections of the inner and «/< a b e j a Ji Fig. 731. — Sections Based Upon the Solid Lines of the Plan, Fig. 780. outer curves, as shown to the left and right of the ele- vation. This is clone for the purpose of obtaining the actual distance between points shown in elevation. For convenience, on G A extended, as H K, lay off a stretchout of A' B' of plan, and from the points therein contained erect the perpendiculars, as shown. From the points in A B of elevation draw lines parallel with H G, cutting perpendiculars of similar number erected from H K. A line drawn through these points of in- to / 7^: Fig. 732. — Sections Based Upon the Dotted Lines of the Plan, Fig. 730. tersection, as shown by H J, will show the shape of A B of elevation as laid out on a flat surface. The development of the inner curve is shown to the right of the elevation. On LN is laid out the stretchout of F' E' of plan, and on the perpendiculars erected from the points in the line are set off the same distances as on lines of similar number in F E Gr of elevation. A line traced through these points, as shown by L M, also shows the shape of F E, as laid out on a flat surface, and gives the distance between points as if measured on the finished article. To obtain the pattern, using the distances between points in H J and L M of Fig. 730, and the diagrams in Figs. 731 and 732, proceed as follows : Draw any line, as B E in Fig. 733, in length equal to 1 12 of the first section in Fig. 731. With E as center, and M 11 of inner curve as radius, describe a small arc, 11, which intersect with one struck from B as center, and 1 11 of Fig. 732 as radius, thus establishing the point 11 of pattern. "With 11 of pattern as center, and 11 2 of the second section in Fig. 731 as radius, describe an- Fig. 733. — Pattern of Splayed Arch in Fig. 730. other small arc, 2, which intersect with one struck from point B of pattern as center, and J 2 in J H of outer curve as radius, thus establishing the point 2 of pattern. Continue in this way, using the tops of the sections in Figs. 731 and 732 for the measurements across the pattern, the spaces in the inner curve L M and in the outer curve H J for the distances about the edges of the pattern, establishing the several points, through which draw the lines shown. Then B A F E is the half pattern of splayed head, shown in elevation by A B E F. The other half can be obtained by any convenient means of duplication. A semicircular splayed arch can be developed in the same manner as above described. The pattern for a blank for a curved molding, either semicircular or semi-elliptical, for an arch in a circular wall comprises really the same relations of parts as are shown in Fig. 730, and could be obtained as above described. 414 TJie New Metal Worker Pattern Book. PROBLEM 216. Pattern for a Splayed Arch in a Circular Wall, the Larger Opening: Being" on the Inside of the Wall. In Fig. 734 is shown the plan and elevation of an arch in a curved wall, such as might be used as the head of a window or door, the jambs and head to have the same splay. In the plan, CED represents the inner curve of wall and A F B the outer. J G M in elevation represents the inner curve and K H L the outer. In order to arrive at a system of triangles by means of which to measure the splayed surface, first the inner and outer lines of plan, as shown. The solid and dotted lines of the plan will form the bases of a series of right angled triangles whose altitudes can be found in the elevation, and whose hypothenuses will give correct measurements across the face of the splayed surface. To determine the hights of these triangles extend to the left the horizontal lines drawn throusrh K H of the ELEVATION G DEVELOPMENT OF OUTER CURVE Fig. PLAN 7S4. — Plan, Elevation and Extended Sections of Splayed Arch. divide J G of the elevation into any convenient num- ber of parts, in this case five, as indicated by the small figures. From the points in the curve thus established drop lines parallel to the center line G F, cutting the inner curve of the plan C E, as shown. Next carry lines from points in J G in the direction of the center X, intersecting the outer curve and establishing the points 7, 8, 9, etc., in it. From these points drop lines to the outer curve in plan A F, establishing the points 7, 8, 9, etc. Connect opposite points in J G with those in K H, as 1 and 7, 2 and S, 3 and 9, 4 and 10, 5 and 11, and 6 and 12. Likewise connect 1 and 8, 2 and 9, 3 and 10, etc., as shown by the dotted lines. In the same manner connect corresponding points in elevation until they intersect lines dropped from J G, as shown by the points b, d, ,/and h. Then b 2, d 3, etc. , will be the required hights. To construct the tri- angles which represent the solid lines in plan and ele- vation, proceed as shown in Fig. 735 : For the first triangle, G H 7, draw the right angle G H 7, making the altitude equal to G H of elevation and the base equal to E F, 1 7, of plan, and draw the hypothenuse, which represents the actual distance between the points 1 and 7 of the elevation or plan. In like manner the hypothenuse of the second triangle 2 5 8 shows the actual distance between the points 2 and 8 of the elevation; 2 b in Fig. 735 is made equal to 2 b of the elevation, while b 8 equals 2 8 of the plan. Pattern Problems. 415 The remaining triangles in Fig. 735 are con- structed in a similar manner, each of the triangles rep- resenting a vertical section through the head on the lines of corresponding numbers in the plan. The triangles shown in Fig. 730 correspond to similar sections taken on the dotted lines in plan. The base a S of the first triangle is equal to 1 S of the plan, and the hight la to 1 a of elevation, the point a of the elevation being on a level with 8, as shown by the dotted line 8 a. The hypothenuse 1 S is then drawn, which gives the distance between the points 1 s H Fig. 735.— Diagram of Triangles Based Upon the Solid Lines of the Plan. and 8 in plan or elevation. The bases of the remain- ing triangles are derived from the dotted lines in plan, and the hights from the distances 2 c, 3 e, ± g and 5 k of elevation. Before the correct measurements or stretchouts for the inner and outer lines of the pat- tern can be obtained it will be neces- sary to develop extended sections of the inner and outer curves of the arch in elevation, as shown at the left and right of that view. For the develop- ment of the outer curve, as shown to the right by A' II' F', proceed as fol- lows : On X M extended lay off a stretchout equal to A F of the plan, transferring it point by point. From the points thus established in A' F' carry lines vertically, extending them indefinitely, as shown, and then from the points in the outer curve K II of the elevation carry lines horizon- tally to the right, intersecting the corresponding lines just drawn from A' F', and through the points thus established trace the curved line A' H'. The de- velopment of inner curve, as shown to the left, is accomplished in a similar manner. On X J ex- tended lay off a stretchout of C E of plan, and from the points thus established carry lines vertically. From the points in the inner curve J G carry lines horizontally to the left, intersecting lines of similar number, and through the points thus established trace the curve C G'. To describe the pattern shown in Fig. 737, first \ \ _\. Fig. 736.— Diagram of Triangles Based Upon the Dotted Lines of the Plan. draw the line g h, or 1 7, in length equal to the hypoth- enuse 1 7 of the first triangle in Fig. 735. From 7 as center, with 7 8 of the development of the outer curve as radius, strike a small arc, as shown at 8 in the pattern. From 1 as center, with 1 8 of the first triangle in Fig. PATTERN Fig. 737.— Pattern for Splayed Arch. 736 as radius, intersect the arc last struck, thus estab- lishing the point 8. From 1 as center, with radius equal to 1 2 of the development of inner curve, strike a small arc, as shown at 2. Then from 8 as center, with 8 2 of the second triangle in Fig. 735 as radius, 416 The New Metal Worker Pattern Book. intersect the arc at 2 already drawn, thus definitely establishing the point 2 in the upper line of the pattern. Continue in this way, using the hypothenuses of the several triangles, as shown, for measurements across the pattern, and the spaces of the inner and outer curves as developed in Fig. 734 for the distances along the edges of the pattern, establishing the several points, as shown. Lines traced through the points from c to g and from a to h will complete the pattern for one-half the arch. The complete pattern is shown in Fig. 737. PROBLEM 217. Pattern for the Soffit of an Arch in a Circular Wall, the Soffit Being: Level at the Top and the Jambs of the Opening Being- Splayed on the Inside. In Fig. 738, A B G is the elevation of the inner curve A' H C of the plan and £ B D that of the outer curve E' F' D'. As will be seen by inspection, the outer curve is drawn from G as center, that portion of the opening from the springing line down to the spring- the outer curve of wall is struck from G as center, divide 12 B into the same number of parts as was A B, and drop lines from these points to E' F' of plan, as shown. Connect opposite points in E' F' of plan with those in A' H, as indicated by the solid lines. Also M 1211 10 9 7U Fig. 7SS. — Plan, Elevation and Extended Sections of an Arch in a Circular Wall. SHAPE ON E F'oF PLAN ing line of the inner curve, as E 12, being straight and vertical. The pattern of the soffit could have been obtained in exactly the same manner had the elevation of this outer curve been a semi-ellipse. Divide A B of the elevation line into any con- venient number of equal parts, and with the T-square parallel with center line B H drop lines from the points in A B, cutting A' H of plan, as shown by the small figures 1 to 6. As the semicircle representing connect the points of the plan obliquely, as shown by the dotted lines, thus dividing the plan of the soffit of the arch into triangles. In order to ascertain the true distances which these lines drawn across the plan repre- sent it will be necessary to construct a series of sections of which they are the bases, as shown in Figs. 739 and 740. In Fig. 739 is shown a diagram of sections corre- sponding to the solid lines in plan, to construct which Pattern Problems. 417 proceed as follows : Draw the right angle P Q R, and, measuring from Q, set off on Q P the length of lines dropped from points in A B of elevation to A F, as shown by the figures 2 to (3. Likewise set off from Qon QR the length of solid lines in plan, as shown by the small figures 7 to 12. With the "[-square parallel with P Q, erect lines from the points in Q R, and, measuring from Q R, set off on these lines the length of lines of corresponding number in E B F of elevation, ----. 10 I - — 41 ~H11 II " — U_ ,12 ! i u Fig. 7S9. — Diagram of Sections on Fig. 740. — Diagram of Sections on the Solid Lines of the Plan. the Dotted Lines of the Plan. and connect the points thus obtained with the points in P Q, as indicated by the numbers in the plan. Thus connect 6 with 7, 5 with S, 4 with 9, etc. To construct a diagram of sections corresponding to the dotted lines of the plan draw the right angle S T U, Fig. 710, and set off on S T the length of lines dropped from points in A B of elevation to A F, or tranfer the distances in P Q, Fig. 739. On T U set off the length of dotted lines in plan, and from the points thus obtained draw lines parallel with S T, making these lines of the same length as those dropped from points in E B of elevation to E F. Connect the upper ends of lines 8 to 12 with points in S T, as indi- cated by the dotted lines in plan. Thus connect 2 with 12, 3 with 11, 1 with 10, etc. The next step is to obtain the distance between points in A B and E B of elevation as if measured upon the curved surfaces of the wall. It is therefore neces- sary to develop extended sections of the two curves of the arch as shown at the left in the enarravins;. The development of the curve of the inner side of the arch is projected directly from the elevation in the follow- ing manner : On A F extended lay off J K, equal to the curved line A' H of plan, making the straight line equal to the stretchout of half of the curve of the plan, as indicated by the small figures. At right angles to J K, and from the points in the same, erect lines, making them the same length as lines of similar num- ber dropped from points in A B, or, with the "[-square parallel with J K and A F, carry lines from the points in A B intersecting the vertical lines of similar num- ber. A line traced through the points of intersection, as shown by JL, will'be the desired shape. The shajDe on E' F' of the plan, corresponding to E B F of eleva- tion, is obtained in a similar manner. On M N in Fig. 738 set off the stretchout of E' F' of plan, as indicated by the small figures, from the points of which erect vertical lines. On these lines set off the same length as the lines of similar number in E B F of elevation. A line traced through the points thus obtained will give the desired outer curve of the arch. To develop the pattern from the several sections obtained proceed in the following manner : Draw the line a e of Fig. 741, in length equal to Q R of Fig. 739, and with e as center, and M 12 of the curve M O as radius, strike a small arc, 12, which intersect with one struck from a as center, and Q 12 of Fig. 739 as radius, thus establishing the point 12 of pattern. With a of pattern as center, and J 2 in the curve J L as radius, describe a small arc, 2, which intersect with one struck from point 12 of pattern as center, and 2 12 of Fig. 740 as radius, thus establishing the point 2 of pattern. With 2 of pattern as center, and 2 11 of Fig. 739 as radius, strike another small arc, which intersect with one struck from point 12 of pattern as center, and 12 11 in the curve M as radius, thus establishing the point 11 of pattern. Continue in this way, using the tops of the sections in Figs. 739 and 2 3 4 Fig. 741— Half Pattern of Soffit. 740 for measurements across the pattern, and the spaces in the inner and outer curves as developed in J L and M O, Fig. 738, for the distances about the edges of the pattern, establishing the several points, as shown, through which draw the lines e f, a h and / h\ thus completing the pattern for one-half the soffit of the arch. The other half of pattern can be ob- tained by the same method or by duplication. 418 The New Metal Worker Pattern Book. PROBLEM 218. Pattern of the Blank tor a Curved Molding in an Arch in a Circular Wall. In the last paragraph of Problem 215 it is stated that the demonstration there given is applicable to the blank for a curved molding in a circular wall. There are many forms of arches and different methods of adapting them to the requirements of a curved wall. An arch may be semicircular or elliptical, having either the long or the short diameter of the ellipse as its width ; and in either case it may be rampant, though rampant arches are seldom used. Any form of arch may be so constructed that its moldings project either from the exterior or from the interior surface of a curved wall. In adapting any form of arch to a circular wall the soffits and roof strip, or portions which appear level at the top of the arch, may, as they are carried around the curve of the arch, arrive at the springing line or top of the impost parallel to the cen- ter line in plan ; or they may at this point be drawn radially to the curve of the wall. In Fig. 7-42 is shown one-half of the elevation and plan of a semicircular window cap and a section on the center line of the same. M K L 1ST is one- half the elevation of all the members constituting the molding, the lines of which are projected from the profile W as shown to the right of the center line. In the plan, those lines which in profile W were drawn horizontally are here drawn parallel to the center line B G. They might with equal propriety have been drawn radially toward the center of the curve E G. Should they be drawn radially the profile of the mold- ing would remain nearly normal throughout its course, but when drawn as in the plan, Fig. 742, it will be seen that the profile is continually changing, that at the foot of the arch or top of the corbel being shown at Y in the plan. This profile is obtained by the usual operation of raking, as shown by the dotted lines. Aa the blank for any curved molding is, to the pattern cutter, a flaring strip of metal, it simply be- comes necessary to determine its width and the amount of flare which it may assume in the different parts of its course, after which its pattern may be arrived at by methods described in Problem 214 and those fol- lowing. The direction of the line determining the amount of flare necessary for the strip to have is de- termined by the judgment of the pattern cutter and the requirements of the machinery used in "raising" the mold. Therefore in making the application of the demonstration given in Problem 215 to the win- dow cap shown in Fig. 742 it is necessary to first draw the lines k g of the profile in elevation, and p r of the plan, establishing the flare and necessary width or stretchout at those points, after which the points J?ig. 742.— Elevation and Plan of an Arched Window Cap in a Circular Wall. p and r may be dropped upon the line M N of the elevation, and the points k and g carried horizontally to the center line K X, as shown. The points thus obtained in M N and K L must then be connected by the necessary arcs struck from X as center, thus completing an elevation of the flaring piece. Likewise the projection of the points g and k from K L must be set off from C on C G of the plan, as shown at g" and k", and the points thus obtained connected with Pattern Problems. 419 r and p by arcs struck from the center used in describ- ing the plan of the wall. Should the width and flare of the blank, as deter- mined by the raked profile Y at the foot of the arch, vary so much 'from those of the normal profile at the top that parallel curved lines could not be drawn to connect the points at the foot with those at the top in either or both views, then centers must be found upon 730 ; after which the demonstration given in that problem may be followed to obtain the required pattern. It will thus be seen from the foregoing that no matter what form of arch be used or in what manner it be placed upon the wall, the method of obtaining the pattern of its flaring surfaces remains the same. It might under some circumstances be desirable Fig. 74-3.— Method of Obtaining a Section through Molding. the center lines of the plan and of the elevation from which arcs can be drawn connecting the required points. Having thus completed a plan and elevation of the flaring piece or blank, it will be seen by reference to Problem 215 that the lines p' r' and 7/ g' of the elevation, Fig. 742, correspond with A F and B E of Fig. 730 ; and that p r of the plan, Fig. 742, and the arcs drawn from it correspond with B' A' F' E' of Fig. to construct stays at several intervals between the top and the foot of an arch, similar to that shown at Y in Fig. 742, for the purpose of more accurately determin- ing the flare in all parts of its sweep, or for the purpose of constructing a form of templet to assist in the operation of raising the mold. The profiles of such stays can be obtained by the usual operation of rak- ing, which is fully described in numerous problems in 420 The New Metal Worker Pattern Booh. the first section of this chapter. In Fig. 743 the operation of obtaining a profile upon the line X' X" is graving must be obtained by developing extended sections of those lines on E C of the plan, as de- Fig. 744.— Perspective View of Templet for Use in Raising the Curved Mold. carried out in all its detail, resulting in the form shown at Q, and needs no further comment. In constructing a form or templet, as shown in Fig. 744, the outlines of the arch shown in the en- scribed in Problem 214 and those following, after which the stays can be placed upon lines drawn to correspond with those from which the respective sec- tions were taken. PROBLEM 219. Details of Patterns for Automobile Dust Pan. This problem explains how to lay out the patterns for an automobile dust pan and how the intersecting lines between the side pocket and pan are projected, and how to place them on the patterns. The problem pre- sents an interesting study in projections and devel- opments. In Fig. 745, A B represents the center line, 5 1 10' H the one half plan of the pan, showing the full length and the one half width. Below the plan is shown the one half front view, the outer curve F 14 represent- ing the section on line 6 14 in plan, while G 10 11 14 shows the section on H 10' in plan. Above the plan is shown the one half rear view, the outer curve 6 D representing a section on 6 14 in plan and is similar to F 14 in the half front view, and the inner curve 5 D in the rear view representing the section on the line 5 1 in plan. In the rear view D e d b shows the head of the side pocket which, in this case, is to intersect with the pan To the right of the half front view is the side view of the pan and pocket, the length being a projection from the plan by the quadrants struck from the center 14 in the front view, as shown by dotted lines, while the vertical nights are obtained from the half front view and rear view Z, which is a reproduction of the half rear view above the half plan. Thus 10 D° 5 6 G° shows the side view of the pan, the rear part being longer than the front as shown, and X F° F° D° showing the side view of the pocket which is to intersect the pan at its sides and bottom. As shown by the half plan, the triangular gore in- dicated by 10 10' 14 is to have a profile on the line 10 10', similar to the shape shown by 10 14 in the one half front view. The loreshortened view of the curve 11 14 in front view on the line 11 14 in plan, is pro- jected to the side view as follows: Divide the curved part in the half front view in equal spaces as from 11 Pattern Problems. 421 to 14, from which points erect vertical lines until they intersect the line 10 14 in plan. From these intersec- tions parallel to H 10' draw lines intersecting the side 10' 14 at 11', 12', and 13'. Using 14 in the front view as center, with radii equal to 14 10', 14 11', 14 12', 14 13', and 14 14, draw the quadrants intersecting the top line of the pan in the side view at 10, 11, 12, 13, and 14. From these intersections draw vertical lines, jections to points 11, 12, 13, and 14 on the line 10 14, and place these distances on similar numbered lines, measuring in each instance from the line L M. Trace a line through points thus obtained and 10 N 14 will be the pattern shape. To obtain the line of intersection between the rear head of the pocket D° F° in the side view with the rear part of the pan, as shown in the rear view (Z) by D E ( Fig. 745. — Half Plan, Half Front and Rear Views, Side View True Lengths and Pattern Shapes. which intersect by lines drawn from similar numbers in the half front view, parallel to 14 X, thus obtaining 10°, 11°, 12°, 13°, and 14, through which the dotted line is traced, completing the side view. The pattern for the triangular gore is obtained as follows: Take the stretchout of the profile 10 to 14 in the half front view and place it on the horizontal line L M, as shown by similar numbers, through which erect perpendicular lines as shown. Measuring from the line H 10' in the half plan, take the various pro- proceed as follows: Starting from the intersection be- tween the inner and outer curves in the half rear view (Z) indicated by 1, divide both curves into an equal number of spaces, as shown by the small figures from 1 to 5 and 6 to 1. Connect opposite points as from 5 to 7 to 4 to 8 to 3 to 9 to 2 and from 9 to 1. From the various intersections on the inner curve 1 to 5, draw horizontal lines (not shown) until they intersect the proper line D° 5 in the side view, as indicated by the figures 1 to 5. In a similar manner from the various 422 The New Metal Worker Pattern Book. intersections on the outer curve 6 to 9 to 1, draw hori- zontal lines (not shown) until they intersect the proper line 14 6 in the side view as also indicated by the small figures 6 to 9 to 1. Connect opposite numbers by dotted lines hi a similar manner as was done in the half rear view (Z), as shown from 5 to 7 to 4 to 8 to 3 to 9 to 2 and from 9 to 1. Where these lines cross the pocket head line D° F°, as indicated by the heavy dots, project these dots of intersections horizontally to the right, intersecting sim- ilar numbered connected lines in the half rear view (Z), as indicated by the intersection 91, 29, 93, 38, 84, 47 and E. In tins case the corner of the pocket F° in the side view intersects the line 5 7 and this corner is pro- jected to the line 5 7 in the half rear view, thus obtain- ing E. The bottom of the pocket F" F° in the side view, cuts the line 7 4 at 74. At pleasure establish another point on the bottom line of the pocket between the center line 14 6 and intersection 74, as shown by a", and draw a line from 4 through a" intersecting the middle or joint hue 14 6 at a'. Project a' back to the outer curve in the rear view, as shown by a and draw a line from a to 4, cutting the base line of the pocket F x E, at a". The intersections a" and 74 in the rear view then indicate similar points a" and 74 in the side view. Trace a curve through the various intersections thus found in (Z) as from 1 to E, then D 38 E F 1 will be the pattern for rear head in the pocket on the line D° F°. Space the profiles in the half rear view above the half plan into the same number of spaces as in the similar rear view (Z) as shown by similar number. From the intersections 1 to 5 drop vertical lines (not shown) cutting similar lines 1 5 in the plan at 2, 3, and 4. In a similar manner from intersections 6 to a to 1 in the rear view, drop vertical lines (not shown) cutting sim- ilar lines in the half plan at 7, a, 8, and 9. Connect opposite points by dotted lines both in the rear view and plan in the same manner as in the hah rear view (Z). Where the bottom line of the pocket F° F° in the side view intersects the lines a' 4 and 4 7 at a" and 74 re- spectively, project lines upward until they cut the top line X D" at a and 74. Using 14 in the front view as center, with radii equal to 14 a and 14 74, draw the quadrants cutting the side of the pan in plan, also at a and 74, from which points draw horizontal lines inter- secting similar numbered lines a 4 and 4 7 in plan at a x and 74 1 respectively. From the intersection of the corner of the pocket F° in the side view, with the line 7 5, project this point to the plan view by the quadrant struck from the center 14 and intersect the similar numbered line 7 5 in the half plan at E°. From the intersection b in the rear view above the plan, between the bottom of the pocket and curve 6 D, project this point to the proper sectional line in plan as indicated by b on the line 6 14. Through points of intersections thus obtained trace the eurve E° to b in plan, which represents the intersects -n or miter line between the rear half of the side pocket with the rear part of the pan. To" obtain the pattern for the bottom and front of the pocket on the rear part of the pan, project a line from the center c from which the curve al e in the half rear view was struck, until it cuts the pocket in plan at d° and 9. Take a tracing of E° d° 9 b and place it as shown by E° d° 9 b in diagram Y. Erect the lines E° d° and b 9 indefinitely, and place on both lines, starting from 9 and d°, the stretchout of d e D in the rear view, as shown by 9 e° D° and d° e x D 1 , which completes the rear part of the pattern for the pocket. To obtain the pattern for the transition piece, or the rear part of the dust pan, shown by D" 5 6 14 in the side view, a set of triangles must be constructed showing the true lengths of the various dotted lines in either side view of half rear view (Z), and are obtained as follows: Extend the lines 5 D" and 6 14 in the side view indefinitely, as shown by 5 W and 6 V. Starting from any point as 5 on the line U W, place the distances of the various lines in the rear view (Z) as 5 to 7, 7 to 4 4 to a, 4 to 8, 8 to 3, 3 to 9, 9 to 2, and 9 to 1, as shown by similar numbers or divisions on U W. From the numbers 7, 8, and 9 and the letter a erect lines at right angles to U W, intersecting the line 6 V at 7°, 8°, 9°, and a°. Draw solid lines from 5 to 7°, 7° to 4, 4 to a° , 4 to 8°, 8° to 3, 3 to 9°, 9° to 2, and 9° to 1, which will represent the true lengths of similar numbered lines shown in the four views. The pattern is now in order and is developed as follows: As 5 6 in the side view shows its true length, take this distance and place it in diagram T, as shown. With 6 7 in the rear view (Z) as radius and 6 in T in center, describe the arc 7, which intersect by an arc struck from 5 as center and with 5 7° in the true lengths as radius. With 5 4 in (Z) as radius, and 5 in T as center describe the arc 4, which intersect by an arc struck from 7 as center and 7° 4 in the true lengths as radius. Proceed in this manner, using first the di- visions on the outer profile 6 D in (Z), then the proper true length; the divisions on the inner profile 5 D in Pattern Problems. 423 (Z) and then again the proper true length, until the line 1 1 in the pattern T has been obtained, which equals the length of 1 1 in the side view. From points 1 and 1 in T, at right angles, draw the line IDC, on each side equal to the stretchout of IDC in the rear view (Z), allowing an edge for wiring as indicated by the dotted line in T. Trace a line through points thus obtained and C 6 5 C will be the pattern shape. It will be necessary to find the outline of the shape to be cut out of the pattern T, to admit the joining of the pocket, as shown by the shaded part D D° E b, which is obtained as follows: Where the bottom of the pocket F° F" in the side view intersects the lines 4 a' and 4 7, at a" and 74 respectively, project lines upward and intersect similar lines 4o° and 4 7° in the true lengths as indicated by a x and 74°. In a similar manner where the side of the pocket D° F° in side view intersects the various lines, project this line F° D° ver- tically, and intersect similar numbered true lengths as shown. For example, the line or side D° F° inter- sects 9 1, 9 2, and 9 3 in the side view; these similar intersections are shown in the true length by 91°, 29°, and 93°, and in this way are the balance of the inter- sections 38°, 84°, 4a°, 47°, and E° found and corre- spond to the numbers shown along the intersecting line D E in the rear view (Z) . The same intersections on the true lengths can be proven as follows: For an example, to prove the inter- section 84° in the true lengths: Take the distance 4 84 in the rear view (Z) on the line 4 8 and place it from 4 to 84 between 4 and 8 on the line U W. From the point 84 erect a perpendicular line to U W, intersecting the true length 8° 4 at 84°, and it will be found that it meets a similar intersection previously obtained from the plan. Obtain the outline of the opening in the pattern by taking the distance from 1 to 11 in the side view and placing it in the pattern T from D to D° and 1 to 11. Take the distances in the true lengths, as 1 to 91°, 2 to 29°, 3 to 93°, etc., and place them on similar lines in T, as 1 to 91, 2 to 29, 3 to 93, etc., until the point E is placed. Then again take the distances 7° to 74° and a° to a x in the true lengths, and place them in T from 7 to 74 and a to of . Finally take the division a to b in the rear view (Z) and place it in T from a to b between a and 8, and trace a line through points of in- tersections shown. Then will D° E b be the desired outline to be cut out to admit the joining of the pocket. The method of obtaining the pocket intersection with the front part of the dust pan and the necessary patterns will be briefly described and are shown in Fig. 746. A reproduction of the one half front view, the half plan of same, including the side view of the front part, has been reproduced in their proper positions as indicated in Fig. 746, to the right of the center line One ho'f Pattern for Front of Dust Pan Full Pattern for Bottom and Front of Pocket D" V" 1 I 1 1 1 1 1 1 1 1 1 D° / Pattern for Front \™ Head m Poqket 5k 1 7rLrp4,pnytHqf5inji!ar ^nurribertdl/tye^phown ynphn, frorJ and $ide \! x ! \i B One half Front Vie Side Mew of Front Part Fig. 746. — Half Plan, Half Front and. Side Views, True Lengths and Pattern Shape. A B. Thus 1 5 8 in the half front view shows the sec- tion on the line 1 8 in the half plan and the line 1 8 in the side view, while 8 10 12 shows the section on 8 12 and also on the line 8' 12 in the side view. The side view is projected from the plan the quadrants struck from the center 8, all as shown. In the front view 8 Yd shows the front head of the side pocket, indi- cated in plan by d a x h° and in the side view by h a d° . 424 The New Metal Worker Pattern Book. The first step is to divide the curves in the front view into equal spaces, as shown from 2 to 4, 6 to 8, and from 8 to 12. Connect opposite points by lines as shown from 12 to 2, 11 to 2 and 3; 10 to 3, 4, 5, and 6; 6 to 9, and 9 to 7 and 8. From the various intersections 1 to 8 in the front view draw horizontal fines (not shown) intersecting the side view from 1 to 8. From similar intersections in the front view, erect ver- tical fines (not shown) cutting the plan view also from 1 to 8. In a similar manner, from the points 8 to 12 in the half front view, draw horizontal and vertical fines (not shown), the former intersecting the side view from 8' to 12 and the latter intersecting the plan view also from 8 to 12. Connect opposite points in both side and plan view in exactly the same manner as was done in the half front view. Complete the side view of the pocket as shown by h a d° so that the intersection between the corner a of the pocket in the side view, and the front part of the pan may be found in the front view, as indicated by a°. Draw a line from 11 in the side view through the corner a cutting the line 1 8 at a'. Establish at pleasure the point b midway between a and d° and from a' draw a line through b intersecting the joint line 8' 12 at b'. In a similar manner, between 9 and 10 in the side view, establish at pleasure an extra point c, and draw a line from c to 6. Project these three points back to the front view, as shown by c, b, and a respectively, and draw lines from c to 6, and b to a. In a similar manner project these points in the plan and draw connecting lines as shown. Where the head of the pocket h a in the side view intersects the various lines as shown b}' the small dots, project horizontal lines (not shown) back to the front view intersecting similar numbered lines as indicated by 89, 79, 69, 6c, 610, 510, 410, 310, a b, a° and b° . For example, where the line h a in the side view intersects the fine 5 6 10 at w draw the horizontal line as shown intersecting the lines 5 10 and 6 10 in the front view, and 510 and 610 respectively. Trace a line through intersecting points thus obtained, and 8 510 a° d Y will be the pattern for the front head 'in the pocket. From the points a°, b°, and d in the front view, erect lines cutting similar lines in plan at a x , b x , and d respectively. Project h in the side view to h° in the plan view, and complete the plan of the front part of the pocket as indicated by h° a x d. From v, the center with which the curved corner of the pocket in the front view was struck, erect a line in the plan as shown, cutting the plan of the pocket at t and r. Take a tracing of the pocket pattern Y in Fig. 745 and place it in Fig. 746 as shown by E° D 1 D° d', and to the line d' D° add a tracing of d a x t r in plan, as shown by similar letters in the full pattern for pocket. Extend D X D° and a x t' until they meet at D°. Then E° D x D" a x d' will be the full pattern for the bottom and front of the side pocket. The true lengths of the lines shown in the front view are obtained by extending the lines 12 8' and 1 8 in the side view, as shown by H J and 8 L, and on the line H J the various distances of the fines in the front view are placed, as indicated by similar numbers on H J. From the various points 2, 3, a, 4, 5, 6, 7, and 8 at right angles to H J, lines are erected, meeting the line 8 L at 2°, 3°, a , 4°, 5°, 6°, 7°, and 8°. Draw the true lengths or slant lines to their proper number, as shown to correspond 'to similar numbered connections in the front view. The one half pattern for front of dust pan is now in order. Take the true length of 1 12 in the side view, and place it as shown by 1 12 in R. With 1 2 in the front view as radius, and 1 in R as center, de- scribe the arc 2, which intersect by an arc, struck from 12 as center and 12 2° in the true lengths S as radius. Then using 12 11 in the front view as radius, and 12 in R as center, describe the arc 11, which intersect by an arc struck from 2 as center and 2° 11 in the true lengths S as radius. Proceed in this manner, using alternately, first the divisions along the profile 1 8 in the front view, then the proper length in S; the divi- sions along the profile 8 12 in the front view, then again the true lengths in S, until the line 8 8' in the pattern R has been obtained, which is equal to 8' 8 in the side view. To this line 8 8' add the girth of the flange and wire edge 8 W in the front view, as indicated by 8' W in R. As the reference letters and figures are similar in the pattern, true lengths and front view, the opera- tions just given, and which will follow, can be easily followed. To obtain the intersecting points on the true lengths, between the pocket and pan, simply extend the side a h and extend a vertical line from b in the side view, cutting similar numbered lines in the true lengths as shown. These points of intersections have been further proved by taking the various divisions where the miter line intersects the various lines in the front view, and placing them between their proper numbers on the line H J, and where by erecting perpendiculars Pattern Problems. 425 to H J similar intersecting points are met, as previously obtained from the side view. To obtain the opening to be cut out in the pattern R to admit the joining of the side pocket, take the dis- tance from 8' to h in the side view and place it from 8' to h in E. Then take the distance from 9 to 89° in S and place it from 9 to 89 in R. Proceed in this manner, taking the true lengths from S and placing them on similar lines in R until the point 6° has been obtained. Take the distance from b to d in the front view and place it in the pattern R between the points b and 10, as shown by d. Trace a line through points thus obtained, as shown shaded, which will be the desired opening. The intersecting points in the pattern are numbered similar to those in the true lengths S so that the proDer line from which the distance was obtained can be located. Edges and locks must be allowed on all patterns for either riveting or seaming. PROBLEM 220. Making a Three-prong Fork in Two Pieces. A quick and novel method of laying out the work so that only three seams are required and no double seam- ing is necessary. It has been found that the fork can be made out of less material and in a great deal less time than with methods commonly employed. It is made in two pieces and formed entirely in the brake with seams as indicated. When finished, the fork looks well and is perfectly smooth inside and outside. This Elevation .-Collar Seam /Co/for Seam .Collar Plan Fig. 7 47. — Plan and Elevation of Three-prong Fork. method is adaptable to any profile and any angle. The first fork used was to convey water and it has been tried with success on general piping work. The fork as shown in plan and elevation in Fig. 747 gives a novel method of construction, thereby mak- ing the development of the pattern much quicker than the customary fork in use. The development of the patterns is given in detail in Fig. 748 in which but one half elevation is shown, as both ends are similar. On the different ends of the openings in the prong, place the profiles as shown. Thus, first using 1' as a center, draw the quarter circle 4' 1. Using 8' as center, Half Elevation Alfow Laps for Riveting Fig. 74S. — Method of Developing Patterns for Three-prong Fork. draw the semi-circle 5' 11' and using 15 as center, draw the quarter circle 12' 15. Divide these sections into an equal number of spaces, as shown respectively from 426 The New Metal Worker Pattern Book. 1 to 4', 5' to '11, and 12' to 15, being careful that the number of spaces between 8' and 11 are similar to the spaces between 12' and 15. At right angles to 1' 11' in elevation and from the various, intersections 1 to 3 and 6 to 10 in the sections, draw lines intersecting the base line 1' 11', as shown by similar numbers. In a similar manner from the intersections 13 and 14 in the quarter section, draw lines at right angles to 12' 15', intersecting the line 12' 15' at 13' and 14'. Draw lines from points 1' to 4', to 15'; from points 5' to 8', to 15'; and from 8' to 14' to 9' to 13' to 10' to 12'. These lines represent the bases of sections which will be con- structed in diagrams L, M and N, the altitudes of which will equal the various similar numbered bights in the sections in elevation. To obtain the true lengths from 15' to 1', 2', 3', and 4', place them on the line D E in diagram L as shown by similar numbers, from which points erect perpendiculars equal to similar numbers in the sections in elevation. For example, to find the true length of 15' 2' in elevation, take this distance and place it on the fine D E in diagram L and make the distances 15' 15 and 2' 2 equal to similar distances in the sections in elevation. A line drawn from 2 to 15 in L is the true length of the fine 2' 15' in elevation. In a similar manner take the various lengths of the lines in B and C in elevation and place them on the lines F G and H J respectively, as shown by similar numbers, and obtain the vertical nights from similar numbers in the sections in elevation, all as shown by similar numbers in both diagrams M and N. The true lengths having been obtained the pattern is developed as follows: Take the true length 1 15 in : diagram L and place it on the vertical line 1 15 in the pattern P. Now with radii equal to 15 2, 3 and 4 in diagram L, and 15 in P as center draw short arcs 2, 3, and 4. Set the dividers equal to the spaces 1 to 4 in the section in elevation, and starting from 1 in P, step to arcs 2, 3, and 4, and draw a fine from 4' to 15. With a radius equal to 4 5 in elevation and 4 in P as center, describe the arc 5 which intersect by an arc struck from 15 as center and 15 5' in diagram M as radius. Draw lines in P, from 4' to 5 to 15. With radii equal to 15 6, 15 7, and 15 8 in the true lengths in M and 15 in the pattern P as center, describe the short arcs 6, 7, and 8. Set the dividers equal to the divi- sions between 5' and 8 in the semi-section in elevation, and starting from 5 in P, step to arcs 6, 7, and 8 as shown. With 15 14' in the section in elevation as radius, and 15 in P as center, describe the arc 14 which inter- sect by an arc struck from 8 as center, and the true length 8 14 in diagram N as radius. Now, with 8 9 in section in elevation as radius and 8 in P as center, describe the arc 9, which intersect by an arc struck from 14 as center and 14 9 in diagram N as radius. Pro- ceed in this manner, using alternately first the division in the lower profile in elevation, then the true length in N; the proper division in the upper profile in ele- vation, then the true length in N, until the line 11' 12' in the true length in the pattern has been obtained, which is equal to 11' 12' in elevation. Trace the out- line in the pattern P as shown by 1 4' 5'11' 12' 15 and trace this hah pattern opposite the line 1 15 as indi- cated by 14 5 11 12 15, which completes the half pat- tern for the three-pronged fork. Laps for riveting and seaming on the collars should be allowed for. Then cut out the metal and it is ready to be taken to the brake and any workman who is familiar with the use of the brake can soon form up the two parts of the fork so that it is an easy matter to rivet them together, at the first trial at making one, into a fork that will have a decidedly pleasing appearance especially when the expeditious procedure is considered. PROBLEM 221. A Spiral Conveyor or Loading Spout. The problem of Fig. 749 assumes that the loading spout is to have a pitch of 45 degrees with a reverse pitch on the same angle, the template for the spout to be semi-elliptical and 14X32 inches in size. Drawings have been prepared, making the angle of the spout in elevation 60 degrees in place of 45 degrees, so as to show more clearly the principles involved. In this case the pitch in the plan is assumed to be as much as indicated by B C. In this connection it is proper to say that no matter what the angle may be in the elevation or the amount of offset in plan, the principles hereinafter ex- plained will apply to any angle, offset or section. Establish at pleasure any point A, from which draw the horizontal line A 9 and the vertical line A B, forming Pattern Problems. 