PMMMiiMiil 'M LIBRARY OF CONGRESS. Chap. _..._Trr7ip. Shelf..- •Li^S.. UNITED STATES OF AMERICA. , JUST IMPORTED, The Lathe and its Uses; OR, INSTRUCTION IN THE ART OF TDRNIN& IN WOOD AND METAL, nrcLUDiNa A DESCRIPTION OF THE MOST MODERN APPLIANCES FOR THE ORNAMENTATION OF PLANE AND CURVED SURFACES. BY THE AUTHOR OF "THE YOUNG MECHANIC." 8vo., Cloth. $6.BO. O. p. PUTNAM & SONS. NEW YORK. THE YOUNG MECHANIC CONTAINING DIREC7V0NS FOR THE USE OF ALL KINDS OF TOOLS, AND FOR THB CONSTRUCTION OF STEAM ENGINES AND MECHANICAL MODELS, INCLUDING THE ART OF TURNING IN WOOD AND METAL. X ^ AUTHOR OF "THE LATHE AND ITS USES," "THE AMATEUR MECHANIC'S WORKSHOP," &c. • I FROM THE ENGLISH EDITION, WITH CORRECTIONS, &^c. NEW YORK G. P. PUTNAM'S SONS 27 AND 29 West 23d Stkeet 1883 1^ Entered according to Act of Congress, in the year 1871, by G. P. PUTNAM & SONS, in the Office of the Librarian of Congress at Washington. INTRODUCTION TO THE AMERICAN EDITION. In presenting tlie American edition of this little work to the public, we believe we are supplying a want that has long been felt by the Young Mechanics of this country, and many others who desire to become versed in the practical use of tools. We know of no other book published in this country or England, in which the method of using tools is so clearly explained ; and although written more especially for boys and beginners, it contains much information that will be of great value to the jDractical mechanic. The author is evidently thoroughly acquainted with his subject, and understands how to communicate his ideas in a simple and concise manner. The first six chapters are devoted to the description of Tools for working wood and the manner of using them, beginning with the simplest operations, requiring but few tools, and gradually leading on to the more difficult, giving examples of all the methods of joining and finishing work that are in common use among good workmen, and in this connection we would like to call attention to the small number of tools the author requii-es for performing all these different operations, the idea among amateurs and boys generally being, that if you only have tools enough you can make anything. This is not so, and if the begin^ ner will follow the advice of the author, and buy a few good tools, and learn the use of them thoroughly, and gradually add to his stock as his knowledge of their use increases, he will find it greatly to his advantage. The next five chapters relate to the lathe, and the art of turn,- ing. The author follows the same plan as in the fii'st part of the book, and gives more practical infoi-mation in these few pages (han we have seen in any other book on the subject, most of them: being written apparently for finished mechanics, and not for beginners. The Art of Turning as an amusement, is beginning: to attract considerable attention in this country, but not so muchi II INTRODUCTION. as it deserves and would obtain, if it were more generally known how many beautiful and useful articles can be produced in tho lathe. The expense of the necessary tools has deterred many from attempting to learn this branch of mechanics ; but we believe if any one has the time and patience to devote to the work, they will never have occasion to regret the money spent for this purpose. The last four chapters contain practical instruction in model- making and working in metal. This part of the book we would particularly recommend to inventors who desire to make their own models, as it contains information in regard to files, drills, and the various small tools used on metal, and also directions for lay- ing out work, which are invaluable to a novice in such operations, and will save him much time and trouble. As this book was originally published in London, where the facilities for getting many kinds of small tools are better than in this country, perhaps a little advice as to the best way of getting such tools as may be required will not be out of place. In most of the large Hardware Stores, carpenters' tools will be found, put up in chests, at prices varying from five to fifty dollars or more ; but we should not advise the amateur to buy any of these, as the quality of the tools is not always reliable, and as they are usually fitted up to make as much show as possible for the money, they contaio. many tools which are of very little use. The best way is to make a list of the tools required, and select them for your- self. The most important thing is to have the Cutting tools of good quality. We give below the names of some of the best makers of tools ; if you purchase any of these, you may be sura of the quality. On Saws, — Henry Disston, Groves & Son. On Chisels and Gouges, — Buck Bros, Moulson Bros. On Plane Irons, — Moulson Bros., Wm. Butcher. On Files, — P. S. Stubs, Greaves & Son, Earl & Co. On Rules and Squares, — Stanley Rule and Level Co. INTKODUCTION. Ill If you live in the City, you will probably find no difficulty in procuring some of the above makes ; but if you cannot find them? there are some others that are good, and you must rely somewhat on the dealer. In regard to the probable cost of the tools, a set such as is described on pages 29 and 30, would cost from fifteen to twenty dollars. Of Foot Lathes, the following are some of the makers : N. H. Baldwin, Laconia, N. H. GooDNOW & WiGHTMAN, Boston, Mass. American Tool Co. " " G. L. Cady, Lowell, Mass. Exeter Machine Co., Exeter, N. H. Jas. Stewart's Sons, New York. From some of the above the amatevir will probably be able to select a Lathe to suit him in size and price. The lowest price at which a serviceable lathe can be bought is about forty dollars; this is without tools or chucks. About fifteen dollars more would be required for these. Lathes can be bought from this price iip to hundreds of dollars, according to the style of lathe and the number of chucks, but of course the beginner would not need an expensive lathe, and seventy-five to one hundred dollars would buy a lathe and tools suitable for all kinds of small work in wood, ivory, or metal. This volume being an exact reprmt of the English edition, it may be well to explain that the material called Deal in England is much the same as our Pine. The article called in England a " Carrier," is with us called a dog (see pp. 112, 114, 115). Articles priced in English currency would cost here now about 35 cents to the English shilling, or $7 per £ stg. Preface. F all people in the world who must not be neglected are, first and foremost, " Our Boys," and, of all boys, mechanical hoys deserve a very high place in our estimation. Whatever others may be, these, at any rate, are possessed of sound heads, and willing hands. Therefore, to help these to carry out their designs, appears to be a special duty of those who, once mechanical boys themselves, have lived to become the progenitors of others. In fulfilment of this very duty I have taken up the pen, and with special reference to young mechanics, but without entirely forgetting those of maturer growth, I have thrown together a few hints upon that absorbing question, " How to make and how to use ? " In doing this, I have endeavoured to carry out the plan of IV PREFACE. small beginnings^ going from the simplest and easiest to tae more complicated and difficult work, although here and there, of sheer necessity, a somewhat different order has been ohserved. The workshops of King's College School prove the capabilities of boys to do high-class mechanical work when their efforts are rightly directed by a master's hand. Where the latter cannot be obtained, guide-books must, however insufficiently, take his place ; but whether instruc- tion in mechanical art be oral or otherwise, practice and