427 a right angle as shown in Fig. 750. From A draw an angle of 60 degrees as shown by A c. Establish at pleasure the throat in elevation as A 1 and using A as center and A 1 as radius, describe the arc 1 b. Make the dis- tance 1 9 equal to 32 inches, as called for, and using draw radial lines to the center A, cutting the inner are as shown. Extend these radial lines until they inter- sect the outer arc. These radial lines then become the miter or joint lines, thus allowing a given profile on the line 1 9 in --14'-. "Elevation ':!? P 5 6 7 &9 ' ! TrueLengfhsof 5olid Lines It.9 ?345'67'8'9 True Lengths of Doffed Lines Fig. 750. — Method of Developing Pattern for Loading Spout. A as center describe the outer arc 9 c. Bisect the line 1 9 in elevation and obtain the point 5. Using A as center and A 5 as radius, describe the arc 5 a. As the spout is to have four pieces, divide the arc 5 a into four equal parts, as indicated by 5, 5°, e, d, a, through which points elevation, to become the true profile on each of the joint lines shown. Thus it will be seen that by dividing the elevation into equal parts, each piece and each joint line becomes equal in length, so that the same profile and girth can be used on every one of the radial fines shown. 428 The New Metal Worker Pattern Book. By using this method and that which will follow, only one pattern need be developed, which can be used for the four pieces, no matter what the offset plan may be. From any point B on the center line A B, draw the horizontal line B 9 and intersect it by a line dropped from 5 in elevation at 5 Z in plan. This point 5 J , then, represents the center, around which the profile shown by 1 5 9 is placed in position and represents the true profile on the line 1 9 in elevation. Knowing the amount of offset that the spout is to have, set off this distance as shown from B to C and divide this distance into as many parts as the spout will have pieces (in this case four), as shown by F, E, D, and C. From the points C, D, E, and F, draw lines parallel to B 5 X , and inter- sect them by vertical lines (partly shown) dropped from points a, d, e, and 5° in elevation, at a°, d°, e°, and 5" respectively, in plan. Draw a line from a° to d° to e° to 5" to 5 X , which will represent the center line of the spout in plan and will show how far each one of the four pieces in elevation will project away from the reader the first piece starting at 5 J 5°, and the fourth piece at d° a°. In working out this problem in practice, all that is required so far as the pattern is concerned, is the center line 5 X 5" in the plan view of the first piece in elevation. As the profile 15 9 in plan shows the true section on the line 1 9 in elevation, the next step is to obtain a horizontal section on the line 1° 9° in elevation, as fol- lows: Divide the true profile in plan into equal spaces as shown by the small figures 1 to 9. From these divisions erect vertical lines (not shown), cutting the base line of the first piece in elevation as shown from 1 to 9. Using A as center, with the various divi- sions 1 to 9 as radii, describe arcs cutting the radial line or joint line of the first piece, as shown from 1° to 9°. Extend the line F 5° in plan as shown, on which place a reproduction of the true profile with the various intersections, as shown by Y. From the various di- visions in Y draw horizontal lines to the left, which intersect by vertical lines dropped from similar num- bers on the joint line 1° 9° in elevation, thus obtaining the intersections 1° to 9° in plan. Trace a line through points thus obtained and 1° to 5° 9° will be the hori- zontal section on the joint line 1° 9° in elevation. Connect solid and dotted lines in plan as shown and connect similar numbers in a similar manner in the elevation. Then will these solid and dotted lines in plan represent the bases of triangles which are yet to be constructed, the altitudes of which will equal the vertical hights of similar numbered intersections in elevation. To obtain the length of the solid lines, proceed as follows: Extend the line A 9 in elevation as shown and from any points on same, as a a and b b, erect perpen- diculars, which intersect by horizontal lines drawn from the various intersections on the joint line 1° 9° in ele- vation, thus obtaining the points 1° to 9° on lines erected from a a and b b. As all the solid lines in plan are similar, take the distance of one and place it to the right of the eleva- tion, from the corner a a to the point marked 1 to 9, and from this point draw lines to the various inter- sections 1° to 9°, which will give the true lengths of the solid lines in plan or elevation. Obtain the true lengths of the dotted lines by taking the various lengths of the dotted lines in plan, and setting them off from the corner b b in the diagram of clotted lines as follows: Take the distance from 8° to 9 in plan and set it off from b b in the diagram and mark the intersection 9. As the dotted line runs from 9 to 8° in plan, draw a line from the point 9 just obtained in the diagram to the point 8° on the perpendicular line erected from b b. Then 8° 9 is then the true length of 8° 9 in plan or elevation. In a similar manner take the various distances in plan from 7° to 8, 6° to 7, 5° to 6, 4° to 5, 3° to 4, 2° to 3, and 1° to 2, and place them in the diagram of dotted lines, measuring in each instance from the point b b and draw lines from 7° on the perpendicular line to 8 on the base line; 6° to 7, 5° to 6, 4° to 5, 3° to 4, 2° to 3, and 1° to 2, which rep- resent the true lengths of the dotted lines in plan or elevation. The pattern is now in order and is developed as follows: Draw any horizontal line 1 1° in X, equal to the true length 11° in R. With 1 2 in the true profile as radius and 1 in X as center describe the arc 2, which intersect by an arc struck from 1° as a center and 1° 2 in diagram of dotted line T as radius. Using the same radius 1 2 of the true profile with 1° in X as center, describe the arc 2°, which intersect by an arc struck from 2 as center and 2 to 2° in diagram R as radius. Proceed in this manner, using alternately first the proper division in the true profile, then the proper solid line in diagram R; again the proper division in the true profile, then the proper line in diagram T, until the line 9 9° in the pattern has been obtained. Trace a line through points thus obtained, then will 1 9 9° 1° be the pattern shape for all four pieces for the spout., to which riveting flanges must be allowed. Pattern Problems. 429 PROBLEM 222. Developing Patterns for an Unusual Two-way Y. In this problem both legs of the two-way Y are to be of equal but short length ; the leg A, however, is to be of a different angle from the leg B, the two legs to form an acute angle in plan. The opening of the feed collar to be square to the plumb line. In this connection, it is only proper to say that it makes no difference how long the legs may be, whether of equal length or not, or what diameters the three Tru_ _ of Left Full Pattern ■for Left Prong 2- Fig. 751. — Method of Developing Patterns for Two-way Y. openings may have or what angles the legs may have in plan or elevation, the principles set forth herein are applicable to any condition. The first step is to draw the correct angle of the two branches in plan as indicated by C 4 E, and using 4 as center with the required radius, draw the plan of the feed collar shown by 1, 11, 6, 8. Now extend the lines C 4 and E 4 until they intersect the circle at D and F respectively. As both branches have different angles in elevation, true elevations must be drawn at right angles to C 4 and E 4 respectively. Bisect the angle C 4 E in plan and draw the miter or joint line A B, cutting the circle at point 6. At right angles to 4 E and 4 C tangent to the circle, draw lines inter- secting each other at 2. Then 6 2 is the length of the joint line in plan, through which a true section or profile must be drawn at pleasure as follows: Parallel 2 6 in plan, draw any line as 1 6 in M, at right angles to which, from points 2 and 6 in plan, erect lines inter- secting the line 1 6 in M as shown. Now take one-half the diameter of the circle R in plan and set it on the center line in M, from / to 4 and draw at pleasure the graceful semi-elliptical figure shown by 1 2 4 6. Divide this true section M in equal parts, making the spaces smaller where the curve is shorter as shown. From these divisions numbered 1 to 6, at right angles to A 6 in plan draw lines intersecting A 6, also from 1 to 6. As C 4 in plan represents the center line of the left prong, a true elevation must be found on this line; also a fore- shortened view on the joint line 2 G in plan, and is ac- complished as follows: From 4 in plan extend the center line 4 G, cutting any horizontal line drawn at pleasure, as 6' 10', at a. From a draw the angle G a 15, as de- sired, making the line a 15 as long as required. Through 15, perpendicular to 15 a, draw the diameter, 13 17 of the required size. Draw a line from 13 to 10'. If 13 10' is required to be longer or shorter, this can be made as desired, which will simply change the length of the center line 15 a. At right angles to 13 17 draw the profile of the opening on 13 17, as shown by N, which divide into equal spaces shown from 13 to 20, from which points perpendiculars are drawn to 13 17 until they intersect 13 17 in elevation as shown by similar numbers. Now from the intersection 1 to 6 . on the joint fine 2 6 in plan, erect perpendicular lines parallel to 4 G, until they cut the line 10' 6', which represents the diameter of the feed collar, as shown. Now measuring from the line 1 6 in the true section M, take the various distances to points 2 to 5 in the section, and place them in the elevation of the left prong on similar fines just erected, measuring in each instance from the fine 6' 10', and resulting in a foreshortened view of the joint fine between the two prongs, as indicated by similar numbers. Draw a fine from 17 tangent to this view at 5', which completes the elevation of the left prong. 430 The New Metal Worker Pattern Book. A plan view must now be obtained on 13 17 in elevation, as follows: From the various intersections 13 to 17 in elevation, drop vertical lines crossing the center line C 4 in plan, as shown. Now, measuring from the line 13 17 in the profile N, take the various divisions to the various numbers 14 to 20 and place them on lines having similar numbers, measuring on each side of the center fine C 4 in plan, and resulting in the elliptical figures shown by 13, 15, 17, 19. In a similar manner obtain the elevation of the right prong. At right angles to E F in plan construct the true ele- vation as before explained in connection with the left prong. It will be noticed that the angle H 6 27 is different from the angle G a 15 in the left prong. The fine 21 25 in the right prong is drawn at right angles to b 27, and the distance 21 9" is made equal to 13 10' in the left prong, although 21 9" in the right prong could be made any desired length. The foreshortened view 1" 4" 6" in the right prong, as well as the plan view on the fine 21 25, is obtained as previously de- scribed in connection with the left prong. In this case the profile T is similar to the profile N. It makes no difference whether these two profiles are similar or not, as the principles can be applied to various measure- ments and sizes. Having drawn the two true elevations of the prongs at right angles to their respective center lines in plan as well as the plan of the prongs and feed collar, fines must now be drawn in plan representing the base fines of triangles, which must be. constructed. All that por- tion of the feed collar between 1, 11, and 6 will be connected to that part of the outlet between 13, 15, and 17; while the portion between the miter joint 1, 2, 4, 6 in plan will be connected to the opposite side of the outlet, as indicated between 13, 19, 17. Thus the points are connected as follows: 1 to 13 to 10 to 14 to 11 to 15 to 12 to 16 to 6. The lower half is con- nected from 17 to 6, 5 and 4 to 18; then 18 to 3 and 2; then 2 to 19 and 20 to 1. These various lines in plan then represent the base fines of triangles which will be drawn, whose altitudes are equal to the horizontal dis- tances between equal numbered points in the left elevation, as shown parallel to 10' 6'. For example, to find the true length of the line 10 14 in plan, take this distance and set it off on the fine 10' 6° in the elevation of the left prong, as shown by 10 14. From point 14 drop a perpendicular fine until it intersects the horizontal line drawn from point 14 in the elevation at 14°. Draw a line from 14° to 10, which is the true length of the line shown by 14 10 in plan. It will be noticed that part of the true lengths have been placed below P, for want of space. In this diagram the vertical distances are all obtained between similar numbered points in the left elevation. For example: The true length of the fine 17 to 6 in plan is obtained by placing this distance as shown from 17 to 6 in P, and from 17 a perpendicular line is drawn, Riqht'Pronq y"i Elevotidn 37' r Fig. 752. — View of Y Developed. making 17, 17° equal to the distance between the horizontal lines drawn from 6 and 17 in the left eleva- tion. The line drawn from 17° to 6 is the desired true length. In obtaining the true lengths of the right prong, the fines are connected in similar manner as shown in plan, the altitudes being equal to the various num- bered divisions between c and d in the right prong. The full pattern for the left prong is developed as follows: Assuming that the seam is to come along 13 1 in plan, take the length of 13° 1 in the true lengths in P and place it as shown by 13 1 in S. Now using 1 10 in the circle R in plan as radius and 1 in S as center, describe the arc 10, which intersect by an arc struck from 13 as center and 13° 10 in P as radius. Now, with 13 14 in the profile N as radius and 13 in S as center, draw the arc 14, which intersect by an arc struck from 10 as center and 10 14° in P as radius. Proceed in this manner, using alternately first the division be- tween 1116 in R, then the proper length in diagram P; the division in the profile N, then again the proper length in P until the line 6 17 in S has been drawn, after which the balance of the divisions between 16 and 13° are obtained from similar numbers in N, and the divisions from 6 to 10° in S are obtained from the true section M, and the proper slant lines in P are placed in their proper position in S. Pattern Problems. 431 Note that points 5 and 4 in S are drawn to 17; 4 3 and 2 to 18; 19 and 20 to 2, etc. Whichever way the lines are connected in plan, so must the lines con- nect in the pattern as shown. Trace a line through points of intersections thus obtained as shown by 1 6 1° 13° 13, which will be the full pattern for the left prong. After the true lengths of the lines have been found for the right prong, the pattern is developed the same as just described. PROBLEM 223. Pattern for Elbow Transition Piece. This problem demonstrates the shortest method of developing the patterns for an elbow, measuring 10X48 inches at one end and making a transition to a 13-inch round pipe at the other end. The radius of the throat and heel of the elbow is shown in Fig. 753. In this figure the section on the line A B is a rectangle, 10X48 inches. The heel of the elbow is ., P XI . Do same with space 2 T 2 and 1 T 1. A line through points Z , 1* etc., gives true profile of the boss. For the pattern draw a line U V at right angles to line o' o" and place thereon the spaces 3* around to 2 ZX in the true profile as s to 6 s . Draw lines through these points parallel to o' o" and intersect them by lines projected from like points in the boss as shown in the diagram. A line traced through the points ob- tained by that procedure will be the pattern to which necessary laps are to be allowed. Exactly the same procedure is followed for the other boss as directed by Fig. 790. 450 The New Metal Worker Pattern Book. PROBLEM 231. Pattern for an Unusual Five-pronged Fork. Many and diverse are the problems arising in the trade and herewith is a demonstration how to lay out the patterns for a five-pronged fork shown in Fig. 791. The lower pipe is a rectangle, from each corner of which a fork is to project with a round outlet. Through the center another fork projects. All parts marked A indicate the round pipe in both plan and elevation. As the corner forks have equal Fig. 791 . — The Five-pronged Fork. flare, the pattern for one can be used for all. In devel- oping this corner fork only one-quarter plan will be required as indicated by a b c. First draw any center line as A B on which estab- lish any point as C, and from this point draw the one- quarter rectangle as indicated by C 1 1° 12. From 1° draw the desired angle of the fork as shown by 1° a. Establish the length of the fork on its center line as 15, through which draw the vertical line 13 17, repre- senting the top line of the round pipe in plan. Make 15 13 and 15 17 each equal to the semi-diameter of the pipe, and draw a line from 17 to 1 and 1° and from 13 to 1° and 12. From 15 draw the horizontal line 15 15' indefinitely, on which establish the center m, with which describe the circle G' equal to 13 17 as shown. Divide this circle into equal spaces from 13' to 20', through which points draw horizontal lines, cutting the line 13 17 and from these points draw lines to the apex 1°. With C as center and the desired radius, draw the quadrant 5 8, which divide into equal parts as shown by 5, 6, 7 and 8. This quarter circle 5 8 represents the quarter section along the base of the center prong 8 5 in elevation. The quarter circle no in plan shows the quarter section on the top line of the prong D E in elevation. Through any point as 12 in elevation, draw the hori- zontal line X Y. Establish at pleasure the liight of the prong as 12 8 in elevation, and draw the horizontal line 8 7 6 5 representing the base line of the center prong- as shown by the dotted lines projected from the plan. Project the point 1 in plan as shown by 1 in elevation and at pleasure draw any desired profile as 5 1. Divide this into equal spaces shown by 1, 2, 3, 4 and 5 and drop these points in the plan as shown by similar numbers. A true section must be drawn at pleasure on 8 12 in plan as follows: At right angle to 8 12 in plan from the point 8 erect the line 8 8° equal in liight to 12 8 in elevation, and from the point 8° in plan draw at pleas- ure the profile 8° 12, which divide into equal spaces as shown by 8°, 9, 10, 11 and 12, from which points draw horizontal lines cutting the line C B in plan at 8, 9, 10, 11 and 12 and vertical lines cutting the base lines X Y in elevation as shown by similar numbers. Using 12 in elevation as center and with radii equal to the various numbers draw quadrants intersecting the vertical line A B at 8, 9, 10 and 11. From 12 in eleva- tion draw the desired angle of the center of the prong as indicated by 12 b, which intersect at 13 17 by a line erected from similar numbers in plan as shown. From 13 17 in elevation draw a horizontal line, on which estab- lish any point as s which use as a center and describe the circle G similar to G 1 . Divide G into the same number of parts as G 1 , being careful that if 13' 17' runs vertical in G 1 it will run horizontal in G. From the various points in G project lines to the line 15 19. Draw lines from 15 to 8 and 19 to 1 and draw the center prong D E 5 8 to correspond to the plan as shown. G and G 1 then represent the section of the top of the prong on the lines 15 19 in elevation and 13 17 in plan respectively; 1 5 in elevation the true section on the line 1 5 in plan; the quadrant 5 8 in plan the true section on the line 5 8 in elevation; the section 8° 12 in plan the true section on the line 8 12 in plan or eleva- tion and the quarter rectangle C 1 1° 12 in plan the section on the base line 12 1 in elevation. Pattern Problems. 451 To avoid a confusion of lines separate plans have been drawn showing the base lines in the bottom and top of the prong. Thus 1 1° 12 13 17 shows the one-quarter plan of the base lines in the bottom of the prong, while A x , which is a reproduction of B x , shows how the base lines are drawn in the top of the prong. Note in the plan B 1 or bot- tom the side 11° connects to 17, while the side 12 1° connects to 13 and all the spaces on 13 17 are connected to 1°. In the plan A x or top, points 1 to 5 connect to 17; points 17 to 15 to 5; points 15 to 13 to 8; points 5 to 8 to 15 and points 8 to 12 to 13. Parallel to the base line X Y from the various intersections in the elevation from 1 to 5; 5 to 8, 8 to 12 and 13 to 20 draw lines to the right indefi- nitely, these hights representing the altitudes of the various tri- angles which will be constructed with bases equal to similar numbered lines in the quarter plans B x and A 1 . To obtain the true lengths of the base lines in the bottom of the prong B x take the various lengths of the lines in B x and place them as shown on the line X Y in elevation. From these points erect perpendiculars in- tersecting similar numbered horizontal lines previously drawn from similar numbered points in the elevation. For example: To find the true length of the hne 12 13 in plan take this distance and place it as shown from 12' to 13' on the line X Y. As 12 in elevation is on the base hne, then 12' remains in the position shown, but from 13' erect the perpendicular line, intersecting the horizon- tal line drawn from 13 in elevation at 13. Then 13 12' is the true length of the hne shown by 13 12 in plan. Pattern for Corner Prong All FburAhhe Pattern for Center Prone Fig. 792. — Details of Pattern for Five-pronged Fork. To avoid a confusion of lines in finding the true lengths of the fines in the top, a reproduction of the one-half elevation showing the various altitudes has been made in 452 The New Metal Worker Pattern Book. C x with all the required numbers and intersections. From the various points in (T draw horizontal lines to the right. Extend the line 12 1 in C 1 indefinitely to the right as shown, on which place the various lengths shown in the quarter plan A* as shown by similar numbers on the lines 12 T, 8 V and 15 W in C x . At right angles to these lines from the various intersections on same draw lines intersecting similar numbered horizontal lines from the various numbers in the elevation C z . Connect points by lines as shown, which will be the true lengths of similar numbered lines in the plan A 1 . Thus to find the true length of the line 9 13 in plan A 1 set off this distance as shown from 9' to 13' on the line 12 T. From 9' and 13' erect perpendiculars inter- secting horizontal lines drawn from 9 and 13 in C J , thus obtaining the intersections 9 and 13, which be- comes the true length of 9 13 in A r . The pattern may now be laid out as follows: If the seam is to come on 1 19 in elevation or 1° 19 in plan, take the true length of 1° 19 in the true lengths in K and place it in the pattern in M as shown from 1° to 19. Using 1° in M as center and a radius equal to 1° IS and then 17 in K, draw the arcs 18 and 17 in M. Set the dividers equal to 19' to 18' to 17' in G 1 and start- ing from 19 in the pattern M step to arc 18 then to 17 and draw a line from 17 to 1°. With 1° in 1 plan B x as radius and 1° in M as center draw the arc 1, which intersect by an arc struck with 17 as center and 17 1' in K as radius. Draw a line from 17 to 1 in M. With radii equal to 17 to 2, to 3, to 4, to 5 in L and 17 in M as center draw the arcs 2, 3, 4 and 5. Set the dividers equal to the spaces between 1 and 5 in the section H in elevation and starting from 1 in M step to arc 2, 3, 4 and 5 and draw a line from 5 to 17. Again referring to diagram L obtain the radii 5 to 15 and 16 and using 5 in M as center describe the arcs 16 and 15. Set the dividers equal to the spaces between 17' and 15' in either G or G 1 , and starting from 17 in M step to arc 16 then to 15 and draw a line from 15 to 5. With radii equal to 15' 6, 7 and 8 in L and 15 in M as center describe the arcs 6, 7 and 8 which intersect by divisions obtained from 6, 7 and 8 in the quadrant in plan B x , and draw a line from 8 to 15. With radh equal to 8 14 and 13 in L and 8 in M as center draw the arcs 14 and 13 and intersect same by spaces obtained between 15 and 13 in G 1 . Draw a line from 13 to 8. Again using the radii in L from 13 to 9, 10, 11 and 12' with 13 in M as center draw the arcs 9, 10, 11 and 12, which intersect by arcs equal to the spaces in the profile J from 8° to 12 in plan. Draw a line from 12 to 13 in M. With 12 1° in plan as radius and 12 in M as center describe the arc 1°, which intersect by an arc struck from 13 in M as center and 13 1° in K as radius. Draw a line from 1° to 13 in M. With radii equal to 1° 20 and 19 in K and 1° in M as center describe the arcs 20 and 19, which intersect by arcs with spaces equal to 13 to 19 in G or G 1 . Draw a line from 1° to 19 in M and trace a line through the various intersections obtained. Then will 1° 1 5 8 12 1° 19 13 17 19 be the pattern for the corner fork, four of which will be required, two formed right and the other two left. The pattern for the center fork is obtained by extend- ing the hue 5 E in elevation until it intersects the center line A B at F. Then using F E and F 5 as radh and F° in diagram N as center describe the arcs E 1 E° and 5 5°. From any point as 5 draw a radial line to F° intersecting the inner arc at E 1 . On the outer arc 5 5° lay off the girth of four times the number of spaces contained in the quarter circle 5 8 in plan as shown from 5 to 8 to 8' to 8" to 5° in N. From 5° draw a radial line to F° and 5 5° E° E 1 is the pattern for the center fork. Allowance must be made on all patterns for riveting or seaming. PROBLEM 232. Circle to Ellipse Offset Transition Piece. An instructive demonstration of the method for developing patterns for a square elbow having an ellip- tical base 7X11 inches to an 8-inch circular section offsetting at an angle of 30 degrees when viewed in plan, as shown by Fig. 793. In developing these patterns the elliptical pipe can be developed by parallel lines while the circular pipe must be laid out by triangulation. The first step is to draw the plan of the elbow as shown in the accompany- ing illustration, in which 8 2 4 6 shows the plan of the elhptical pipe. Draw the two diameters in the ellipse which intersect each other at V. From this intersection V draw a hne at the desired angle or 30 degrees, as shown by V 1'. Pattern Problems. 453 Establish the desired length of the arm of the elbow from V to 1' and at right angles to this line, through the point 1' draw the line 3' 7', making 1' 7' and 1' 3' equal to the semi-diameter of the S-inch circular pipe. In line with 3' 7' in plan draw the profile of the circular pipe, as indicated by X, as shown. This completes the plan view of the elbow, offsetting at an angle of 30 degrees. Before the side elevation of the elbow can be drawn (which however is not necessary in the development of the patterns), an oblique elevation must be drawn as follows: At right angles to V 1' in plan, draw the oblique elevation of the elbow, as shown by 5' 5 S T 1 1, mak- ing both arms of the elbow at right angles to each other, both in the throat and on the heel, as per requirements of the problem. In line with 1' 5' in the oblique view draw the profile Z similar to the profile X in plan. Assuming that the seams are to come in the throat of the elbow, start point 1 in the throat line in profile Z and divide the profile in an equal number of divisions, in this case 8, as shown from 1 to 8 to 1. From these small figures parallel to the arm 5' 5 in the oblique view draw lines to the left, cutting the elevation line from 1' to 5', as shown. In a similar manner divide the profile X in plan in similar number of spaces, as shown from 1 to 8 to 1, being careful to start 1 in the profile X, as indicated, thus making a quarter turn from that in the profile Z. From the small figures 1 to 8 in X, parallel to the 30 degree fine V 1' draw lines as shown, cutting the plan fine from 3' to 7', as shown. Now divide the elliptical profile in an equal number of divisions, being careful to have the points 1 and 5 at the points of tangency where lines drawn at right angles to V 1' are tangent to the extreme outline of the elliptical section, as indicated by 1 and 5. Note that the two ends of the ellipse have been divided into smaller spaces than the sides, all as indicated. In developing the transition arm from circular to elliptical, triangulation will be used, and as the circular section is divided into 8 parts and the elliptical section into 12, for that reason are the divisions in the elliptical section numbered 1 1°, 2, 3 3°, 4, 5 5°, 6, 7 7°, 8, so that the two ones, the two threes, the two fives and the two sevens will join with 1', 3', 5' and 7' respectively when joining the base fines of the triangles in plan. As previously mentioned, the side elevation is not necessary in the development of the patterns and if it was desired to draw this correctly, inasmuch as it is good practice and allows of a better conception of the problem, it would be done in the following way: From the small figures in the elliptical profile in plan, drop lines at right angles to V 1' crossing the miter line 5 1 in the oblique elevation, as shown by similar numbers and intersecting the base line of the elbow S T, as shown. In similar manner at right angles to the diameter 4 8 in the elliptical profile in plan, erect fines indefinitely and at pleasure draw the line S° T° parallel to 4 8 in plan. Now, measuring in each instance from the line S T in the oblique elevation, take the various distances to the numbered points on the miter line 5 1 and place them on similar numbered fines in the side elevation, measuring in every instance from the line S° T°, thus obtaining the points of intersection shown, which repre- sents the miter line between the two arms. From the intersections 1 and 5 which represent respectively the throat and heel fines of the elbow, draw horizontal fines to the right, which intersect by the vertical fine erected from the point 1' 5' in plan, thus obtaining points 1" and 5". In line with 1" 5" in the side elevation draw the profile Y similar to profiles X or Z. As point 1 begins at tfie throat fine in profile Z in the obhque elevation, then, also begin 1 in the throat line in profile Y in the side elevation, as shown, and space the profile in eight equal spaces. From these small figures 2 to 8 draw horizontal lines to the left and intersect same by vertical lines erected from similar numbered points in plan, thus obtaining the points of intersection 8" to 2" in the side elevation. Then will T° 1 1" 5" 5 S° be the true side elevation of the elbow. The patterns are now in order and the pattern for the elliptical pipe is obtained as follows: Extend the line T S in the oblique elevation as T l x and starting torn 1° set off the girth of the elliptical profile in plan, as shown by similar numbers on T I s . At right angles to T l z from the small figures on same, draw lines which intersect by lines drawn parallel to T l x from similar numbered intersections on the miter line in the oblique elevation. A fine traced through points thus obtained, as shown by 1 1" l x 1 will be the desired pattern. Now connect the base lines in plan from which the true lengths are obtained. Draw solid fines from 1 and 1° to 1'; from 2 to 2'; 3 and 3° to 3'; 4 to 4'; 5 and 5° to 5'; 6 to 6'; 7 and 7° to 7' and 8 to 8'. Draw dotted lines from 1° to 2'; 2 to 3; 3° to 4'; 4 to 5'; 6 to 5'; 7 to 6'; 8 to 7' and 1 to 8'. These lines then represent the bases of triangles which will be constructed whose altitudes will equal the difference between similar num- bered points in the oblique elevation. For example: To find the true length of the solid fine 2 2' in plan, take 454 The New Metal Worker Pattern Book. this distance and set it on the horizontal line 2 2' in the true solid length. 5 Side Elevation 5 the miter line carry lines to the right, meeting the line a b, as shown. In same way from intersections on the True Lengths of Dotted Lines Fig. 793. — Patterns for Offsetting Transition Elbow. —5' True Lengths of Solid Lines At right angles to 2 2' erect a line from point 2 equal to the difference in hight between 2 and 2' in the oblique elevation. These hights are found as follows: At pleasure, at right angles to the upper arm of the elbow draw any line as a b. From the various intersections on line 5' 1' in the oblique elevation carry lines to left, cut- ting the line a b. Now find the difference in hight between 2 and 2' by following the line drawn from 2 and 2' to the line a b indicated by h i. Set off this hight h i from 2 to 2", Pattern Problems. 455 as shown in the true lengths. Then will the slant line marked T L from 2" to 2' be the desired length. In similar manner obtain all of the true lengths on solid lines in plan. The true lengths of the dotted lines are ob- tained in the same manner. For example take the length of the dotted line 6 5' in plan and place it as shown by 6 5' in the true dotted lengths. Find the difference in hight between 6 and 5' by referring to the line a & in the oblique view where the height is indicated by n o, which is placed as shown by 6 &. &" 5' is then the desired true length. As there is no difference in hights between 1 1' and 5 5' in the oblique elevation then will 1 1' and 5 5' in plan show then - true lengths. When laying out the pattern for the transition arm, the true lengths just obtained, the divisions in the circles X, Y or Z and the divisions along the miter cut in the elliptical pipe pattern are used. The pattern may now be laid out. Take the dis- tance of 1 1' in plan, which shows its true length and place it as shown by 11' in the pattern P. Now with the radius equal to 1 1° in the miter cut in the pattern for elliptical pipe and with 1 in the pattern P as center describe the arc 1°, which intersect by an arc, struck from 1' as center, with the (T. L.) of the solid line 1' 1° in the true lengths of solid lines as radius. Now with 1 2 in either circular profiles as radius, and 1' in the pat- tern P as center, describe the arc 2' which intersect by an arc struck from 1° as center, and the (T. L.) of the dotted line 1° 2' in the true lengths of dotted lines as radius. Now with 1° 2 in the miter cut in the pattern for elliptical pipe as radius, and 1° in the pattern P as center describe the arc 2, which intersect by an arc, struck from 2' as center and the (T. L.) of the solid line 2 2' in the true lengths of solid lines as radius. Proceed in tins manner, using alternately, first the divisions in the circle, then the proper true length; the divisions in the miter cut in the elliptical pipe pattern, then again the proper true length until all the spaces have been transferred. The length 5 5' in pattern is obtained from 5 5' in plan. Trace a line through points thus obtained in P. Then will 1 5 1 1' 1' be the desired pattern. Allow edges for seaming or riveting. PROBLEM 233. Pattern for Fitting of Unusual Design. The irregular fitting shown in Fig. 794 presents some interesting problems in pattern development. The lower pipe is 24 inches square, the upper is a 36-inch octagon, in section, leading to a 36-inch round pipe. Fig. 795 shows the developing the patterns. First, draw the side view of the fitting according to the dimensions and pro- jections desired, and indicated in the side view by 1, 8, 8 1. In its proper position below 8 8 draw the profile of the square end of the pipe, and above 1 1 the profile of the octagon. Project the corners of the octagon to the line 1 1 in the side view indicated by 14 14. From these two points of intersection draw graceful curves, gradually tapering to the corners, 8 and 8 and 7 and 7. Great care must be taken in drawing these curves, or miter fines, in the side view, because when once drawn they become fixed lines which cannot be changed in developing the patterns. This, then, completes the side view, showing the transitions D and E from octagon to square. To the right, in line with the side view, draw the front view of the fitting. Both halves in this view are symmetrical on either side of the center line. In order to avoid drawing the octagon and square profiles in the front view, measurements are taken from 1 to 14 in 36'Round Side Front Fig. 794- — Front and Side View of Fitting. the side view, and placed, as shown, from 14 to 1 in the front view, on either side of the center line. From point 7 in the side view, where the miter line ends, project 456 The New Metal Worker Pattern Book. this point horizontally to the right, cutting the outline of the front view also at 7. Now from point 1, in the front view, draw a gradual tapering double curve to Pattern'] torS.des; C-C in ! Profile , Pattern forTransition' Shown by D-D in Profi Pattern for Side B m Profile Pattern for Transition I* shown byE-E in Profile Front View H Pattern for Side A in Profile True Lengths True Lengths W of Transit.ons of Transitions D'm Profile E in Profile True Lenqth I ofa-2 m Plan Diagram Fig. 795. — Front and Side Views, Profiles, True Lengths, and the Various Pattern Shapes. point 7. This can be traced to the opposite side of the center line, although one-half of the front view is all that is required, because both halves are alike. This then completes the front view showing the miter or joint line of the object or fitting. The four sides of the fitting indicated by A B C C in the profile can be laid out by parallel lines, while the sides D D and E E in the profile, which form the tran- sition from octagon to square, must be laid out by triangulation. To avoid a confusion of lines only one outline (the left in the side view) will be equally divided and from these points horizontal hues are carried through the two views, cutting the right-hand outline in the side view and the left-hand outline in the front view. This will divide these out- lines in unequal parts and also intersect the various miter lines, all as shown. The first pattern to be developed will be that shown by A in the profile. Therefore, extend the center line in the front view, H J, on which place the girth of the outline shown from 1 to 8 on the left side of the side view, as indicated by similar figures 1' to 8' on H J. Through these small figures at right angles to H J, draw measuring lines indefinitely, in- tersecting them by lines drawn parallel to H J from similarly numbered intersections on the miter line in the front view. Trans- fer these points of intersection on the oppo- site side of the center line H J, and trace a line through the points of intersection thus obtained. This forms the pattern for side A in the octagon profile. Now extend the cen- ter line upward in the front view as in- dicated by G F. On this place the girth of the outline on the right side in the side view, measuring each space separately as they are all unequal as indicated from 1' to 8' on F G. Through these small figures draw perpendic- ulars to F G, intersecting them by lines drawn parallel to F G from similar points in the right side miter line in the front view. Transfer One these points in the pattern on the opposite side of F G, and trace a fine through the various intersections, which becomes the pat- tern for the side marked B in the octagon profile. As both curves in the front view are alike, the patterns for the two sides marked C and C in the octagon profile will be similar. To obtain this pattern erect any line at right angles to 1 1 in the side view shown by K L, and on this place the girth of the curve, 14 8, in the front view, measuring each space separately, as indicated by the small figures 8" to 14" on K L. Through these points at right angles to K L Plan Pattern Problems. 