perseverance are the secrets of success. " Qui studet optatam cursu contingere metam, Multa tulit fecitque puer ; sudavit et alsit." Content^. ORiX. I. INTRODTTCTORT, . , n. HOW TO MAKE A CAGE, . _ni. MORTICE AND TENON JOINTINO, IV. HOW TO MAKE A TABLE, . Y. DOVETAILING AND MITRING, VI. REBATING, TONQUEING, AND GROOVINO, Vn. THE TOUNG MECHANIC AT THE LATHE, VlII. ON WOODS AND MATERIALS FOR TURNIKO, IX. SHARPENING AND SETTING TOOLS, X. HAND-TURNING IN WOOD, XI. HARD-WOOD TURNING, XII. HOW TO MAKE A STEAM-ENQINB, Xin. watt's ENGINE, . XIV. HOW TO MAKE AN ENGINE, XV. HARDENING AND TEMPERING TOOLS, tkom 1 15 29 49 66 89 103 122 144 163 203 226 264 281 325 Chapter I. |-^^HERE never was a time wlien a taste for practical mechanics was so general among boys as it is now, in this year of grace 1870. There are comparatively few homes in which evidences of this hobby are not apparent in every odd nook and corner, in the shape of carpenter's tools, not always in first-rate condition, nor by any means generally in their proper places. A saw here, a hammer there, a gimlet, bradawl, or chisel elsewhere. This probably results from the giant strides which have been made of late years in mechanical enterprise, and the introduction of machinery into every department, as a means of saving labour and facilitating the production of the: various necessaries of life. Man is an imitative animal, and in this as in other things^ " the child is father to the man ; " and hence it comes to pass that the boy whose eyes are continually resting upon machinery of one sort or another (agricultural implementSj THE YOUNG MECHANIC. if a villager ; engines for jilaning, savvying, turning, and so forth, if resident in a town) sooner or later feels an innate desire to construct models of these gigantic mechanical labourers, by whose incessant but unfelt toil our several daily needs are so cheaply and plentifully supplied. Even if the youthful mind does not always display highly-developed inventive faculties, there is very gener- ally manifested a desire of personally constructing some one or more of those articles which conduce to the gratifi- cation of a particular hobby. If the boy has a taste for natural history, cases and cabinets will be made, for the reception of eggs, butterflies, and insects, or to contain stuffed specimens of animals and birds. If he has wdthin him the elements of a sailor, his ingenuity will be exercised upon model boats and shijjs. If fond of dumb pets, rabbit hutches, dove-cots, or cages will afford him opportunities for the exercise of his constructive powers, and thus the young mechanic frequently lays the founda- tion of future eminence in that particular line of life to which his tastes naturally lead him. There are few boyish hobbies in which assistance haa not of late years been given by instruction books and guides of a high degree of excellence — natural history, botany, gardening, rearing and breeding all manner of pets — to each of these, well-written volumes have been devoted by able and experienced writers, but mechanical and ''SMALL BOYS NEED FEW TOOLS." 3 constructive art lias been somewhat neglected. Here and there, in periodical magazines, a few pages are dedicated to the subject, but no book about practical mechanics, written expressly for boys, has yet appeared. The author of the present volume, himself father of ~ four lads, all of whom in turn occasionally try their hands at this kind of work, and who has himself for many years practised the mechanical arts of carpentry, turning, and model-making, hopes that the hints contained herein may prove valuable to those young friends whom he now ad- dresses. Some of the following chapters will be arranged for very little boys, some for those who are older, while it is believed that other parts of the work may not prove altogether useless to those who have dropped jacket and knickerbockers and rejoice in the vigour of manhood. Thus the little boy, who receives the book as a present, will find it a fast and faithful friend as his years, and, we trust, knowledge and bodily powers increase. " Small boys need few tools, but much perseverance.'''' Let this be their motto, as it will stand them in good stead. A pocket-knife, gimlet, hammer, and a few nails will generally serve their purpose ; but there is one other tool, namely, a square, which is of great importance, and of which it is well to learn the use as early as possible. A small saw and a bradawl may also be added to the list, and likewise a chisel half an inch wide. Thus equipped, THE YOUNG MECHANIC. a very youthful carpenter can do a good deal, and, let me tell him, a good deal has been often done without even this moderate supply of tools. It must be taken for granted that the knife and chisel are sharp, because blunt, tools make bad work, and by far the best plan for small boys is to get some friend to sharpen them when blunt, as the operation is not easy and requires practice. It is a very foolish plan to try and work with a blunt knife, for the fingers are just as much in danger ; and a boy who intends to learn how to use tools must learn at the commencement to use them with due care, so as not to damage himself. There are small boxes of tools sold, containing generally a wooden mallet, saw, plane, chisel, and gimlet, at about 3s. 6d. or even 58. Such a box is simply useless. The tools are of iron — will not take a good edge, and are generally disposed to bend and twist. Avoid these, and buy, or get a friend to buy, those I have named, of good quality, and be sure to take care of them, for which pur- pose you may try your hand at making a box. For this purpose, you will require some thin board (half-inch thick) planed on both sides. (The carpenter will prepare this for you.) Let us see how much you will need. Measure your longest tool, the chisel or saw, if the latter is quite a small one fit to go into a little box ; if not, it can be hung on a nail, and you can make your box to contain your knife and chisel and gimlets. I daresay if the box is 9 inche"* HOW TO MAKE A BOX. 5 long, 4 inches wide, and 3 inches deep, it will be large enough to take these few tools, for I have just now mea- sured such a hammer and chisel as I have recommended, and find them each about 9 inches in length. The top and bottom of a box should project a little all round, so that you will want them about an inch and a half wider and longer, which will also allow for the thickness of the wood; for you must remember we have given the size of the box inside. To make this clear, I shall here give a plan of the bottom of the box (Fig. I). Fig. 1. Fig. 2. It is 10^ inches long, and 5^ inches wide. The broad black line shows where the edges of the sides and ends will come, these being half an inch thick, so that there is a quarter of an inch all round the outside as a border. Reckon across and you will understand this better. A quarter of an inch outside, half an inch for the black line (equals three-quarters of an inch), 4 inches for the inside THE YOUNG MECHANIC, width, half an inch again for the black line, and a quarter of an inch outside as before, — altogether making 5^ inches. Now reckon the length. A quarter-inch border, half an inch for the black line, 9 inches inside, half inch for the second black line, and another quarter outside — making 10^ inches. You require, therefore, two boards 10^ inches long and 4^ wide for the top and bottom. Now the two long sides and the ends are to be 3 inches wide to forna the depth of the box, and here you want no extra width, but as the inside of your box is to be 9 inches long, and the sides are usually nailed over the ends, like Fig. 2, where I have shown them put together, you see that you must have the sides as much longer than 9 inches as will allow them to lap over the ends ; that is, half an inch at each end where I have made them black, or altogether, one inch; so that you will want two pieces 10 inches long and 3 wide. The ends will be also 3 inches wide and 4 inches the other way, and here no additional size is needed. Now, the usual way to cut the sides is to get a narrow strip of board of the required width and thickness, and long enough to make both the sides and ends, just such a piece as Fig. 3, on w^iich are marked the lines where it will have to be cut across, and you will easily perceive that you re- quire 28 inches in length and 3 in width. But you must understand that when you cut with a sa"W you waste a little of the wood, which falls in the shape o/ A CARPENTER'S RULE. 7 sawdust, and so if you did not allow for this, your box would be too small. The waste depends on the thickness of the edge of the saw, where you will, if you examine it, see that the teeth spread out right and left to prevent it from sticking fast as it is used. Probably, you would waste three-eighths of an inch, which is nearly half an inch in cutting off the pieces, so that instead of a piece exactly 28 inches long, you must have it 28^ inches, or even a little more. I want you to understand all this before you set to work, even though at first you may get a carpenter to measure and cut it for you; because most small boys take no trouble of this kind, and consequently they are sure to make their boxes too large or too small, and they look very bad when done. However, as I said before, I expect my young- readers to understand what they are about, and they must set out their work carefully, or they will never get on so as Fix 4. to be able to make good use of the later chapters of this book. A carpenter's rule is made like this (Fig 4\ THE YOUNG MECHANIC. Sometimes there is a brass slide, to add to its length wlien necessary, and sometimes it is hinged so as to fold up again. If you want one for your box, you can get it so made, when it will go in nicely. It is 2 feet long — 1 foot on each side of the central joint. A foot is 12 inches ; the whole rule, therefore, is 24 inches. Now, you will see that each of these inches is divided by short lines into eight equal parts, called eighths ; at the second, the line is rather longer, this being a quarter of an inch : at the fourth, there is a still longer line, this being the half-inch ; then comes another eighth, then the three-quarters, another eighth, and the inch is made up, — eight-eighths being equal to one whole inch. Very likely you will find one edge of the rule, or sometimes only one inch^ divided into smaller parts, which are sixteenths, or half-eighths ; and sometimes, but not very often, divisions still smaller are used, which are half-sixteenths, or thirty-seconds, because thirty-two such divisions make the complete inch. Three feet make one yard, but carpenters always reckon by the foot and inch, and by eighths and sixteenths of an inch. In some trades the inch is divided into a hundred parts, and work is mea- sured up and fitted so carefully, that it would be considered faulty if a mistake of less than a thousandth of an inch were made ; but you will not yet understand how it is possible even to measure so very small a quantity. You should certainly learn and understand how to measure with a THE SQUARE. common two-foot rule, and when you can add one to your box of tools, do so. Now, let us examine the tool called a square, without which the marks could not readily be drawn as a guide for the saw, where the strip of board is to be cut to make the sides and ends of the proposed box. Here is a drawing of one (Fig. 5). Fig 5. Fig. 6. It is a handle and a blade, like a knife half opened, the one being fixed exactly square, or at right angles with the other. The blade is thinner than the handle, and when the latter is placed as in Fig. 6, a line marked across the board against the edge of the blade will be, of course, square to the side, so that when cut off, the piece will be like the end of Fig. 6. This is not the shape which the sides of boxes generally have when made by small boys, because they have not a square, and do not know how to work properly. Nevertheless, if one end of a board is cut square, you might get the piece right by m^easuring the same 10 THE YOUNG MECHANIC, distance on each side (say 10^ inches), and drawing a line across from point to point, as a guide for the course of the saw. But, then, as it is absolutely necessary that the end of the board should be square to the side, to do this you had better get a proper square at once, and learn how to use it. You will, indeed, find this tool most necessary for all kinds of work, and you will be quite unable to do with- out it, even though you only have, besides, a knife and gimlet. Now, if you want to cut off a piece of board with the saw, you must never cut out the line you have marked as a guide by the help of your square, because if you do, you will get the piece too short, owing to the width of the saw-cut which I explained before. Cut, therefore, j^'e^s^: beyond it, leaving it upon the piece you are going to use for the side of your box, or other article. At first, you will find it difficult to saw neatly and close to the line, but you will get used to it very soon ; and if the saw does not go quite straight, you can trim the piece with a sharp knife neatly up to the line, which you see you could not do if you cut out that line by sawing exactly upon it. All these direc- tions in little matters are very important, because you will find that, by attending to them, you will work well, and the various things you make will look neat and trim, and be fit to show to your friends. Now, let us go on with the box, which was laid down now TO MAKE A BOX. n jnst to allow a little explanation about the carpenter's ruk and square. I shall suppose you to have cut off all the pieces quite squarely and neat, and that the edges are also square to the sides, which you must take care to insure by keeping the blade of the saw upright when you use it. It is a good plan to measure and mark both sides of your board for this purpose, and to mark the edges from one of these lines to the other. You will then have guide-marks all round, and, by keeping close to these, you will be sure to cut your work truly. It would not so much signify if the long sides were cut a trifle too long, as I shall explain presently ; but the ends must be square and true to mea- sure, 4 inches by 3 inches. You must now proceed to nail them together. This must be done with small brads, which are fine nails, and which for the present purpose may be one inch long. If your pieces are all exact to measure, draw a pencil line across the two side pieces, a quarter of au inch from the ends, by the help of the square, as if you wanted to cut off a quarter of an inch at each of those parts, and with your bradawl make two or three holes (three will be best) along those lines. Do not make the first and last too near the edges, or you will split the wood, and spoil the box. Now set up one of the short pieces, and place upon it the piece which you have bored holes in. If you have a bench with a vice, you can screw up the short piece into it ; but it will stand up very well upon the 12 THE YOUNG MECHANIC. bench if you have no vice. It is now in the position 0/ Fig. 7, C. Fig. 7. Hold it thus, and run the bradawl a little way into the lower piece, through the holes already made in the upper. Drive a brad through the middle hole first, which will hold it together, and then through the other two holes. If you have beeri careful, you will find this