457 draw lines to the left indefinitely, which are intersected by lines drawn parallel to K L from similarly numbered intersections on both miter lines in the side view. Trace a line through the points thus obtained, from 14 to 8 to 8' to 14', which will be the pattern for the two sides C C in the octagon profile. The next patterns in order are the two chamfers or transitions, D and E, in the side view. As the true lengths of the edge lines along 1 7 and 7 14 in D, and 14 7 and 7 1 in E in the side view are obtained from the miter cuts in the patterns for A C and B respectively, then the next step is to find the true lengths of the connecting fines in both views as follows, Draw lines in both D and E in the side view from 2 to 14, 3 to 13, 4 to 12, 5 to 11 and 6 to 10; in a similar manner connect similar lines in the front view. Care should be taken to number the points in both views accurately. Thus the outline 8 to 14 in front view represents the section through similar points in the side view. Out- lines 1 to 8 in the side view show sections through the center line in the front view. These various lines 1 to 14 to 2 to 13 to 3, etc., in the front view, then rep- resent the bases of triangles which will be constructed, whose altitudes will equal the horizontal distances be- tween similarly numbered points in the side view. They are constructed as follows: Below the side view draw any vertical fine as M N, upon which place the various distances shown in the front view by 1 14, 14 2, 2 13, 13 3, etc., until the length 6 9 is reached as developed on the line M N from 1' to 9'. From these various small figures at right angles to M N, draw lines indefin- itely, intersecting them by fines drawn parallel to M N from similarly numbered intersections in D and E in the side view. Connect the points in the diagram of true lengths, shown by the heavy lines, those to the left indicating the true lengths of similarly numbered lines in D, in the side view, and those to the right indicating the true lengths of similarly numbered lines in E in the side view. In developing the pattern for the transition piece D, the true lengths for D are used in connection with the divisions along the miter cut in the pattern for A, and the divisions along the left miter cut in the pat- tern for C C. When developing the pattern for the transition, E, the true lengths for E are used in con- nection with the divisions along the miter cut in the pattern for B, and the divisions along the right miter cut in the pattern for C C. For the pattern for the transition shown by D in side view and profile, proceed as follows: Take the length of the side D in profile or 1 14 in the true lengths D and place it as shown by 1 14 in B. Now, with 1 2 in the miter cut in the pattern for side A as radius, and 1 in R as center, describe the arc 2, which intersects an arc, struck from 14 as center and 14 2 in the true lengths for D as radius. Now, with 14 13 in the left miter cut in the pattern, C C as radius, and 14 in R as center, describe the arc 13, which intersects an arc, struck from 2 as a center and 2 13 in the true length for D as radius. Pro- ceed in this manner, using alternately, first the proper divisions along the miter cut in pattern for side A, then the proper true length in D; the proper division along the left miter cut in the pattern for side, C C, and again the proper length in the true lengths for D, until the line 6 9 in R has been obtained. Now using 6 7 in the pat- tern for a side, A, as radius and 6 in R as center describe the arc 7, which intersects an arc struck from 9 as center and 9 7 in the left miter cut in the pattern for a side and C C as radius. Trace a line through the points thus obtained in R, and this will be the desired pattern. In a similar manner obtain the pattern for the transi- tion side marked E in side view and profile. Take the length of the side E in the profile or 1 14 in the true lengths for E and place it as shown by 1 14' in S. Now, using 1 2 in the miter cut in the pattern for side B as radius and 1 in S as center, describe the arc 2, which will be intersected by an arc struck from 14' as center and 14 2 in the true lengths for E as radius. Now, with 14' 13' m the right miter cut in the pattern for sides C C as radius, and with 14' in S as center, describe the arc 13' which will be intersected by an arc struck from 2 as a center, and 2 13 in the true lengths for E, as radius. Proceed in this manner using alternately, first the divisions along the miter cut in the pattern for side B, then the proper true length in E; the divisions along the right miter cut in the pattern for sides C C and again the proper true length in E, until the line 6 9' in S is obtained. Now, using 9 7' in the right miter cut in pat- terns for sides C C as radius and 9' in S as center describ- the arc 7, which will be intersected by an arc struck from 6 as center and 6 7 in the miter cut in the pattern for side B as radius. Trace a line through the points thus ob- tained. This will be the desired pattern. Another pattern will be required, that of the transi- tion from octagon to round, as shown in Fig. 794. This is shown developed in diagram X in Fig. 795. First, draw the plan view of the octagon and circle, through the center of which draw the seam line, as shown. Con- struct the elevation above the plan, although this is not necessary in practice, all that is required being the ver- tical hight indicated by a a'. As each of the eight sides of the transition piece are similar, all that is necessary is 458 The New Metal Worker Pattern Book. to draw radial lines from the corners a a in plan to the center e, intersecting the circle at 2 and 2. Divide the distance between 2 and 2 in equal parts (in this case two) as indicated by 1. As the side of the octagon is tangent to the circle at 1, the true length on this point is equal to the vertical hight of the article indicated by a a' and the true length of a 2 in plan is found by placing this dis- tance from a' to 2 perpendicular to a a', when a 2 will be the desired length. The pattern can now be laid out as shown above the elevation, as follows: Take the vertical hight of the transition piece a a' and place it in the pattern shown by 1 1'. From 1' draw the perpendicular line 1' a equal to one-half the octagon side indicated by 1 a in the plan. Draw a line from a to 1 in the pattern. Now using a 2 in the true length as radius, and a in the pattern as center, draw the short arc at 2. Again using a as center and a 1 as radius, continue a short arc opposite 1 at 1°. Now set the dividers equal to the spaces 1 2 in plan. Starting from 1 in the pattern, step to arc 2 and 1° and draw line from 1° to a. Using 1° as center and 1° a as radius, draw the short arc a° . Now take the full side a a in plan and set it off from a to a° in the pattern. Draw line from a° to 1° and continue in this manner until the opposite half side is obtained, as indicated by a 1" 1. Trace a line through points thus obtained, then 1 1' and 1" 1 will be the half pattern for the transition piece octagon to round. All patterns shown are net, to which edges "or laps must be allowed for seaming and riveting. PROBLEM 234. Pattern for French Style Auto Hood. A very interesting demonstration" follows on how to develop the patterns for a French style of motor hood as shown in the sketch, reproduced in the accompany- ing illustration by the plan, side and rear views, Fig. 796. As the corners of the base of the hood are squares, that is, the sides at the base having no taper, as shown by C 1 C in plan, and as the top of the hood shown by E° 7 7" F° has a taper, thus making D° C X 6 in plan a warped surface, for this reason the sides will have to be developed by triangulation. The miter lines of the chamfer both in plan and elevation have been drawn at pleasure and can remain so, with the exception of the miter line 1 to 3 in plan, which line must be projected from the side view so that the lower mould of the base shown from 1 to 3 in the rear view can be developed by parallel lines. The first step is to draw the plan of the rectan- gular base as shown by H 1" 1 C, above which draw the rear of the hood as shown by H G F E D C, drawing the curves and angles to any required dimensions. From the corners of the chamfer G F and E D in rear view, project lines in the plan, thus obtaining G° F° and E° D°. Now from the corner C in plan erect the vertical line C E 1 and from points E and D in rear view draw horizontal lines intersecting the vertical lines previously drawn at E 1 and D 1 . Then, with C as center and radii equal to C D 1 and C E 1 draw arcs intersecting the horizontal line drawn from C in plan at P 2 and E 2 . Draw the desired pitch E 2 7 in side view and parallel to it, the line D 2 6. Extend the line 7 6 in side view cutting the plan at the desired locations as 7 and 6 respectively. Now from the points 7 and 6 in the side view draw to the required dimensions graceful curves from 7 to 1 and 6 to 1. As the lower part of the side of the base shown from C to 3 in rear view will be developed by parallel lines, the true miter line in plan must first be found before the entire miter line of the chamfer can be drawn in the plan view. This is accomplished as follows: Divide the small curve in rear view into equal spaces as shown from 1 to 3, from which points horizontal fines are carried to the right, cutting the vertical line C E 1 as shown by the heavy dots. Using C as center with these various dots as radii describe arcs cutting the perpendicular line in side view at 1 2 and 3 as shown. Parallel to the base line 1 1 in side view, lines are drawn from the points 1, 2 and 3 on 1 E 2 until they cut the inner curve of the chamfer in side view also at 1, 2 and 3 and from which points they are drawn horizontally or parallel to 1 1° in plan and are intersected by vertical lines dropped from 1, 2 and 3 in the rear view, thus obtaining the points of intersections 1, 2 and 3 in plan. Now, through these points 1, 2 and 3 in plan draw a graceful curve until it meets the point 6 in plan previously obtained, which represents the plan view of the inner curve of the chamfer. From point 7 in plan draw a gradual graceful taper to point 1 as shown by the curve 7 1, which shows the plan view of the outer curve of the chamfer. The proper drafting of the rear, Pattern Problems. 459 side and plan views is half the battle. The pattern for the combined top and front piece is developed as follows : From the points 2 and 3 previously obtained in the side view draw horizontal lines cutting the upper curve in the side view at 11 and 10, and the inner and outer curves in plan view at 2, 3 and 11, 10 respectively. Now, between the points 7 and 10 a in the side view introduce equal spaces shown by 8 and 9 and in- troduce an extra point between 7 and 8 where the curve is small as at a'. From these various intersections 7 to 9 in" side view draw lines indefinitely in the plan, cutting the inner curve in side view at 6, a, 5 and 4, and corre- sponding points in the plan as shown by similar numbers and letters. Now ex- tend the center fine A B of the hood as shown by A J, upon which place the girth of the top and front of the hood shown in the side view by E 2 7 a' 8 9 10 11 1 C and as shown by similar numbers on B J. At right angles to B J through these small figures draw fines as shown which intersect by ver- tical fines, partly shown, drawn parallel to B J from similar numbered intersec- tions in plan. Trace a line through points thus obtained as shown by the intersections E" to C" and trace this cut opposite the center line B J, which will show the full pattern for the top and front of the hood, and the spaces along the miter cut E" C" will give the true top edge line when developing the chamfer pattern. The pattern for the lower part of the side is developed by extending C H in plan as H P upon which place the girth of the mold C to 3 in rear view as shown by the small figures C, 1, 2, 3 on HP. From these small figures perpendiculars are drawn and intersected by fines drawn parallel to H P from similar numbered points C, 1, 2, and 3 in plan view, as shown. Trace the miter cut 1" to 3" in the pattern for sides. Then, 3", 3 C 1" is the pattern for the lower curve to Rear View ,A E Fig. 796. — Pattern for French Auto Hood. 460 The New Metal Worker Pattern Book. which the balance of the side piece must be added by triangulation. Where the line 7 6 extended in side view, crosses the lines 3 in both side view and plan, designate these two points X, as shown. Now, from the intersections 4, 5, a, 6 and D° in plan, draw lines to X and in a similar manner connect similar points to X in the side view as shown. The lines in plan will then rep- resent the bases of triangles which will be constructed, whose altitudes will equal similar numbered hights in the side view and are obtained as follows: Extend the line 3 X in side view, as shown by X Y, upon which place the various lengths of X D°, X 6, X a, X 5 and X 4 in plan as shown by similar numbers on the line X Y. From these points at right angles to X Y, erect lines intersecting them with lines drawn from similar num- bered points in the side view, thus obtaining the points of intersections D" 6", a", 5" and 4". From these points draw lines to X which show the true lengths of similar numbered lines in plan and side view. The true edge line must now be found along the miter line D° 3 in plan as follows: Draw any vertical line as L M, upon which place the girth of the miter line D°, 3 in plan measuring each space separately as shown by similar numbers on L M. Through these small fig- ures at right angles to L M draw lines making them equal in hight to similar numbered points, measuring in each instance from the line 3 3 in the side view and thus obtaining the points of intersections D" 6" a'" 5" 4" and 3" in the developed section. A line traced through these points gives the developed section or true edge line along D° 3 in plan. The pattern is developed with 3 D in rear view as radius, and 3 in the pattern for sides S as center describe the arc D". Take the distance from 3 to X in the side view and place it as shown from 3 to X in S. Now using the true length X D" in T as radius and X in S as center intersect the arc previously struck at D". Now, with radii equal to X 6", X a", 5" and 4° in the true lengths in T, and X in S as center describe the short arcs 6", a", 5", and 4." Now set the dividers equal to the various spaces in the developed section V as 3" to 4" to 5" to a'" to 6" to D" and starting from 3" in S step to similar numbered arcs as shown. A line traced through points thus obtained as shown by D", 6", 1", C will represent the outline of the pattern for the sides. As the pattern for the chamfer will be considered next, the true lengths of the solid and dotted lines shown in the plan of chamfer must be obtained. This is accomplished as follows: Connect opposite points in both plan and side view of the chamfer as indicated from 6 to a', a to 8, 5 to 9, 4 to 10, and 3 to 11. Now draw any line below the side view, as shown by N R, upon which place the various 'lengths in plan as D° 7, 7 6, 6 to a' to a to 8, to 5, to 9, to 4, to 10 to 3, to 11 to 2 and place them on the line N R, as shown by similar letters and numbers. From these points at right angles to N R, erect lines which intersect by lines drawn from similar numbered points in the side view, parallel to N R, thus locating the points D x , 7 X , 6', a' x , Vg^ -■*■*- V' N \\ -^ 1 1 1 1 1 1 il i : i i ! 1 1 J 1 1 1 .1 1 1 1 I I 1 i "1 I 1 1 1 1 1 1 1 1 1 l 1 1 1 1 2 J A 3 2 1 m^Feode' V°$£ b Fig. 799. — Showing Development of Pattern. semi-circular end, as shown in diagram T. A section of the raised bead or swedge is shown in the pattern. Edges must also be added to this pattern for seaming or riveting. The pattern for the lip of the fender rim shown by X 1 in the side elevation has been transferred to diagram, Fig. 799, as shown by 14 4' a in elevation. While this lip can be developed by triangulation, a simpler method can be used, that of parallel lines. Knowing that the true section on the line 4 1 is a true semi-circle 10 inches in diameter, place this profile in its proper position as shown which divide in equal parts, as shown by the small figures 1 to 4, on both sides. Through these intersections at right angle to 4 1 in elevation, draw fines intersecting 4 1 in elevation at 1, 2, 3, and 4. From these intersec- tions parallel to 4 4' draw lines indefinitely, as shown, cutting the lower line of the lip at 1', 2', 3', and 4'. At pleasure at right angles to the fines just drawn, draw the line 4 b'. In similar manner draw the perpendicular 4 b in the semi-circle. Now, measuring from the fine 4 b in the true profile or semi-circle, take the various distances to points 1, 2, and 3, and place them on either side of the line 4 b' on similar numbered lines, thus obtaining the points of intersections 1 to 4 in P. Trace a line through points of intersections thus obtained which will be the true section at right to 4 4' in elevation. Using this section from which to , obtain the girth, the pattern is developed by drawing the girth line c d, parallel to 4 b', upon which place the girth of the section P. From these small figures perpendicular to c.d erect lines, which intersect by fines drawn from simi- lar points of intersections on the upper fine of the lip 1 4 in elevation, and parallel to c d, and through these points of intersections trace the miter cut 1° 1°. In a similar manner from the points of intersections 1' to 4' on the lower fine of the hp in elevation, parallel to c d, draw lines (not here shown), and obtain the lower miter cut, 1" 1". Now, using 1 a in elevation as radius and 1° on both ends of the pattern as center, describe the arcs indicated by a', which intersect in turn by arcs struck from 1" as Centers and 1' a in elevation as radius. This cut 1° a' in the pattern for lip will join 1 in the pattern for the apron, S, also 1 in the pattern for the l^-inch rim, shown in the side elevation. The rim pattern can be pricked direct from the side elevation. aH ■J&* PROBLEM 237. Patterns for Mason's Chute. Numerous queries anent pattern cutting come to the journals aforementioned and in many of these queries tins book is mentioned, often by the remarks that the solution desired cannot be found herein. The solution presented here to one of these queries, evidently moved the author to certain reflections apropos the mentioning of this book and as these reflections are decidedly per- tinent and of value to readers of this book they are incor- porated in this demonstration, as was done in other prob- lems contained in this book. As has often been stated, it is to be borne in mind that this book is a collection of representative problems, Pattern Problems. If,-, some of which will, or rather its principles, apply to any new problem that may come up. However, it is a difficult matter for the average mechanic to apply the principles expounded for a similar problem to his particular case. This, of course, is no invidious reflection on the abilfty of the mechanic, because pattern drafting is a decidedly abstract science based on the higher mathematics, hence the innumerable problems that have appeared since the publishing of the last edition of this book. These prob- lems were not added to the book but are available in a series entitled "Practical Sheet Metal Work and Demon- strated Patterns" and the reader will find that a set of these books will materially help him in solving the prob- The axial line C S being continued indefinitely, the pro- file of the chute is built about it, as it were. Divide the curved part of the profile and project the lines from these division points to the miter line, as shown, finishing thereby that much of the elevation. Parallel to P C and at a distance of one-half the width of the hopper on the top fine of it, draw a short dotted line, as indicated by the clotted line at A 2 . With the trammels or com- pass set to 17 inches (the slant bight of the hopper), and with point 4° on the miter line as a center, describe an arc intersecting the dotted line, establishing thereby the point A 2 . From A 2 draw a horizontal line the width of the top line of the hopper as A 2 P A. Connect A 2 C, vation Plan Fig. 800.— Sketch of the Problem. Fig. S02. — Diagram of Triangles. Fig. SOI. — -First Steps for Obtaining Patterns. Fig. 803.— One-Half Pattern of Hopper. lems arising daily in his work. As his specific problem does not appear in any of the books aforementioned, and as it would be more difficult to show how to apply the principles of similar problems to the case, a demonstra- tion of Iris particular case appears herewith. The deign of the object as here given conforms as nearly as possible to his requirements as given in the sketch, specifications and other information furnished. To give the reader an idea of the design of the article various views are given in Fig. 800. As in Fig. 801, one draws a full-size side elevation of the object in this manner: Draw the center or axial fine P C S, P C vertical and C S at the required angle. Bisect the angle PCS, as shown, which gives the miter hne between the chute, or trough, and the hopper or bin. A C, and A B. Also A 2 to 3° and 2° with dotted lines, all as shown. No further work need be done on the ele- vation, so that now the developing of the patterns is in' order, and as follows: Therefore, for the chute pattern, continue the line R S T and place thereon the stretchout of the profile of the chute, that is to 4 and repeat, as shown. Draw the usual parallel fines which are intersected by the projectors from the miter dine. Tracing a line through the points of intersection completes the net pattern of the chute. Before the pattern for the hopper can be obtained it is necessary to ascertain the true lengths of lines 4° A 2 , etc., of the elevation and to accomplish this a customary diagram of triangles is generated as in Fig. 802. That 466 The New Metal Worker Pattern Book. is to say, on any horizontal line, the distances of the eleva- tion Fig. 801, as A 2 4°, A 2 3°, A- 2° and A 2 C are placed. For instance, keeping C of Fig. 802 constant for all spaces, the distance A 2 4° of Fig. 801 is C 4° of Fig. 802, and so on. From C, in Fig. 802, erect a vertical line equal in length to one-half the top line of the chute, or A 2 P of Fig. 801. It is to be remembered that tins space A 2 P can be taken because all four sides of the hopper are equal in width at the top ; in other words, the hopper is 20 inches square at its top. In Fig. 802 from 3° A and 2° erect verticals, making 3° 3 X the same distance as 3 3' of Fig. 801 in the profile of the chute. And 2° 2 X in Fig. 802 like 2 2' in Fig. 801. 2° A 2 of Fig. 801 like 0' of Fig. 801. Draw lines to X of Fig. 802, as shown, which completes the diagram of triangles. The first step in developing the pattern of the hopper is to draw any fine as B A in Fig. 803 equal in length to B A of Fig. 801. At right angles to B A in Fig. 803 draw line B B° of a length coincident with 0' of Fig. 801. Again, at right angles to B A in Fig. 803 and from A draw fine A A° equal to say A 2 P of Fig. 801 (one-half the width of the top line of the hopper). Connect B° and A° of Fig. 803. Set the compass to span A 2 X of Fig. 802 and with A° in Fig. 803, as center describe a small arc, which is in turn intersected by an arc described with B° as center and a radius equal to C B of Fig. 801. Connect lines as shown. From C of Fig. 803 as a center describe an arc of a radius equal to A° C of Fig. 803. From A° of Fig. 803 as center intersect this arc with one of a radius equal to the full width of the top line of the hopper, or say A 2 P A of Fig. 801. Connect A° A 2 of Fig. 803. Employing A 2 of Fig. 803 as center, describe arcs of radii of the spaces 2 X X, 3 1 X, and 4° X of Fig. 802. Then from C of Fig. 803 as center describe an arc of a radius equal to the space C x H of the pattern of the chute in Fig. 801, the point of intersection in Fig. 803 being labelled H. Again, from this point H in Fig. 803 describe an arc of a radius equal to space H K of the pattern in Fig. 801, calling that point of intersection in Fig. 803, K. Now, from K, Fig. 803, as a center describe an arc of a radius equal to space K M of the pattern in Fig. 801, that point of intersection in Fig. 803 being designated as M. Trace a line through H K and M in Fig. 803 and join these points with A 2 as shown. From A 2 in Fig. 803 describe an arc of a radius equal to one-half the top fine of the hopper, or A 2 P of Fig. 801. From M in Fig. 803 describe an arc of a radius equal to A 2 4° of Fig. 801, the point of intersection in Fig. 803 being called 4 X . Connect M 4 X and 4 1 A 2 of Fig. 803, angle M i 1 A- being posi- tively square if the work is correctly done. This, then (Fig. 803), is one-half the net pattern of hopper. The small circles on the lines in the patterns indicate fines to be bent. PROBLEM 238. Pattern Details for Double Offset Y Branch. Two methods of developing the patterns will be required. The main pipe pattern can be developed by means of parallel fines and the branch pattern by triangulation. The first step is to draw the plan and elevation showing their relative positions from which the various views and miter lines are obtained. Let A 1 in Fig. 804 represent the profile of the 15-inch main pipe. Divide this into any convenient number of equal spaces as shown from 1 to 5 to 1. From 1 draw the horizontal line 1 B indefinitely and from any point as 1 in the side elevation draw the line 1 C at the required angle of 45 degrees. At right angles to 1 C lay off the distance of 12 inches or the diameter of the branch, as shown by C D. From D, parallel to C 1, draw a line which intersect by a horizontal fine drawn from the point 5 in the profile A 1 , thus obtaining the point 5 in the side elevation. Draw a fine from 5 to 1 which will represent the miter line between the branch and main pipe. Intersect this fine by fines drawn parallel to B 1 from the numbers 2 to 4 in the profile A 1 . At pleasure in plan draw the profile A, a duplicate of A 1 , and divide it into the same number of spaces as shown, being careful that if 1 and 5 are placed vertical in A 1 , they will be horizontal in A in plan, thus making a quarter turn. From the point 3 in the profile A draw horizontal lines, which intersect by a line dropped from 3 in the miter line 1 5 in the side elevation, thus locating 3 and 3 1 in plan. From 3 in plan, at the 45-degree angle, draw the fine 3 8 indefinitely, as shown. At right angles to 3 8 from any point, draw the diam- eter 8 12 equal to 12 inches, which bisect and obtain the point a. Using a as center, with a 8 as radius, draw a Pattern Problems. 467 circle which divide into equal spaces, as from 6 to 13. From 12 draw a line parallel to 8 3, meeting the line drawn through the center of the profile A at 12. Now, from the various intersections in the profile A, draw horizontal lines which intersect by lines dropped ver- tically from the various intersections in the miter line 1 5 in the side elevation. A line traced through points lines erected from d and c in plan, at e and c" respect- ively, as shown in the diagram. From c" in elevation draw the horizontal line inter- secting the vertical line previously drawn at d". The vertical hight is equal to d" e, which is used in obtaining the oblique view, and is placed from d' to e in the oblique view. Draw a line from e to c' in the oblique view at Fig. 804. — Plan and Elevation for Obtaining Miter Lines and Pattern for Y Branches from Horizontal Main. True Lengths of Dotted Lines in Top I T 6' i'B Elevation of -ff Branch 6' True Length of Dotted Lino n Bottom Iff If 9 JMV5 7 H3-5-Z I! ISS&7II True Lengths of Solid Lines in Top Plan of Top Of Branch 2? True Section on Joint Line between two Branches 4 II ' W True Lengths of Solid Lines in Bottom ii e Half Paltern for Horizontal Pipe SftoTkX 3 Profile of Branch , Fig. 805. — Method of Obtaining True Lengths of Lines for Developing Pattern for Forty-five-degree Branch. Pattern Details for Double Offset Forty-five-degree Y Branch. thus obtained as from 1 to 3 to 5 to 3 1 will be the miter line between the two branches and main pipe. Before the plan view of the upper end of the branches can be obtained an oblique view of the branch on its center line must be obtained as follows: Through a in the profile of branch H, draw the center fine a b on which establish any points as d and c. Equal in length and parallel to c d draw the line c' d' and extend d d' indefi- nitely. Through the branch in elevation draw the center fine e c" indefinitely, which intersect by vertical right angles to which through the point e draw the line 6' 10', as shown. With t on the line c' e extended, as center, draw the profile of the branch pipe, H 1 , being a duplicate of H in plan. Divide H 1 the same as H. Make a quarter turn in numbering the intersections as shown. From the small figures 6 to 13 in H 1 draw lines parallel to t c', cutting the line 6' 10' as shown by similar numbers. From these intersections 6' to 10' in the oblique view, project lines in the plan parallel to e d' and intersect same by lines drawn parallel to d c in plan from similar 468 The New Metal Worker Pattern Book. numbers in the profile H. A line traced through points thus obtained will give the plan view of the upper end of the branch, shown from 6' to 13'. Trace this elliptical figure on the lower branch shown by 8 X 12*, although this is not necessary in practice, as only one branch is required. This completes the plan view, as shown. As the branch will be developed by triangulation the view of the upper end of the branch in elevation will be necessary. It is projected as follows: Extend c" d" in elevation to the right, as shown, and on this line place a duplicate of the oblique view in plan as shown by the similar letters c' d' e and numbers 6' to 13'. Parallel to c' d' in the elevation, from the various intersections 6' to 13' draw fines to the left indefinitely, which intersect by fines erected from similar numbers 6' to 13' in plan, thus obtaining the points of intersections 6 to 13 in elevation as shown. Trace the elliptical figure shown which will complete the side elevation of the branch and main. A true section must now be found en the joint line 1 12 in plan, which may best be found as follows: From the intersections 11 and 12 in the profile H in plan, draw lines parallel to the lines of the branch, until they inter- sect the joint line 1 12 in plan at 11 and 13. Now from the intersections 11, 12 and 13 in plan, erect perpendic- ular lines in the elevation winch intersect by lines drawn from points 11, 12 and 13 in elevation also parallel to the line of the branch, thus obtaining the points of niter- sections shown by 11°, 12° and 13°. Trace the profile through points thus obtained as shown from 1 to 13° to 11° to 5, which will be the true section on 1 12 in eleva- tion. This completes the plan shown by F 3 8' 12' 12 12* 8* 3* G and the elevation shown by B 1 6 11 5 E. For the pattern for the horizontal pipe, draw any girth line as K L at right angles to B 1 in elevation, on which place the girth of the profile A 1 , as shown by similar numbers. Through these small figures at right angles to L K draw the usual measuring fines, which intersect by lines drawn parallel to L K from similar numbered inter- sections on tfie miter line 1 5 in elevation. A line traced through points thus obtained as shown by 1° 1°° will be the miter 'cut and L 1° 5° 1°° K will be the pattern for the main horizontal pipe. To avoid a confusion of lines in obtaining the pat- tern for the branch pipe, a duplicate of the elevation of the branch shown by 1 6 11 5 with the various intersec- tions on same has been placed, as shown, by similar numbers in A in Fig. 805. In a similar manner a tracing of the top of the branch shown in plan Fig. 804, by 3 1 12 12' 6' 8' has been placed as shown in B in Fig. 805, while a tracing of the bottom of the branch shown in plan, Fig. 804, by 3 5 12 12' 10' 8' has been placed in Fig. 805, as shown by similar numbers in diagram C. A tracing of the profile H of the branch pipe in plan Fig. 804 has also been placed in Fig. 805, as shown by similar num- bers in diagram H. The half pattern for the horizontal pipe shown by J with the various points of intersections on same, is a reproduction of a similar half pattern shown in Fig. 804. Thus the half plans B and C in Fig. 805 will show the base lines of the triangles winch will be constructed, with alti- tudes equal to the various hights in the elevation. With these true lengths which are to be found together with the true girth along 1 13° 5, in A, also in J and H, the pattern for the branch can be developed. The true lengths for the top of the branch will be found first as follows: Having placed the branch A at an angle of 45 degrees to the horizontal as required, draw a horizontal fine through all the intersecting points shown from 6' to 12' at the top, 1 to 5 at the bottom and through points 11°, 12° and 13° in the joint line or true section between the branches. At pleasure to the right and left of the branch draw the horizontal fines NO, PR, T S and M L. In the plan of the top of the branch B draw solid lines from 2 to 7', 1 to 6' and 13 to 13' and connect by dotted fines 3 to 7', 2 to 6', 6' to 13 and 12 to 13' or the shortest way to opposite points. Take the various lengths jaf the solid fines in B and place them on the fine N O, as shown by similar numbers. For example to find tne true length of 1 6' in plan B, take tliis distance and set it off on N O as shown from 1 to 6', from which points erect perpendiculars until they intersect horizontal lines drawn from similar numbered points in the elevation A, thus obtaining the points 1 and 6 in the true lengths. Draw a fine from 1 to 6 which is the true length of a similar numbered line in either plan B or elevation A. In this manner all the true lengths in diagram D are found. In a similar manner take the various lengths of the dotted lines in B and place them as shown by similar number on L M, from which points drop vertical fine cutting hnes drawn from similar numbers in the eleva- tion. Thus in diagram D are shown the true lengths of the solid lines and in diagram E, the true lengths of the dotted lines for the top of the branch. Connect the points by solid and dotted lines for the bottom of the branch as shown in diagram C. Take the lengths of the solid fines and place them on the line P R and the length of the dotted lines on the line S T. From the various numbers on these two lines, perpendiculars are Pattern Problems. 469 drawn, which will intersect similar numbered horizontal lines drawn from the branch A in elevation. Connect these points by solid and clotted lines. Then will the slant lines in F show the true lengths of the solid lines and the slant lines in G the true lengths of the dotted lines for the bottom of the branch. As the seam of the horizontal pipe was placed at the top in branch A, the seam should be placed along the top of the branch or on the line 1 6' in plan B. First, draw any line as 1° 6 in L equal to the true length 1 6 in D. With 1° 2° in the half pattern J as radius, and 1° in L as center, describe the arc 2°, which intersect by an arc struck from 6 as center and 6 2 in the true lengths in diagram E as radius. With radius equal to 6 7 in profile H and 6 in the pattern L as center, describe the arc 7, which intersect by an arc struck from 2° as center and 2 7 in the true length in D as radius. Proceed in this manner, using alternately, first the divisions in the pattern J, then the true length in dia- gram E, the proper division in the profile H, then the true length in diagram D until the line 5° 10' in the pattern L has been drawn. With radius equal to 5 11° in A, in elevation, and 5° in L as center describe the arc 11°, winch intersect by an arc struck from 10 as center and 10 11° in the true lengths in diagram G as radius. With 10 11 in the profile H as radius, and 10 in L as center, describe the arc 11, which intersect by an arc struck from 11° as center and 11° 11 in the true lengths in F as center. Proceed in this manner, using alternately, first the divisions in the true section on the joint fine between the two branches, shown in the elevation E, then the proper true length in diagram G; the proper division in the profile H, then the true length of the proper fine in dia- gram F, until the last fine I 1 Q 1 in the pattern L has been drawn, which is equal in length to 1° 6 in L or 1 6 in D. Trace a line through points thus obtained in L. Then will 1° 5° l x 6 X 6 be the desired pattern. Laps must be allowed for seaming or riveting. PROBLEM 239. Designing Elbows for Rectangular Pipes. As has often been stated the first and most impor- tant essential in pattern cutting is to make a correct design of the object and to prepare as many correct views of the object that could possibly be of help to develop the patterns. Elbows are a leading article of sheet metal work and it would seem that there never can be too much written about them. Commenting not as a criticism but as additional discussion of some elbow problems herein, it is to be said a study of the elbow prob- lems appearing on pages 472 and 473 discovers some points to which attention is drawn. The elbows shown, especially the ones on page 472, which prescribe a curve for the back or heel, are ideal, inasmuch as a sweep is given for the shunting of the air from one fine of piping to the other. It could be said though that those designs give an excess of area, with a consequent waste of material, but this is not of importance as it only appears in the first cost of the outfit, while it might, however, cause friction. An experienced tinsmith will see that the parts must be joined by the common double seam along the corners of the elbows. An article so small as a furnace elbow may be rather difficult to make when it comes to turning the edges along the irregular outlines of the patterns. It is almost impossible to fit a stake head or dolly in the fitting to close down the double seam in the elbows shown on page 472, but perhaps the size of that elbow would permit the use of a stake of special shape, although ex- treme care would have to be taken in closing down the seam, owing to the irregularity of the corners. The popular Pittsburgh seam could not be employed on an elbow of that type, and it would appear that a more simple elbow could be designed for such a situation. Elbows similar to those of Figs. 816 and 817 must at times be constructed, irrespective of the form of the duct to which they connect. In at least one of the methods of laying out elbows, if an ordinary round pipe elbow is to be laid out, first a right angle is drawn, as shown in Fig. 806. Then, de- pending on the diameter, a quarter circle is described, using the apex of the angle or A for the center. If the elbow is large, as for blowpipe work, when it is made of as many as six to eight pieces, the throat and back will have a big sweep, and, by reason of having a large number of pieces, the sweeps of the throat and back will conform very nearly to a true circle, giving an ideal condition 470 The New Metal Worker Pattern Book. for a gradual turning of the direction of the air or other substance passing through it. In furnace work, however, a larger number of pieces than four is seldom used, and, for wall stack, the space available seldom permits more than three pieces. For that reason the quarter circle as in Fig. 806 is made as small as is practicable in putting it together. This quarter circle is divided into four equal spaces, as 1 to 5. From A through 2 a line is drawn which represents the rise of the miter hne. The remainder of the work of laying out elbows has been so often explained that it would be a waste of space to do it here, and this prelim- inary step is given because it is employed in developing Fig. 806. — Finding Rise of Miter Line. Fig. 807. — Procedure for Drawing Elevation. Side Elevatio. ^^-^"1 / Plan 1 Front Elevation Fig. SOS. — Complete Views of Elbow. the patterns of all elbows belonging in this class, which includes both plain elbows and transformers. If an elbow of the center reversible type, shown on page 273, Fig. 817, is to be laid out, so much of the preliminary as is shown in Fig. 806 is used. The next step is to draw the profiles in their correct positions, and complete the side elevation, as shown in Fig. 807, a plan and side and front elevation being given in Fig. 808. The back of the elbow is a straight line, and is easier, quicker and cheaper to make than the curved back that would be required by the design of Fig. 817, as shown as a dash hne in Fig. 807. Observe particularly that nowhere is the area of piece No. 2 reduced. It is understood that, if friction and its continual handicap is to be avoided, these elbows could be made of any number of pieces, which would make them very nearly similar to the ideal in the matter of friction-eliminating sweep. In joining the pieces of this elbow, there is a choice of seaming along the miter lines or the corners, but seaming along the corner admits of much more rapid and stronger work. However, the patterns would be essentially alike. In one case there would be two cheeks, with a throat in one piece, and a back, or heel, in one piece; whereas, in the other case, the pieces Nos. 1, 2 and 3 would be in one piece, with a seam at one corner, or wherever con- venient, and then joined at the miter lines. The pat- tern cutting differs but little in either case, so, assuming A „3( G D B * ^~~~~"~-— — . Fig. 809.— Pattern Fig. 810.— Pattern Fig. 811.— True of Throat. of Heel. Length Diagram. e>^ Right Front Elevation Fig. 812— Pattern of Cheeks. Plan from left Fig. 818. — Right Reversible Elbow. that the seams are to be along the corners, a hne is drawn on which is placed the stretchout of the throat as shown by Fig. 809 and labeled E F G H. At right angles to this hne draw lines through these points. On E, and to both sides of the hne E to A, place one-half of the narrow side of the profiles, also do likewise with the wide side of the profiles at H. Finish the pattern, as shown, and follow similar procedure in Fig. 810 for the pattern of the back, or heel. For the pattern of the cheeks, the first step is to determine the true length of line G C, Fig. 807, which indi- cates the hne of bend of the cheek due to their having a warped surface at the piece numbered 3. Draw a hori- zontal hne equal in length to G C in Fig. 807, as G C, Pattern Problems. 471 Fig. 811. From these points erect verticals of a length equal to one-half the short side and long side of the pro- files, respectively. Connect these points with a line, which is then the true length of G C of Fig. 807. In the elevation of Fig. 807, the pieces No. 1 and No. 3, there shown, would also answer as the patterns of two sides of them, so anywhere redraw a duplicate of the elevation of piece No. 1, as shown in Fig. 812. From 2 in Fig. 812 describe a short arc the diameter of which is equal to the length of Gl CI of Fig. 811. Intersect this arc by one having its center at B of Fig. 812 and its diameter of a length equal to B X, C X of Fig. 810, giving C as the point of intersection, in Fig. 812. From C in Fig. 812 describe an arc of diameter equal in length to the miter line in Fig. 807 of piece No. 3. Intersect this arc by one having its center at 2 of Fig. 812 and its diameter equal in length to F X, G X of Fig. 809, making the point of inter- Side Elevation of both Front Elevation of Right Reversible El bow Plan of Left Reversible Elbow Fig. 811).. — Views of Right and Left Reversible Elbows. section at 3 in Fig. 812. Attach to line C 3 of Fig. 812 the other part of piece No. 3 of Fig. 807, which completes the pattern for the cheeks. These are net patterns only, and to these the usual edges and laps must be allowed for seaming, etc. It is a good scheme to mark on the pattern where these different parts fit together, also where and how much the slight bends are to be made in the parts, as shown by the lines on the figures which have the cross-hatching, which means the inside. The rise of the miter line, as shown by Figs. 806 and 807, is for any kind of a three-piece elbow, and hence the pattern for piece No. 1 will do for a three-piece elbow with the miter cut along the long side of the profile. Two pieces of No. 1 make a 45-degree offset with the miter along the wide side, and, similarly, with piece No. 3, elbows and offsets can be made having miters cut along the narrow side of the profile. Thus, a number of sets of patterns are obtained from one design or elevation of an ■elbow, with the consequent saving of time in developing the patterns, which is of more importance with elbows of elliptical profiles. In Fig. 813 is shown a design for what is termed a " right reversible elbow." The side elevation for this design is obtained in precisely the same manner as for that of Figs. 807 and 808. The procedure for developing the patterns is essentially the same as for the elbow of Fig. 808, and, by consulting Figs. 807 to 812, the methods should be apparent. Note, however, that the side ele- vation of Fig. 813 is also the pattern of one of the cheeks designated A in the front elevation, omitting the warp line, inasmuch as the cheek is a true, flat plane and that a pattern for cheek B, only, must be developed. In Fig. 814 is shown a right, or a left, reversible elbow that also offsets somewhat to the side. The entire pro- cedure is identically the same as for the foregoing, and it Side Elev ation Front Elevahon.offsetting to right Ran, offsetting to left Fig. 815. — Combination of Ninety-degree Elbows. would seem unnecessary to present the drawings of the patterns. It is to be said, however, that the design, as here shown, is applicable only when the offset is slight, for the offsetting to the side squeezes in, as it were, the contour of piece No. 3, which means that the area is reduced. Projecting an oblique elevation may produce the means of obtaining miter lines that would avoid this restriction. However, it will be found that that will help but little by reason of the positions of the profiles, and that a complicated process is evolved which avails nothing in the end, for simple and rapid methods should always be followed. It is within the range of possibility that, in all cases, the offset could be produced some- where else in the line of piping than at the elbow, or else the offset could be made enough more to allow a com- bination of 90-degree elbows, as shown in Fig. 815. The patterns for these elbows are from pieces Nos. 1 and 3 of Fig. 807, and these elbows can be made by either method explained before. 472 The New Metal Worker Pattern Book. PROBLEM 240. A Reversible Elbow Problem in Furnace Fittings. In furnace work it is often necessary to heat a room on the second floor by a wall register placed in the par- tition. The partition on the first floor, where the wall pipe runs, is not directly underneath the partition on the second floor, and is also at a right angle to the partition on the second floor. With the use of a flat elbow and a , reversible elbow these conditions can easily be met. Reversible elbows are usually made in three styles, center reversible, left reversible and right reversible, as shown in Fig. 816. In all three the methods of laying out the patterns two bends could be found by drawing a rear elevation, but the tinsmith will readily see the required angle by laying Ms parts together, leaving these two breaks until the last. Next, directly below the side elevation at Fig. 818, draw a plan, as shown in Fig. 819, which is a view of the elbow looking down from the top. Then, draw a front elevation as shown in Fig. 820 as it would appear if looking at the front of Fig. 818. Develop the pattern for the front piece a b c d, as shown by Fig. 821, making the distance T the same as Fig. SIS. — Side Elevation of Center Reversible Elbow. Fig. 816.— Right Reversible Elbow. Fig. Si 7. —Center Reversible Elbow. Fig. 819. — Plan, s Fig. 822.— Pattern for Bach. 3£, Fig. 820. — Front Elevation. I 1' i-z it 1 1 in Q 8 Fig. 821. — Pattern for Front. Fig. 823 .—Pattern for Sides. Fig. 824.— True Length Diagram. are similar. Here is shown a method for drafting the pat- tern for a center reversible elbow 3| X 10 inch, as in Fig. 817. First, draw an elevation as in Fig. 818, making a 1 the required width, say 10 inches and a b and 1 2 the required depth for collar flange, say 2 inches. Let b c be the desired size, say 4 inches, and let a b and 1 2 (the required size for presenting the width of the pipe), be any desired size, say 3| inches. Then draw the bottom or curved back of the elbow to any curve desired. Extend ol c through until it meets the curved back and from this point draw a line b, then from b to 2, parallel to a 1. These lines represent the portion of the material which is bent to get the spreading effect of the sides, the angle of the bend for c 4 being taken from the front elevation, Fig. 819, at the point s. The exact angle for the other s 0, Fig. 820. Next develop the pattern for the back by first dividing off the curved back of the side elevation in Fig. 818 into equal spaces having one of the points come where the line extended from c intersects the back, also number the straight parts as 1 2 and 12 13. Now lay out a stretchout line N M, Fig. 822, having it come- directly from the center of the plan, Fig. 819, and lay off on this the spaces marked off on the back of the side ele- vation. Then drop vertical lines from the side elevation, Fig. 818, to the outside lines of the plan, Fig. 819, and carry them horizontally to vertical fines with corre- sponding numbers drawn from the stretchout Fig. 822, as shown by the lines carried from the points 8. Trace a line through these points of intersection. This line will be the pattern for the back. Pattern Problems. 