corner square and neat, and the wood not split in the least. Do the same with the other short piece, and then nail on the long side that is left. The frame of the box will now be complete. I told you a short time ago, that it would not much HOW TO MAKE A BOX. 13 signify if the sides were cut too long. The reason is this : Suppose B to be the side half an inch too long. You would mark off 9 inches of the middle by two lines drawn with the square as before, which would be the length of the inside of the box ; you would then place the inner edges of the end pieces against these lines, and nail them on like A, and afterwards neatly saw off the two pieces which lap over these at each end. If the wood is likely to split when the holes are made for the nails, or if the work- man is pressed for time, he very frequently does his work in this way, and then cuts it off and planes it neatly. It is, however, better to work as directed, only be sure to bore holes carefully for the nails, so as never to split the wood. No very special directions are needed about putting on the bottom. Leave all round an exactly even border of a quarter of an inch, and after it is nailed, you may neatly round off all its edges, to give it a finished appearance. The cover is, of course, to be attached by a pair of small hinges. Brass hinges are the neatest, and when you buy them, ask for screws to match. The hinges may be three- quarters of an inch long, and they will be, when shut, about half an inch wide, which is the size you need. Lay them (shut up) upon the edge of the back, about two inches from the ends, and with a hard pencil cut to a fine point, or with the point of your bradawl, make a mark at each end, as if you were measuring the length of the hinges on »4 7 HE YOUNG MECHANIC. the edge of the box. Between these marks you have to cut out pieces like Fig. 8, Fig. 8. which will be just the length of the hingep, and deep enough to allow them, when shut up, to fit and lie even with the top edge of the box. Open them, make holes with the bradawl, and put in the screws. If you have not a screwdriver, you can turn them with the end of an old knife ; but you may as well get a small screwdriver, for if you intend to do good work, you will often use screws in- stead of nails. Hinges are always screwed on. Now lay the cover in place carefully, mark its position, so that you have some sort of guide-line to direct you, and then by laying the cover flat on the bench, and standing the (open) box on its side, you can screw on the hinges upon the cover. Bound all the edges of the cover as you did the bottom, but keep the edges of the box square and sharp ; and so you have now a really well-made little tool-chest. A little brass hook and eye will do to fasten it, for a lock is rather difficult for a small boy to put on. Chapter II. " HE method of constructing a simple "box has been given in the first chapter, because so many other articles are made upon exactly similar principles. The rules laid down comprise two or three essential points, the neglect of which render the ordinary carpentry of boys so essentially bad. Foremost of these is the use of the square. There is no tool of more general use in the hands of workmen in wood and metal, and yet, generally speaking, either none at all, or a very faulty one is added to the collection of tools ordinarily supplied to boys. In the next place, I have insisted upon accuracy in measurement. The carpenter's rule is not at all difficult for a young boy to understand; but even if he is not in possession of such at his first attempts, he should always be induced to work by measure of some kind. This causes him of necessity to exercise his mind as well as his hands, and teaches him to consider well at starting as to what he must allow for thickness of wood, the difierence between 1 6 THE YOUNG MECHANIC. inside and outside measurement, and so forth; all this will greatly conduce to his success, and consequently satisfac- tion in his work, and will lessen the chances of his begin- ning a number of articles and casting them aside unfinished — a propensity too common in ill boys. I shall now resume my directions in the first person, which I think is the more easy method both for master and pupil. The next specimen I propose, because it re- quires even more care than a box, but is at the same time perfectly within a boy's powers, is a birdcage. Of these there are such a number of varieties that it is difficult to settle upon the best kind to begin upon. I think, how- ever, a wire cage will on the whole be the easiest to con- struct, only you must take great care in boring holes in the thin strips of wood, and, indeed, if you can get a birdcage- maker's awl besides the one you have, it will save both time and trouble. It is not made round with a flat end, but is three-cornered with a sharp point, so that it has three edges, and when it is carefully used and twirled round and round by the fingers in making holes, it will hardly ever split even very thin strips and pieces of wood. However, if you cannot get one never mind, you must use the com- mon bradawl according to directions here given. I shall suppose you now in possession of a carpenter's rule, and that you have carefully learned all I told you 0/ the inches and eighths, so that you may be able to measure HOJV TO MAKE A CAGE. 17 and mark your work very truly. The front of tlie cage is represented in Fig. 9, before the projecting roof-boards have been put on. Fig. 9. Here you see two upright strips at the corners, which shall be 8 inches long. These are 12 inches apart, outside measure. They are f (three-eighths) of an inch square^ and you must get them ready planed from the carpenter- There will be four of them required, as they are at the four corners of the cage ; so that, as they are each 8 inches long,, you can get a strip 36 inches in length by three-eightha- wide, and this being 4 inches more than you need, will allow for waste. At the lower part of the drawing, you see the edge of the bottom board, which projects a little all round. As the outside of the front pillars are 12 inches 1 8 THE YOUNG MECHANIC. apart, this board may be 13 inches long, which will allow a border of \ an inch (half an inch), and it may be 8 inchea wide. It need not be thicker than a quarter of an inch. A little above this board (say half an inch) is another board from one pillar to another, which is to be 1| inches wide and three-eighths of an inch thick. As the pillars are also three-eighths thick, and their outside edges 12 inches apart, you must take |- (six-eighths) of an inch from 12 inches to find the length of this board. If you look at the divisions upon your rule, you will see that six-eighths of an inch amounts to exactly f (three quarters), so that your board must be 11 inches and one quarter long. This will also be the length of the board at the top where it falls between the pillars, and this too must be three-eighths thick. I shall now show you how to mark and cut this top piece into the shape here sketched. Cut the board first of all into an oblong, and mind that you mark it by your square, so that the ends shall be square to the sides. Let it be 2\ inches wide. Here it is (Fig. 10). Measure a length of 6 inches from either end to the middle at A, and make a mark at that place. Draw a line, C B, one inch from the opposite side, the whole length of the board, and mind you draw it correctly. You should measure an inch at B, and at C, and then draw a line from one point to the otlier along tlie edge of your rule. You must IfOlV TO MAKE A CAGE. 19 now draw two lines from the spot you marked at A to the ends of this line (where you see the dotted lines). In Pig. 10. order to cut this piece, you must begin at A, not at B or C, or else if the saw should stick you will be sure to split off a strip right across the piece; but if it should stick when you are cutting from A, you will only split off a bit of one of the three-cornered outside pieces, which would not signify at all. When you are sawing, be sure, as I told you before, not to cut into the line you have marked, but saw just outside it, so that the lines will be left upon the two sloping sides of the board. You may cut as close to it as you can, but you must not destroy it, and then you can with your knife neatly shave off the rough edges which the saw has made, until you have pared the wood quite neatly all along the line. If you cut this line out, you will no longer have any guide to work by. Cutting out guide lines is a very com- mon fault, not confined to small boys or big ones. You will find it easy to pare this sloping side if you begin to 20 THE YOUNG MECHANIC. work from A downwards to B and C, but you cannot cut it in the other direction. A carpenter would, of course, run his pL^ne down the slope, and so will you by and by ; but planing is difficult, and it is better you should wait for a time before you buy a plane ; for, remember, those foolish little things in boys' tool-boxes are no use at alh You had better now prepare the holes into which the wires are to be put as you see in the drawing. You can use either iron wire or brass, but the first is cheapest. These will have to be a quarter of an inch apart. Both the top and bottom strips, you will remember, are \\\ (eleven and a quarter) inches long. Now, 1 1 inches will be 44 quar- .ters, and one more will be 45 ; but as the first hole must be a quarter of an inch from the ends, you will find that 44 holes will be required. Look at your rule and count this. You must mark all these by little dots with a pencil on one piece, and then laying the other upon it, mark the rest exactly even with the first. Do this with great care, or the wires will not stand upright when the cage is finished. The space between the top and bottom pieces will be 5^ inches, so that if you allow the wires to enter a quarter of an inch at the top and bottom, you will want 44 wires 5f inches in length — you may say, 6 inches. You can have them all cut and straightened for you, but if you have a pair of pliers with cutting edges, you can do it yourself, and it is almost necessary you should get a pair, or borrow HOW TO MAKE A CAGE. 21 them, if you intend to construct wire birdcages. You wili want a few less in each side of this cage, as it will not be there so wide as it is in front. We shall presently see how many it will require. You may put together the front of the cage at once and set it aside, or proceed to cut out the rest of it. Gener- ally speaking, it is the best plan to cut out and prepare all the main parts of your work before proceeding to fix them in their respective places ; but the front of such a cage as I am describing, being complete in itself, you may do as you like about it. V/e will begin with the wires. Insert the ends one after the other in a row in one of the pieces, laying it upon the bench, or fixing it on its edge in a vice, but taking care not to bend them. When one piece is thus stuck full of wires, lay it flat on its side, and put the other piece in its place, and one by one insert into it the other ends of the wires. A pair of pliers will help you greatly in doing this. I daresay the two pieces of wood will not be very parallel, but will be closer at one end than at the other. This does not matter, because you will set it right in nailing on the upright strips or corner pillars. This, therefore, is the next thing you must do; and you must have two brads top and bottom, each an inch long, but as fine as you can get. Nail to the top board first, and then place the other in position half an inch from the bottom of the pillars. If you have no carpenter's vice, 23 THE YOUNG MECHANIC. j^ou had better work with the front of the cage laid down flat and near the right hand edge of the bench or table, so that the pillar almost overlaps it. In this position, you can bore the two holes and nail it together ; but be guarded as to splitting the pillars. You ought now to have the Tront well and firmly put together and standing square and true as in the sketch; only the bottom board, of which you see the front edge, is not to be attended to at present. There is another way of going to work, namely, to put the whole frame-work of the cage together and add the wires afterwards. In this case (the holes having all been made beforehand as directed here) the wires are in turn Fig. 11. inserted at the top, and then being slightly bent are put in place in the bottom piece — each wire being completelr now TO MAKE A CAGE. n fixed bofore the next is added. Either way may be tried, but in that given above the wires are not bent at all, and therefore have not to be straightened. Adding them, how- ever, afterwards is the common practice among the cage- makers. Indeed, it generally happens in large establish- ments that one set of workmen make the woodwork, and another set add the wires — such division of labour proving more advantaoeous. Attention is now to be given to the sides, of which Fig. 11 is a drawing. Here you need not make any corner pillars. You have only to cut out the top and bottom strips — the lower one, 1 f inch wide, to match that in front : Fig. 12. the top, 1 inch wide, to match the straight part of the ends of the uppc? front piece or gable, as you see in Fig. IJi. «4 THE YOUNG MECHANIC. You will also see by this drawing that you must nail the side pieces inside the corner pillars, and not upon them, so that the nails go in from the front of the cage into the ends of the two side pieces which carry the wires. I have shown by dots (Fig. 12) where the nail holes are, and they must be carefully made, avoiding the places where the other two nails come, which you hammered in when you fitted together the front. The side strips, A B (Fig. 11), may bo 8 inches long. Both sides of the cage are to be made exactly alike. I have told you to make the lower side-rails If inch wide, because they must come to the bottom of the pillars, for no half-inch space is required at the sides between these rails and the bottom of the cage. It is so left in the front, because a tray, or cleaning-board, has to be slid in there. You had certainly better put together the side pieces by means of the wires, as in Fig. 11, before you nail them in their places. You now require a piece of board for the back, and quarter-inch stuff will do very well. Bought cages are made of much thinner wood, generally mahogany, but at first it will be easier for you to use thicker boards. If you round off the edges, they will not appear so thick. Very thin deal will warp or bend after it is made up ; and, in- deed, it is quite possible the back of this cage will do so. Get the wood, however, as dry as you can, and the top boards, when nailed on, will probably prevent it. JIOIV TO MAKE A CAGE. 25 To cut out this back board, you may lay down upon the piece from which it is to be cut the whole front of the cage, and draw a pencil round it, only, when you come to the bottom of the side pillars, you must draw a line straight across from one to the other. Then Q,\\.ifrom the point at the top, as you did before. Let the grain of the wood run up and down, not across, the back. Nail the back thus cut to the side strips, as you nailed on the front, and you will then only have the roof to put on, and the bottom. This roof may consist simply of a thin board, cut square and true, nailed on to the two gables, and it will look much prettier if it is made to project beyond the front. If you measure down the slope of the front or back top-piece, you will find it 6 inches long, and a little more. Your board should therefore be 7 or 8 inches wide, because, although the roof pieces meet at the top, they should come down a little beyond the sides of the cage. As the sides are 8 inches wide, cut the top 1 1 inches long, which will allow it to project in -front 3 inches. If you look at the cage at the end of these directions, you will understand this. You must slope, or hevil off, the top edges of these roof boards, to make them fit neatly together along the ridge ; and as you will paint the cage, you can glue on a narrow strip of paper, to make it quite water-tight. The door of these cages is generally in the back. You merely mark and cut out a square hole about 26 THE YOUNG MECHANIC. 