473 To get the pattern for the side, first transfer a b and 1 2 from Fig. 818 to one side, as Fig. 823. Then set the compasses to H L, Fig. 822, to get the true length of 2 4, Fig. 818. With 2 of Fig. 823 as a center, strike an arc. Then, with the compasses set to the true length of the line, b 4 of Fig. 818, and with b of Fig. 823 as a center, strike an arc cutting the first arc. Now, to get the true length of this line lay off a diagram of triangle as Fig. 824, in which b 4 is the same as 6 4 in Fig. 818 and X 4 the same as X 4 of the plan Fig. 819, b X then being the required length. Now, with the compasses set to s o of Fig. 820, strike an arc from b, Fig. 823 as center. Then with the compasses set to 12 4 of the plan, Fig. 819, and with point 4, Fig. 823, as center, swing an arc cutting the one swung from b. Draw a line from point 4 through c and on to d, making c d the same as c d of Fig. 818. Make d 13 the same as d 13 of Fig. 818, and 13 12 the same as Fig. 818. Now transfer each of the spaces from 12 to 4 of the plan, Fig. 819 to the line c 4 of Fig. 823. Then drop lines at right angles from each of these numbers and make those lines the same length as the dotted lines on the side elevation, Fig. 818. Then draw the curved line from 2 to 12, Fig. 823, so it touches the outside points. The pattern is now complete for the side. Allow for flanges or folds, bend each side the opposite way when putting the fitting together. PROBLEM 241. Patterns for Sheet Metal Transforming Elbow. In the front and side elevation in Fig. 825 is shown a reproduction of the elbow and referring to the drawing it will be seen that the opening of the elbow at the bottom lies on a horizontal plane, the size of which is indicated by D E F G, and the opening of the elbow at the top hes on a vertical plane, the size of which is shown by 2, 2, 14, 14 in the front elevation, the elbow forming an angle of 90 degrees. In this connection it is proper to say that it makes no difference what size the elbow may have at either end or at what degree it is set, the principles hereinafter set forth are applicable to any size or shape. In develop- ing the patterns the top and back, also the bottom and front, will be laid out by means of parallel lines, while the sides will be developed by triangulation. First draw the side elevation of the elbow, making 1 14 the hight of the upper pipe and 8 9 the width of the lower pipe, the quadrants 2 to 6 and 10 to 13 being struck from the cen- ters a and b respectively. Below the line 8 9 in side view, draw the full profile of the pipe, as shown by D E F G, which, however, can be omitted in practical work. To the left of the side view draw the center line A B and on either side of same proceed to draw the front elevation. In practice it will only be necessary to draw but one-half elevation. Make the distance from 8 to 8 in the front elevation equal to E F of the profile. Project the corners 1 and 14 in the side elevation to the front, making the distance from 2 to 2 equal to the width of the upper pipe, and complete the profile of the top of the pipe, shown by 2, 2, 14, 14. From point 10 in the side view, where the quadrant runs tangent to the vertical line, project a line to the front as shown, and intersect this line at 10 and 10 by vertical lines erected from the points 8 and 8. Now, from 10 in the front elevation, draw lines to 13 and 2, as shown on either side of the cen- ter line. These lines represent the miter or joint hues forming the transition from a given size rectangular pipe at the bottom whose opening is placed horizontally to given size rectangular pipe at the top whose opening is placed vertically. The side and front elevations being correctly drawn the patterns are now in order. Divide the quadrant on the heel also the quadrant in the throat in equal spaces as shown by the small figures 2 to 6 and 10 to 13 respectively. Number the brake line 7 and the ends 1, 8, 9 and 14, as shown. Now, take the girth of the heel of the elbow from 1 to 8 and place it on the center line A B, as shown by similar num- bers, through which draw horizontal lines indefinitely, which intersect by lines drawn parallel to A B from the various intersections 1 to 9 in the front elevation, which points were obtained by projecting horizontal fines from similar numbered points in the side elevation. Trace a line through the various points of inter- sections thus obtained in the pattern, as shown on the left side from 1' to 8', and complete the full pattern shape by transferring the left hah pattern opposite the center line A B, as shown. Now, from the various points of intersection 9 to 14 in the side elevation draw horizontal lines to the left, cutting the miter line in the front elevation from 9 to 14, as shown. Take the girth of the throat of 474 The New Metal Worker Pattern Book. the elbow from 9 to 14 in the side and place it on the cen- ter lines A B, as shown by similar numbers. Through these small figures at right angles to A B draw horizontal lines, which intersect by lines drawn parallel to A B from similar numbered intersections in the front elevation. Trace a line through points thus obtained, as shown by 9' to 14' and trace the left half opposite the center line A B for the complete pattern. As the pattern for the side must be developed by triangu- Pattern for Sides of Elbow , Patte-rn for Bottom and Front-/ B ^ /0 2 12 II 10 True Lengths of Lines in 2-10- 13 In Side Elevation True Lengths of Lines in 10-2-6 in Side Elevation Fig. 825. — Patterns for Transforming Elbow. lation, a series of lines representing the bases of triangles must first be drawn in the side elevation, as follows : As the lines 7 10, 10 2 and 2 13, represent brake lines or lines on which slight bends must be made in the bending brake, then it will be best to draw the base lines of the triangles from 11 and 12 to 2; and from 3, 4, 5, and 6 to 10. The apex 2 in the side elevation lies on a plane indicated by 2 h in the front, and the various points 12, 11, and 10, in the side elevation rise above this plane, 2 h, in front elevation as much as is indicated by the points 12, 11, and 10, on the miter fine 14 10 in the front elevation, and represent the altitudes of the triangles, which will be constructed as follows: In diagram V draw any horizontal line as c d, upon which place the length 2 10, 2 11, and 2 12, in the side elevation, as shown by similar numbers in V. At right angles to cd from points 10, 11, and 12, erect fines, making 10 10', 11 11', and 12 12' equal, respectively, to the distances measured from the line 2 h in front eleva- tion to points 10, 11, and 12. Lines drawn in V, from 10', 11', and 12' to 2 will give the true lengths of similar numbered lines in the side elevation. In a similar manner the apex 10 in the side elevation lies on a plane indicated by 10 i in the front elevation, and the various points 3, 4, 5, and 6, in the side elevation rise above this plane 10 i as much as is Fig. 826. — Perspective View of Finished Elbow. indicated by the points 3, 4, 5, and 6 on the miter line 2 10 in front elevation, and represent the altitudes of the triangles shown in diagram W, which are obtained by drawing any line as ef, upon which place the lengths of 10 3, 10 4, 10 5, and 10 6, in the side elevation as shown by similar numbers in W. At right angles to e / from points 3, 4, 5, and 6, erect lines, making 3 3', 4 4', 5 5', and 6 6' equal respectively to the distances measured from the line 10 i in the front elevation, to points 3, 4, 5, and 6. Lines drawn in W from 3', 4', 5', and 6' to 10, will give the true lengths of similar numbered fines in the side elevation. Having found the true lengths of the triangles, and as the divisions in the miter cut in the pattern for top and back are used for describing the edge line for the heel, in the side pat- tern, and the divisions in the miter cut in the pattern for bottom and front are used for describing the edge line for the throat, the pattern can be laid out as follows: Pattern Problems. 475 Take a reproduction of 7, 8, 9, 10 in the side elevation and place it as shown by 7', 8', 9', and 10' in the pattern for sides marked X. Now with 7' G' in the miter cut in pattern for top as radius and 7' in pattern X as center, describe the arc 6', which intersect by an arc struck with 10' as center and 10 6' in diagram W as radius. Using radii 10 5', 10 4', and 10 3', in diagram W and 10' in pat- tern X as center, describe the short arcs 5', 4', and 3'. Now, set the dividers, equal to the spaces between 6' and 3' in the miter cut in pattern for top, and starting from 6' in pattern X step to arc 5', 4', and 3'. Again using the division 3' 2' in the pattern for top and 3' in pattern X as center, describe the arc 2', which intersect by an arc struck from 10' as center and 10' 2 in diagram V, as radius. Now, with radii equal to 2 11' and 2 12', and using 2' in pattern X as center, draw the small arcs 11' and 12'. Set the dividers equal to the spaces between 10' and 12' in the miter cut of pattern for bottom, and starting from 10' in pattern X step to arc 11' and 12'. Now, with the division 12' 13', in the pattern for bottom, as radius, and 12' in the pattern X as center, describe the arc 13', which intersect by an arc struck from 2' as center and 2 13 in the side elevation as radius. The line 2 13 in the side elevation shows its true length, because it lies on a ver- tical plane, shown in the front elevation by 2 13. Now take a tracing of 2 1 14 13 in the side elevation, and transfer it to the pattern X, placing the line 2 13 in the side elevation upon the line 2' 13' in pattern X. Trace a line through points thus obtained as shown, then will 1' 8' 9' 14' be the pattern for the sides of the elbow. If the elbow is of such size that it will require heavy metal for its construction, then allowance must be made for laps for riveting purposes. If the elbow can be made of light material, edges must be allowed for seaming. In Fig. 826 is shown a perspective view of the elbow, laid on its back, to more clearly show the miter joints. The numbers shown from 1 to 14 are similar to those shown in the patterns, while B. L. denote where the brake lines take place. PROBLEM 242. Ornamental Roof Flange Pattern for Flag Pole. In discussing the procedure for obtaining the pat- tern for a flag pole on an ornamental roof, it might be said that the problem appears to be an easy one, but all the trouble is in the development of the patterns for the sides. The top is to be 4| inches square. The profile for the front is indicated by A and for the back by B. A reduced reproduction of the side elevation of the problem is shown, in Fig. 827, above the plan in the accom- panying illustration in which a side view of the desired molded flange is given. In this problem the patterns for the front and back will be developed by parallel lines, while the two sides must be developed by triangulation. After the side elevation is drawn, as shown, a plan of the flange must be drawn directly in line with the side elevation, the top opening to receive the flag pole being 4i inches square. The first step is to obtain the patterns for the front A and back B, but as the part above arrows a and b is simply a square miter cut, this portion will be omitted in the solution. In practice the pattern for the upper head can be joined to the front, back and sides, before cutting and forming up. Divide the given profiles A and B into any desired number of spaces, being careful to make the spaces closer where the mold is smaller, all as indicated from 1 to 6 in A and 7 to 12 in B. At right angles to the plan of the front draw any line as C D, on which place the girth of the profile A in elevation, as show by similar numbers 1° to 6°. Through these points and at right angles to C D draw the usual measuring lines, which intersect by lines drawn parallel to C D from similar nmnbered inter- sections on the miter line in plan, which were previously obtained by dropping lines from similar numbers in the profile A in elevation. Trace a line through points thus obtained, as shown from 1 to 6 and transfer this half pattern opposite the has C D. The various divisions along the miter cut 1 to 6 will be used in obtaining the pattern for the side. In a similar manner from the various intersections 7 to 12 in the profile B in elevation drop lines, intersecting the miter line in plan, also indicated by similar numbers. Proceed as was done in obtaining pattern A for front A until the full pattern B is obtained as shown. The divi- sion along the miter cut, 7 to 12, will also be used in devel- oping the side pattern. As the pattern for the side must be developed by 476 The New Metal Worker Pattern Bock. triangulation, both in plan and elevation, connect the opposite points by lines, as shown by the solid lines drawn from 4 to 9, 3 to 10 and 2 to 11; and by dotted lines from 5 to 9, 4 to 10, 3 to 11, and 2 to 12. Then will these solid and dotted lines in plan represent the bases of sections which will be constructed with altitudes equal to the various vertical nights shown by similar numbers in the elevation. To obtain the true lengths of the solid lines shown in True Profile through X-YinPlanorElevatra« Pattern for Front A Fig. 827. — Pattern for Ornamental Roof Flange for Flag Pole plan, proceed as follows: From point 5 in elevation draw the horizontal line 5 H. As 5 8 and 1 12 in elevation show their true lengths, no sections need be developed for these lines. Now, take the lengths of the solid lines in plan as 4 9, 3 10 and 2 11, and place them on the line 5 H, as shown by 4' 9', 3' 10' and 2' 11', starting from the left and leaving space between 4' 3' and 2'. From these points of intersections erect perpendicular lines which intersect by lines drawn parallel to 5 H from similar numbered points in both profiles A and B, as shown by the points of inter- sections 4, 9, 3, 10, 2, and 11, in the true lengths. Solid fines connected from 4 to 9, 3 to 10, and 2 to 11 will show the true lengths of similar numbered fines in either plan or elevation. In a similar manner take the various lengths of the dotted fines in plan as 5 to 9, 4 to 10, 3 to 11, and 2 to 12, and place them on the horizontal fine 5 H, beginning at point 5' and leaving a small space between starting points, as shown by 5' to 9', 4' to 10', 3' to 11', and 2' to 12'. From these intersections erect vertical lines, intersecting them by horizontal fines drawn from similar numbers in both the profiles A and B, resulting in the points of intersections 5', 9, 4, 10, 3, 11,2, and 12. Dotted fines drawn from 5' to 9, 4 to 10, 3 to 11, and 2 to 12 will show the true lengths of similar numbered lines in either plan or eleva- tion of the diagram. The pattern is now in order and is developed as follows: Take a tracing of 5 6 7 8 in the side elevation and place it as shown by 5 6 7 8 in the pattern for the side. With 8 as center and 8 9 in the miter cut in the pattern for back as radius, describe the arc 9 in the pattern for side. With the true length 5' 9 as radius and 5 in the pattern for sides as center intersect the previous arc at 9. With radius equal to 5 4 in the miter cut in the pattern for front A and 5 in the pattern for sides as center, describe the arc 4, which in- tersect by an arc struck from 9 as cen- ter and the true length 9 4 in the diagram as radius. Proceed in this manner, using alternately first the divi- sions along the miter cut in the pattern for back B, then the proper true length in the diagram of true lengths; the proper division along the miter cut in the pattern for front A, then again the proper true length, until the line 1 12 in the pattern for the sides is placed, which is made equal to 1 12 in the side elevation, its true length. A line traced through points thus obtained as shown by 1 6 7 12 will be the desired side pattern. The square miter pattern for the bead above the arrows in the side elevation must be added to the patterns for the front, sides and back on the fines 1 1, 1 12, and 12 12, respectively. When forming up the sides one Pa+ternforBackB Pattern Problems. 477 must be formed right and the other left. They must be bent or molded so that they will miter with the front and back pieces. If, however, a profile is desired so that the sides can be accurately formed, the method of finding the true profile through the center X Y in either plan or ele- vation is as follows: Where the solid and dotted lines in elevation cross the center line X Y as indicated by the heavy dots, take a tracing of these intersections, numbering each dot to correspond with the number of the line passing through X Y and place these numbers on the vertical line X 1 Y 1 , as shown in the true profile. In a similar manner where the solid and dotted lines in plan cross the center line X Y, also indicated by the heavy dots take these various distances with the number of the lines which they rep- resent and place them on the horizontal line X 2 Y 2 , as shown. From the various intersections on the vertical line X 1 Y 1 , draw horizontal lines, which intersect by vertical lines, erected from similar numbers on the hori- zontal line X 2 Y 2 , resulting in the points of intersections shown. A line traced through these points will be the true profile through X Y in either plan or elevation, and represents the profile to be used along the center of the pattern when forming up the sides of the flange. PROBLEM 243. Pattern for Irregular Shaped Box. Although there are hundreds of problems of a diver- sified nature worked out herein, the book could not pos- sibly contain all the problems that may arise owing to the great number of articles made from sheet metal. Oftentimes the book is misjudged by the statement that it does not give a rule for a special case inasmuch as there are really but three principles or rules in all pattern cutting, viz.: Parallel development, radial development and development by triangulation. All these are thor- oughly elucidated and some one or all would apply to the solution of a problem. Many artisans are not well versed in descriptive geometry and accordingly are not familiar with the fun- damental principles of the systems of surface develop- ments mentioned, consequently they cannot apply the rule or rules to their problems when guided by the explan- ations of similar problems in the book. This is no dis- credit to them as everyone cannot have the necessary preliminary training to be masters of pattern drafting and it is, therefore, imperative to expound their problems step by step. It is best not to refer to a like problem in the book for a hint to the procedure unless it can be said that the problem referred to is identical with that required and it is most desirable that all owners of the book make an effort to grasp the fundamentals of pattern cutting by diligent study of the first parts of the book for they will then more readily grasp the solution of the later problems. To solve this problem draw a rectangle A B C D to the required size as in Fig. 828, which represents the out- line of the base of the object in plan. Also draw another rectangle for the top as shown by E F H G. The side elevation is represented by the trapezoid labeled I J L K and the front by the one marked M N P O, which also outlines the back or rear elevation. By drawing the hip lines F B and H D the plan is completed. Fig. 828. — Method of Obtaining Patterns for Parts of Box. The object has four sides, the only one of which is shown true is the back. This means that the front eleva- tion will do for the pattern of the back. To show the front of the object true, that is to develop the pattern, extend the center fine a & of the plan indefi- nitely and place thereon the length J L of the side eleva- tion as indicated by c d. At right angles to the line a b 478 The New Metal Worker Pattern Book. and fromc and d draw lines equal to B D and F H, as shown by e f and g h. Connecting these points makes efgh the pattern of the front. For the sides draw a line equal in length to and parallel to C D as i j. Extend the line G C downward and from i place the distance M N (or OP), of the front elevation as shown by i k. From k and parallel to i j draw a line of the same length as G H which is k I. Draw a line from I to j, which completes the pattern of the sides. The angle of the back and side is square, while the angle of the side and front is unknown. To find it, make an oblique elevation of the hip F B by drawing any fine as m n parallel to it and of its length. At right angles to m n draw the line m o equal in length to I K of the side elevation. Connect o and n, which then is the oblique elevation of the hip. At right angles to F B draw a fine from the side to the front as 2 3, which project to the base fine of the oblique elevation and mark the point 4. At right angles to the line o n and from 4 draw the line 4 5. Through point 4 and parallel to o n draw a fine and make 4 6 to the length of 2 9 of the plan and 4 7 to the length of 9 3. Then 6 5 7 will be the true angle of the side and front. To have the patterns of the different parts of the object in one piece with the seam through the center of the back, redraw the pattern of the front anywhere as e' g' In! f in Fig. 829. To the sides of this connect the patterns of the sides as h' f i' j' and e' g' k' V. To these connect one-half of the back as V k' n' w! and i' j' p' o'. This gives the full pattern of the object. Along the outer hne w! to o' allow the wire edge Fig. 829. — Pattern in One Piece required and also allow similar edges on the inner Hne n! to p' and on the fines o' p' and m! n'. In bending up the object square bends are made on the fines V k' and i' j' and bends to the angle 7 5 6 of Fig. 828 on lines e' g' and /' h'. In conclusion it may be said that the rule employed is a combination of the parallel and triangular systems, principally the parallel. PROBLEM 244. Pattern for Compound Curve Elbow. As a rule most all these problems emanate from readers of journals published by the publishers of this book, who, having a problem and unable to find a solution, appeal to the editors or otfier readers of these journals. The query pertaining to this case stated that his sketch Fig. 830 has inlet A rectangular in shape, but makes a quarter turn to outlet B. Incidentally, the reader stated further that he was unable to find a solution of similar nature in this book. A study of the sketch leads to several inferences as to the requirements and it could be said that in heating and ventilating work having rectangular ducts, such a turn and offset would commonly be negotiated by the use of six ordinary elbows, two 90-degree elbows and four 45- degree offsets. It has been stated, however, that the elbow is to be of copper and from a close inspection of the sketch it would seem safer to presume that the object is for leader, that is to say, roof drainage work, or some such similar purpose. The sketch in plan, indicates that narrow side and narrow side of outlet and inlet and wide side and wide side, are not to connect, but just the reverse, wide side to narrow side. It would be more proper to twist narrow side to narrow side and wide side to wide side, like in Fig. 831. Such an object then comes within the range of spiral problems in the nature of the spiral package chute, and a very clear description of the pattern developing for an elbow of this land can be found on page 32, Vol. 1, of " Practical Sheet Metal Work and Demonstrated Pat- terns." In recommending that demonstration the cau- tion, or rather reminder, accompanies it that the two sides which are developed by triangulation are distinctly warped surfaces and require a certain amount of stretch- ing or Humping, to bring them to their correct contour. Pattern Problems. 479 Another supposition that may be formed from the sketch, Fig. 830, is that the quarter turn and double offset could be made by utilizing straight sections of the pipe, as shown in the plan of Fig. 830. Although this supposition is refuted by the data furnished and the elevation of the sketch, a procedure for obtaining the patterns for such an elbow is explained herewith: In Fig. 832 a plan was drawn indicating thereon the outlet and inlet which have the proper amount of offset in two directions and the quarter turn, all as prescribed by the plan of Fig. 830. In the development of the pat- terns for tins problem an oblique elevation is necessary and to acquire that elevation it is customary to employ one line as a basis to work on. In a cylindrical object Fig. 830. — Curve in Elevation. the axial line is used, while for objects having, say, a rectangular profile or shape, an edge or corner line is used. Therefore, line 4° 4 in the plan of Fig. S32 is used as a basis to project the oblique view, as shown. Continue the line 4 C and make F C the hight of F' C in the front elevation. Lengths A B and C D being as con- venient, bisect angles ABC and BCD which will give the miter lines C G and B H. Project line ABC and D to front elevation and thence to the side elevation. In the plan connect points 1° 1, etc., and also oppo- site points as 1° 2. Project the plan view of the oblique view as shown and also to the front and side elevation, carrying the hights of the lines in oblique view as 1° I s , etc., on the dividers to the elevations as 1°° l 60 and l 0o ° 1 6 °° and l c l" to l''r° and 1" l co ° in the elevations, etc. The patterns for the vertical pieces of the elbow are obtained by the parallel line system from the oblique elevation, as shown, at X. Before the pattern of the mid- dle or offsetting piece can be developed the correct length of the corner lines and the lines connecting opposite corners must be found. To the right of the elevations project lines indefinitely from all the points in the eleva- tions as l"° l co C B', etc. Erect two convenient vertical fines as shown in the diagram of triangles. On those lines and in diagrams marked P and marking always from the vertical line, set the distances in plan of the corner fine, 1 ° 1 in plan is l 1 1" in diagram P, etc. Connect the p^^^\^^ w Fig. 831. — Curve in Elevation and Plan. points thus located to proper points on the vertical line as 1™ to l xxx , etc. Do likewise on diagram R, the dis- tances, as l r and 2 TT , being taken from the fines in plan joining opposite corners, as 1° 2. For the pattern as shown at K, draw any fine as 1 ° 1 of a length equal to l xx l xxx in diagram P. Then with the point of the compasses placed at 1 °, in K, and set to the distance 2 X 2 XX in R, strike a small arc. Then with the dividers spaced to 1 2 in the plan, intersect this arc giving point 2 in K. Repeat this procedure until the full pat- tern is obtained. It should be remembered that the surfaces of this object are what is termed " warped surfaces," hence 480 The New Metal Worker Pattern Book. slight bends should be made on R lines. However, the amount of warp in this object is so small that it really elevations. On page 39 of Vol. 1 of " Practical Sheet Metal Work and Demonstrated Patterns," will be found a Fig. 832. — Patterns for Three-Piece Sectional Elbow. could be ignored and only the square bends made on lines P. Laps should be allowed as required. 1 1 1 b, a 1 c r Fig. 83/,.— Plan Diagram of Fig. 833. As was said in the foregoing, the requirement in this case is for an elbow that must be curved when viewed in problem of like nature, except that it does not make the quarter turn. The plans as shown in that book are not correctly represented, strictly speaking, for when the development ignores the plan, so to speak, straight lines in plan are not obtained, but the result is an irregularly curved line or lines in plan. As an additional aid to the study of such a solution of the problem, refer to Fig. 833 of the accompanying drawings. As was mentioned the plan is not required in this scheme of development, but to make this demonstration somewhat different than the others, the amount of offset one way is made greater than the other way. Supposing the amount of offset is, as shown in Fig. 834, by a & and b c, it is transferred to the horizontal line of the elevation in Fig. 833, as shown, and no further use is made of the Pattern Problems. 481 plan for only the profiles of the inlet and outlet are needed and are placed as shown. The hight of the elbow a M is as required and having established points A and M, a Fig. 833. — Using Curve in Elevation Only. graceful compound curve is sketched in free hand, as in this drawing, or by means of the compass as in Fig. 830. Set the dividers to a convenient space and starting at M step off spaces, letti: lg the final space B A be unequal if it across to the right. Establish points M' and A' in the front elevation and also M" and A", and M'" and A'" in the side elevation. Draw similar curves to these points -iW Plan Fig. 835. — Zolu'ion Conforming to Requirements. as shown, being careful to keep the distance apart of each side of the object, never less than 1 2 of the profiles. In doing this it is well to remember that it is best to so happens. Draw horizontal lines from these points I err in the matter of having greater area in the elbow than 482 The Neiu Metal Worker Pattern Book. to have a restricted area, and so it might be said of Fig. 833 that it would have been better if the outlines of the front elevation, at about J, K, and L, were a trifle farther apart, to give greater area. The patterns for the four sides are obtained by the parallel line method. That is to say, stretchout A to M of the front elevation is set on line A to M above the side elevation and stretchout A' to M' (taking each space separately as they all differ), is set on the line A' to M' and the usual parallel lines are drawn as shown. These lines are intersected by lines projected from corresponding points on the curves in the side elevation so that pattern Y is for the side 1° 4° to 1 4 of profiles in the front eleva- tion, while Z is for 2° 3° to 2 3. Similarly, X is for 3° 4° to 3 4 and V is for 1° 2° to 1 2. Bear in mind also that stretchout A" to M" is above the front elevation as also is stretchout A'" to M'". In shaping these parts it is to be remembered that the stay (for instance, for V would be curve A'" M"' of the elevation), should always be held at right angles to the parallel lines as shown by the line g and h of V, for the idea is that V is simply cut out of a piece of metal like A'" k m and M'", which is curved to the shape of line M'" A'" of the side elevation. A solution of the problem conforming, so it would seem, the nearest to the requirements as stipulated, is presented in Fig. 835. This is nothing more than a manip- ulation of the principles of projection to obtain an object that is curved in both views of the elevation, although having straight lines when viewed in plan. The plan was drawn identical to Fig. 831 and the curve AM in the front elevation drawn at pleasure and divided into spaces as shown. These points were dropped to the plan on lines 1° 1 and 2° 2 carried horizontally ■across to line 3° 3, vertically back to line 4° 4 and then horizontally back to line 1° 1, meeting the same points in that line. Lines were drawn horizontally across to the right in the elevations from the points A to M. These were inter- sected by lines projected up from the plan on line 3° 3, which gave the curve A' M'. Similarly, the points on lines in plan were projected to the right to line S T and swung around, using S as a center, to line S W, thence upward to intersect hke lines from curved line M A, giving the curved lines A" M" and A'" M'" or the side elevation. Patterns X, V, Y, and Z were obtained by the parallel line system just as was done for Fig. 833, this solu- tion differing from that one only in the fact that the plan was not ignored but employed to govern the elevation. In conclusion it might be stated that in this book a problem giving the principles that could be applied to the solution of this problem is No. 48. In that problem, however, the profiles are differently situated than in his case and would therefore require skill in adjusting to this case. PROBLEM 245. Offsetting Elbow Problem. The exigencies of the exacting requirements of the sheet metal trade give birth to many perplexing problems, one of which follows: It rises on the elevation 30 degrees and then turns away on the plan 40 degrees. The problem presents an interesting study in projection and developing surfaces of solids. There are probably many ways of solving problems like these, but no matter how solved it is a formidable task. Authorities differ on the many systems of projection, but without arguing as to which is better, the third angle or the first angle, and a lot of other technical premises, it can be said that the system best understood by sheet metal workers is that in which the general view is called an elevation and a view looking down on the object and placed below the elevation is called a plan, as pre- sented in Fig. 836. Perhaps this would be called first angle position, but it all is a little too deep for busy mechanics. In developing the pattern required, the first essential is to consider a certain imaginary line, known as an axis, about which the body proper of each piece of the object is built, because it is impossible to tell at once just what shape and position these pieces will have and this axis line is a central fine of the pieces, shown in these diagrams by the heavy solid line, and can be readily located. Presume that in plan of Fig. 837, the oval shown is as required and that the axis line A B, indicates how and how much the elbow turns away in plan. Projecting this fine to an elevation, that is to say, to a view on lines Pattern Problems. 483 of sight, the direction of which is shown by arrow pointer x, the axis line would be A' B' in elevation and prescribes Fig. 836.— Sketch of the Problem. Oblique Elevation Fig. 837. — Orthographic Study of the Proposition. the amount of rise in the elevation. The axis line of the oval piece in elevation, is labeled A' C and can be as long as desired. Neither the elevation nor the plan show the axis line A B in its true length because in both views one end of the line leans away from the observer and therefore shows foreshortened. To see this line in its true position and exact length it is necessary to pro- ject a view along arrow pointer X Y, called by most pattern draftsmen an oblique elevation. To do this, first draw a horizontal fine in the elevation, from point A' as shown by the heavy dotted fine, terminat- ing it where it touches the projector line from B in plan and calling it point D. At right angles to the axis line in plan and from points A and B, project lines indefinitely. Draw line A" D" parallel to line A B and then take the distance D to B' in the elevation place it from D' in the oblique view obtaining thus, point B". Connect A" to B" which will be the true view and length of the axis fine A B. Make C" A" m the oblique view equal to C A' in the elevation and then bisect the angle C A" B" in the oblique view, as directed by points b d and e. A line from e through A" bisects angle C A" B" and is the edge view of the cutting plane between the pieces of the elbow, or the miter fine. Continue line A" B" in the oblique view and place thereon the profile of the round end of the pipe as shown by 12 3 4. Divide this profile into equal spaces and draw the fine 1' 3' at right angles to fine A" B" and pro- ject to it the divisions in the circular profile as shown. Divide the profile in plan also, and project the division points up to the miter fine and connect points 69' and 1' and 91' and 3' also draw the line g h. Place a duplicate of the circular profile on the ex- tended line A B in the plan as shown by 1°, 2°, 3° 4°. Project the division points of this profile into the plan to intersect like numbered projectors from line 1' 3' in the oblique view. Like this: 1' in the oblique view is to intersect at V" in the plan and so on, resulting in the elliptical view in plan of the circular end of the elbow. Complete the plan by drawing the two outside lines as shown. Project the division points upward to the elevation, then draw the horizontal fine through point C. Measuring always from this line and taking the various lengths of the same lines from fine g h to the miter line 69' 91' in the oblique elevation, obtain thus the elevation view of the oval piece of the elbow. For instance, point 100 in plan is fine k 100' in the oblique elevation. This length is placed in the elevation on line from point 100 in plan, as 484 The New Metal Worker Pattern Book. k' 100 J . The elliptical view of the circular end of the elbow is obtained in precisely the same manner, measuring from line D' in the oblique elevation and line D in the they are placed in the plan of Fig. 837 as 50 100 base and apex 3", also 70 80 base and apex 1" ' and projected to the elevation and oblique view as shown. All the foregoing was absolutely necessary to study the proposition and is a sort of preliminary survey. Knowing just what is wanted, a good deal of that work could be dispensed with; in fact, the many projector and working lines will make a terrible mix-up in the further developing of the solution. So then, as in Fig. 838, turn Fig. S3S.—A Duplicate in Part of Fig. 837. elevation which completes the different views of the object and ought to tell just how the object will actually appear. Inasmuch as there are flat parts to the oval profile, which by the way, should be termed a rectangular figure F*&l ?c* x 6-r^EDCB'J n Fig. S39. — First Set of Solid Lines. with same circular ends, there will be flat triangular portions in the transformation pieces of the elbow. The apex of these triangles can be any one of the division points on line 1' 3' in the oblique view, it being immaterial owing to the transformation piece being decidedly twisted, no matter how it would be designed. Therefore, follow- ing one's judgment for the best position of these triangles the axis line A B completely around to facilitate things in general and in correct position, to duplicate Fig. 837, place the profile of the oval as shown. This is really all -""-- — — &£T GffFEDC Fig. 840.— First Set of Dotted Lines. that is needed of the plan. The original elevation of the axis fine is also shown in Fig. 838 and this much is all that would be drawn, supposing that Fig. 837 had not been Fig. 841. — Second Set of Solid Lines. 10, 11-9- IZ-8 1-7 .\M X ,N* Fig. 842.— Second Set of Dotted Lines. developed. Only the axis lines and line 7' 1' also elevation of the oval piece and miter lines as shown, is required in duplicate of the oblique elevation of Fig. 837. Pattern Problems. 485 The first pattern to develop is that for the oval piece and the procedure is to extend line g h, Fig. 838, and place thereon the stretchout of the oval profile, these division points having been rechristened A to to prevent con- fusion with the symbols of the circular profile. From the points A to A of the stretchout erect vertical lines. Project lines across from the miter line to intersect like lines of the stretchout. For instance, K' on the miter line is projected across to intersect line from K° in the stretchout giving point K°°. A line drawn through these points completes the net pattern of the oval piece. The transformation piece will naturally have to be triangulated to develop its pattern. Now, as the trans- forming of the shape takes place in the entire girth of the object the entire pattern must be developed, whereas if the object was in symmetrical halves or quarters, one- half of the pattern would do for the other half or one- quarter for all quarters. Such being the case it requires 6-F Fig. 843. — Reproduction of Part of the Oblique Elevation of Fig. S3S. additional patience and care because triangulation is the most tedious process imaginable. The precise definition of triangulation is, having the base fine and the altitude of a right-angled triangle, the hypotenuse gives the required true length of a line, shown foreshortened in the views. This method has been modified in several differ- ent systems and a system ideally suited for this problem is where the line in the oblique elevation is considered the distance and the base fine between two parallel fines, the length of one of these parallel fines is taken from one profile, while the length of the other is taken from the second profile, to wit: Point 4 1 in Fig. 838 is the same as point 4" in Fig. 837, and is only used here to explain the system. Line E' to 4' in the oblique elevation is the base line spoken of and is placed where convenient, as from 1 7 to E of Fig. 839. Vertical lines are erected from points 1 7 and E in Fig. 839 and are the parallel lines mentioned. The distance B 4 1 of Fig. 838 (or what is the same thing, 10 to 10° of the circular profile) is placed from 1 7 to 4 of Fig. 839. Also, space E to E 1 of the plan, Fig. 838 is placed from E to E 1 in Fig. 839 so that the fine from 4 to E x in Fig. 839 is the true length of line E' of the oblique elevation of Fig. 838. In other words, the figure bounded by the corners B E 1 E and 4* of Fig. 838 is placed in Fig. 839 as shown by 17EE 1 and 4, only the true length of the line B W of the plan Fig. 838 was taken as explained from the oblique elevation E' to 4' and placed in Fig. S39, 1 7 to E. This is the system followed throughout: that for the dotted lines being the same and four diagrams, Figs. 839 to 842 were used to avoid a bewildering mass of fines. In all four diagrams, the distances, like 1 7 to 2 6, 17 to 3 5 and 1 7 to 4 are taken from the circular profile as 10 to 10°, 9 to 9° and 8 to 8°. The space in all four Fig. S44- — The Full Pattern of the Transformation Piece. diagrams like E to E*, D to D* in Fig. 839 are taken from the plan of Fig. 838 measuring always from the line A B, as shown. The seam will be set at A of the plan Fig. 838 and the oblique elevation of Fig. 838 gives the base lines of the solid lines from A around to 1, like A' to I', of the oblique elevation, B' to I', C to 2', etc., and the con- necting dotted lines as I' to C, 2' to B' etc. In Fig. 843 is given the base lines for solid and dotted lines from I around A; like I to 7 (Fig. 843) J to 8, K to 9, etc., and connecting dotted line I to 8, J to 9, K to 11, etc. The pattern would be developed by placing the line anywhere equal in length to A 1 1 7 of Fig. 839, as 1 A of Fig. 844. From 1 in Fig. 844 describe a small arc the radius of which equals 1 7 to B* of Fig. 839. From A of Fig. 844 describe an arc equal to the length to A°° B°° of the pattern Fig. 838. This arc is to intersect the one 486 The New Metal Worker Pattern Book. from A in Fig. 839 and locates point B. Again from 1 of Fig. 839, describe an arc of a radius equal to 1 7 C x of Fig. 840. Intersect this with one from B of Fig. 844 the radius of which equals space B°° C°° of the pattern of Fig. 838 giving this point C in Fig. 844. From C in Fig. 844 describe an arc the radius of which equals 2 6 C x of Fig. 838. From 1 in Fig. 844 describe an arc to intersect the one just made from C, the radius of this arc is to equal the division space of the circular profile 1 to 2 of the oblique elevation, Fig. 838. Continue in this manner up to line 7 1 of Fig. 844 when the true lengths of lines are taken from Fig. 841 for the solid lines and Fig. 842 for the dotted lines. Also be sure to take the radius of the small arcs of the lettered points from the pattern Fig. 838 as directed and the larger spaces, numbered, from the circular profile Fig. 838. The final line l x A x of Fig. 844, is the same length as the first line 1 A. Drawing a line through points 1 to l x and A to A x of Fig. 844 results in the net pattern for the transformation piece. When shaping objects like these it is necessary to be careful to have the right side out of the patterns, so that the elbow will offset in the right direction. As the patterns are now stretched out the side up will be the inside of the objects. PROBLEM 246. Pattern for the Revolving Blade of a Spiral Conveyor. Boilers of heating plants are frequently supplied with fuel by means of automatic stokers fed with pul- verized coal by spiral conveyors. The conveyor here described consists of a pipe in which revolve three spiral blades which cany the material forward. These blades are identical in construction, and a method is here given for developing the pattern for the blade. The conveyor pipe is 6 inches in diameter. The blades are three in number, and meet in the center, as shown in the cut. Each blade makes one-half of a com- plete turn in conveying the material two feet (which is the usual length of the pipe) as shown in Fig. 845. It is impossible to develop a true pattern for a spiral, as a certain amount of stretching of the metal is necessary to form a spiral from the flat surface. The surface of a spiral is a warped surface, and the only pattern which would be correct would be a sec ion of a solid. This will at once be apparent if an attempt is made to lay the spiral out flat after it has been once formed into shape. Assuming that it is desirable to make blades for a small number of conveyors in the beginning for use as models, and also assuming :hat they are to be made by hand and that the amount of metal used is not as impor- tant as the amount of stretching necessary to put it into the proper shape, the process for getting the approximate rjattern is as follows : Draw any line 7 A and with as center draw a circle of the diameter of the spiral, in this instance 6 inches. This spiral is required to make one-half revolution in the length of 24 inches. Draw the line 1' T' parallel to 7 A. From 7 through 1' draw a line to 1 and from A through T' draw a line to T, making them the length of the half revolution, in this case 24 inches. Draw the line 1 T in the elevation. The length of the lines 1 T and 1' T' in the elevation and the line 7 A in the plan should be equal. Divide the arc which represents the one-half revolution in the plan into any number of equal parts. Divide the length of one-half revolution in the elevation into the same number of equal parts. Using one of these spaces, B C in the plan, as the base B' C and the space 1' 2' from the elevation as the hight A' B' construct the triangle A' B' C, as shown in Fig. 845. Draw a line half way between A' and B', cutting the triangle parallel to the base C D' as shown at M and Z. Upon any line as D X, Fig. 846, locate the points D' and X', using the length of the radius 7 from the plan as the distance to space them apart. Through D' and X' draw line at right angles from the line D X. Set off the distance A" D' equal to A' M and the distance X' X" equal to the distance A' Z. Now draw a line through A" X" and continue it until it intersects the line D X at O' . With 0' as center draw the arc through the point A" and continue it on either side, as shown. This arc does not pass through D', but slightly above it. With dis- tance D' C" equal to the space between A' C, step off as many distances on the arc that passes through A" as there are spaces in the required rise. Half of the spaces are stepped off on each side of the line D X in Fig. 846 for Pattern Problems. 