3 inches square. You then fit a piece in, and hinge it either with wire, or (which is easier) by sticking on a strip of calico down the edge of it, and fasten with a wire hook. As the back is but a quarter of an inch thick, you will be able to cut out the hole (before nailing on the back), with a sharp pocket-knife; and again I say, don't cut out the guide-lines — cut inside them, and then neatly pare exactly up to them. Make the bottom 13 inches long, and 10 wide, which will allow it to project in front, and also half an inch on each side. You have now to make the tray, to slide into the space left in the front below the bottom front rail. This is to hold sifted sand, and is made loose, because it requires to be taken out and cleaned every day (Fig. 13). It is merely Fig. IS. a fiat thin board (one-eighth of an inch will be quite thick enough), with a strip nailed on, or glued on, in front, to fit the space left for it, and other smaller strips glued on all round it, so as to form a very shallow tray or drawer. The IfOIV TO MAKE A CAGE. 27 small strips can be glued on flat upon the top of the board, but to fasten on the front, you must first glue on a similar strip to those round the sides, and just such as you made the pillars of, but not quite so thick, and then glue, or nail on with very small brads, the front piece, nailing or glu- ing it to this strip. This will make it very firm, and will do well enough for your first cage. A, Fig. 13, shows a part of the drawer, C is the front, and D the strip it is glued to. The handle of this drawer or tray is to be made of wire, unless you can find some little knob or other that will do. If you succeed in making this cage, you will have learned a good deal, because, although not really difficult, it requires care and consideration ; and if you are in a hurry, you will split the wood, or make it crooked, or cut the pieces too short. It should be neatly painted in oil-colour — green is a favourite colour — but the top boards may be red, and the wires should be left clean and bright, because the bird often pecks at them. If you paint the inside of the woodwork, it should be white. I have not here put any feeding-boxes, or seed-drawers, because glasses are the best ; but yon will see two holes (Fig. 11), one inch across, in the lower side pieces, for the bird to put its head through to get at the seed and water. A bit of wire, for'ning half a hoop, supports the glasses or trays. These ou'^ht to be cut with a centrebit — a tool you have not, an4 the carpenter had better do it for you. Here is 28 THE YOUNG MECHANIC. the cage complete (Fig. 14). You can do without making holes in the sides, if you put two wires longer than the i?'ig u. rest, and bend them, a^j you see at B in Fig. 13, before putting them in place. Chapter TIT. HE previous chapters were devoted to such exceed- ingly simple and easy specimens of carpentry as can be made by any boy of eleven or twelve years of age, or even younger, who has the necessary perseverance, and will take sufficient care in measuring and fitting. In both and all similar cases, it is better for such to buy pieces of board already planed, and of nearly the desired size ; but I shall no longer presuppose such necessity, but advance the young mechanic to the dignity of a plane, and a few more of the more necessary and useful tools. The list may therefore now comprise — 1 Hand Saw, 16 inches or so in length, a full-sized one being almost beyond the powers of a boy. S Firmer Chisels, quarter, half, and one inch wide. 1 Mallet.— Chisel handles should never be struck with a hammer, which splits the handles. 1 Hammer. — This should be light. The best way is to buy a hammer-head, and make the handle. A heavy one can be added, but will hardly be required at first, and is useless for light work. 1 Jack Plane, 1 Smoothing Do.— The jack plane is not usually added to a boy'a tool-chest, but it is impossible to plane up a long straight 30 THE YOUNG MECHANIC. edgn without it ; and as these planes can be had from 12 inches in length, I should certainly recommend one, say 12 to 15 inchee. 3 Gimlets, 3 Bradawls. — One of each of these should be as small as can be obtained. Add a medium and a larger one. 1 Screwdriver, 1 Pincers, 1 Cutting Pliers. — Screwdriver should be of a medium size ; the pliers such as are used by bellhangers. 1 Compasses. — These should be light carpenter's compasses, not such as are made of brass and steel. They are very useful. 2 Gouges. — Carperder^s gouges, not turner's. They will answer for the pre- sent, in many cases, to make round holes in boards. The centrebita and braces are expensive. 1 Oil-stone. — There is a cheap and quick-cutting stone called Nova Scotia which will answer the purpose well. Mortice- GAUGE. — The use of this will be shown presently, 1 Square, 1 2 Foot Rule, Glue Pot, and Brush. — These are, as before stated, indispensable. The rule need not have a brass slide ; the square may be made entirely of wood, or with a metal blade 6 to 9 inches in length. The above, witli tlie addition of a carpenter's brace and bit, two or three augers, about three mortice chisels, and a hatchet, would suffice for a very large amount of good work. Indeed, it represents almost a complete set of tools, the only additional ones that are at all likely to be needed being a longer (trying) plane, rebate plane, and pair of match, or tongue and groove planes. Without any of the latter, the young carpenter will find it easy to carry out a good many light specimens of his ingenuity. It is much better, in general, to work with a few tools, and contrive to make them answer all sorts of pm*poses, than to lay in a larger and more expensive set at starting, for the latter are sure to be abused and kept in bad order, because, if one chisel gets blunt, another is taken up, in- MORTICE AND TENON JOINTING. 