487 convenience but in actual work they may be all stepped off on one side if desirable. The line 1° X"' is located at the extreme end of the pattern, the arc cutting X" is drawn and continued on either side as shown, cutting the extreme end of the pattern at X'". As the true length of the pattern on the inside edges and the outside edges is only correct after the stretching and forming operation, the length of the pattern must be determined in the center. U' V construct the triangle R' U' V. With the space R" U" in Fig. 846 equal to the space R' U' in Fig. 845, step off the required number of spaces as shown in Fig. 846 which will represent the true length of the center of the pattern. Joining this line to the point 0' and running it up to the edge completes the pattern. By repeating the operation on all lines the amount of stretching required will be shown. The completed drawing of the spiral is not necessary Fig. 845. — Preliminary Fig. 848. — Connect- Drawiug. ing the Blades. Fig. 847. — Straight Pattern. Continuing, divide the line 7 in the plan into any number of equal parts as shown at U V W. Proceeding again in this fashion, divide the line 1° X'" in Fig. 846 into the same number of equal parts. Draw concentric circles in the plan cutting these points and draw concentric arcs cutting the correspond- ing points in Fig. 846. With the space R V in the plan as the base R' V, Fig. 845, and the space 1' 2' in the elevation as the hight to get the pattern and is given here only to show the ap- pearance of the completed article. If the triangle T" B" S is constructed with the distance B" S made equal to one-half the diameter of the spiral and the distance T" B" made equal to the hight of the half revolution T T' in the elevation, the dis- tance between T" and S will be the true length of the outer edge of the finished spiral. And also if the triangle so determined is cut out and formed up to the diameter of 488 The New Metal Worker Pattern Book. the spiral in half circle, keeping the edge T" B" parallel to the forming rolls it will serve as a guide for putting the spiral partition into shape. If these conveyers were to be made in large quantities, the partitions could be made of a piece of metal straight on all sides, size 6 inches wide and 24 inches long with laps added as shown in Fig. 847, in which case the metal used would need to be of a thicker gauge and a suitable method arranged for drawing and stretching it into the proper shape. Fig. 848 shows a suggestion for fastening the partitions together with rivets after they have been formed into shape. If one-half the circumference of the concentric circles in the plan which represent lines of the surface of the spiral are set off as shown at B" S'", and B" S" and B" S' in Fig. 845 and these points joined to T", the distances T" S'", T" S" and T" S' will be the true length of the corresponding lines on the surface of the finished spiral. Divide the body of the pattern in Fig. 848 into the same number of equal parts as the fines 7 in the plan and set off the true length of the lines as just determined in Fig. 845. Tins shows the amount of stretching that will be required at each line. Project the line A' to P, Fig. 845, and if all of the work has been accurate thus far, the distance P S will be the same as the distance A' C Likewise the distance P' S', P" S" and J'" S'" will be the same as on the other triangles which could be constructed similar to the triangles A' B' C and R' U' V in Fig. 845. The lines of the pattern in Fig. 846 and the corre- sponding fines of the pattern in Fig. 847 should measure the same length to the points that are located to show the amount of stretching required. Now, by comparing the difference between the true length of these fines in Fig. 847, it will be easy to see that they are unequal or in other words the amount of stretch- ing required for lines located equal distances apart from the center of the spiral does not vary in equal proportion. And tins proves the statement that the surface of a spiral is a warped surface. If it is desirable to stamp these partitions out in parts and no better means is available, it may be done by making a solid pattern for the sweep of the desired section, using plaster of Paris, and painting with one or two coats of shellac. This may be sent to an iron foundry and the pattern for the sweep cast and then a lead form moulded at the shop from the iron casting or, instead of an iron casting, scrap zinc is suitable for use with lead, but of course would not do for long service. With the aid of a drop weight press or even a heavy sledge and by putting the metal between the upper and lower forms just described, the parts may be stamped out. PROBLEM 247. A Collar Intersecting a Transformer. The pipe and branch shown in Fig. 848 A furnishes a very interesting and intricate problem. It is necessary to get out patterns for a 7-inch collar intersecting a transformer at an angle of 60 degrees, with the dimensions as given. The problem is to develop a pattern for both the collar and the opening to be cut in the transforming section. It will be noted that the 8-inch round end of the transformer in the perspective view is divided into twelve spaces, and that the axis of the collar would intersect at about the point 2, thus apparently setting on the corner of the transformer. In the elevation this collar sets at an angle of 60 degrees 3 inches from the corner of the transformer. In the plan the transformer sets in a central position. In this case the conditions are seemingly impos- sible of fulfillment. In the diagram, Fig. 849,' is a reproduction to scale of the problem. Analyzing this problem on a practical basis, it must be said that it is a very queer proposition, and it is wondered if a more simple solution would be possible, if all the con- ditions were known, viz.: What is the object? Where does it go? And isn't there a run of 8-inch pipe joined to the transformer, and if so, why couldn't the 7-inch collar be tapped into the 8-inch pipe with an ordinary tee joint or Y, or, perhaps, there is a rectangular pipe joined to the square part of the transformer and pos- sibly the 7-inch collar could be tapped into it. And, again, isn't it unusual to have the miter line B as given, Pattern Problems. 489 instead of the customary miter line B', which bisects the angle C. Note that the profile of the 8-inch end is divided into the number of parts directed. Also that axis A' of the 7-inch collar is projected down to intersect No. 2 element at A at the transformer as directed, and would be point A" when projected down to the plan. A par- tial plan view of the 7-inch collar is shown, and it will be seen that a large part of the collar falls clear of the transformer, or positively will not intersect the trans- former. Then wnat does this mean? It means that the requirements laid clown cannot be fulfilled, and therefore some modification of the conditions is necessary. Shall the collar be made a sort of offset elbow so that all of it v.^ r -/3r-i Perspective Plan Fig. 84S A. — The Problem as Presented. will intersect the transformer? That would be one method, and would seem to be the best plan to follow in this particular case. The elevation, shown in Fig. 849, is drawn to the specifications furnished. Note the positions of the profiles of the 7-inch and 8-inch collars, the 8-inch collar being spaced as shown. The plan is made by drawing a square to the dimension of that part of the object. Center line P X and its points are placed in the plan as P' X' and horizontal projector lines from this, intersecting vertical projector lines from line Z Z', gives a plan view of round end of transformer. Complete the plan as shown. To avoid mixing things up too much, that portion of Fig. 849 which is really needed is reproduced as in Fig. 850. Divide the 7-inch profile into twelve spaces, and drop lines to line C B in the elevation. Project these points on C B down to plan. Draw the 7-inch profile in the plan and project lines across to intersect those from line C B. Observe that it is merely coinci- dence that lines from 9 and 3 pass through points, as at a, of the round end of transformer. It is also coincidence that lines 9 and 3 should touch fines C B' and C B". Plan Fig. 849. — Reproduction of the Problem to Scale for Analysis. It will be noticed now that a major part of the 7-inch collar intersects that flat part C B' C B" of the surface of the transformer, and that but one set of elements of the collar, 2 and 10, touches the rounded surface of the transformer. Of course, if the collar were made to offset both ways, that is, if it were offsetted so that all of the collar fell on the flat surface, a much simpler miter fine would be obtained, but it would complicate the 490 The New Metal Worker Pattern Book. developing of the collar patterns to the extent of making it not worth the trouble. So then it is, therefore, necessary to determine just projected to the plan to like elements of the transformer, giving C" D" E" F". A line traced through these points gives the lines of intersection in plan of where 0-F 1 --'2 "3 -4 Fig. 851. — Length of Elements. Fig. 853. — Half Pattern of Square Part of Transformer. where these elements touch the mentioned rounded sur- face. Element or projector 2 and 10 in elevation is drawn, or rather continued, to pass through elements C D E F. Where they intersect, as C D' E' F', they are elements 2 and 10 intersect those, in elevation, of trans- former elements. Where point 10 in plan intersects this line (or the same thing point 2), as 10', is where these elements, 2 and 10, touch the rounded part of the Pattern Problems. 491 transformer. This point 10' is projected up to inter- sect line 2 10 in elevation, giving point 10". To facilitate matters, another point is introduced where the line of intersection of the collar leaves the flat surface of the trans- former as A' and A" and A and A'" on profile. This is projected up to the elevation as A"". A line traced through points in elevation as shown gives sought-for line of intersection, or as geometricians term it, line of penetration. An oblique view is now drawn of the collar to delin- eate amount of necessary offset. Draw line 6 6' parallel to the collar in elevation. Also draw line K parallel to 6 6', and as far from 6 6' as A" K in plan of Fig. 849. Draw 7-inch collar profile, as shown, being careful to have numbered points situated correctly, especially point A, being guided by profile in plan. Draw the offset piece R to what would seem about the right size. Project lines up from the profile in the oblique view to terminate at miter line S. Also intersect these hnes with projectors from the elevation. Be careful to select correct points in the elevation, especially A"", then 10" and then 3 and 9. Observe the contour of the cut in the collar in oblique view, at the intersecting end of the collar. Draw a line as 1 A 2 3, etc., spaces being taken from the 7-inch profile. Draw lines through these points as shown, which are intersected by hnes from the oblique view — to 0; 1 to 1; A to A, etc., both from miter line S and the bottom cut of the collar, which gives the pattern of piece T. Set the dividers to span h h of oblique view of piece R, then step this off on the stretchout lines of patterns, as h' h' at 9, which is then the pattern of piece R. For the pattern of piece W take the distance h m in the oblique view and place it on stretchout fine 9 in the pat- tern, as h m. Parallel to the stretchout line, draw a line through to, which will then give the pattern for piece W. When joining these three pieces the X marks should be opposite each other. For the transformer pattern it is first necessary to find out actually how long the various elements are; so in Fig. 851 draw a line and place thereon the lengths of the elements as given in the elevation of Fig. 849, for instance, 6' F in elevation, Fig. 849 is F 6 in Fig. 851, and say, 3' C in Fig. 849 elevation is C 3 in Fig. 851. Erect perpendicular hnes from these points. Make C C of Fig. 851 equal to space C C" in plan of Fig. 849. Make fine 2 equal to 2' 2 in 8-inch profile in elevation of Fig. 849, and so on, which gives the true lengths of the elements. In Fig. 852 draw a fine, F F' equal to C C" of plan Fig. 849. At right angles to F F', in Fig. 852, draw line F' 7 equal to F Z' or 7 of elevation, Fig. 849. Join 7 to F; then with F as center, swing short arcs of radii respectively of Fig. 851, C 6', C 5' and C 4'". Set the dividers to place the 12 spaces of the 8-inch pro- file in elevation, Fig. 849, and starting at 7, in Fig. 852, step on the arcs to 4. From 4 as center, in Fig. 852, draw an arc of a radius equal to 4" C cf Fig. 851. Intersect this arc with one from F, in Fig. 852 of a radius of C F in elevation of Fig. 849 which is miter fine B of Fig. 849. This establishes point C in Fig. S52, and with that as center, describe short arcs, taking their radius from Fig. 851, as C 1, C 2, etc. Step these off, as from 7 to 6, giving then points 3 2 and 1. From 1, as center, describe arc of a radius equal to 2 C of elevation, Fig. 849. Intersect this with an arc of a radius equal to F' F' of Fig. 851, giving point C, which completes the one-half pattern of the transformer. For the hole to be cut out for the collar, take the points in fine C B, in Fig. 850, and place them on fine 1 C of Fig. 852, as 1 to 0, 1 to 1' and 11, 1 to A, omitting 10 and 2, and then 1 to 4' and 8", etc. Draw hnes at right angles to 1 C and then place on 1' and 11' the dis- tance from center line C in plan, Fig. 850 to 1*. Then on A, in Fig. 852, fine C to A' in plan, Fig. 849, and so on. Now, the best way to find the location of point 10 or 2 — which is on the rounded part of the transformer — is to set the compass to the space A x 2 X of the pattern of offset in Fig. 850, and then using A 1 , in Fig. 852, as center, swing a small arc. Set compass now to space T 3 1 in the pattern of offset, Fig. 850, and with 3*, in Fig. 852, as center, intersect the arc from A x , locating thereby point 2 X . Trace a hne through these points, as shown by the cross-hatching, which is the outline of the hole for the collar, or line of penetration. Fig. 853 is the one-half pattern of the square part of the transformer, and is simply the placing of space C C", in the plan of Fig. 849, on a line, as shown. From C" to C is double the distance of C C" and C" to P is C P, in Fig. 849 elevation, while C D, in Fig. 853 is F D in eleva- tion Fig. 849. 492 The New Metal Worker Pattern Book. PROBLEM 248. Patterns for Cone Hopper Intersected by a Spout. As will be noticed, especially by Fig. 854, the hopper is round, of conical shape, and is intersected by a rect- angular tapering spout, the taper of which is in the side elevation only, the front of the spout showing parallel lines, as indicated in the front elevation. This model shows the one side of the spout a b in the front elevation to be in line with the center line of the conical spout, while the tapering side of the spout is to have the position shown in the side elevation. The problem presented by our correspondent gives an interesting study in pro- jections, intersections and developments, and is worked out as shown in Fig. 855. First, draw the center line A B, on either side of which draw the cone hopper as shown by 4 4 B in eleva- r Round Hopper ... Rectangular h H —Tapering Spout-" ^ Side Elevation Front Elevation Fig. 854- — Reproduction of Paper Model. tion. Locate as desired, the center line of the spout as indicated by a b. Establish the hight a b, also the semi- width at the top a 7 and a f, as well as the semi-widths at the bottom, as b d and 6 e. Now draw the taper 7 d and / e. 7 / e d then represents the side elevation of the spout which is to intersect the cone hopper. Above the line 4 4 in elevation draw the plan of the hopper, shown by 4 C 4 D. As the spout is to set to one side of the center of the cone, as shown by a b in Fig. 854, and as the sides are to be parallel as shown in this view, then establish the desired width as indicatedby X in plan in Fig. 855, and draw a line parallel to 4, 4, in plan until it intersects the center line A D in plan at c' and the top outline of the cone at 4'. As the one side of the spout sets on the center line 4 4 in plan, then will 7 8 e d in elevation be the pattern for that side. To obtain the pattern for the side on the line 4' c' in plan, it will be necessary to obtain a vertical plane of the cone on the line 4' c' in plan as follows. Using A as center with radius equal to A c' draw the semi-circle cutting the center line 4 4 and 1 1. From point 1 on the right side in plan, at right angle to 4 4, drop a line intersecting the right side of the cone in elevation at 1, from which point at right angles to the center line A B draw the line 1 1, which represents a hori- zontal plane shown in the semi-plan by 1 c' 1. Divide the distance between 1 and 4 on the left side in plan in any convenient number of spaces (in this case three), as shown by 2 and 3. Then, using A as center with radii equal to A 2 and A 3 draw the semi-planes 2 2 and 3 3, intersecting the side of the spout 4' c' in plan at 2' and 3'. From points 2 and 3 on the right side of the center line 4 4 in plan drop perpendiculars, cutting the side of the cone at 2 and 3, from which points draw similar horizontal planes in elevation, indicated by 2 2 and 3 3. From the inter- sections 2' and 3' in plan drop perpendicular lines in the elevation cutting similar planes 2 and 3 at 2' and 3'. As the distance between the points c' and 2' in plan is too great, bhect this distance and establish another point as 11' and using A as center, and radius equal to A, 11' draw the semi-plane 11 11. Project point 11 on the right-hand side to the eleva- tion, cutting the side of the cone at 11, and draw the horizontal plane in elevation as 11 11, which intersect at 11' by a perpendicular line dropped from the intersection in the side of the spout 11' in plan. From 4' in plan project a perpendicular to the top line in elevation, also shown by 4'. Through the points 4' 3' 2' 11' c' in eleva- tion trace the curved line, as shown, which represents a vertical plane in elevation on the line 4' c' in plan. Now extend the sides of the spout in elevation as d 7 , and e 8, cutting the plane in elevation at 6' and 5', respec- tively. Then will 6' 5' e d represent the pattern for the side of the spout on the line 4' c' in plan. Project the points 5' and 6' in elevation up to the plan, thus locating similar points shown by 5' and 6'. From points 5' and 6' in elevation draw horizontal lines cutting the sides of the cone also at 5 and 6. From these two points 5 and 6 on the right side of the cone B 4 erect perpendicular lines to the plan cutting the center line 4 4 in plan at 5 and 6. Again using A as center with radii equal to A 5 and A 6, Pattern Problems. 493 draw the semi-planes 5 5 and 6 6, which intersect by lines drawn vertically from 5' and 6' in elevation at 5' and 6' in plan, as shown. It will be noticed that these two lines just projected from 5' and 6' in elevation come directly on the inter- sections between the planes 5 5 and 6 6 in plan and the side of the spout 4' c', thus proving the operations. So that an accurate pattern for either the right or left side of the spout can be obtained, establish at pleasure any point as 9' between 5' and 8 in elevation and between 6' and 7 in elevation as shown by 10'. Through these two points 9' and 10' draw the horizontal planes in elevation as indicated by 9 9 and 10 10. From 9 and 10 on the left side of the cone erect perpendicular lines to the plan cutting the center line 4 4 at 9 and 10, re- spectively, and using A as center with radii equal to A 9 and A 10 draw the short arcs shown by 9 9 and 10 10 in plan, which inter- sect by vertical lines erected from points 9' and 10' in elevation, thus obtaining the intersections 9' and 10' in plan. Project the points 7 and 8 in the elevation of the spout, to the plan, thus locating these two points in plan, all as shown by the dotted lines. 7 6' 5' 8 in plan then shows the plan view on 7 6' 5' 8 in elevation, while h i n 3' shows the plan view of the bottom of the spout on d e in elevation. For the pat- tern for the left side of the spout proceed as fol- lows: At right angles to 6' d in elevation from points 6', 10', 7 and d draw lines indefinitely as shown. Parallel to 6' d draw the line 6 X G. Take the width of X in plan and set it off from 6 1 to 6" and G to H and draw a line from 6° to H as shown. Now measuring in each instance from the line 4 4 in plan, take the vertical dis- tances to points 10' and 6' and place them in the pattern on similar numbered lines, measuring in each instance from the line 6 3 G, thus obtain- ing the points of intersections 10° and 6° as shown in the diagram. Trace the curved line 6" 10" 7*. Then will 6° T G H be the desired pattern. For the pat- tern for the right side, draw lines indefinitely from points 5' 9', 8 and e at right angles to 5' e, parallel to which draw the fine 5 X J. Make the distance 5 X 5° and J K equal to X in plan, and connect the two points 5° and K. Now, again measuring from the line 4 4 in plan measure the vertical distances to points 9' and 5' and place them on similar numbered lines in the pattern, measuring in each instance from the fine 5 X J as shown from 9* to 9' and 5 1 to 5". Trace the curved fine 5", 9", 8 Z . Then 5' K J 8* is the desired pattern. If the pattern is desired in one piece, then the various Fig. 855. — Plan and Elevation, with Pattern Shapes Developed. patterns can be joined together as follows: Take a tracing of the pattern for the right side of spout, indicated by 8 T J K 5° and on the fine 5° K join the pattern of the taper side, shown in elevation by e 5' 6' d and to the side 6' d join the pattern for the left side, as indicated, by 6° H G T and on the line 7 1 G join the other tapered side indicated 494 The New Metal Worker Pattern Book. by 7 d e 8, all as shown complete in one pattern in Fig. 856. To obtain the shape of the opening to be cut in the side of the conical hopper, proceed as shown in Fig. 855. Using B as center with radii equal to B 8, 9, 5, 11, 2, 3, 7, Fig. 856. — Pattern for One-piece Spout. 10, 6, and 4 draw the arcs as shown. At pleasure from the apex B draw any line as B E. Now, measuring from the line 4 4 in plan, measure off along the curve from 6 to 6' and place it on the arc 6 6 in the pattern measuring from the line B E along the curve from 6° to 6'. In a similar manner measuring from the line 4 4 in plan take the distance along the curve from 10 to 10' and place this distance along the curve 10 10 in the pattern from 10° to 10'. As the one tapering side in elevation lies directly on the side of the cone and intersects the various planes in elevation at 7, 3, 2, 11, 9, and 8, then will the arcs struck from the apex B and intersecting the line B E at 7°, 3°, 2°, 11°, 9°, and 8° show the true points of intersections and a line drawn from 8° to 7° in the pattern shape of opening will be the outline on one side. Now in a similar way, measuring in each instance from the line 4 4 in plan take the various distances along the curves or arcs, as from 3 to 3'; 2 to 2'; 11 to 11'; 5 to 5', and 9 to 9', and place these distances in the pattern measuring in each instance from the line B E, along the curves having similar num- bers as shown respectively from 3° to 3'; 2° to 2'; 11° to 11'; 5° to 5' and 9° to 9'. Trace a line through points thus obtained as shown from 8° to 5' to 6' to 7°. Then will the shaded portion represent the shape of opening to be cut in the conical hopper. The full pattern for the conical hopper is not given as that is simply the pattern for a right cone in which the shaded opening must be cut. PROBLEM 249. Pattern for Gooseneck with Compound Curve. This discussion is on methods of how to obtain the patterns for a gooseneck having a compound double curve as shown in Fig. 857, in which the plan, front and side elevations are shown. In the plan, A represents the gutter from which a gooseneck is to connect at B, and pass over to the inside corner of the wall at an angle of 45 degrees, as indicated by C. The front elevation of this gooseneck is shown by D, the projection from the wall being equal to c a and hight equal to a b. In the elevation E shows the side of the gooseneck, the projec- tions a' c' and a' v' being similar to those in the front view. The usual method of developing these patterns is by parallel lines, but in Fig. 858 is shown how the patterns can be laid out by radial lines, and the area of the pipe will be maintained throughout the entire curve. In Fig. 858 let A B C D represent the section of the top of the leader at the gutter and A 1 B 1 C 1 D 1 similar section on the inside corner of the wall. Let the pro- jection between the gutter and wall be as much on either side as is indicated by the arrows X and Y. Connect opposite corners of the leader sections as shown from A to Wall line Wall line - ' - ' --~'i&" ' s J- \- - -{■ ■ > ^~i'; m Fig. 857. — Elevations in Gooseneck in Problem. Pattern Problems. 495 A 1 , B to B 1 , C to C 1 and D to D 1 . At right angles to these lines an oblique view must now be constructed as follows: Parallel to the line A A 1 in plan draw the line E F and G H, making the distance between these two lines equal to the hight of the gooseneck. From the corners in the section A B C D erect lines at right angles to A A 1 , cutting the top line G H at A, B, C and D, as shown. In a similar manner erect lines from the sec- tion A 1 B 1 C 1 D 1 in plan, cutting the base or bottom line E F at A 1 , B 1 , C 1 and D 1 . proceed as follows: At right angles to G H from the point J, draw the line 3 m. In a similar manner at right angles to E F from the point R, draw the line K n. Extend the lines D A, A B, C B and D C in the section in plan until they intersect the line projected from the center J in the oblique view at d, e, f and h, respectively. In a similar manner extend the lines A 1 D 1 , B 1 A 1 , B 1 C 1 and C 1 D 1 until they intersect the line projected from the center K in the oblique view at d', e', f and h', respectively. These various points d, e, /, and h and d', e', /', and h' represent the centers with which to develop the patterns for the sides of the elbow. The next step is to divide the various curves in the oblique view into equal spaces, from which the girth is obtained in developing the patterns. Thus, divide the outer curves from D to D 1 in the oblique view, as shown from 1 to 10 and the inner curve B 1 to B, as shown from 11 to 20. To obtain the pattern for the side of the gooseneck from D to A in plan proceed as follows: Draw any hori- C B 50 \9 s / va . Pattern for ITK - >■ SideB-C Fig. 858. — Method of Developing Pattern for Gooseneck with Compound Curve by Radial Lines. At pleasure establish the centers J at the top and K at the bottom with which to describe the curves shown. The radius J B at the top and K D 1 at the bottom may be made similar or dissimilar as desired. Using J as center and with radius equal to J B draw the arc B t. With radius equal to KB 1 at the bottom draw the arc B 1 u. Tangent to these two arcs, draw the line 16 17 and from J draw a line through 17, extending it indefinitely. In a similar manner from K draw a line through 16 indefinitely as shown. With radii equal to J C, A and D draw arcs cutting the line J 6 as shown. Also with radii equal to K C 1 , A 1 and D 1 draw arcs cutting the line K 16 as shown. Connect arcs by straight lines as shown. Then B D D 1 B 1 represents the oblique view of the gooseneck. To obtain the radii with which the patterns are struck zontal line in diagram as shown by D d. With radii equal to d A and D in plan and d in as center draw the arcs D 6 and A 6'. On the arc D 6 set off the girth of 1 to 6 in the oblique view as shown from 1 to 6 in and from 6 draw a radial line to d, cutting the inner arc at 6'. At right angles to the radial line 6 d draw lines from 6 and 6' equal in length to 6 7 in the oblique view as shown in by 6 7 and 6' 7'. Extend the line T 7 indefinitely as shown. With radius equal to d' A 1 in plan and with 7' in O (which represents the fine of the corner joint A or A 1 ), draw the arc d' intersecting the lines drawn from 7'. Using the same radius, with d' as center draw the arc 7' A 1 . Again using the center d', with radius equal to d' 7 draw the arc 7 10. Take the girth from 7 to 10 in the oblique view and place it as shown from 7 to 10 in diagram O, and draw a line from d' through 10 intersecting 49G The New Metal Worker Pattern Book. the outer curve at A 1 . Then ADD'A 1 represents the pattern for the side of the gooseneck shown by A D or A 1 D in plan. To obtain the pattern for the side A B in plan, draw- any line, as A e in diagram P. With radii equal to c B and A in plan and e in P as center, draw the arcs B 17 and A 17' respectively. On the arc B 17 set off the girth of 20 to 17 in the oblique view, as shown by similar num- bers in P. Draw a hue from e through 17 cutting the outer arc at 17'. From points 17 and 17' draw the lines 17 16 and 17' 16' at right angles to e 17' equal to 17 16 in the oblique view. Extend 16 16' indefinitely as shown in P. With radius equal to e' B 1 in plan, and with 16 in P (which represents the line of the corner joint B or B 1 in plan), describe the arc e' intersecting the line previously drawn from 16. With the same radius and e' as center draw the arc 16 B'. Again using e' as center and e' 16' as radius describe the arc 16' A 1 . Take the girth from 16 to 11 in the oblique view and place it as shown from 16 to 11 in P, and draw a fine from 11 to e' cutting the inner arc at A 1 , and A B B 1 A 1 will show the pattern for the side A B or A 1 B 1 in plan. The pattern for the side D C in plan is obtained by drawing any line, as D h in diagram R. With radius equal to h C and D in plan and h in R as center draw the arcs C 6' and D 6. On the arc D 6 set off the girth of 1 to 6 in the oblique view, as shown by similar numbers in R, and draw a line from 6 to h intersecting the inner arc at 6'. At right angles to 6 h from points 6 and 6' draw the lines 6 7 and 6' 7' equal in length to 6 7 in the oblique view. Extend 7' 7 indefinitely as shown, and using h' C 1 in plan as radius and with 7' in R (which represents the fine of the corner joint C or C 1 in plan), describe the arc h' intersecting the fine drawn from 7'. With the same radius and h' as center describe the arc 7' C 1 . Again using h' as center and h' 7 as radius, describe the arc 7 D 1 . Take the girth from 7 to 10 in the oblique view and place it as shown from 7 to 10 in R and draw a fine from h' through D 1 until it cuts the outer arc at C 1 . Then D C C 1 D 1 is the pattern for the side C D or C 1 D l in plan. For the last pattern draw any line, as / C in S. With radius equal to / B and C in plan and / in S as center describe the arcs B 17 and C 17'. On the arc B 17 set off the girth of 20 17 in the oblique view, as shown by similar numbers in 3. From / draw a line through 17 until it meets the outer arc at 17'. From 17 and 17' draw fines at right angles to 17' / equal in length to 17 16 in the oblique view. Draw a line in S through 16 and 16' indefinitely as shown, and using/' B 1 in plan as radius and 16 in S (which represents the corner joint fine B or B 1 in plan) as center, describe the arc /' intersecting the fine drawn from 16. Use the same radius and/' as center and draw the arc 16 11. Again using/' as center and/ 16' as radius, describe the arc 16' C 1 . Take the girth from 16 to 11 in the oblique view and place it on the outer curve in S, as shown by similar numbers, and draw a line from 11 to /' cutting the inner arc at C 1 . Then BCC'B 1 shows the pattern for the side B C or B 1 C 1 in plan. Laps must be allowed for soldering, seaming or rivet- ing, according to the method of constructing. PROBLEM 250. Short Rule for Spiral Strip in Separator. The following text and diagrams describe a short method of developing the spiral strip in a dust separator without the use of triangulation; it, however, must be remembered that only an approximate pattern results inasmuch as no method can develop a strictly accurate pattern. Referring to Fig. 859 proceed as follows: Divide the outline of the plan in an equal number of spaces, in this case 8, as shown by the small letters a, b, c, d, e, /, g and h, from which points draw lines to the apex r. Assuming that the spiral strip is to make two revolutions, divide the vertical bight of the sepa- rator in two tunes the number of spaces in the plan, or 2X8 or 16 spaces, as shown from a' to h' on the vertical fine a' t. From the divisions a to h in plan, erect fines, partly shown, intersecting the top line of the separator as shown by similar letters, from which points radial lines are drawn through the elevation to the apex X. Now from similar lettered divisions on a' t, draw hori- zontal lines intersecting similar radial fines in elevation at 1, 2, 3, 4, 5, etc., to 17, as shown. If desired trace a spiral fine through these divisions as shown. From these numbered intersections 1 to 17 in elevation, drop perpendicular fines in the plan, cutting similar lettered radial lines as shown by similar points of Pattern Problems. 497 intersection 1 to 17. If desired trace the plan view of the spiral through points just obtained, although this is not necessary in the laying out of the pattern. The pattern strips are now in order and are developed by means of parallel lines. The method to be given is based on the principle that a cone cut by a plane obliquely through its opposite sides as A B in elevation produces an elliptical figure. Therefore for the pattern for the upper revolution of the spiral proceed as follows: Take the girth in elevation of the spiral line, 1, 2, 3, 4, 5, 6, 7, 8, ana 9, and place it on the center line in plan extended as e i as shown by 1, 2, 3, 4, 5, and then go backwards to 6, 7, 8, and 9. Through these points draw vertical lines which intersect by' fines drawn parallel to e i from similar numbered points of intersections in plan. Trace the outline 1, C, 5, D, 9, which will meet the inside of the cone. Now set the dividers to the required width as I m and scribe the inner line 9 m 8 as shown. In precisely the same manner obtain the pattern for the lower revolution. The girth of 9 to 17 in elevation is placed on line a n in plan, the usual measuring lines drawn and intersected by lines drawn from similar numbers in plan. Trace the outline of the lower pattern as shown, and allow the proper width V m' , as shown. In this case the patterns have been made in two parts. In making a spiral for a full-size separator, one-quarter sections would be used, that is, four pieces for every revo- lution. As the pattern is but approximate, slight stretch- ing of the edges will be necessary, before turning the rivet- Elevation Pattern for Lower Revolution Pattern for Upper Revolution Fig. 859. — Short Method of Developing Pattern for Spiral Strip in Separator. ing flange. In riveting in the spiral, best results are obtained by starting at the bottom of the cone. The patterns are net and riveting flanges must be allowed to all patterns. PROBLEM 251. Pattern for Offset in Ventilation Pipe. The following demonstration is an interesting and unique procedure for developing a pattern for offset in a T ventilation pipe which is 48X72 niches and made of 16-gauge galvanized iron. In Fig. 860 is shown a picture of a finished offset which is shown developed in Fig. 861. The first step is to draw the profiles of the pipes in plan in their proper positions, as shown by 1 2 3 4 and 1' 2' 3' 4', giving the proper projection from the line H to the side of the lower pipe 2 3 and from the fine G to the side of the pipe 1 2, as desired. Through the two profiles draw diagonal fines (not shown), intersecting each other at b and a respect- ively, and through the two intersections draw the line A B. At right angles to this fine a diagonal elevation must be constructed as follows: Parallel to A B draw the line E F, and at the desired distance as E D draw the fine D C parallel to B A. From the points 1 2 3 4 in the profile in plan draw lines at right angles to A B, cutting the line C D in the diagonal elevation as shown by similar numbers. In a similar manner, at right angles to A B from the corners 1' 2' 3' 4' in the profile in plan, draw lines cutting the top 498 The New Metal Worker Pattern Book. •6 Fig. 860. E Finished Elbow V \\\^xV S-T-U-V Patterns for Upper Part of Elbow Ft \ / Vv // / - tf /Y / / / y / / / / 3 0/ S // 4 3 4 T Fig. 861. — Developing Patterns for Offset in Ventilation Work. ~0 2 Pattern Problems. 499 line F E in the diagonal elevation as shown. Now, establish at pleasure the centers 5 and 6 in the diagonal elevation with which the throats of the elbow are struck. Using 5 as center on the top line E F, with radii equal to 5 4', 5 3', 5 1' and 5 2', draw arcs indefinitely as shown respectively by c, d, e, and /. In a similar manner with any desired eenter as 6, on the line C D, with radii equal to 6 2, 6 3, 6 1, and 6 4, draw the arcs shown respectively by g, h, i, aad j. Now connect similar numbered arcs by fines drawn tangent to each arc as indicated from 4° to 4°, 3° to 3", 1° to 1' and 2° to 2". From the point 4" draw a radial fine to the center 6 and from the point 2° draw a radial fine to the center 5. Connect the points of tangency by the fines 4° to 3° to 2° to 1° to 4°, also from 2" to 3" to 4' to 1° to 2". From these points of tangency 1° to 4° and 1" to 4" erect lines in the plan at right angles to A B, intersecting similar num- bered lines as shown from 1° to 4° and 1" to 4". Connect these points as shown, and draw lines from 1° to 3" to 4°, also from 1° to 3° to 2". These fines will be used when laying out the straight portion between 1° and I s by triangulation, while the circular parts of the elbow will be developed by radial lines. To obtain the radii for striking the various sides of the curved elbow, proceed as follows: From the center point 5 at right angles to F E draw the line 5 G indefinitely. Now extend the sides of the pipe 2' 1', 2' 3', 2' 4', and 1' 4' until they intersect the line 5 G at G, H, J, and K, respectively, which joints represent the centers for strik- ing the patterns. In a similar manner at right angles to C D in the diagonal elevation from the point 6 erect the line 6 indefinitely, as shown. Now extend the sides of the pipe 1 2, 3 2, 4 3, and 4 1, until they intersect the fine 6 at L, M, N, and 0, respectively. The pattern for the side 1' 2' of the upper curve is obtained by using G 1', G 2', in plan as radii and G 1 in diagram S at center, and describing the arcs V 1° and 2' 2°, as shown. As the fine 1 V in plan lies in a hori- zontal plane or parallel to A B, then will the compound curve 1 1' in diagonal elevation show a true section or profile from which measurements can be taken and placed on the pattern shape being developed in S. Therefore, starting from 1 on the lower part of compound curve 1 1' in diagonal elevation, divide that part between 1 and the radial line 4" 6, as shown by the points numbered 1, 7, 8, 9, 10, and 11. In a similar manner, starting from where the radial fine 5 2° intersects the compound curve at 12, divide the distance between 12 and 1' into equal spaces as indicated by the numbers 12, 13, 14, 15, 16, and 1'. Now take the various divisions between 1' and 12 in the diagonal elevation, and starting from 1' in the pattern S, step off similar divisions as shown from 1' to 12. From the apex G 1 draw a radial fine through 12 and 1', inter- secting the outer curve at 2° and 2'. Now take the dis- tance from 12 in the diagonal elevation to the point of tangency 1°, and set it off from 12 to 1° on the inner arc in the pattern S. Draw a fine from 1° to 2°. Then 1° 2°, 2' V is the pattern desired. Now with radii equal to H 3', H 2' in plan and H 1 in diagram T as center, draw the arcs 3' m and 2' 2°. Divide the outer arc 2° 2' in dia- gram S in equal spaces as shown and place the same numbered divisions along the outer arc in diagram T, as shown, from 2' to 2°, and from 2° draw a radial fine to the apex H 1 intersecting the inner arc at m. Now, measure the distance from the point of tangency 3° in the diagonal elevation to the point m on the radial fine and place it from m to 3° in the pattern T and draw a fine from 3° to 2°, also a fine from 2' to H 1 , cutting the inner arc at 3'. 2' 3' 3° 2° is then the pattern for the side 2' 3' in the upper curve. Now, using from the plan the radii J 4', J 3' and J 1 in diagram U as center, describe the arcs 4' 4° and 3' m. Draw a fine from 3' to J 1 , cutting the inner arc at 4'. Now, divide the inner arc in pattern T between 3' and 3° in equal spaces as shown, and place these divisions along the outer arc 3' m in pattern U, as shown by similar numbers between 3' and 3°. Take the distance from 3° to m in T and place it from 3° to m in U. Draw a fine from m to J 1 , cutting the inner arc at 4° and draw a line from 4° to 3°. Then 3' 4' 4° 3° will be the pattern for the upper part of the elbow whose side is marked 3' 4' in plan as shown. Using as radii K 4', K 1' in plan and K 1 in diagram V as center, describe the arcs 4' 4° and 1' 1°. From 1' draw a radial fine to the apex K 1 , intersecting the inner arc at 4'. Now, take the girth along the inner curve 1' 1° in the pattern S and place these divisions along the outher curve in pattern V as shown by similar numbers. From 12 draw a radial fine to the apex K', cutting the inner arc at 4°, and draw a line from 4° to 1°. By measuring the divisions along 4° 4' in pattern U, they will be found to correspond to similar girth along 4° 4' in pattern V. The distance 12 1° along the outer arc in V will also cor- respond to 12 1° in the diagonal elevation. 4' 1' 1° 4° will then be the pattern for the side 4' 1' in plan of the upper curve of the elbow. For the patterns for the lower part of the elbow proceed as follows: Using as radii L 2, L 1 in plan and L 1 in diagram W as center, describe the arcs 2 2° and 1 1° respectively, and draw a radial fine from 1 to the apex 500 The New Metal Worker Pattern Book. L\ cutting the inner arc at 2. Now take the various divisions along the compound curve 1 1' in the diagonal elevation, indicated from 1 to 11, and place these divisions on the outer curve in the pattern W as shown by similar numbers. From point 11 draw a radial line to the apex L 1 , intersecting the inner arc at 2°. Now take the dis- tance from 11 to the point of tangency 1" in the diagonal elevation, and place it as shown from 11 to 1" in the pat- tern W and draw a line from 1° to 2°. 