31 stead of sharpening the first ; and phines and other tools are treated in a similar manner, and a carelessness is en- gendered fatal to success. It is astonishing how much may- be done with few and inefficient tools, but then the utmost patience and industry have to be exercised, much as we see prevailing among the native workmen of India and America, who execute the most beautiful and delicate work with tools which, in the hands of a European, would be generally simply useless. The next work that should be attempted by the young mechanic should be mortice and tenon jointing, as used in constructing frames of various kinds for doors, window- sashes, tables, and other articles of everyday use. Perhaps one of the simplest and easiest examples will be a towel- horse, which, at any rate, will be of use when completed. Now, it may be at once stated, that for work of this kind especially, but generally also for all work, it is essential to be able to square up truly the several pieces required. This will require practice — long and careful practice — and the beginner will meet here with his first and chief difficulty, but he must not despair. It has been presupposed that a strong work -bench, table- plank mounted upon trestles, or some sort of tolerably efficient and firm bench has been obtained, or is accessible, and, in addition, a strong stool upon which to saw, cut out mortices, and so forth. A small carpenter's bench, with a 3* THE YOUNG MECHANIC. wooden vice, is most handy and serviceable, but is not absolutely necessary. It will be easy to make one by and by ; for the present, any available substitute must be used. The height of the proposed towel-rail may equal the length. About 2 feet 6 inches will be a fair size, and it may be of the simplest possible form, such as is here delineated (Fig. 15). ri Fig 15. The upright sides may be made of strips of pine, one inch wide and three-quarters of an inch thick — the rails 1^ wide and three eighths of an inch thick. The feet will be con BO IV TO MAKE A TOWEL-RAIL. 33 sidered presently. If careful attention is given to the fol- lowing directions, not only will the result be certainly satisfactory, but the way will be paved for the workmanlike construction of a great number of similarly useful articles The size of the rough material must always be greatei than that ultimately needed, to allow of the necessary waste in sawing and planing. Pine boards, however, are usually cut of certain general widths and thicknesses; and although we have here set down stuff of one inch by three-quarters, it may be cut from inch board, because very little will be wasted by the plane, and the finished work will be suffi- ciently near to the above measure for the intended purpose, one-sixteenth of an inch or so being of no practical import- ance in the construction of such an article as a towel-rail. Get, therefore, from the carpenter, a strip of pine 1 inch wide and 6 feet in length, cut from a board 1 inch thick,, and also a strip for the rails (of which there will be three),. 4 inches wide and 2 feet 9 inches long, cut from a half-inch board. The rails you are to saw yourself from the latter strip, which will give you practice in sawing a straight course, and the work is easy in half-inch stuff. You may therefore begin by cutting these, for which purpose you) will want guide-lines dividing the strip into three of equal width. There is a very simple way of marking these by means of a chalk line, which I will here describe. The width of the board I set down at 4 inches, because 34 THE YOUNG MECHANIC. the rails, when finished, will be 1^ inches each, or, in all, 3f inches. As each contains eight eighths, as already explained, 4 inches will contain thirty-two eighths. Divid- ing by 3, we shall have ten eighths for each strip, or 1^ inches, and two eighths, or a quarter of an inch, to spare for waste. Take the compasses, therefore, and open them io\\ and a little over (rather less than to the next division, on the rule), and take it off at each end of the board (Fig 16, A B). rig. 16. Take off, again, from this to mark the width of the next strip, and the board will be divided with sufficient accuracy for our present purpose. Take a piece of twine, long enough to stretch from end to end of the plank, and some- thing over, and tie a knot at one end. Stick a bradawl through the string, close to this knot and into the board, as seen at C of the same figure. Take a lump of chalk, and chalk the line from end to end. Then strain it down the board, holding it by the left hand, so that it is stretched PLANING. 35 from one mark to the other, where the saw-cut is to be made. With the finger and thumb of the other hand, raise it a little in the middle, and let it suddenly go, when it will make a perfectly clear and straight line upon the board. Make a similar and parallel line for the next saw- cut. In the present case, you need not mind cutting this chalk mark out. Try and saw right down, so as to split it. You now have your strips cut out, but they require to be planed. You might, indeed, with advantage, have planed the whole strip on both sides before marking and cutting it, but it is equally easy to do it afterwards. The jack plane is the one to be used for this purpose, I must sup- pose it to be sharp and in good order ; if not, ask some carpenter to set it for you for the present, but I will soon tell you how to do it for yom'self. Indeed, you will have 36 THE YOUNG MECHANIC. to learn liow to sharpen all your tools before yon can be called a good workman. If the plane is properly set, the cutting edge will project very slightly only from the bottom; so that when held as in Fig. 17, and the eye directed along the sole, only a narrow shining slip of metal will appear. If too far out, it will hitch and make bad work ; if not far enough, it will not cut at all ; but the common fault of beginners is to have it too far out, because from their imperfect handling of this tool they often fail to make it cut, when in the hands of a carpenter it would work well. Now, if the iron projects too far, hold it as shown, so that you look along the sole, and give it a tap with your wooden mallet on the upper face at A, and this is also the way to loosen the wedge and irons for removal. By a blow at B, you can send the cutting edge forward to cut more deeply, or in this case you may tap the iron itself with a metal hammer, but tapping the end of the wood is better. To plane the edges of these strips, you ought to have a bench with a vice, but there are ways and means to do without it, and one is so good that I shall speak of it here, although it necessitates a somewhat abrupt break-off in my description of the towel-rail. It is a kind of vice that is fixed to a board which is laid upon the work-bench when required. In Fig. 1 8 is a drawing of one of two kinds of such vices HOJF TO MAKE A VICE. 37 which I will explain. This first consists of two pieces of wood (ash will be better than pine^ about 9 inches long ■Jllllllliillilllillilliililllliiiiiiliiililli'illll Fig. 18. and 2 inches thick. They are cut in the shape given in the drawing, and screwed to the board, not tightly, but so as to move freely upon the screws. The board should be an inch thick to give the screws a firm hold. You can see by the figure that the tails of the pieces cross each other sometimes when in use. To allow of this, they are cut like B and C, so that one can go inside the other. Now, if you consider a little, you will understand that if we stand a Btrip of board between the two, and push it forward against the insides of the tails of these curiously-shaped blocks, it will make the opposite knobbed ends close nearer together, and these will grip the piece of wood, and the harder we 38 THE YOUNG MECHANIC. push it forward, the more closely it will be gripped and held ; but the moment we draw back the piece, the two jaws will open to let it go free. You can try first of all upon a thin piece, which can be shaped by your knife, and make a model of this vice, and then if you can't manage to cut out such a one of thick wood, the carpenter would do it for you, and it will be handy for many purposes. If you have nothing of this kind, nor a vice to your bench, drive in two pins or pegs of wood, or two nails, a little way apart, so as to allow your strip of wood to stand upon edge be- tween them, and drive two more a little way from these; then one at the end to form a planing stop. A tap at the Fig. 19. sides of these nails will cause them to hold the strip edge- wise, quite well enough to allow you to plane it. There PLANING. 