1 2 2" 1" then gives the pattern for the side 1 2 in plan of the lower curve of the elbow. Using as radii M 2, M 3 in plan with M 1 in diagram X as center describe the arcs 2 2° and 3 n. Draw a line from 3 to the apex M 1 , cutting the inner arc at 2. Divide the inner arc 2 2" in the pattern W, as shown by the small figures 26 27, and transfer these divisions as shown by similar number on the inner arc 2 2" in the pattern X. From the apex M 1 draw a radial line through 2°, cutting the outer arc at n. Now measure the distance in the diagonal elevation from the radial line n to the point of tangency 3" and place it, as shown from n to 3° in X, and draw a line from 3 C to 2". Then 2 3 3" 2" will be the pattern for the lowc* ">art of the_elbow, indicated by the side 2 3 in plan. Using as radii N 3, N 4 and plan with N 1 in diagram Y as center, draw the arcs 3 n and 4 4" respectively. From 4 draw a radial line to the apex of N 1 , cutting the inner arc at 3. Now take the various divisions placed on the outer curve 3 n in X, and starting from 3 in Y place similar divisions on the inner curve as shown by similar letter and numbers. From the apex N 1 draw a radial line through n, intersecting the outer arc at 4°, and draw a line from 4° to 3°. The distance from n to 3" repre- sents the distance from n on the radial line in diagonal elevation to the point of tangency 3". 3 4 4" 3° then shows the pattern for the lower part of the elbow indi- cated in plan by the side 3 4. The final pattern for the curved elbow is obtained by using as radii 1 and 4 in plan and with O 1 in dia- gram Z as center, describe the arcs 1° 1 and 4° 4. Draw a radial line from 4 to O 1 , cutting the inner arc at 1. Now take the various divisions between 1 and 1° in pat- tern W and set them off on the inner arc in pattern Z as shown between 1 and 1°. From the center O 1 draw a radial line through 11, intersecting the outer arc at 4°, and draw a line from 4" to 1°. The distance 1" 11 equals the distance from the point of tangency 1° in diagonal elevation to the intersection between the radial line and curve at 11. 1" 1 4 4" is then the pattern for the lower part of the curve shown in plan by the side 1 4. The pattern Z may be further proven, if desired, by compar- ing the spaces between 4 and 4° on the outer curve in the pattern Y with those shown by similar numbers in pat- tern Z. The next step is to develop by triangulation the various sides of the straight portion of the elbow joining the curved parts. It will first be necessary to find the various true lengths of the lines shown in plan as follows: As the lines 1° 1° and 3" 3° in plan he on a horizontal plane, then will the corresponding lines 1" 1° and 3° 3° in diagonal elevation show their true lengths. Now, from the various points of tangency in the diagonal elevation as 1°2° 3° 4°, also 1* 2" 3" 4", draw lines to the left indefinitely parallel to C D, as shown. At pleasure erect any perpendicular as shown by P R. Now take the length of 2" 2° in plan and set it off on the line drawn from 2" in diagonal elevation, measuring from the line P R, as shown, from 2"° to 2", and draw a fine from 2" to where the line drawn from 2° in elevation intersects the line P R also at 2°. 2° 2° in the true lengths then shows the true length of 2° 2" in either plan or elevation. Proceed in similar manner for the balance of the lines in plan. Take the length of 4° -4° in plan and place it in the true lengths measuring from the line P R on the line drawn from 4° in elevation, as shown by 4' in the true lengths, and draw a line from 4" to where the line drawn from 4° in elevation intersects the line P R in the true lengths at 4°. This line from 4° to 4° is the desired true length. Now take the lengths of 2" 1° and 2" 3° in plan, and place them in the true lengths on the lines drawn from 1° and 3° in the diagonal elevati'on, measuring in each instance from the line RP, indicated in the true lengths by 1° and 3°" respectively. From 1° and 3° draw lines to where the line- drawn from 2° in elevation inter- sects the perpendicular P R at 2™, which gives the desired length. Finally take the length of the lines in plan shown by 4° 1° and 4° 3° and place them in the diagram of true lengths, measuring from the fine R P on lines drawn from 1" and 3° in the elevation as shown by 1° and 3° in the true lengths. From these two points 1" and 3° draw lines to 4°, which point is the intersection between the line drawn from 4° in elevation and the perpendicular line R P. Having obtained all of the true lengths, the various patterns for each complete side is now in order, starting with the side 1' 2' at the top. Let the diagram S 1 be a reproduction of the pattern S. Now using 2° 2" in the true lengths as radius and 2° in S 1 as center draw the arc 2°, which intersect by an arc struck from 1° as center Pattern Problems. 501 and 1° 2 m in the true lengths as radius. Now, using 1° l r in the diagonal elevation (which shows its true length), as radius, and 1° in pattern S 1 as center, draw the arc 1", which intersects by an arc struck from 2° as center and 2° 1° in pattern W as radius. Take a reproduction of pattern W and place it, as indicated, by W 1 placing the line 2° 1" in W upon the line 2° 1' in W 1 . 1' 2' 2 1 is then the full pattern for that side. Take a tracing of the pattern T and place it, as shown, by T 1 . Using 2° 2" in the true lengths as radius and 2° in T 1 as center, de- scribe the arc 2\, which intersect by an arc struck from 3° as center and 3° 2" in the true lengths as radius. With a radius equal to 2" 3" in pattern X and 2° in X 1 as center describe the arc 3", which intersect by an arc struck from 3° in T 1 as* center and 3° 3° in the diagonal elevation as radius. Take a tracing of the pattern X and place it as shown by X 1 , placing the line 2" 3° in pattern X upon the line 2" 3" in X 1 . 2 3 3' 2' is then the full pattern for that side shown by similar numbers in plan. In a similar manner take a tracing of the pattern U and place it as shown by U 1 , then using 3° 3" in the diagonal elevation (which shews its true length), as radius, and 3° in U 1 as center, describe the arc 3°, which intersect by an arc struck from 4° as center and 4° 3" in the true lengths as radius. With radius equal to 3" 4' in pattern Y and 3° in Y 1 as center draw the arc 4", which intersect by an arc struck from 4° as center and 4° 4" in the true lengths as radius. Take a tracing of the pattern Y and place it as shown by Y 1 , being careful to place the line 3"4*iriY upon the line 3° 4" in Y 1 . 3 4 4' 3' is then the pattern for similar numbered side in the plan. Finally take a tracing of the pattern V and place it, as indicated, by V 1 . Using 1° in V 1 as center, with 1° 1° in the diagonal elevation (which shows its true length), as radius, de- scribe the arc 1° in V 1 , which intersect by an arc struck from 4° as center and 4° 1" in the true lengths as radius. Now with radius equal to 4° 4" in the true lengths and 4° in V 1 as center, describe the arc 4", which intersect by an arc struck from 1° as center and 1" 4" in pattern Z as radius. Take a tracing of 4' 1" 1 4 in pattern Z and place it as shown by similar numbers in Z 1 , being careful to place the line 1° 4" in Z on the line 1" 4" in Z 1 . 1 4 4' 1' is then the pattern for the side shown by similar numbers in plan. Allow flanges on all patterns for rivet- ing, being careful to punch all holes accurately, as the material to be used is to be of number 16-gauge gal- vanized iron. PROBLEM 252. Patterns for a Branch Leaving in Two Directions. The tap is a 9-inch branch on a 30-inch main line pipe, and it leaves the center of the top of the main at an angle of 45 degrees and also points to the side of the main line at an angle of 45 degrees. It is a simple proposi- tion to solve in so far as the pattern cutting is concerned, because the parallel line system of developing surfaces of solids can be employed, once the view is obtained, in which the elements, always parallel in cylindrical objects, are shown in their true lengths. RSTU represents a plan view of the 30-inch joint of pipe of the main line, while W X Y represents the top center line of the joint. X Z is the axial line of the tap which is an imaginary line through the center of the tap. It does not touch the outer line or surface of the tap in any place, whereas W X Y is an element of the main joint and lies on the surface of the joint. P is the profile of the tap and is just placed there to show that line X Z is the tap. No other work need be done on this plan for obviously line X Z leans so that it is not seen in its true length and now the side elevation is projected from the plan and W' X' Y' is the top line of the main joint, while X' Z' is the axial line of the tap. Profile P' again is placed there just as an aid in recognizing the relation of the lines W' X' Z' and X' Z'. It is apparent when this view is studied, that line X' Z' leans both ways and is not shown in its exact length ; so, the pattern cannot be developed from this view and, therefore, the miter line need not be projected, as with the plan, unless a finished drawing is wanted. Even then this much of the plan and side elevation must be left as it is until the required view is obtained, when the various points of intersection and elements would be projected back from view to view. All that work is unnecessary, and as this is an attempt to show shop practice, where not more than one hour would be allowed to cut this pat- tern, the next step in the procedure will be described, although it is a good thing for those who have the time to construct all views complete. 502 The New Metal Worker Pattern Book. The next step, therefore, will be to project an end view or elevation. In this view, the profile PP, of the main joint is given and line W° X° Y° appears as one point only, while axial line X Z is shown as a line X° Z°. Once again, it is apparent that this axial line leans both ways and is not shown in the true length, and although this line is 45 degrees from the horizontal similarly to the the element, or line 3, is tangent to profile PP; had it occurred that element 3 fell outside of profile PP, it would have been necessary to shift line Z° X° until element 3 would touch profile PP, which would mean that the rela- tive positions of line Z X would be altered in both the plan and side elevation. If now the axial line of the tap in the end elevation is / 2 Developing Patterns for a Tap. side view, it happened so because the line is 45 degrees from a relative line in plan. This would not be so if angle in the plan was 30 degrees, or any other angle for •then angle in end view would not be like either the one in side elevation or plan. Profile P° is now necessary and placed as shown and divided into equal parts. Lines parallel to Z° W° are drawn from these division points until they touch the profile PP of the main joint, all as shown. Note that viewed at right angles to it or along the direction of the arrow, it will be seen in its true length. Therefore an oblique elevation along the line of the arrow, projected from the end view, will be projected in this wise: Draw a line a b, parallel to Z° W°. Draw projector lines from points D and c of the profile PP, also from points Z° and W° of the end elevation. Make W x X x Y z of the oblique elevation equal to W X' Y' of the side elevation— that is to say, distance from W 1 to X 1 and then to Y x is the Pattern Problems. 503 same as W to X' and then to Y'. On the projector line from Z° in the end elevation and measuring from b in the oblique elevation, place the distance b' Z' of the side elevation, locating thereby point Z z in the oblique eleva- tion. Draw a line from Z 1 to X J . Complete the oblique view of the 30-inch joint, which will look and have the same dimensions as in the plan and side elevation. The heavy line representing the top line of the main joint and axial line of the tap having been projected from view to view, the miter line, or rather the line of intersection of the tap and main can be developed like this: Place profile P 1 in the oblique view as shown, with the same divisions as in the end elevation, being careful to number them correctly. Draw lines from these divi- sion points in profile P x indefinitely toward line Y x W. Draw projector lines from the points of intersection of the lines from profile P° with profile PP toward the oblique view, as shown, until they meet those drawn from profile P 1 , being careful to have like numbered projector line intersect that from profile P 1 . To illustrate, point 3 on profile PP will intersect line from 3 in profile P 1 at 3* in the oblique view. Trace a fine through these points of intersection, as shown, which will give the desired miter line and correct view of main joint and tap with their elements shown in true length. The elements now being shown in true length the pattern can be developed by continuing the fine from 7/ and placing thereon the stretchout of profile P 1 , 1 2 3 4 5 67891011 and 0. Draw parallel lines at right angles to the stretchout line from these points, which are inter- sected by the like numbered lines from the miter fine; like 3* is 3° in the pattern. A line drawn through these points of intersection completes the full pattern for the tap. Continue line b a and place thereon the half stretch- out of profile PP. Spaces ABCDE and MNO can be at pleasure, only care should be taken that these divisions are carefully placed on the stretchout line, especially those which are numbered. Draw lines from the numbered points on the stretchout line as shown, which intersect by lines from the miter fine — 3* is 3' in the pat- tern, and so on. A fine drawn through the points of inter- section will give the hole to be cut in the main joint. When shaping these patterns in the rolls, it is neces- sary to roll them so that they will have the right side out, otherwise the tap would point in the opposite direction. As the patterns now appear, the surface of the pattern of the tap showing should be outside when rolled, or in shop talk, "marks outside"; whereas, with the main joint the pattern surface now showing should be rolled so that that surface will be inside or " marks inside." The oblique view is complete, and to finish the others, . points on Z J are projected back to Z° in the end view, which would show the end of the tap, elliptical. These points in the elh'pse at Z° are then projected across to the side elevation to intersect points from P' which again would give a similar ellipse at Z'. Also the points on profile PP would be projected across to meet those lines from P' which would give a complete view of the tap in the side elevation. Likewise, all these points in the side elevation are projected down to the plan to either inter- sect fines from P or those swung around from the end elevation, which would then give a complete plan. As was said, this is unnecessary labor and would be dis- pensed with in shop practice. The procedure as explained here calls for a large drawing board which most well equipped shops have. Should, however, no large board be available, the work could be laid out on the floor, as is often done in many shops. On a small board the various views could be drawn singly, completing one view on separate sheets of paper and carrying the dimensions and the like from drawing to drawing. The actual pattern cutting could then be done right on the sheet metal, by scribing thereon the stretchout fines, and so on, and then carrying the lengths of the element lines by any convenient method. Or else the drawing would be quarter size and pattern full size. PROBLEM 253. Pattern for Irregular Transition Piece. The pattern here developed is for an irregular transi- tion piece which is to connect the opening in the blower to a flat pipe that runs along the ceiling of the basement, in a building where an indirect heating system is to be installed. The opening in the blower is an irregular .shape with five sides. The profile for one-half of the opening in the blower is shown in the cross section in Fig. 863. The shape of the main pipe which runs along the ceiling is also shown by cross section in Fig. 863. The plan of the blower and the transition piece is shown in Fig. 864. A close inspection and study of the proposed form of 504 The New Metal Worker Pattern Book. the transition piece as shown in the elevation in Fig. 864 will show that if the corner of the outlet from the fan was connected directly to the far side of the pipe at the bottom, and also if the next corner, upon the outlet from the fan, was connected to the upper far corner of the pipe, the surface, which would form the side of the transition piece, would be vertical at the intersection of the flat pipe and on a slope at the intersection with the outlet from the blower. This would make the surface of that side of the transition piece a warped surface and only an approximate pattern could be developed, and this would necessitate the use of the triangulation method to develop the pattern. Pattern for an Irregular Transition Piece. It will also be easy to see that a direct line of con- nection between the two openings, as shown in the eleva- tion Fig. 863, would make an abrupt angle at the upper part of the connection and would decrease the size of the pipe so much as to interfere with its efficiency. There- fore, before a pattern can be developed, it is necessary to draw an arbitrary miter line. The most natural shape that suggests itself is formed by natural, graceful and gradual curves from the outlet in the fan to the end of the pipe. One miter line is drawn from X through the points ab c, etc., to I as shown in the elevation in Fig. 863, and the other one from through the points 2 3 4 and 5, etc., to 15. It will also be noticed that the fifth corner or high point of the outlet from the fan is not taken into consid- eration at this time. Next draw a miter line on graceful curves in the plan Fig. 864, which will represent the edge of the lower surface of the transition piece and is desig- nated in Fig. 864 by the figures 5, 6, etc., to 15. In order to keep the surface of the side of the transition piece from being a warped surface, the line which represents the edge of the upper part of the transition piece must be drawn exactly vertical and directly over the other line which represents the edge of the bottom of the transition piece. These lines which have been drawn arbitrarily may be taken for the miter lines of the transition piece and all that is necessary to complete the last run is to connect it with the point in Fig. 864. When these fines have been drawn the proc- ess of getting the pattern is very simple and consists of the following: Draw any fine A B at right angles with the parallel sides of the lines which are located on the sides of the transition piece. The stretchout for the far sides of the transition piece should now be laid off on this fine A B, the spaces being taken from the plan in Fig. 864 on the line 0', 2', 3', 4', etc., to 15'. The first space will be from 0' to 2', the second from 2' to 3', the third from 3' to 4', etc. It will be noted that the spaces on the fines in the plan in Fig. 864 which occur on a short curve, have been placed nearer together. These spaces do not need to be equal when it is convenient to make the work easier. It will also be noted from the point to the point 2 in the elevation in Fig. 863, there is no division and this is explained by the simple fact that when a fine is straight in the plan and also in the elevation, it will be straight on the pattern. The points on the sharper parts of the curve are located closer together to make the pattern more accurate. Now, from the points in the plan Fig. 864 on the line from 0', 2', 3', 4', etc., to 15', project lines down vertically until they intersect with the edges of the transi- tion piece in the elevation Fig. 863. Draw lines through these points parallel to the fine A B in Fig. 864, until they intersect with lines from the stretchout for pat- tern. A line through the points thus obtained will be the true shape of the pattern, as shown in Fig. 865 for the larger side of the transition connection. The stretchout for the bottom of the transition con- Fig. S65. Pattern for Larger Sid Pattern Problems. 505 nection is taken from the elevation in Fig. 863 and laid off on the line C D which must be drawn parallel to the line A B and at right angles to the end of the flat pipe and to the lines which have been drawn on the side of the transition piece in the plan and elevation as shown. The stretchout for X a b c d, etc., to I is taken from Fig. 863 and copied onto the line CD in Fig. 866. Lines drawn vertically upward from the points on the side of transi- tion piece, as shown in Figs. 863 and 864, are projected over to the pattern parallel to the line C D until they inter- sect at the stretchout line of the pattern. The line traced through these points will be the true shape of the pattern for the bottom of the transition piece as shown in Fig. 866. The stretchout of the pattern for the top of the transition piece, as shown in Fig. 867, is taken from the true profile of the top, as shown in the elevation in Fig. 863 in the same manner as in the preceding pattern. The location of the points on this pattern are determined, as in the preceding case, by projecting lines from the points in the plan Fig. 864 to the pattern in Fig. 866. It will be noted in Fig. 867 that a cut has been made in the pattern for a part of the transition piece over which a " boss " is to be placed that will connect the fifth point of the outlet from the fan to the transition piece. The pattern for the boss is shown in Fig. 868. The stretchout for the pattern in Fig. 868 is taken from the section through the outlet, one-half of which is shown in Fig. 863 by cross- hatched section. The points on the pattern for the boss in Fig. 868 are located by projecting them from the ele- vation of the boss in Fig. 863. The projection must be at an angle of 90 degrees with the hne which runs from point 1 to point 2 in the elevation Fig. 863. The line E F, which is to be the center of the pattern, must be parallel to the line that runs from 1 to 2 in the elevation Fig. 863. No allowance has been made in the pattern for any of the parts for the transition piece to be secured together and the necessary laps must be added by the mechanic to suit the requirements of the method of fastening which he uses. PROBLEM 254. Pattern for Forty-five Degree Y Branches. This problem has to do with branches leaving a main pipe at an angle of 45 degrees. In the plan A shows the profile of the main, 10 inches in diameter, and W Z B C shows it in side elevation, from which two 5-inch branch pipes, E and D, are taken at an angle of 45 degrees. The distance that the bottom of the pipe E sets below D is indicated by X. The branch pipes incline at an angle of 45 degrees in both plan and elevation, as indicated by E 1 and D 1 . They are so placed that a hne through the center of branch E 1 will meet the side of branch D 1 extended at center A, so that the distance from the center hne at Y to the side of pipe E 1 equals Y 6', while the distance to the side of pipe D 1 will equal Y 1'. As none of the views in either plan or elevation shows the true lengths Or true angles of the branches, a true elevation must be found showing the true length and true angle between the branch and main, from which the patterns are obtained, as follows : Through the center of pipe D 1 in plan, draw the center hne 3' 3, on which establish H as center and draw the required size circle. In a similar manner draw the center line through branch D in elevation, as shown by 3 1 a, and using a as center draw the circle shown. Estab- lish any point as F on the center line 3' 3 in plan, and from this point and the intersection between the center line and main pipe at 3', erect vertical lines intersecting the center line in branch D in elevation at F 1 and 3 1 respectively. From Z x draw a horizontal hne, cutting the vertical line, previously drawn, at G and forming the right angle triangle F 1 G 3*. With points 3' and F in plan and G and F 1 in elevation located nothing further is required in finding the true length and angle. Equal in length and parallel to 3' F in plan draw the hne 3* F 2 in the true elevation. At right angles to this line from F 2 erect the perpendicular F 2 F 3 equal in night to G F 1 in elevation. Draw a hne from F 3 to 3* in the true elevation, which on its center hne will give the proper or true pitch of the branch pipe shown by D in elevation. The true joint or intersecting hne between the branch and main pipe is found as follows: Extend the center line in the true elevation as 3 X c and using c as a center draw the circle H l , a duplicate of H in plan. Divide both of the circles H and H 1 into an equal number of spaces, as from 1 to 5 to 1 being careful to have the numbers so placed that if 3 and 3 come on the center hne in profile H, similar numbers 3 and 3 will be at right angles to the center hne in the profile H 1 . From the intersections 1 to 5 to 1 in the profile H draw fines parallel to the center line 506 The New Metal Worker Pattern Book. 3 3' until they intersect the profile of the main pipe from 1' to 5' and from which points lines are projected to the true elevation at right angles to 3' 3 in plan, and inter- sected by lines drawn from similar numbers in the profile H 1 in the true elevation parallel to the center line c Z x , resulting in the points of intersections 1, 2, 3, 4, and 5 on both sides in the true elevation. A line traced through Openin large Pi Opening in large Pipe Pattern for Main Pipe in one Piece Fig. 869. — Patterns for Y Branches Leaving Main at Different Points. points thus obtained will give the joint or miter line, from which the patterns are obtained. For the pattern for the branch pipe proceed as fol- lows: At right angles to 5 F 3 in the true elevation draw the line J K, on which place the stretchout of the profile H 1 , as shown by similar numbers. At right angles to J K from the various intersections 1 to 5 to 1, draw lines which intersect by lines drawn parallel to J K from similar inter- sections on the joint line in the true elevation. A line traced through these points, as shown by K L M N J, will be the pattern for the branch pipe. The opening in the main pipe is obtained as follows: At right angles to the line of the main pipe in the true elevation draw any line as P, on which place the girth of that portion of the main pipe in plan shown from 1' to 5', measuring each space separately, as they are all unequal. At right angles to P draw lines from the small figures which intersect by lines drawn parallel to P from similar numbers on the joint line in the true elevation. The shaded portion indicates the pattern for the opening which is traced through points thus obtained. Establish any point on the center line of pipe E 1 in plan as d, which use as a center and describe the 5-inch diameter circle, as shown. In a similar manner chaw the center line through pipe E in eleva- tion, as shown by 8 1 b and using b as center, draw the circle shown. Establish any point as S on the center line of branch E 1 in plan and from this point and the intersection between the center line and the profile of the main pipe at 8' erect perpen- dicular lines, intersecting the center line of the branch E in elevation at S 1 and 8 1 respect- ively. From 8 X draw a horizon- tal line, intersecting the per- pendicular line previously drawn, at R, and forming the right triangle S^S*. The true elevation may now be found as follows: Equal in length and parallel to S 8 1 in plan, draw the line S 2 8 X . At right angles to S 2 8* from the point S 2 set off the distance S 2 S 3 , equal in hight to R S 1 in the side elevation. Draw a line from S 3 to 8 X in the true elevation, which will give the true pitch on its center line of the branch pipe shown by E in elevation or E 1 in plan. The true joint or miter line between branch E and main pipe is found in the true elevation, as follows: Extend the center line in the true elevation 8 X d' and using d' as center draw the circle, which is a duplicate of d in plan. Divide both of the circles d and d' into an equal number of spaces, being careful to have the numbers so placed that if 8 and 8 come on the center line in d similar numbers 8 and 8 will be at right angles to the center line in the profile d'. From the inter- sections 6 to 10 in the profile d draw lines parallel to Pattern for Branch Pipe, Pattern Problems. 507 the center line 8 8' until they intersect the profile of the main pipe from 6' to 10', as shown, and from these intersections lines are drawn at right angle to 8 8' into the true elevation, and intersected by lines drawn from similar numbers in the profile d parallel to the center line d' 8. A line traced through points thus obtained, as shown, from 8 to 6, 10 to 8 will give the joint line between the branch and main line. To obtain the opening in the main pipe for the branch proceed as follows: Take the girth of the various spaces between 6' and 10' in the plan view of the main pipe and place it on the line h i at right angles to the lines of the main pipe in the true elevation. At right angles to h i, from the small figures, 6' to 10', draw lines which intersect by lines drawn parallel to h i from sim- ilar numbered intersections in the joint line in the true elevation. Trace a line through these points, as shown shaded, which will be the desired opening. The pattern for the branch is obtained by drawing any line at right angles to S 3 8 X , as shown, by T U and on this the girth of the profile d! is placed. The usual measuring lines are drawn and intersected by lines drawn parallel to TU from similar numbered intersections on the joint line, 8 8, in the true elevation. The pattern shape is represented by TU/j. As the two branches intersect the main pipe in different positions, namely, one tangent and the other central, with one branch higher than the other, it will be necessary to lay out the pattern for the main pipe in one piece, with the openings placed in their proper positions. Take the hights from W to 3° to Z in the side elevation and place it as shown, by similar numbers in pattern A. Take the hight of X in elevation and place it, as shown, from 3° to 8° in (A). At right angles to Z W from 3° draw a line indefinitely to the right, while from 8° draw a line indefinitely to the left. Take the girth from Y to 1' and Y to 6' in plan and place it, as shown, from 3° to 1' and 8° to 6' respectively in (A). From 1' and 6' erect perpendiculars, as shown. Take a tracing of the opening B and place the angle 1' 1' 3° on similar angle 1" 1' 3' in the pattern A. In a similar manner take a tracing of the opening C and place the angle 8° 6' 6° on the angle 8" 6' " in the pattern A. Take the girth of the semi-circle Y to v in plan and place it on either side of the center fine Z W in A, as shown, by V 1 V 2 and W 1 W 2 , which completes the pattern for the vertical pipe in one piece. A lap must be added to all patterns for seaming and riveting. PROBLEM 255. Pattern for Offset Blower Connection. In a large building, the existing conditions made it necessary to reduce the size of a blower pipe in a given distance and at the same time to drop it down from the ceiling and to shift it out from the wall with the result that the finished connection appeared as shown in Fig. 870. The method of developing the patterns for the re- quired offset and reducing section is as follows: Draw the plan and elevation as shown in Fig. 871 and divide the line X Y into any number of equal parts. Extend these lines up and down, as indicated by arrow, until they intersect the plan and elevation on each side as shown. To develop the pattern for the top, take the distances 1, 1 2, 2 3, 3 4, 4 5, 5 6 from the profile of the top in the elevation and lay them off on the fine A B located at the right of the plan. Care must be taken to transfer them in the proper order, as the spaces are now unequal. Carry the lines over from the points 0', 1', 2', 3', 4', 5', 6', in the plan until they intersect with lines drawn at a right angle from the points located on the true stretchout line A B. By tracing a line through the intersection of these Fig. 870. — Finished Blower Connection. lines, the correct outline is developed for one side of the pattern for the top of the connection. In like manner, if lines are carried over from the points A', B', C, D\ 508 The New Metal Worker Pattern Booh. E', F', G', in the plan, a line traced through the points of intersection of these lines, and lines extended from the points 0, 1, 2, 3, 4, 5, C, on the line A B, the resulting figure will be the correct outline of the other side of the the bottom of the connection as shown on the hne C D must be taken from the profile of the bottom as shown in the elevation. The spaces on the pattern for the front, as shown on line E F, must be taken from the profile of F T 6' Fig. 871.— Plan, Elevation, and Patterns for Offset Blower Connection. pattern for the top of the connection. Now by adding the proper amount of material from the points and 6 on the line A B to make the straight sections on either end of the connection, the pattern is complete. To develop the patterns for the other parts, simply repeat this operation. The spaces on the pattern for the front, as shown in the plan. Also the spaces for the pattern of the back as shown on the hne G H must be taken from the profile of the back as shown in the plan. No laps are added to the patterns in this solution as the practice of different shops for fastening corners together calls for different allowances. PROBLEM 256. Pattern of a Raking Soffit Bracket. A finished view of a right and left raking soffit bracket is shown in Fig. 872, such as is used in the soffit of bay windows, as shown in plan in Fig. 873. In this the soffit plan of part of the base mold is shown, as well as the normal bracket in the center, the right and left raking brackets C and D, and the panels. A sectional view through A B in plan is shown by a b c in the section and represents the given profile of the center or normal bracket, from which the various measurements and joints of intersections are obtained in developing the raking bracket. The various steps required in developing the patterns for the raking soffit bracket are shown in detail in Fig. 874, in which A, 2, 26, shows the true profile of the normal or center bracket shown by A B in plan in Fig. 873. Now, divide this normal profile in Fig. 874 in equal Fig. 872.— View of Bight and Left-hand Soffit Bracket. Pattern Problems. 509 spaces as shown by the small figures 1 to 27 and in line with this normal bracket place the plan view of the raking bracket, as shown by C, B, 1, 27, which represents the raking bracket shown by D in the soffit plan in Fig. 873. Now, from the small figures 1 to 27 in the normal bracket in Fig. 874 erect perpendicular lines until they intersect the sides of the bracket 1, 27 and C B in plan, as shown numbered on the lower side. At right angles to the lines dividers equal to the width of the face 1 B in plan and step off this distance on every one of the lines, 1 to 27, in the pattern. This makes the cut B H similar to F G and F G H B becomes the pattern for the face of the raking bracket, which can be formed right and left as desired. The pattern for the side of the raking bracket is now in order and is obtained as follows: Take the length of the line 1 27 in plan with the various intersections on ,12 3456 7S9IO J *4, : Soffit Plan Sectional View through A- B Pattern for Sides of Raking Bracket Fig. 873. — Soffit Plan and Sectional View of Raking Brackets. 27 hx 26 25 Fig. 874. -Developing Patterns for Side and Face of Raking Bracket — Note Plan and Profile of Normal Bracket — Finished View is Shown in Fig. 872. just drawn, draw the stretchout line D E, upon which place the girth of the normal bracket 1 to 27, as shown by similar numbers on D E. From these intersections, at right angles to D E, draw fines which intersect by lines drawn parallel to D E from similar numbered intersec- tions on the side 1 27 in plan. Trace a fine through points thus obtained; then F G will be the cut of one side of the face of the bracket. The opposite cut B H could be obtained from the various intersections on the side C B in plan, but in this case the cut B H has been obtained as follows: Set the same, and place it at right angles to the line A 26 in the normal profile, as shown by the similar intersections on the line J K. At right angles to J K, from the various intersections on same, drop fines, which intersect by lines drawn parallel to J K from similar intersections in the normal bracket. Trace a fine through points thus obtained ; then L M N will be the pattern for the sides of the raking bracket. The pattern for the front of the raking bracket is formed after the normal profile, and the pattern for the sides are soldered along the miter cuts in the face pattern, as shown by a in Fig. 872. 510 The New Metal Worker Pattern Book. PROBLEM 257. Patterns for Offset Y from Circular Pipe. Side Elevation Top Piece ■ One of the users of a previous edition of The New Metal Worker Pattern Book asked for method of de- veloping patterns for a Y from a round pipe which offsets from the main in two directions as indicated in the sketch reproduced in Fig. 875. He was unable to locate the problem in which the principles underlying his problem were given. As others may have the same difficulty this new problem has been included. As has often been stated in this book and many other publications, pat- tern drafting is the manipulation of the principles of geometry, and the most difficult part of the procedure in develop- ing the patterns for any object is the obtaining of view, or views of it from which certain and exact measurements may be taken. In other words, it is the determining of the true lengths of the elements embraced in the surface of the object, for pattern drafting is simply laying the surface out flat. Many sub- mitted problems are facsimiles of prob- lems in the book. Just because a profile may be differently situated, or the offset the true lengths of the elements. In Pig. 876 is shown the final study of the object. In this figure there is a front elevation which obviously does not give the true lengths of the elements of the middle piece, for these elements lean away from the observer. Nor does the Profile Profile Fig. 875. — Correspondent's Sketch. Oblique Elevation Fig. 876. — Development of Several Views of Offsetting Y Branch. is in another direction, the owner of the book fails to rec- ognize the similarity. A problem similar to the one under discussion is Problem 45 herein. However, that Y branch does not offset, consequently in the problem submitted a some- what different procedure must be followed, although the patterns would be developed by the same parallel line system once the view of the object is obtained showing plan give these lengths, or again, neither does the side elevation. Naturally, the question arises, what is neces- sary to obtain these lengths? In projecting various views of cylindrical objects, it is best to work from one element of the cylinder, prefer- ably the center or axial line and, after projecting this axial line to build about it the cylinder proper. In the various views of Fig. 876 the axial line is represented by Pattern Problems. 511 the heavy three dot and long dash line, the ends of these lines and their intersecting points are represented by heavy dots surrounded by a small circle and attention is called to how these axial lines appear in the various views and also the relative positions of the cylinders about Fig. 817. — Development of Patterns. these axial lines. When a line is viewed so that the line of vision, which is an imaginary line from the eye of the observer, is perpendicular or at a right angle to the line, that line is viewed in its true length regardless of the position of the line. Then, if the axial line of one of the' middle pieces of the object is viewed at right angles to its axial line in plan, as shown by Arrow A, that line is seen in its true length and an elevation projected in the line of the arrow will have the axial lines of that piece in true length. It would be the axial line of the one middle piece but not of the other. It would also give the axial lines of the top piece and the two bottom pieces because they he in parallel planes to the plane in which the axial line of the middle piece in question lies. Such a view is shown in Fig. 876 and is called an obhque elevation and is what is required. A drawing is given which is like those made by the cutters in the big shops who must economize in tune and yet make drawings that can be understood. This is given in Fig. 877 with the accompanying description. Before leaving Fig. 876, however, those interested in pro- jection should know that the drawing reproduced in Fig. 876 must be clear enough to follow the various steps, the oblique elevation being commenced by first projecting the axial lines. Note that after projecting the points in plan B B B, points on these projectors are chosen at will as B° and B°° both on a line at right angles to the projectors as shown by the heavy- dotted fine. The hight then from this line to B°° is the hight given in the front elevation from the arrow point D, up to D°. Now then, for the practical treatment of the problem and referring to Fig. 877, it will be assumed that the line 2 K is the center or axial of the top piece of the branch, and that angle X is the approximate branching off of the middle pieces and Y T the axial line of the bottom piece, Y K of course, being the axial line of the middle piece, giving then K W° as the vertical hight of the points of intersection K and Y or the axial lines. Point 3' in the plan represents the point of intersection K and also the axial line in plan of the top piece. Point S in the plan is the center of the axial fine of the bottom piece at point of intersection Y. It must be understood that the middle and bottom piece of the other part of the object need not be represented as the idea is to do only such work as is absolutely necessary. At the right of plan R shows the amount of offset of the branch. About S draw a circle the size of the pipe which then depicts the plan view of the bottom piece. Do likewise about point 3' one-half circle only being necessary which then is a plan of one-half the top piece. Divide these profiles into equal spaces as shown, and draw the sides of the middle pieces and also its elements. Continue the elements 2, 3, and 4, to the center line. This center line represents the edge of a > Full Pattern of Top Piece / required 512 The New Metal Worker Pattern Book. vertical plane against which the elements terminate as V 2' 3' 4' 5' and 6'. Parallel to the axial line in plan 3' S, draw a line as W 12°. Project a line at right angles to this and from 3' passing through W and of indefinite length. Do the same from S stopping at 12°. Set off the space W 12" equal to W° K of the front elevation. Connect 12° 12" in the oblique elevation which then is the required view of the axial line of the middle piece and shows the true length of the axial line. The space 6" M' and 6° M° in the oblique elevation coincide with K 2 and Y T of the front elevation. This now gives a true view of the axial lines and consequently, the true angle they form with each other. Bisect these angles in the customary manner, that is, place the compass on 12° and swing arcs N' and N°. Extend the compass a bit farther, place the point on N° and describe a small arc as N which is bisected by an arc described with the com- passes at the same adjustment and the point at N'. Draw a fine from N through 12° which then is the miter line between the bottom piece and the middle piece. Do the same for the angle of the top and middle pieces giving miter line 1" 9". Project the element points 1 to 12 to the miter line 3° 9° and thence parallel to the axial line to miter fine 1" 9". Project 1' in plan to inter- sect 1" in the oblique elevation 2' to 2", 3' to 3", 4' to 4" and so on, always being careful to intersect the right lines realizing the complete oblique elevation of one bottom piece, one middle piece and one-half of the top piece. For the patterns draw any line as a to a at right angles to the axial line in the oblique elevation of the middle piece. On tins line set the spaces of the profile as 1 to 1 on fine a a. Draw the usual parallel lines through these points which are intersected by lines projected from the oblique elevation as shown, always being careful to intersect the right fine. Now the pattern so obtained for the middle piece will also do for the top and bottom pieces. The bottom cut is for the bottom piece as indicated by the note on the drawing. The part from A to B of the top cut is one-half the pattern for the top piece, two of this part joined make the whole pattern. To better show what is meant, how- ever, the top piece pattern is developed to the right of the oblique elevation though it is not necessary and in prac- tice would not be done because all the patterns are con- tained in that of the middle piece. The plan of the other middls piece of the branch could have been used to project the oblique elevation, but the same elevation would have resulted. Similarly, the oblique elevation could have been projected to the other side of the plan, reverse of the arrow A in Fig. 876, but again the result would be the same, for the method always comes back to the principle of projecting the view with the line of vision at right angles to the axial fine in plan. PROBLEM 258. Pattern for Range Hood with Reduced Sides. The front and side elevations and plan presented in Fig. 1 show the dimensions for the hood to go over a range. The hood is to be 34X45 inches and 27 inches high. The front is a regular circle, but it is desired to carry the sides in on the back at the top but 7 inches, so that the side curve will be as shown in the eleva- tion for the side at the back. This will make quite a different curve, and the problem is to cut out the pattern for this end as well as the front piece. The problem is similar to that of developing a pat- tern for a molding having a square return with less pro- jection thai: the front. In this case the front molding is composed of but one member, the profile or shape of which is an arc, the hight of which is 27 inches, while the projection or width is to be 34 inches; the length, of course, of the hood is not a governing factor, and the return of this molding is to be of a shape similar to the front, but is to have but 7 inches projection, with the same hight as the front. Now, such problems can be solved in two ways, although, in either method the patterns are developed by the parallel-line system. One way is by deciding on the shapes of both front and side and projecting parallel elements in each profile and at right angles to each other, to meet in a plan the result of which will be the producing of a required miter line, which, however, will be an irregu- lar fine, as shown. As may be supposed, an irregular joint line be- tween the side and the front is going to give consider- able trouble in making the seam, and the only advantage will be in having a profile for both front and side as pre- determined. The other way would be to draw a plan, as Pattern Problems. 513 in Fig. 878, which has a straight line for the miter or joint between the front and side, which, obviously, is highly desirable. However, but one profile can now be as chosen, while the other is modified and controlled by a developing process from the normal or chosen profile. It would seem that it really does not matter just what the contour of the sides are so long as they have the specified projection of 7 inches. Therefore, in Fig. 879, A B C D is the outline of the plan of hood drawn to scale, viz. : A to D is 34 inches and A to B 45 inches and A to 1" 34'^ T Elevations Fig. 878. — Problem. Fig. S79. — Pattern for a Symmetrical Hood. is 7 inches; also B to 1°° is 7 inches. The miter lines drawn from 1°° to C, and 1" to D complete the plan. Deciding that the profile of the front shall be arbi- trarily established, rather than that of the side, let 1' 7 be a base line of profile XX and 1' to 1 the hight of the hood, which is 27 inches. It is required that this profile be part of a circle, and as the hight is less than the pro- jection the profile cannot be a quadrant, but less than a quarter circle. So then set the compasses, or trammels in the actual work, to more than 34 inches, and, with the point at 7, strike a small arc outside of the diagram. Setting the point of the compass at 1, and keeping the same radius, intersect the arc just described, getting thereby point a. With a as center, and keeping the compass set to the same radius, describe the arc from 1 to 7', completing the profile of the front. In range-hood designs, or, in fact, drawing profiles like these which have much less hight to projection, or vice versa, it is cus- tomary to set the compass to the smallest dimension, as 27 inches. Then 27 inches from 1 is at b, and from b a vertical line is drawn ; also from b a quarter circle of 27-inch radius is described from 1 to c, as shown dotted. This gives a flat deck from c to 1, which is a good thing in hood designs; and again, when the side profile would be devel- oped, it will be found that that, too, will have a more pleasing contour, not changing so abruptly at 1° in the full profile on line A B. That, however, is a matter of taste, so to speak, for it does not matter what shape the front has in this procedure. It is to be noted that in drawing the arc 1 to 7 a radius greater than 34 inches was pre- scribed, because, if 34 inches — point d then as center — was used for the radius, the arc would dip down somewhere between points 2 and 1, which certainly would not be a good feature in hood design. Divide profile XX into equal parts, as shown by 1 to 7, project these points to the left and through the plan. Mark with points, as shown, where these lines cross the base line of profile XX and where they intersect the miter lines. From where they intersect the miter line D or 7", to 1" of the plan, and at right angles to line A D, project the points upward indefinitely. Draw the line 7° B 1 , and then take the lengths from the base lines to the arc in profile XX and place them on like numbered lines in profile X, measuring from line 7° B', like this: 1' to 1 in profile XX equals in length l x to 1° in profile X; again, 2' to 2, in profile XX, equals in length from 2 X to 2°' in profile X, and so on. A line traced through points 7° 6° 5° 4° 3° 2° and 1° will be the modified profile of 7 inches projection. Complete the section, or profile X, as shown. For the patterns proceed this way: Extend line B C downward, and place thereon the spaces from the arc of profile XX, as l A to 7"\ Parallel to line D C draw lines from the points in the stretchout line. These parallel lines are intersected by lines projected from the miter line in plan, like line from point 3" in the plan is to inter- sect the line from point 3 A in the stretchout line. Lines through these points complete the pattern. Extend line A B to the left and place thereon the spaces 7° to 1° in the profile X, taking each separately, 514 The New Metal Worker Pattern Book. as they all differ from each other, as shown from 7 B to 1 B . Draw lines parallel to line A D from these points and intersect like numbered lines from points in the miter line in plan, like line from point 3" in the plan is projected to line from point 3 B in the stretchout line. Trace a line through the points and obtain the pattern as shown. To prove that the pattern is correct, measure the miter cut of each pattern, and if they coincide in length both pat- terns are correct. Pattern for ends would be shaped on line 7 s I s to the profile XX at 1° 7°, and pattern for front would be shaped on line H K to the profile XX, from 1 to 7. PROBLEM 259. Marquise Construction and Patterns. /There is no end to the number of designs possible for marquise or entrance canopies and the problem is essen- ever, and, therefore, requires attention and discussion. The design presented here is a very common one and, of \ Sheet Metal Molding '^Olass pendants in stamped zinc -frame Fig. 880. — Front Elevation of Marquise and Glass Work in Arch. Fig. 8S1. — Side Elevation of Marquise. r. Ouilet_ 'y+mre Glass on 2. 2'Ts Fig. 882. — Architect's Scale Drawing of the Marquise. tially one of construction rather than pattern cutting. It is an important object in the sheet-metal trade, how- course, can be elaborated more or less, as required. It is reproduced as actually constructed. Pattern, Problems. 515 The architect's sketches are reproduced in Figs. 880 to 882, which show the front elevation, side eleva- tion and plan and give a good idea of the general design. Figs. 8S3 to 886 are groups of diagrams each being a detail section through some important part of the marquise. The patterns for the bars in the arch, all caps, this profile, draw a vertical line to represent the wall. Then, from the numbered points in the front profile draw parallel lines to the wall line. These parallel lines are to be pitched to the amount of inclination shown in the side elevation of Fig. 881. Note that from such hori- zontal members, like 7 8 or 13 14, two lines result instead of one, as in ordinary square return problems; this is due a Glasi Paint Skin Joint Sheet Mete! Flashing Sheet Metal- '■A||r||A / 'Wood Nailing ,, Soffit sfn P Glass .■••"■ Pendants \ Upper Light Loner Light of Glass \ Cl/p,& : of Glass Mil Fig. 883. — -Vertical Section through Longest or Front Section of Molding. Fig. 884- — Vertical Section through the Raked Side Moldings. Fig. 885.— Vertical Cross Section at Central Channel Iron. cross clips, gutter strips and so on, are merely the stretchout of these sections given in the diagrams, be- cause no miter cuts, or cuts that are very simple, are required. The patterns of the front and side moldings are given in Fig. 887. The first thing to do is to draw the profile of the front elevation, as shown. This profile is divided into spaces and numbered. A convenient distance from to the raking of the side molding, which perhaps is better shown in the problems herein of raking pediments, only in those problems the pitch is the opposite to this so that the square members of the profile in those cases would be more than square in the raked profile, while in this case they are less than square in the raked profile, as may be seen in Fig. 887. The miter cuts on both ends of the front molding are 516 The New Metal Worker Pattern Book. square miters like Problem 3. Therefore, draw a stretch- out line, like A B of Fig. 887, which should be vertical, that is parallel with the vertical members of the front profile, as 16 17 or 23 24. On this stretchout line place the spacings 1 to 28 of the front profile, as 1° to 28°. From Skylight Bar 1 t V .-'' y\ Bolt .■" < y \ G/3! S-* • Vertical Section of Work at Arch Soffit. Horizontal Section of Bar in Arch Fig. 881. — Vertical Section showing Contour of Gutter, Arch Work and Other Details. Additional Details of Construction. the points 1° to 28° draw horizontal lines which intersect by projector lines from like numbered points in the front profile. For instance, point 10 in the front profile is projected down to horizontal line from point 10° on the stretchout fine, giving point lCf, and so on. A fine drawn through these intersection points completes the pattern cut of the ends of the front molding. Fig. 887. — Procedure for Developing the Patterns of the Molding. The New Metal Worker Pattern Book. 51< A horizontal line is drawn under the profile, as shown by C D and where the projector lines, from the front profile, cross this fine, small dots are made to indi- cate the intersections. This fine, C D, is then trans- ferred over the rake fines as shown by C x D 1 , being sure that it is parallel with the rake fines. Of course, the front profile could be transferred to this position, as directed in the problems herein of raking pediments, but this method is more expeditious. It is, however, neces- sary to be very careful with this method so that the proper points are projected down from line C x D x . For that reason it is probably best to number the points on both fine C D and C z D x . From points in line C x B x drop fines, at right angles to C x D x , to intersect like numbered lines from tfie front profile. Draw a line through these points which will produce the raked profile of the side moldings, as shown. The soffit part, 24 to 28, is not raked owing to the absolute need of having the soffits of the side moldings level to fit the structural work to which they are fastened. The slight misfit at the miters, caused by this, would not be of any consequence because the pendants and electric lights cover most of the soffits. For the pattern of the sides, draw stretchout line, F G, at right angles to the rake or pitch lines of the side. Place on this stretchout line the spacings in the raked profile, 3' to 28', taking each space separately as they all differ. Draw parallel lines through these points, 3" to 28", on the stretchout line F G. These fines nat- urally, are parallel with the raked or pitched lines of tfie side as shown. Project lines from the points in the front profile, parallel to the stretchout line F G. These projector fines are to intersect like numbered fines as for instance, line from point 10 would intersect the line from point 10" on line F G giving point 10'", and so on. A line drawn through these points of intersection will give the miter cut of side moldings to the front molding. For the butt miter against the wall, project lines up from the points where the rake or pitch fines of the side molding hit the wall line; like point 10 ZI on the wall line is projected up to line from point 10" on line F G giving point 10 I2Z , and so on. A line drawn through these points of intersection gives the butt miter cut of the .side molding against the wall of the building. The miter cuts of the side molding would be extended apart to the required length of the molding and laps provided on the miter cut for the miter with the front molding. There would be two side moldings, bent right and left. INDEX. PAGE A Abacus (Fig. 90) 13 Acute angle, Geometrical definition 2 triangle, Geometrical definition 3 Alphabetical list of architectural terms 15, 16 Altitude of a pyramid, Geometrical definition 8 of a triangle, Geometrical definition 3 Angle, Comparison between butt miter and miter between two moldings at any 76 Elbow 13 Finding true at hips of irregular square box 477 Finding true in compound offsetting elbows in piping. . . . 147 Geometrical definition 2 in plan, From profile of horizontal molding to obtain pro- file of inclined molding mitering with horizontal molding at octagon angle 205 in plan, From profile of inclined molding to establish pro- file of horizontal molding to miter with it at octagon angle 266 To divide into two equal parts 39 To trisect given 39 Angular pediment (Fig. 81) 11 Anvil 162 Apex, Geometrical definition 3 Arc compared with chord (Fig. 260) 85 given, To find center 40 given, To find center by use of square 90 of circle, To erect perpendicular to without recourse to center 41 of circle, To strike, by triangular guide, chord and height given 41 To find center, chord and height of segment of circle given. 40 Arch, curved molding blank, in a circular wall 418 in circular wall, soffit 416 in circular wall, splayed 414 in circular wall, splayed elliptical 412 semicircular wall, soffit development 408 Semi-elliptical — Architectural definition 11 To draw joint lines of elliptical 67 Architectural terms 10 Alphabetical list 15, 16 Architrave, definition 10 Article, Base rectangular and top elliptical 330 Base rectangular and top round 328, 331 Base round and mouth elliptical 381 Base square, Octagonal 188 Bottom rectangular and top oblong, semicircular ends 310 One end rectangular and the other round 337 Rectangular rounded corners, ends flaring more than sides. 316 Bound to ellipse offset 452 Round to oblong, circle wider than narrow side of oblong. 328 Round to oblong, top and bottom placed centrally 327 Round to octagon 455 5 PAGE Article, Round to square, top not central over base 331 Bound top, elliptical base, one side vertical 345 Round top, elliptical base, top and base central 343 Round top, elliptical bottom, top and bottom not parallel.. 364 Bound top, oblong bottom, semicircular ends, one side vertical and one with offset 348 Round top, quadrant base 354 Square, inclined base, top round 333 Top and bottom round, one side vertical 341 Top and bottom round, small end at one side of center line 339 Top oblong with semicircular ends, bottom a rectangle. . . . 310 Top rectangular, base round, base larger than top 335 Top round, base square and inclined 333 Top round, bottom oblong, semicircular ending, Two cases. 312 Top round, bottom oblong, semicircular ends, top and bot- tom central 346 Automatic stokers or spiral conveyor, Revolving 482 Automobile dust pan 420 fender, Special design 462 Axes of given ellipse, To find 66 Axis, Geometrical definition 9 B Ball, miter between moldings of adjacent gables on square shaft formed by a 176 Fitting against octagon shaft 122 Fitting against square shaft 122 To construct in any number of pieces of the shape of gores 124 Balustrade pedestal, Architectural definition 11 Bar, Common, single or double pitch skylights, at right angles 138 Hip, in hipped skylight 219 Jack, in hipped skylight 221 Base a quadrant, top round, transitional object 354 elliptical, top round, top and bottom not parallel 364 elliptical, top round, transitional article, both central 343 elliptical, top round, transitional object one side vertical. . 395 for chimney stack 327 Geometrical definition 3 molded, in which projection of sides differs from ends... 182 oblong, semicircular ends, top round, transitional object, straight back, and one with offset 349 oblong, semicircular ends, round top, transitional object, top and bottom central 346 oblong and top square, flaring article 177 of column, definition 11 of finial of curved profile, square in plan, mitering over peak of gable coping with a double wash 169 of octagon finial 123 of pedestal, definition 1 1 rectangular and inclined, top round, transitional object. . . 333 rectangular, top elliptical, transitional object 330 rectangular, top round, transitional object, top wider than narrow side of rectangle 328 19 520 Index. PAGE Base round, mouth elliptical, Ship ventilator 381 round, top square, transitional object base larger than top. 335 square, top octagonal, Tapering article 188 Bath, Hip 318 Bath of regular flare, Hip 273 Bathtub 366 Flaring, tapering ends, semicircular head, head having more flare than sides 314 Lining head of 378 Beam compasses or trammels, description 23 Bed course, Architectural definition 13 Bed molding, Architectural definition 13 Bell, elliptical, base round, Ship ventilator 381 Bifurcated pipe, the arms leaving at same angle, having same diameter as main pipe 137 Blade of spiral conveyor, Revolving 486 Blank for curved molding 254 for curved molding in circular wall arch 41S Block, Head, Architectural definition 12 Stop, Architectural definition 12 Blower connection of irregular shape 503 for grate ISO Offsetting 507 Boat, Cracker, ornamental fan 267 Boards, Drawing, Description 18 Boiler cover with round corners, Raised 309 with semicircular ends 258 Locomotive, Blaring section of 179 Boot, Double offset, round to rectangular 443 for furnace pipe, bottom oblong, semicircular ends, round top, both central 346 for furnace pipe, bottom oblong, semicircular ends and top round, straight back 346 for furnace pipe, offsetting, bottom oblong, semicircular ends, top round 349 Furnace, offsetting round to oblong with semicircular ends. 393 Boss, Conical 271 Faucet, for cans 434 fitting over molding miter 120 to fit around faucet 379 to fit around faucet of can 181 Bosses for sheet metal hand pumps 448 Box, Cold air, inclined portion to meet horizontal obliquely. 214 Cold air, inclined portion joining the level 210 Irregular shaped 477 of instruments for drawing, description 28 Bracket, Architectural definition 12 Diagonal, under cornice of hipped roof 198 molding, Architectural definition 13 ornament 119 Eaking 193 Raking, for curved pediment 356 Raking, raised panel on face 196 Raking soffit 50S To draw scroll to specified width for 69 Branch at other than right angle of two pipes 151 at other than right angles of two pipes intersecting at other than right angles ' 154 at right angles between pipes of different diameters 153 between elliptical and round pipe of larger diameter, at other than a right angle, two cases 155 in tapering pipe, axes crossing at right angles 292 leaving in two directions. 501 PAGE Branch of pipe tapping into a four-piece elbow 159 or T-joint at other than right angles between pipes of different diameters, axis of smaller at one side of larger 158 on tapering pipe, axis of branch at other than right angle to axis or side of tapering, on taper-joint, axes being at right angles 300 on tapering pipe, axis of branch piece at right angles to side of taper joint 296 or T-joint between pipes of different diameter and at right angles, the axis of the smaller pipe passing to one side of the larger 156 or T-joint between two pipes of same diameter • . . 139 pipe tapping reducing joint off the top 323 Square pipe, from round main 146 Tapering, intersected at lower end by main pipe, axis crossing at other than right angle 290 Tapering, intersected at lower end by main pipe, axis crossing at right angles 270 Three-pronged fork with tapering 391 Unusual two-way Y 429 Y, arms same diameter as main and leaving at same angle 137 Y, Double offsetting 466 Y, of two tapering pipes joining larger pipe at an angle. . 3S9 Branches, Y, forty-five degrees to main pipe 505 Breast and spout for cans 302 Breeches or Y-branch, arms being same diameter as main and leaving at same angle 137 Breeching, Double offset Y-branch 466 Oblique offsetting Y-branch 310 Bnusual two-way Y 429 Y-branch of two tapering pipes joining larger pipe at an angle 389 Broken pediment, definition 12 To obtain profile and patterns of returns at top and foot of segmental 204 Butt miter against curved surface 99 against irregular or molded surface 103 against plain surface, oblique in elevation 97 ami miter between two moldings at any angle, comparison 76 Architectural definition 15 of molding inclined in elevation, oblique in plan 173 C Can boss to fit around faucet 181, 379 breast and spout 302 for faucet 271 Canopy, on range hood, with reduced sides 512 or marquise for entrances 514 Cap, curved moldings for elliptical wind 256 of a pedestal, Architectural definition 11 Simple curved moldings for window 255 Square to round base, for chimney 327 Capital, Architectural definition 13 Construction of volute for 142 of a column, Architectural definition 11 Cavalier projection, Architectural definition 14 Center, Geometrical definition 4 of arc, To find when chord and height of segment of circle is given 40 of given arc, To find 40 of given arc, To find, by use of square 40 Centers, three sets, To draw approximate ellipse with com- passes to given dimensions 65 Index. 521 PAGE Centers, To draw spiral from, with compasses 68 To find in a given ellipse by which approximate figures may be constructed 66 two sets, To draw approximate ellipse with compasses to given dimensions 64 Champfer, Octagon to square, transition piece 191 Octagon to square mold, transition piece 192 Chimney top 327 Chord and height of a segment of circle given, To find center from which arc may be struck 40 and height of circle given, To strike the arc of, by tri- angular guide 41 compared with its arc 85 Geometrical definition 5 Chute, Mason 's 464 Circle, General rule for inscribing regular polygons within . . 44 Geometrical definition 4 given, To inscribe regular dodecagon within 44 given, To inscribe regular nonagon within 44 or arc of circle, To draw a tangent at a given point without recourse to center 41 To divide into eight equal parts by use of a 45 degree triangle : 50 To divide into eight equal parts by use of 22 i Ax67 1 /j degree triangle 51 To divide into four equal parts by use of triangle or set-square 50 To divide into twelve equal parts by use of 30 x 60 degree triangle. 50 To draw an octagon about 56 To draw a square about 57 To draw ellipse as oblique projection of 61 To draw equilateral triangle about 55 To draw hexagon about 55 To draw through any three points not in a straight line. . 41 To ellipse offset, transition piece 452 To inscribe a dodecagon within 59 To inscribe a regular decagon within 44 To inscribe a regular polygon of eleven sides (undecagon) within by general rule 45 To inscribe a square within 43 To inscribe an equilateral triangle within 51 To inscribe equilateral triangle within 43, 57 To inscribe hexagon within 52 To inscribe octagon within 53, 58 To inscribe regular hexagon within 43 To inscribe regular heptagon within 43 To inscribe regular undecagon within 44 To inscribe regular octagon within 43 To inscribe regular pentagon within 43 To inscribe square within 52, 5S Circles, Two, and intersecting lines of given dimensions, To construct ellipse with 63 and their properties, Geometry of 4 Circular broken pediment, to obtain modified profiles of re- turns at foot and top 204 cylinder, Geometrical definition 8 wall, Blank for curved molding in arch in 418 Soffit of arch in 416 Soffit of semicircle arch in two cases 408 Splayed arch in 414 Splayed elliptical arch in. 412 PAGE Circumference, Geometrical definition 4 of ciicle or part of circle, To draw straight line equal in length to 42 of given circle, To ascertain 41 Circumscribed polygons, Geometrical definition 5 Cloth for drawing, Tracing, description 28 Coal hod funnel 399 Cold air box in which inclined portion joins level portion obliquely in plan — two solutions 210 joining furnace at an angle on a central line 147 to meet horizontal portion obliquely in plan 214 Collar, Elliptical, tapping wire of larger diameter at other than right angle, two cases 155 intersecting a transformer 488 of piping intersecting main of larger diameter at right angles 153 intersecting main pipe of same diameter at right angles 139 intersecting main pipe at other than right angle 154 tapping main pipe of larger diameter at other than right angle axis of collar being to one side of main pipe 158 tapping main pipe of larger diameter, at right angles, axis of collar passes to one side of main pipe 156 of round piping tapping four-pieced elbow 159 on taper joint, axes crossing at right angles 292 axis of collar at other than right angle to axis or side of taper-joint 298 axis of collar being at right angles to side of taper joint 296 Flaring, round top and bottom, placed obliquely to each other 361 round top, square bottom, to fit around pipe passing through inclined roof 333 Round, tapping main pipe at angle in two directions 501 Tapering, intersected at lower end by main pipe, axes crossing at right angles 270 intersecting the main pipe at other than right angle .... 290 on taper-joint, intersecting obliquely 302 on taper-joint, axes being at right angles 300 straight back, reducing joint at top 323 to join two pipes of unequal diameters at an angle 359 Collars, Two round, tapping main pipe at forty-five degrees. 505 Column, Architectural definition 11 Common bar for skylights 138 Compasses and dividers, description 22 use of for drawing approximate ellipses 64 use of to draw spiral from centers 68 Complement, Geometrical definition 6 Compound curve rectangular shaped elbows 494 curved elbow for square 478 in square pipe 140 offset in rectangular pipe 210, 214 offsetting elbows in round piping 147 Concave, Geometrical definition 10 Concentric circles, Geometrical definition 5 Concrete, Mason's chute for 464 Conductor or roof leader pipe, compound curved elbow for square 478, 494 Cone and frustum, Envelope of, described by pin and thread 80 base an elliptical figure, Envelope of the frustum of 260 base a true ellipse, Frustum of 317 522 Index. PAGE Cone, base an approximate ellipse, upper plane of frustum oblique to axis, tapering article with equal flare through- out corresponding to frustum of 276 base oblique to its axis, E'nvelope of right 265 cut by a plane parallel to its axis, Envelope of a right. . . . 265 contained between planes oblique to its axis, Envelope of frustum of right 274 Envelope of an elliptical 308 of a right 249 of frustum of right 250 of scalene 306 of frustum of scalene 311 fitting against a surface of two inclinations, Frustum of. . 269 Frustum of, intersecting a cylinder of greater diameter than itself at other than right angles 290 deriving the pattern from the drawing 82 deriving the pattern of from wooden model 82 Geometrical definition 9 right 80 triangulated, elliptical 92 Geometrical definition 8 having irregular base, Envelope of frustum of elliptical. . 322 hopper intersected by spout 492 intersected at its lower end by a cylinder, axes intersecting at right angles, Frustrum of 270 intersected by cylinder at its upper end, axes crossing at right angles 275 intersected by a cylinder of less diameter than itself at right angles to its base 294 intersected by cyliuder of less diameter than itself, axes crossing at right angles 292 intersected obliquely by a cylinder, axes not lying in same plane, Frustum of a scalene 323 in which axis of cylinder not at right angles to axis nor to side of cone, Cylinder joining frustum of 298 joining a cylinder of greater diameter than itself, axis of frustum passing to one side of cylinder, Frustum of.... 291 Method of obtaining the lines upon elevation 81 of greater diameter than itself at right angles, Cyliuder joining 296 perspective view for tiangulating illustration, Frustum of elliptical 92 plan and elevation for constructing a wooden one for pur- poses of illustration 81 Badial line triangulating frustum of elliptical 92 Eight, generated by the revolution of a right-angled tri- angle about its perpendicular 79 Eight, with thread fastened at apex to which are attached points for marking upper and lower base of frustum. ... 79 Eight, Unfolding envelope of 80 Scalene, System of triangulation for 94 upper plane oblique to its axis, Envelope of frustum of right 265 To draw ellipse as a section 62 Triangulated elliptical 91 truncated obliquely 81 Cones of unequal diameter intersecting at right angles of their axes 300 joined and pin with string attached at apex of larger sector, third step in constructing solid of elliptical flar- ing article 85 of unequal diameters intersecting obliquely, Frustums of. 302 parts joined and completed, final step in constructing solid of an elliptical flaring .article 85 PAGE Cones, Sectors of small, second step in constructing solid of elliptical flaring article 84 Conical boss 271 development or flaring work 79 hip batch, Eegular flare 273 lip for sheet metal pitcher 272 method for rectangular oblique offsets 494 method for rectangular oblique twisted offset 497 roof flange to fit around pipe and against roof of one inclination 266 to fit around pipe and against roof of double inclina- tion 269 scale scoop, both ends alike 278 spire mitering upon eigh* gables 282 mitering upon four gables 280 system for octagonal semicircular pipe 253 two-piece elbow 284 Conic section, Geometrical definition . . . . • 9 Constructing ellipse to given dimension by two circular and intersecting lines 63 equilateral triangle upon given side 45 regular polygon of thirteen sides by general rule, length of side being given 48 triangle, length of sides being given 45 Construction of regular polygons by protractor 57 by compasses and straight edge 43 by T-square and triangles or set-squares 49 Convex, Geometrical definition 10 Conveyor or loaded spout, Spiral 426 Eevolving blade for spiral 482 Corbel, Architectural definition 12 Corner piece of mansard roof 105 Corners, rounded, for regular flaring oblong article 258 Cornice, Architectural definition 10 Deck, Architectural definition 12 Lintel, Architectural definition 12 Co-secant, Geometrical definition 7 Co-sine, Geometrical definition 6 Co-tangent, Geometrical definition 6 Cover with round corners, Eaised boiler 309 with semicircular ends, Oblong raised 258 Cowl or ship ventilator, base round, mouth elliptical 381 Cracker boat 267 Cripple or jack bar of hipped skylight 221 Crown molding, Architectural definition 13 Cube, Geometrical definition 8 Curved elbow, Compound for square pipe 478 line, Geometrical definition 1 mansard roof, Hip finish in 101 square base, octagonal top, Fascias of a hip molding finishing against 230 molding, Blank for 254 in an elliptical window cap 256 in arch in circular wall, Blank for 418 in window cap 255 meeting straight molding of same profile, Obtaining miter line of 152 pediment, Baking bracket for 356 surface, Double, Geometrical definition 3 Single, Geometrical, definition 3 Curves for molding covering hip of curved mansard roof, to obtain 238 Cylinder cut off obliquely 125 Index. 523 PAGE Cylinder of different diameters intersecting at other than right angles 154 Frustum of scalene cone intersected obliquely by 323 Geometrical definition 8 intersected by cone of smaller diameter at its lower end, at other than right angles 290 intersected by an elliptical one of smaller diameter at other than right angles. Two cases 155 intersected by another of smaller diameter at right angles, axis of smaller passing to one side 156 intersected by another of smaller diameter at other than a right angle, axis of smaller cylinder being to one side of. 158 intersected by frustum of cone of smaller diameter at right angles, axis of frustum passing to one side 291 intersected obliquely by a rectangular pipe 146 intersecting cone of greater diameter, axes crossing at right angles 292 intersecting double plane 127 intersecting another of larger diameter at oblique angles. . 501 intersecting another of larger diameter at right angles. . 153 intersecting another of same diameter at other than right angle 151 intersecting another of same diameter at right angles. . . . 139 intersecting irregular shaped object 488 intersecting miter of a molding 120 intersecting lower end of frustum of cone, axes intersecting at right angles 270, 271 joining a cone of greater diameter than itself 296 joining frustum of cone, axis of cylinder not at right angles to axis nor to side of cone 298 mitering with peak of gable having double wash 171 penetrating a four-piece elbow 159 To draw ellipse shape of oblique section of 61 True angles in compound intersecting 147 Cylinders, two, intersecting larger cylinder at forty-five de- grees 505 D Decagon, Geometrical definition 4 patterns for newel post, plan of which is a 117 regular, to draw upon a given side 47 regular, to inscribe within a given circle 44 Deck cornice, Architectural definition 12 molding, Architectural definition 12 Definitions and terms, Glossary of geometrical 1 Degree, Geometrical definition 5 Dentil, Architectural definition 12 band, Architectural term 10 course, Architectural term 10 molding, Architectural term 10 Descriptive geometry, Relationship to pattern cutting 1 Detail drawing. Architectural definition 14 Development of surfaces, Geometrical definition 15 Diagonal bracket under cornice of hipped roof 198 Geometrical definition 4 scale rule for drawing, description 25 Diagram of sections for triangulation 92 Diameter, Geometrical definition 5 Diamond faucet boss for cans 434 shaped frustum of pyramid 178 Die of pedestal, Architectural definition 11 Dividers and compasses, description 22 Dodecagon, drawing upon a given side 48 PAGE Dodecagon, Geometrical definition 4 regular, to inscribe within a given circle 44, 59 urn, plan 118 Dodecahedron, Geometrical definition 9 Dormer, Molding on side of _. . . . 165 Double curved surface, Geometrical definition 3 elbow joining two other pieces not in same plane, Inter- mediate piece of 147 offset in rectangular pipe 210, 214 Y-Branch 466 Drafting, Pattern, Exemplification of principles of 71, 95 tal iles, description 17 terms and definitions 14 Drawing approximate ellipse with compasses, length only given 64 with compasses to given dimensions, using three sets of centers 65 with compasses to given dimensions, using two sets of centers 64 boards, description 18 circle through any three given points not in straight line. 41 detail or working, Architectural definition 14 ellipse to given dimensions by square and strip of wood. . 61 to given dimensions by a trammel 60 within given rectangle by means of intersecting lines. . 63 elliptical flaring article by the usual method 83 equilateral triangle about given circle 56 upon a given side 53 hexagon about a given circle 55 ionic volute 67 joint lines of elliptical arch 67 Linear 30, 35 line parallel to another by triangles or set-squares 36, 37 Method of deriving pattern of frustum of cone from 82 Obtaining envelope of molding from, by T-square 75 octagon about a given circle 56 pins or thumb tacks, description 27 regular decagon upon a given side 47, 48 regular hexagon upon a given side 46, 54 regular heptagon upon a given side 46 regular nonegon upon a given side 47 regular octagon upon a given side 47, 54 within a given square. . . . , 49 regular pentagon upon a given side 46 regular polygon, length of side given, by a general rule. . 48 regular undecagon upon a given side 4S Scale, Architectural definition 14 scroll to specified width for bracket or modillion 69 simple volute 67 spiral for centers with compasses 68 with spool and thread 69 square about a given circle 57 square upon a given side , 53, 57 straight line equal in length to the circumference of a circle or part of circle 42 parallel to a given line 36 tangent to circle, or arc of circle at a given point without recourse to center 41 tracing paper and tracing cloth, description 28, 29 tools and materials, Discussion of 17 Drip, Architectural definition 13 Drop upon the face of a bracket 119 Dust pan for automobiles 420 524 Index. PAGE Dust pipe, Compound curved elbow for 47S Conical method for oblique offset 494 Conical method for oblique twisted offset 497 Offsetting blower connection 507 separator, Spiral strip for, short rule 496 Spiral strips in 432 work, Compound elbow in square pipe 140 E Eccentric circles 5 Edges, Straight, description 19 Egg-shaped flaring pan 263 Eight-sided tinial base 123 pedestal 115 Elbow, Compound curve 478 Conical method for octagonal shaped pipe 253 Five-piece 133 for five pieces, Regular tapering 287 Four-piece 132 intersected by round pipe through a miter 159 tapering 440 in elliptical pipe, Two-piece 130 in square pipe, Compound curved 140, 494 Oblique twisted offset 497 Intermediate piece of double, joining two pieces not in same plane 147 in tapering pipe, Three-piece 2S5 Two-piece 284 Oblique offset, in rectangular pipe 210, 214 Offsetting, round to oblong, semicircular ends 482 one end round, the other elliptical, Eight angle two-piece. 387 problem in furnace fittings, Reversible 472 Eight angle piece, to connect round with rectangular pipe. 405 Eound to elliptical three-piece 453 Eound to rectangular 437 Bound to rectangular, transition piece 431 Square to round seven -piece 405 Square, in elliptical pipe, two cases 130 Square, in round pipe, Two-, three-, four- and five-piece. 131, 133 Square transforming 473 Three-piece, to join round with elliptical pipe 403 with middle piece gored 187 Two-piece 130 Two-piece, circle to ellipse offsetting 452 Elbows, square or rectangular pipe 469 of two smaller pipes, Junction of large pipe with 384 Elevation, Drawing, Architectural definition 14 Eleven-side regular polygon (undeeagon), To inscribe within a given circle 45 Ellipse, Approximate, Drawing with compasses to given di- mensions, using three sets of centers 65 Drawing with compasses to given dimensions, using two sets of centers 64 To draw with compasses, length only given 64 Finding true axes 66 Geometrical definition 7 treatise 59, 67 given, To find centers so that an approximate figure may be constructed 66 of given dimensions, To draw with square and strip of wood 61 of given dimensions, To draw with a trammel 60 of specified dimensions, To draw with a string and pencil. 60 PAGE Ellipse, To construct, to given dimensions by two circles and intersecting lines 63 To describe shape of an oblique section of cyilinder, or as oblique projection of circle 61 To draw, as section of a cone 62 To draw, within a given rectangle by intersecting lines. . 63 Elliptical arch, To draw joint lines of 67 base and round top, base and top central 343 one side vertical 345 top and bottom not parallel 356 cone, Envelope of 308 having an irregular base, Envelope of a frustum of.... 322 system of triangulation 91, 93 cylinder, Geometrical definition 8 flaring article 260 Circling cones and their sectors to obtain solid of. . 84, 85 corresponding to frustum of cone 317 Describing envelope with pin and thread 85 top placed eccentrically to bottom 320 Usual method of drawing 83 frustum of cone, upper plane of frustum oblique to axis. . 276 mouth and round base, Ship ventilator 281 pipe and round pipe of larger diameter at other than right angles, Joint between two cases 155 flange to fit against, when pipe passes through center of pyramid or hipped roof 145 to fit against roof 125 splayed arch in circular wall 412 to circle offset transition piece 452 to round pipe offset 396 three-piece elbow 403 two-piece elbow Z 387 rectangular base, transitional object 330 two-piece elbow, two cases 130 vase constructed in twelve pieces 183 window cap, Curved molding for 256 End, Flaring of oblong tub 178 Engaged column, Architectural definition 11 Engine hood, French style, for autos 458 F"ntablature, Architectural definition 10 Entrance canopies or marquise 571 Envelope of cone and frustum described by pins and thread. 80 molding, Obtaining from a drawing by T-square 75 Obtaining by using lines from model 74 ordinary elliptical flaring article described by pin and thread 85 right cone, Unfolding 90 solid, Geometrical definition 9 Equilateral triangle 3 pedestal Ill To construct upon given side 45 To draw about given circle 55 To draw upon given side 53 To inscribe within given circle 41, 51, 57 Eraser or rubber for drawing, description 29 Erecting perpendicular at given point in straight line by compasses and straight edge 36 to arc of circle without recourse to center 41 E volute 7 F Face and side of plain tapering keystone 104 Face miter at an angle 108 Index. 525 PAGE Face miter at right angles in molding around panel 106 Square, produced where square return was intended. ... 78 miters of molding bounding irregular shaped four-sided figure . 109 Fascia, Architectural definition 13 Faseias of hip molding finishing curved mansard roof, square base, octagonal top 236 Faucet boss for cans 379 problem 434 Can boss to fit around 181 Conical can boss for 271 Fender, Special design automobile 462 Figure, Plane, Geometrical definition 3 Quadrilateral, Geometrical definition 3 Rectilinear, Geometrical definition 3 Figures, straight sided, Geometrical terms and definitions. ... 3 Fillet, Architectural definition 13 Finial, Architectural definition 13 base of curved profile, square in plan, centering over peak of gable coping having double wash 169 Irregular polygon 185 Octagon, with alternate long and short sides 189 Fitting, Unusual design 455 Five-piece elbow 133 tapering elbow 2S7 Five-prong fork 450 Five-sided vase 112 Flag pole, Ornamental roof flange for 475 Flange, Architectural definition 14 Conical, to fit around pipe against roof of double inclination 269 to fit around pipe against roof of one inclination 266 Flaring round bottom, top to fit pipe passing through in- clined roof 363 for a pyramidal flange to fit against sides of round pipe passing through its apex 144 Ornamental roof, for pipe or flag pole 475 to fit around pipe passing through inclined roof 369 to fit against sides of elliptical pipe passing through center of pyramid hipped roof 145 to fit around pipe and over ridge of roof 128 Flaring article, base oblong, top square 177 corresponding to frustum of cone whose base is a true ellipse 317 elliptical describing the envelope with a pin and thread. . 85 Irregular, elliptical at base, round at top 345, 364 top and bottom round and parallel, but placed eccen- trically in plan 311 with circular top and quadrant base 354 or transition piece, round top, oblong bottom 346 Rectangular 104 with rounded corners 316 Regular, oblong with semicircular ends 258 round base, square top 335 round top and bottom 339 round top and bottom, one side vertical 341 top round, bottom oblong, semicircular end, two cases. . . 312 collar, lower end intersecting main straight pipe at other than right angle 290 lower end intersecting main straight pipe, axes crossing at right angles 270 top and bottom round, placed obliquely to each other, pattern for 361 elliptical article, Combined portions of cones to make 83 PAGE Flaring elliptical article, Obtaining solid of and envelope of 84, 85 Usual method of drawing 83 end of an oblong tube 178 flange, round bottom, top to fit around pipe passing through roof 368 Regular, oblong article, round corners 259 pan, Oval or egg-shaped 263 section of locomotive boiler 179 shape, forming transition from round horizontal base to round top, placed vertically 376 tray, Heart-shaped 261 tub, tapering sides and semicircular head 314 two-piece elbow 2S4 work or regular tapering forms 79 Flat arch, Architectural term 11 scale rule for drawing, description 25 Float, Soap maker 's 320 Foot molding, Architectural definition 13 Forge, Hood of portable 371 Fork, making three-pronged in two pieces 425 Three-pronged, with tapering brandies 391 two-prong, consisting of two tapering pipes joining larger pipe at an angle 389 two-pronged offsetting 466 Unusual five-pronged 450 Forms, Irregular or triangulation 86, 95 Parallel, First system of pattern cutting 72 Four-piece elbow 132 through a miter, Pipe intersecting 159 tapering elbow 440 Four-sided figure, Molding mitering around an irregular 109 pedestal 112 Frieze, Architectural definition 10 French style auto hood 458, 461 Frustum and cone described by pin and thread, Envelope of. . SO Envelope of right cone 250 of cone, base an approximate ellipse, upper plane of frus- tum oblique to axis, Tapering article with equal flare corresponding to 276 base an elliptical figure, Envelope of 260 deriving pattern 'from drawing 82 deriving pattern from wooden model 82 fitting against surface of two inclinations 269 Geometrical definition 9 intersected at its lower end by cylinder 270 intersected by cylinder, axis neither at right angles nor side of frustum 298 intersecting cone of larger diameter at right angles to axis 300 intersecting cylinder of greater diameter, at other than right angles 290 joining cylinder of greater diameter at other than right angles 291 Using right cone with a thread fastened at apex, points marking upper and lower base of 79 of elliptical cone having irregular base, Envelope of 322 octagonal pyramid, Envelope of 243 having alternate long and short sides 244 pyramid, Envelope of, diamond shaped 178 Geometrical definition 9 of right cone contained between planes oblique to its axis, Envelope of 274 526 Index. PAGE Frustum of right cone, lines showing portion of cone removed to produce it 80 upper plane oblique to its axis, Envelope of 265 of scalene cone, Envelope of 311 intersected obliquely by a cylinder 323 of square pyramid, Envelope of 242 Frustums of two cones of unequal diameters intersecting obliquely 302 Funnel end scale scoop 279 coal hod 399 furnace bonnet, Collar intersecting axes crossing at right angles 292 Collar intersecting, axis of collar at right angles to side of bonnet 296 Collar intersecting axis of collar neither at right angles to axes nor to side of bonnet 298 boot, Double offsetting .' 443 elbows, Reversible fitting 472 fitting for quarter turn in pipe, oblong, semicircular ends. . 350 oblong, semicircular ends at bottom, round top, back straight, two cases 348 offsetting, round to oblong, semicircular ends 393 rectangular bottom and oblong, semicircular ends at top. 310 round to oblong, with semicircular ends, two cases 312 pipe, oblong, semicircular ends, Taper-joint for 258 G Gable, Architectural definition 12 copmg, Cylinder mitering with peak of, with double wash. 171 square shaft of curved profile, mitering over peak of gable coping double wash 169 cornice mitering upon inclined roof 164 miters, Simple 110 molding, Architectural definition 15 From profile of inclined molding to establish profile of horizontal molding to miter with it at octagon angle.. 206 mitering against a molded pilaster 161 at octagon angle to horizontal molding, obtaining modi- , fied profile in inclined molding from normal profile in horizontal molding 205 or broken pediment, To obtain profile of horizontal return at top of 202 or pediment with modified profile and normal profile in horizontal return 201 or pediment with normal profile and modified profile in horizontal return 200 moldings and roof pieces of octagonal pinnacle 174 and roof pieces of square pinnacle 173 Gables, Adjacent, having different pitches upon an octagon pinnacle, Miter between moldings of 20S Miter between moldings of, with different pitches, upon pinnacle with rectangular shaft 207 Eight, Conical spire mitering on 282 Octagon spire mitering upon 245 Four, Conical spire mitering on 280 Octagon spire mitering on 246 Square spire mitering on 244 General rule for inscribing any regular polygon within given circle 44 Geometrical problems 36, 70 Geometry, definition 1 Globe or sphere, Geometrical definition 9 Glossary, Architectural and geometrical 15 PAGE Goose-neck square roof leaders, Compound curved elbow 478 with compound curve 494 Gore piece forming transition from octagon to a square. . . . 191 Molded article forming transition from a square to an octagon 192 three-piece elbow, middle piece being a gore 187 Gores, To construct ball in any number of pieces of the shape of 124 Grate blower ISO Grocers' display receptacle for coffee 273 scale scoop, funnel shaped end 279 Guard, Automobile, Special design fender 462 Gusset piece in three-piece elbow 187 H Head block or truss, Architectural definition 12 for curved or inclined molding butting against oblique flat surface, To find true profile of 104 of bath-tub lining 378 Heart-shaped flaring tray 261 Height and chord of circle given, to strike an arc of circle by triangular guide 41 Heptagon vase 115 Heptagon, regular, To draw upon a given side 47 To inscribe within a given circle 43 Hexagon, Geometrical definition 4 pedestal 114 regular, To draw on given side 46, 54 To inscribe within a given circle 43 To draw about given circle 55 To inscribe within given circle 52 Hexagonal prism, Geometrical definition 8 pyramid, Envelope of 241 Hexahedron, Geometrical definition 9 Hip, Architectural definition 14 bar, top and bottom of 219 bath 318 Regular flare 273 finish, Curved mansard roof 101 mold on octagon angle in mansard roof mitering against bed molding of corresponding profile 223 molding, Architectural definition 13 bottom of on mansard roof, octagon at top, square at bottom 233 covering curved mansard roof 238 mitering against bed molding of deck cornice on man- sard roof square at base, octagonal at top 230 mitering against planceer of deck cornice on mansard roof, square at eaves, octagon at top 227 octagon angle of mansard roof mitering upon inclined wash at bottom 225 on right angle in mansard roof mitering against planceer cf deck cornice. .'. 215 Eight angle, in mansard roof mitering on bed molding. . 217 Straight, corner piece of mansard roof, embodying prin- ciples upon which mansard finishes are developed.... 105 Hipped roof, Flange to fit against sides of elliptical pipe passing through center of 145 Pipe passing centrally through apex of 144 Hod, Funnel coal 399 Hole in roof for pipe to pass through 105 Hood, French style auto 458 Oil lank 374 Index. 527 PAGE Hood, Portable forge 371 Range, with reduced sides 512 Hopper 104 Cone shaped, intersected by spout 492 or flaring article, base oblong, top square 177 or irregular shaped box 477 Horizontal lines, Geometrical definition 2 molding, to miter with inclined molding at an octagon angle, and patterns for both arms, To establish profile of 206 To obtain profile of inclined molding to miter with it at octagon angle and patterns for both arms 205 return at foot of gable to miter at right angles with inclined molding of normal profile 200 at top of broken pediment to miter with inclined mold- ing, To obtain the profile of 202 Horseshoe arch, Architectural term 11 House, Architectural diagrams of 14 Hyperbola, Geometrical definition 7 Hypothenuse, Geometrical definition 3 I Icosahedron, Geometrical definition 9 Import, Architectural term 11 Inclined molding, From the profile of a given horizontal molding to obtain the profile of inclined molding neces- sary to miter with it 205 mitering upon wash, including return 166 to miter at right angles with horizontal return, To obtain profile of 201 or oblique lines, Geometrical definition 2 roof, Gable cornice mitering upon 164 Incised work, Architectural definition 13 India rubber for drawing, description 28 Ink, India, for drawing, description 27 slab for drawing, description 27 Inscribed circles. Geometrical definition 5 polygons, Geometrical definition 5 Inscribing dodecagon within given circle, 59 eleven-sided regular polygon (undecagon) within given circle by general rule 44 equilateral triangle within given circle 43, 51, 57 hexagon within given circle 52 octagon within given circle 53 regular decagon within given circle 44 dodecagon within given circle 44 heptagon within given circle 43 hexagon within given rule 43 octagon within given circle 43 within given square 49 pentagon within given circle 43 polygon within given circle by general rule 44 undecagon within given circle 44 square within given circle 43, 52, 58 Inside miter, Architectural definition 15 Instruments for drawing, description 28 Intersecting elbows, Junction of large pipe with elbows of smaller pipes 384 lines and circles, To construct ellipse of given dimensions. . 63 to draw ellipse within given rectangle by 63 Intersection of solids, Geometrical definition 9 Involute, Geometrical definition 7 Ionic volute, To draw 67 PAGE Irregular forms of triangulation 86, 95 four-sided figure, Face miter patterns for molding bounding 109 or mold surface, Butt miter against 103 shaped article, illustrating principles of triangulation 87 Isometrical projection, Architectural definition 14 Isosceles triangle, Geometrical definition 3 J Jack bar pattern for top of skylight 221 Joint at other than right angles between two pipes of dif- ferent diameters 151 between an elliptical and round pipe of larger diameter. . 125 two pipes of different diameters intersecting at other than right angles 551 two pipes of same diameter at other than right angles.. 415 lines of elliptical arch, To draw 67 T -joint between pipes of same diameter 139 Junction of large pipe with elbows of smaller pipes of same diameter 3S4 K Keystone, Architectural term 11 having molded face with sink 120 L Level molding mitering obliquely against level molding of different profile, pattern for 167 Lead pencils for drawing, description 25 Leaders, Square, Compound curved elbows for, conical method 494 Compound curved elbows for 478 Line, Geometrical definition 1 parallel to another. To draw by triangles or set-square.... 36 perpendicular to another, To draw by triangle or set squares 37 Straight, To divide into equal parts by scale 38 To divide into two equal parts by a pair of dividers. ... 37 To divide into two equal parts with compass 37 To divide into two equal parts by triangle or set square. 38 To draw equal in length to circumference of circle or part of circle 42, 43 Linear drawing, Principles of 30, 35 Lines, Joint, in elliptical arch, to find 67 Rise of, in obtaining envelope of molding from model 74 Straight and parallel to given line and at given distance from it, To draw with compass and straight edge 36 Lining of head of bathtub 328 Lintel cornice, Architectural definition 12. molding mitering obliquely against arch molding of differ- ent profile 167 Lip, Sheet-metal pitcher 272 Loading, Spiral spout or conveyor 476 Locomotive boiler, Flaring section of 179 Lozenge, Rhombus, Geometrical definition 4 M Mansard roof, Corner piece of, embodying principles upon which all mansard finishes are developed 105 Hip finish in curved mansard roof, hip being a right angle 101 Hip molding mitering against bed molding of deck cor- nice on mansard roof, square base, octagonal top. . . . 208 Hip molding mitering against planceer of deck cornice on mansard roof, square eaves, octagon top 227 528 Index. PAGE Mansard roof, mitering against bed molding at top, Hip molding upon a right angle in 217 mitering against bed molding of corresponding profile, Hip mold upon octagon angle in 223 mitering against planceer of deck cornice, Hip molding upon right angle in 215 mitering upon inclined wash at bottom, Hip molding upon octagon angle of 225 octagon top, square bottom, Miter at bottom of hip mold- ing on 233 square base, octagonal top, Fascias of hip molding finish- ing curved 236 To obtain curves for molding covering hips of curved.. 238 Marquise, Construction and patterns 514 Mason 's chute 464 Materials and tools for drawing, discussion 17 Middle piece gored in three-piece elbow 187 Miter, Architectural definition 15 between moldings of adjacent gables upon square shaft formed by means of a ball 176 between moldings of different profiles 102 butt against curved surface 91 against irregular or molded surface 103 against plain surface oblique in elevation 97 against plain surface oblique in plan 97 cutting or parallel forms, first system of 72 Requirements for 76 . Rule for 77 face at right angles, as in molding around panel 106 line, Curved molding of same profile, for straight 110 or jack bar of hipped skylight 221 return at other than right angle as in cornice at corner of building. . .'. 98 Square, Comparison between the short rule for cutting square miter and the method prescribed by rule 77 Square faced, produced where a square return miter was intended 78 Square return, or miter at right angles 98 Usual method of cutting 76 Miters, Simple gable 110 Model, Cardboard, perspective view illustrating application of principles of triangulation 89 illustrating principles of triangulation 89 Use of for obtaining envelope of molding by lines 74 Wooden, Method of deriving pattern of a frustum from. . S2 Modified profile in horizontal return of broken pediment .... 202 in horizontal return of raking molding or pediment with normal profile 200 in raking molding or pediment and normal profile in horizontal return 201 profiles for return at top and bottom of segmental broken pediment 204 Modillion, Architectural definition 12 course, Architectural term 10 head, Architectural term 10 land, Architectural term 10 molding, Architectural term 10 To draw scroll to specified width for 69 Molded base, projection of sides different from ends 1S2 face, Keystone with 120 or irregular surface, butt miter against 103 Pilaster, Gable molding mitering against 161 Molding, Architectural definition 13 PAGE Molding, against octagonal side of lower roof of dormer mitering 165 Crown, etc., Architectural term 10 Curved blank 254 ' Face, miter at right angles 106 Gable, mitering against molded pilaster 161 Generating, in plastic material by reverse stay. 73 Hip, at right angles in mansard roof miter against planceer of deck cornice 215 covering curved mansard roof 238 finishing curved mansard roof, square base, octagonal top 236 mitering against planceer of deck cornice on mansard roof, square eaves, octagonal ridge 227 mitering against bed molding of deck cornice on mansard roof, square base, octagonal top 230 miter at bottom of, on mansard roof, octagon top, square bottom 233 upon octagon angle of mansard roof, mitering against bed molding of corresponding profile 223 upon octagon angle of mansard roof mitering upon inclined wash 225 upon right angle in mansard roof, mitering against bed molding at top 217 inclined in elevation against plain surface, Butt miter of. . 173 in elliptical window cap, Curved^ 256 mitering around irregular four-sided figure 109 Obtaining envelope of from model by use of lines 74 Raked or modified, Architectural definition 14 Straight, meeting curved molding of same profile, To obtain miter line and pattern 152 Moldings and roof pieces in gables of octagon pinnacle .... 174 in gables of square pinnacle 173 bounding panel triangular in shape 108 Face miter, bounding irregular four-sided figure 109 for window cap, Simple curved 255 of adjacent gables on square shaft, miter between formed by ball 176 of different profiles, Miter between 102 of different profiles mitering at angle 167 at any angle, Comparison between butt miter and miter. . 76 Monument, octagon, with alternate long and short sides 189 Moresque arch, Architectural term 11 N Neck mold, Architectural term 13 Newel post, Decagon 178 Ninety-degree elbows in elliptical pipe, two cases 130 in pipe, two, three, four and five pieces 133 Nonagon, regular, To draw upon given side 47 To inscribe within given circle 44 Norman profile in horizontal return and modified profile in raking molding or pediment 251 in raking molding and modified profile in return 200 or normal stay, Architectural definition. . 14 O Oblique cone, Geometrical definition 8 cylinder, Geometrical definition 8 offset in rectangular piping 210, 214 offsetting blower connection 507 Y-Branch 510 or inclined lines, Geometrical definition 2 or scalene cones 306 Index. 529 PAGE Oblique projection of circle, To draw for an ellipse 61 section of cone, Describing for an ellipse 62 of cylinder, To describe form of for ellipse 61 Oblong base and square top flaring article 177 pipe with semicircular ends, To join round pipe and offset. 373 raised boiler cover, semicircular ends 258 to round double offsetting boot 443 tub, Flaring end of 178 vessel, semicircular top, rectangular bottom, End" of 310 Obtuse angle, Geometrical definition 2 Obtuse-angled triangle, Geometrical definition 3 Octagon, Geometrical definition 4 miter, Architectural definition 15 pinnacle, miter between moldings of adjacent gables upon. 208 pipe, Semicircular elbow for 253 regular, To draw upon given side 47, 54 To draw within given square 49 to inscribe within given circle 43 shaft fitting over ridge of room, Curved 123 fitting over ridge of roof 126 mitering upon ridge and hips of roof 127 to fit against a ball 122 spire, mitering upon eight gables 245 mitering upon four gables 246 mitering upon roof at junction of ridge and hips 248 square transition piece 455 To draw about given circle 56 To inscribe within given circle 53, 58 to square, gore piece forming transition at end of chamfer 191 gore piece forming transition in molded article 192 with alternate long and short sides, patterns of 1S9 Octagonal pedestal 115 pinnacle, Moldings and roof pieces in gables of 174 Pyramid, alternate long and short sides, Envelope of frus- tum of 244 Envelope of frustum of 243 side of tower, Dormer molding mitering against 165 top and square base tapering article 188 Octahedron, Geometrical definition 9 Offset between two pipes, oblong in section whose long diam- eters meet at right angles 350 blower 507 boot, Developing double 443 circle to ellipse transition piece 452 in ventilation pipe 497 to jom an oblong pipe with a round one 393 to join round pipe to one of elliptical profile 396 twisted, for square pipe 478 Y, from circular pipe 510 Offsetting branch 466 compound elbows in round piping, True angles of 143 elbows at any angle 136 elbows for square pipe, oblique 494 elbows for square pipe, obliquely twisted 497 elbow, oblong, semicircular ends to round 482 furnace bottom, round to oblong semicircular ends 349 square to octagon transition piece 455 Oil tank-hood 374 Opening in roof for pipe to pass through 128, 129 Ornamental roof flange for flag pole 475 Orthographic projection, Architectural definition 14 Outside miter, Architectural definition 15 PAGE Oval flaring object or hip bath 318 or egg-shaped flaring pan 263 P Pan, Automobile dust 420 Elliptical flaring 260 Elliptical or frustum of elliptical cone 317 Pour-sided and flaring 104 or flaring article, base oblong, top square 177 Oval or egg-shaped flaring 263 Eectangular flaring, rounded corners, ends flaring more than sides 316 Panel, Architectural definition : 13 molding, Architectural term 10 patterns for face miter at right angles 106 on face of racking bi'acket 196 triangular in shape, Moldings bounding 108 Paper, Drawing and tracing, description 2S, 29 Parabola, Geometrical definition 7 Parallel lines, Geometrical definition 2 forms or miter cutting 96, 239 Pattern cutting, Its application to sheet metal work 1 Exemplification of the principles of 71, 95 Sheet metal, Geometrical definition 1 of frustum derived from wooden model 82 derived from drawing 82 of irregular shaped article by triangulation 90 Pedestal, Architectural definition 11 Equilateral triangle Ill Hexagon 114 Octagonal 115 Square 112 Six-sided 114 Pediment, Architectural definition 11 Broken, Architectural definition 12 Modified profile of horizontal return at top 202 on a wash 164 with modified profile and normal profile in horizontal re- turn 201 or raking molding with normal profile and modified profile in return 200 Baking bracket for curved 356 Segmental broken, To obtain modified profiles in returns at foot and top 209 Pencils, Lead, for drawing, description 25 Pens, Puling, for drawing, description 26 Pentagon, 'Geometrical definition 4 regular, To draw upon given side 46 To inscribe within given circle 43 vase 112 Pentagonal prism, Geometrical definition 8 Perimeter, Geometrical definition 4 Perpendicular at given point in straight line, To erect by compasses and straight edge 36 lines, Geometrical definition 2 near the end of a given straight line to erect by compasses and straight edge 36 To erect to arc of circle without recourse to center 41 Perspective projection, Architectural definition 14 Pilaster, Architectural definition 1 Gable molding mitered against molded 161 Pillar, Architectural definition 11 Pinnacle, Architectural definition 12 530 Index. PAGE Pinnacle, gable moldings and roof pieces, Octagonal 174 moldings and roof pieces of square 173 Octagon, with different pitches, Miter between moldings, of adjacent gables of 208 with eight sides, Conical spire mitering on 282 with four sides, Conical spire mitering on 280 with rectangular shaft, Miter between moldings of adjacent gables of different pitches 207 Pins, Drawing, or thumb tacks for drawing, description.... 27 Pipe against roof of one inclination, Flange to fit around. . 129 arms of same diameter as main pipe leaving at same angle, bifurcated 137 at forty-five degrees, Two collars tapping 502 circle to ellipse offset transition piece 452 cut off obliquely 125 elbows, see Elbows. intersecting cylinder obliquely, Rectangular 146 four-piece elbow through one of the miters 159 taper-joint axis not at right angles to axis or side of taper -joint 298 axes parallel but to one side of each other 294 axis crossing at right angles 272 axis not at right angles 96 Oblique offset in rectangular 210, 214 offsetting blower, Connection for rectangular 507 offsetting round to elliptical offset for 396 over ridge of roof, Flange to fit around 128 passing through apex of pyramid or hipped roof, Flange to fit against 140 passing centrally through a pyramid or hipped roof, Flange fitting against 145 Rectangle to round seven-piece elbow 405 Rectangular, Designing elbow for 469 intersecting a cylinder obliquely 146 Oblique offsetting blower connection 507 Transforming elbow for 473 Reducer, Collar tapping main at an angle in two directions 501 Double Offset Y-Branch for 466 Five-piece elbow for 133 flange to fit at top and bottom of flange resting in in- clined roof 363 Four-piece elbow for 132 Four-piece tapering elbow for 440 intersecting elliptical pipe or smaller diameter at other than right angles, two cases 155 intersecting straight back reducing joint at top 323 joint between pipes of different diameters at other than a right angle, axis of smaller pipe at one side of larger 158 joint between pipes of different diameters at right angles, axis of smaller pipe passing to side of larger 156 joint between two diameters at other than right angle. . 151 joint with straight back 311 Junction of large pipe with elbows of two smaller ones. 384 Oblique offsetting Y-branch for 510 of unequal diameters, Collar to join at an angle 359 on taper joints 292, 302 on flag pole on inclined roof, Ornamental flange for. . . . 475 passing through inclined roof, flange having equal projec- tion on all sides, Flange to fit 368 round, carried around a semicircle by cross joints 134 Tapering collar for axes crossing at right angles 270 Tapering collar for axes crossing at other than right angle 290 PAGE Pipe reducer, Tapering two-piece elbow for 284 Three-piece elbow for 131 T-joint between, at right angles of different diameters.. 153 to fit against roof of one inclination 125 to fit over ridge of roof 127 to elliptical offsetting 396 to elliptical two-piece elbow 287 to oblong, semicircular ends, Offset for 393 to octagon, transition piece 455 - to rectangle, Seven-piece elbow for 405 Two collars tapping main at forty-five degrees 505 Two-piece elbow for 130 with straight back for reducer joint 311 Square, Compound curved elbows 478 Describing twist or compound curve 140 Designing elbows for 469 Elbows for 494 intersecting a cylinder obliquely 146 oblique offsetting, blower connection 507 Oblique offsetting elbows for 494 to square, straight back transition 446 Transforming elbow for 473 twisted offset elbows for 497 Twist or compound curve 140 Tapering five-piece elbow for 287 intersected at lower end by straight pipe of larger diam- eter, crossing at right angles 270 intersecting one of larger diameter obliquely 302 three-piece elbow for 2 two-piece elbow for 284 taper- joint for small, at one side of center line 334 for straight back 341 Tapping a straight back reducing joint off its top 323 T-joint between pipes of same diameter 139 Three-pieced elbow for round to elliptical 403 three-pronged fork for 391 to fit against a roof of one inclination 125 to fit against a roof of one inclination, Elliptical 125 to fit over ridge of roof 127 True angle in compound offsetting elbows 147 with circular ends, Round to oblong 393 with semicircular ends, Taper-joint for oblong 258 with semicircular ends, Round to oblong 482 Y-braneh for 387 Pipes of different diameters axis of smaller pipe passing to one side of the larger, T-joint between 156 axis of smaller pipe placed to one side of larger one, Joint at other than right angles between 158 intersecting at other than right angles, joint between. 154 T-joint between 153 of same diameter at other than right angles, Joint between. 151 of unequal diameters, Collar joining at an angle 359 Pitcher, Lip of sheet metal 272 Planceer, Architectural definition 13 Plain tapering keystone, Face and side of 104 Plane, Geometrical definition 3 figure, Geometrical definition 3 Point, Geometrical definition . 1 given, To draw tangent to circle or arc circle without re- course to center 41 Pointed arch, Architectural term 11 Points not in a straight line, To draw a circle through three. 41 Polygon, Geometrical definition 3 Index. 531 PAGE Polygon, finial, Irregular 185 regular, General rule for miseubing within a given eircler. 44 of eleven sides (undeeagon), To inscribe within given circle by rule 45 rule for drawing when length of side is given 48 Polygons, regular, Constructing by tractor 57 Construction of by compasses and straight-edge 43 To construct by T-Square and triangles or set-squares.. 49 Polyhedron, Geometrical definition 9 Portable-forge hood 371 Prism, Geometrical definition 7 Profile, Normal, Architectural definition 14 of horizontal molding to miter with it at octagon angle and patterns for both arms, Prom the profile of given inclined molding to establish 206 return at foot of gable to miter at right angles with inclined molding of normal profile and miter patterns of both, To obtain 200 return at top of broken pediment to miter with inclined molding and patterns of both, To obtain 202 of inclined molding to miter at right angles with horizontal return and miter patterns of both, To obtain 201 of returns at top and foot of segmental broken pediment. . 204 Eaked, Architectural definition 14 to obtain the profile of inclined molding to miter with it at octagonal angle and patterns for both arms 205 True, at line of intersection of curved or inclined molding against oblique flat surface 104 Profiles in seven-sided figure, Changing 185 Miter between two moldings of different 102 Projection drawing, Architectural definition 14 or linear drawing 30, 35 Properties of circles, Geometry of 4 Protractor for drawing regular polygons 57 Protractors for drawing, description 24 Pumps, Bosses for sheet metal hand 448 Pyramid, Diamond shape, Envelope in frustum 178 Envelope of hexagonal 241 envelope of frustum of octagonal 243 envelope of frustum of square 242 Envelope of square 241 Envelope of triangular 240 Frustum of, Geometrical definition 9 Geometrical definition 8 having alternate long and short sides, Envelope of frustum of octagonal 244 Square to fit against sides of elliptical pipe which passes through its center 145 Pyramidal flange to fit sides of pipe passing through its apex 144 Q Quadrant base and round top, Transitional object 354 Geometrical definition 5 Quadrangular prism, Geometrical definition 8 Quadrilateral figure, Geometrical definition 3 R Eadial line system of pattern cutting 7 system of triangulation for elliptical cones 91, 93 Radius. Geometrical definition 5 Railing molding or broken pediment, modified profile of hori- zontal return at top 202 Earn water cut-off 137 PAGE Raised oblong cover with semicircular ends 258 panel on face of raking bracket 196 Rake miter, Architectural definition 15 molding, Architectural definition 13 Raked molding, Architectural definition 14 profile or stay, Architectural definition 14 Raking bracket 193, 356 Raised panel or face of 196 molding or pediment with modified profile and normal pro- file in horizontal return 201 or pediment with normal profile and modified profile in return 200 soffit bracket 508 Range hood with reduced sides 512 Rectangle base and round top transitional object, top not central over base 331 and square top flaring article 177 Geometrical definition 4 pipe, Compound curved elbow for 478 describing twist or compound curve 140 Oblique offsetting elbows for 494 Oblique twisted offsetting elbows for 497 To draw an ellipse within, by intersecting lines 63 to round straight back transition piece 446 Rectangular flaring article 104 Reduced return miters 182 Reducer-joint for pipe 341 small at one side of center line 339 with straight back 311 Requirements for cutting miters 76 Return miter at other than a right angle, as in cornice at corner of building 98 Returns at top and foot of segmental broken pediment 204 Reversing joint for oblong pipe, semicircular ends 350 Revolving blade of spiral conveyor 486 Rhomboid, Geometrical definition 4 Rhombus lozenge, Geometrical definition 4 Ridge molding, Architectural definition 13 Right angle, Geometrical definition 2 Right-angle elbows in round pipe, two-, three-, four- and five- piece 1, 133 Triangle, Geometrical definition 3 Right cone, base oblique to its axis, Envelope of 265 cut by plane parallel to its axis, Envelope of 278 Envelope 249 Envelope of frustum of 250 contained between planes oblique to its axis, Envelope of frustum 274 Geometrical definition 8 upper plane oblique to its axis, Envelope of 265 cylinder, Geographical definition 8 pyramid, Geometrical definition 8 Roof collar, round top, square base, to fit around pipe passing through inclined roof 333 flange, Conical, to fit around pipe against inclined roof. . 266 to fit around pipe against roof of double inclination. . 269 Flaring, round bottom, top to fit pipe passing through inclined roof 363 Ornamental flag pole 475 to fit against sides of elliptical pipe passing centrally through a pyramid or hipped roof 145 to fit against sides of pipe passing through apex of pyramid or hipped roof 144 532 Index. PAGE Roof flange, to fit around pipe against inclined roof 129 to fit around pipe over ridge of roof " 128 to lit pipe passing through inclined roof, flange to have equal projection from small sides 308 Octagon, shaft mitering on ridge and hips of 127 shaft to fit on ridge 126 pieces and moldings in gables of square pinnacle 173 Pipe to fit against inclined 125 Pipe to fit on ridge 127 Rubber or eraser for drawing, description 28 Rule for cutting miters 77 for inscribing any regular polygon within circle 44 Rules, Pattern cutting 71 95 Ruling pens for drawing, description 25 S Scalene cone, Envelope 306 Envelope frustum of 311 intersected obliquely by a cylinder their axes not in the same plane, patterns of frustum of 323 Scale scoop, having both ends alike, pattern 278 one end of which is funnel shaped, patterns 279 drawing, Architectural definition 14 rules for drawing, description „ 27 Geometrical definition 8 system of triangulation for 94 Triangle, Geometrical definition 3 Scoop, Scale, both ends alike 278 one end funnel shaped 279 Scroll for bracket or modillion, To draw to a specified width. 69 Scuttle, Funnel coal 399 Secant, Geometrical definition 7 Section, Conic, Geometrical definition 9 drawing, Architectural definition 14 of cone, Drawing to obtain an ellipse 62 Sector, Geometrical definition 5 Segment, Geometrical definition 5 of a circle, Height and chord given, to find center from which arcs may be struck 40 Segmental arch, Architectural term 11 broken pediment, To obtain profile and patterns of returns at top and foot 204 Semicircle, Geometrical definition 5 Semicircle, Protractor for drawing, description 24 Separator, Spiral strips for dust 432 Spiral strip for dust, short rule 496 Set squares or triangle, description 21 Sets of centers, To draw approximate ellipses with compasses, using two or three 64 Seven-piece square to round elbow 405 Seven-sided vase 115 Shaft, Architectural definition 11 Miter between moldings of adjacent gables of different pitches upon pinnacle with rectangular 207 Octagon, alternate long and short sides 189 Sheet-metal pattern cutting, Geometrical definition 1 Ship ventilator, round base, elliptical mouth 381 Side, Pace of plain tapering keystone 104 Geometrical definition 3 Simple gable miters 110 Sine, Geometrical definition 6 Single curved surface, Geometrical definition 3 Sink, Architectural definition 13 PAGE Skylight bar, Top and bottom of common 138 Top and bottom of hip bar 219 Top of jack bar in 221 Slabs for India ink for drawing, description 27 Slant heights, Geometrical definition 8- Soap maker 's float 320 Soffit, Architectural definition 13 bracket, Raking 508 of arch in circular wall, level at top and jambs of opening splayed on inside 416 of semicircular arch in circular wall, level at top and jambs of opening at right angles to walls, two cases 408 Solid, Geometrical definition 7 of ordinary elliptical flaring article obtained by combin- ing parts of cones S4, 85 Solids, Geometrical terms and definitions of 7 Intersections of, Geometrical definition 9 Spacers, Steel spring, description 22 Sphere, Octagon shaft fitting against 122 or globe, Geometrical definition 9 Square shaft fitting against 122 Spiral by spool and thread, To draw 69 conveyor or loading spout 426 Revolving blade for 486 from centers with compasses, To draw 68 strips in dust separator 432 strip in dust separator, short rule 496 Spire, Dormer molding mitering against octagonal side of... 165 mitering upon eight gables. Conical 282 upon eight gables, Octagon 245 upon four gables, Conical 280 upon four gables, Octagon 246 upon four gables, Square 244 upon roof at junction of ridge and hips, Octagon 248 Splayed arch in circular wall, larger opening being on inside of wall 414 elliptical arch in circular wall, larger opening on outside.. 412 Spool and thread, To draw spiral with 69 Spout bosses for sheet metal hand pumps 448 Can breast 302 intersecting cone hopper 492 Loading, or spiral conveyor 426 Watering can 290 Springing lines, Architectural term 11 Square about a given circle, To draw 57 Geometrical definition 4 face miter produced where square return miter was intended 78 pinnacle, Moldings and roof pieces in 173 pyramid, Envelope 241 Envelope of frustum of 242 to fit against sides of elliptical pipe passing through its center 145 Square return miter, comparing short method of cutting square miter and method inscribed by rule 77 Method of cutting 76 or miter at right angles, as in corner cornice 98 shaft to fit against sphere 122 curved profile mitering over peak of gable coping having a double wash 169 spire mitering upon four gables 244 T, description 20 To inscribe within given circle 43, 52, 58 upon a given side, To draw 53, 57 Indt x. 533 PAGE Starter or furnace boot, round to oblong, semicircular ends, one straight back, other with offset 34S round to rectangule double offsetting 443 semicircular ends, openings central, Bound to oblong. 346 offsetting furnaee boot, round to oblong, semicircular ends 393 Stay, Architectural definition °. . . . 13 Normal, Architectural definition 14 Baked, Architectural definition 14 Steel square, description 20 for drawing circles 41 testing for accuracy 21 Stile, Architectural term 10 Stilted- arch, Architectural definition 11 Stoker, Automatic, or spiral conveyor, Revolving blade 4S6 Stop block, Architectural definition 12 Straight-edges, description 19 Straight line, Geometrical definition 1 sided figures, Geometrical terms and definitions 3 Striking arc of circle by triangular guide, chord and height given 41 Strip in dust separator, Spiral 432 Spiral, in dust separator, short rule 496 Surface, Butt miter against irregular or molded 103 Double curved, Geometrical definition 3 Geometrical definition 3 Systems of pattern cutting 71, 95 T Tables for drafting, description 17 Tacks or drawing pins for drawing, description 27 Tangent of an arc, Geometrical definition 6 To draw, to circle or arc of circle at a given point without recourse to center 41 Tank, Hood of oil 374 Tapering article, square base, octagonal top 188 with equal flare corresponding to frustum of cone, base an approximate ellipse struck from centers, upper plane of frustum oblique to axis 276 elbow in five pieces, Begular 287 five-piece elbow 287 forms or "flaring work, Begular 79 four-piece elbow 440 joint intersected at large end by straight pipe, axes cross- ing at right angles 270 intersected at large end by straight pipe at other than right angles 290 intersected at small end by straight pipe axes crossing at right angles 275 plain keystone, Face and side of 104 three-piece elbow 285 middle piece tapering 355 two-piece elbow 284 Taper-joint for round pipe, small end at side of center line. . 337 iu oblong pipe with semicircular ends 258 intersected at large end by straight pipe, axis of taper passing to one side of straight pipe 291 obliquely intersecting another of larger diameter 302 with round collar branching off at right angles to side of taper-joint 296 with round collar branching off axis, collar not at right angles to axis nor side of taper-joint 298 with round collar branching off, axis crossing at right angles 292 PAGE Taper-joint with straight back 311 with straight back for round pipe 341 with tapering collar branching off, axis crossing at right angles 300 Ten-sided newel post 117 Testing drawing boards, Description of methods 19 steel squares 21 triangles or set squares 22 Tetrahedron, Geometrical definition 9 Thread and spool, to draw a spiral 69 Thirteen-sided regular polygon, length of sides given, To construct by rule 48 Three-piece elbow 131 in tapering pipe 285 middle piece being a gore 187 middle piece tapering 355 to join round with elliptical pipe 403 Three-prong fork in two pieces 425 with tapering branches 381 Three sets of centers, to draw approximate ellipse with com- passes using 65 Three-sided pedestal '. Ill Thumb tacks for drawing, description 27 T- Joint between pipes of different diameters 153 between pipes of different diameters, axis of smaller pipe passing to one side of the larger 156 between pipes of same diameter, patterns 139 smaller pipe tapering and intersected at large end by larger straight pipe, axes crossing at right angles 270 Tombstone, Octagon, alternate long and short sides 1S9 Tools and materials for drawing, Description 17 Top elliptical, base rectangular 330 for square to round chimney 327 oblong, with semicircular ends and rectangular bottom.... 310 octagonal, base square, tapering article 186 rectangular, base round, base larger than top 335 round, base elliptical, one side vertical, transitional object. 345 and base elliptical, top and base central 343 base quadrant, transitional object 354 base rectangular, top not central over base 331 base rectangular, top wider than narrow side of rect- angle, transitional object 328 base square and inclined transitional object 333 bottom elliptical, top and bottom not parallel 356 bottom oblcng, semicircular ends, one with straight back ami another with offset 348 bottom oblong, semicircular ends, top and bottom cen- tral 346 square, bottom oblong, flaring article 177 Tower, Dormer molding mitering against octagonal sides. . . . 165 Tracing paper and cloth for drawing, description 29 Trammels or beam eompasses, description 23 Transformer, Collar intersecting 4S8 Transforming square elbow 473 Transition from rectangular base to elliptical top, Article forming 330' from round horizontal base to round top placed vertically. 376 piece . 503 Circle to ellipse offset 452 from square base to octagonal top 1S8 gore in molded article forming from a square to an octagon 192 gore octagon to square, as at end of a chamfer 191 joining two pipes of unequal diameter at an angle 359 534 Index. PAGE Transition piece, octagon to round 455 rectangular at one end, round at the other, round end not parallel to rectangular end 337 rectangular base, round top, both central 327 rectangular base, round top, diameter of circle greater than narrow side of rectangle 328 rectangular base to round top, top not central over base. 331 rectangular top, round base, base larger than top 335 round to quadrant 35-1 round top, elliptical bottom, both central 343 round top, elliptical bottom, one side vertical 345 round top, oblong bottom, ends concentric 346 round top, bottom oblong, semicircular ends, two cases. . 312 round top, oblong bottom, two cases 348 round top, rectangular base, inclined 333 square to octagon 455 square to round elbow 431 square to round, circle wider than square 328 square to round, top and bottom central 327 square to round, top not central over base 331 square to round, straight back 446 top square, base round, base larger than top 335 Trapezium, Geometrical definition 4 Trapezoid, Geometrical definition 4 Tray, heart-shaped flaring 261 Triangle, acute-angled. Geometrical definition 3 Equilateral, Geometrical definition 3 To construct upon given side 45, 53 To draw about given circle 55 To draw upon a given side 53 To draw without a given circle 57 To inscribe within a given circle 43, 51 Geometrical definition 3 Isosceles, Geometrical definition 3 length of three sides given. To construct 45 Obtuse angled, Geometrical definition 3 or set square, description 21 Proper method of using a 45-degree to divide a circle 51 Proper method of using a 30X60 degree triangle for divid- ing a circle 52 Eight-angled, Geometrical definition 3 Scalene, Geometrical definition 3 Triangular panel, Face miters of moldings 108 prism, Geometrical definition 7 pyramid envelope 240 scale rule for drawing, description 25 Triangulation by radial line systems for elliptical cones. .. 91, 93 obtaining pattern by 90 or irregular shaped forms 86, 95 system for scalene cones 94 Trisecting an angle 39 True augle at hips of irregular square box 477 in compound offsetting elbows of round piping 143 Truncated cone, Geometrical definition 8 Truncating cone obliquely 81 Truss or head block, Architectural definition 12 T-Square, description 20 Twelve-sided elliptical vase 1S3 urn 118 Twisted elbow for square pipe 478 oblique offsetting elbows in square pipe 497 or compound curbed elbow in square pipe 140 Two-piece circle to ellipse offset transition elbow 452 elbow 130 PAGE Two-piece elbow in tapering pipe 284 one end round and the other elliptical, Eight angle 387 in an elliptical pipe, two cases 130 three-prong fork 425 Two-pronged double offset fork 466 Two-prong fork for pipe 389 Two sets of centers, To draw approximate ellipse with com- passes, using 64 Two-way Y, Developing patterns for unusual 429 Tub, Flaring end of oblong 178 tapering sides, semicircular, head flaring more than sides 314 Hip bath 318 Portable bath 366 U Undecagon or eleven-sided figure, To inscribe within given circle by general rule 45 Eegular, To draw upon given side , 48 To inscribe within given circle 44 Urn, Dodecagon 118 Five-sided true polygonal 112 Seven-sided true polygonal 115 Twelve-sided elliptical 183 V Vase, Heptagon 115 Pentagon 112 Twelve-sided elliptical 183 Ventilation pipe, Oblique twisted offsetting elbows 497 work. Compound curved elbow in square 140 Ventilator, Ship, round base, elliptical mouth 381 Versed line, Geometrical definition 7 Vertex, Geometrical definition 3 Vertical lines, Geometrical definition 2 Volute, Architectural definition 13 Construction for a capital 142 Geometrical term 67 To draw Ionic 67 To draw simple 67 Voussoirs, Architectural term 11 W Wash, including a return, Inclined molding mitering upon. . 166 pediment 164 Wheel, Special design, fender for automobiles 462 Window cap, Simple curved moldings in 255 Wooden cone, plan and elevation from which to construct .... 79 model, Method of deriving pattern of frustum from 82 Words, Architectural and Geometrical, Alphabetical list. . 15, 16 Working drawing, Architectural definition 14 Y Y-branch, arms of same diameters as main pipe, leaving it at same angle 137 Double offsetting 466 for round pipe, Oblique offsetting 510 Unusual two-way 429 Y-branches, forty-five degree 505 Y, consisting of tapering pipes joining larger pipe at an angle 389 Zones, To construct ball in any number of pieces of shape. . 251 ■ m °#l \Y'v ;-'% :>^' ; ■'"■^ -■■:'.'' 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