39 are other ways, and I shall describe them by and by. In the meantime use nails, or any other plan that will answer. I shall suppose, therefore, that one of the narrow strips is thus set on edge upon your bench ready to be planed. Grasp the handle of your plane firmly with the right liand, and lay hold of it in front of the iron with the left. Draw it back, and then send it steadily forward, pressing it downwards at the same time. Now the advantage of a long plane is, that it does not descend into the hollows of the work, but rests upon the projections, as in Fig. 19, A. A short plane would do as seen at B, and therefore would never make a long straight edge. You have two special points here to attend to. You have to plane a level line from end to end, and also keep the edges square to the sides, which is by no means easy at first. You must keep trying it with your square, as I have shown you in Fig. 20, Fig. 20. and not rest satisfied until the handle fits close to the side of the strip, and the edge lies also close upon that of the strip anywhere along its length. I daresay you will think this of no importance in such a common thing as a pine 40 THE YOUNG MECHANIC. towel-horse ; but I may tell you this is the very secret of carpenter's work, and when you can saw and plane truly, and work " to square," you can make almost anything. It is true that the strips for the rails are not of great import- ance in this case, but the upright side pieces are, and if these are out of truth, the holes cut through them for the rails, which are called mortices, will be out of truth also, and you will see the towel-horse, when it is made, all twisted and awry, and nothing you can do will make it stand firm or look well. It is, in short, no use to pretend to learn carpentry unless you at once make up your mind to succeed, and therefore you must always use the square and try your work as you go on. All the difference between the usual work of carpenters, and that of boys or men who do not know how to work, consists of the squareness and good fit of what the former make. Boys never seem to trouble themselves about such things, and so you see their boxes and rabbit-hutches look twisted, and being badly *fitted, they soon go to pieces. Having planed up the sides and edges of the rails as square and true as you can, cut the other long strip in half, and square up this also, taking care that both pieces are alike and both truly worked. If your bench is sufficiently long to take the whole strip, plane it up before you cut it across, and you will be sure to have the sides of your towel- rail equal in size. You have now to make your first essay MORTICING. 41 in cutting mortices. Follow these directions, and you will not fail. I shall not limit the description to these special mortices, but give you general directions. Fig. 21 represents a bar of wood — the side of the towel- 3, horse, for instance — with a mortice cut through it at A, and others marked out at a 3, c d. Below, at B, is a gauge, of which the construction and use will be explained pre- sently. F shows how the feet are to be attached and cut. They are morticed while in a " squared-up " condition, and shaped afterwards according to fancy ; sometimes they are left square, and knobs screwed below to make two feet. These mortices may, of course, be of any desired length or width. Those required for the towel-rail sides will be 1^ inch long by half an inch wide nearly. The planing of the strips may have reduced them more or less below the exact size specified, try therefore with the compasses what the precise thickness is of the ends, and measm-e that 42 THE YOUNG MECHANIC. thickness on your two-foot rule. You now want to draw tlie lines a t, which I have represented as extending the whole length of the strip, and as all the mortices are to be alike, you may so mark them. The gauge B is of two parts, a sliding piece, C, and a rectangular bar of wood about 9 inches long and half an inch square: This slides stiffly through the mortice in C, and is fixed at any part by the small wedge D. This gauge you can easily make. It is not a mortice gauge properly so called, because the latter has two marking points instead of the one seen at k, and which may be the point of a brad driven in and filed up to an edge. Loosen the wedge slightly, and draw back the rectangular bar, or push it forward, until you think that the space between the sliding piece and the point is about that which is required on each side of the mortices, so that if you set the wedge firm, and resting the sliding piece against the edge of the board, cause the point to make a mark, and repeat this on the other side of the same face of the wood, there will be left between the marks thus made the exact width of the required mortice. Try it, and if not, give a tap to the instrument, and adjust it until the space is exactly correct. Then fix all firm, and holding it so that the little point will mark the wood, while the head or slid- ing piece is against the side of the board, run the tool from end to end, or run it along just where the mortices are required, using both hands. You will thus make the two MORTICING. 43 long lines between which the mortices have to be cut. Now turn the wood over, and do the same on the other side. You are now quite sure that these lines, on opposite sides of the piece, agree exactly in position, which is the object of using a gauge ; and as you have planed up a second strip to exactly the size of this first, you have but to repeat the process (no measuring being necessary) upon that; and you may be satisfied that thus far the two sides of the towel-rail will tally. You now set off with the compasses upon one of these lines the lengths of the mortices in their proper places, and at the j^oints thus marked, using your square for the purpose, mark the end lines of these mor- tices ; but when so doing, carry the lines across, as a 3, ^ inches high, of some such shape as seen in the fig. G; and in the lower part (which must be cut to fit between the lathe-bearers, and must be made square at the sides and true, so that the whole will stand squarely across the lathe-bed), either cut a mortice, a, for a wedge, or bore a hole for a screw, which must have a plate and nut to fasten under the bed like other poppits. Near the top, and exactly no IV TO MAKE A CONE-PLATE. 185 in the centre, bore a hole to receive the bolt K, similar to that in the metal cone-plate already described, and which will be tightened by a nut at the back. This supplies the place of the short iron poppit, and now you have to con- trive something to replace the circular plate of holes. Cut two or three strips of any tolerably hard wood, H (beech will answer very well), 6 inches long, half an inch thick, and 2 inches wide. Cut in these a slot and a round hole, which must be carefully made with a centrebit. This hole is to be for one of those in the usual round plate, so be careful in making it. Work thus: Plane up the piece from wood rather more than the half inch required ; draw a line exactly down the middle of it on both sides e^f ; choose a centrebit of the size you require j put the point upon this line, about 1^ inches or more, according to the size of the required hole, and bore steadily a little way into the wood. Then turn it over, measure carefully so as to get the precise spot right, and finish from that side. If the centrebit is sharp, and the wood sound, you will now have a neat round hole. Let the slot be also cut from both sides of the piece of wood with a sharp chisel, taking care that the centre of it agrees with the line that you made for a guide. Three or four of these should be made, each with a dif- ferent sized hole, or more if required ; but you can add new ones at any time. The bolt, K, is to be made with a large i86 THE YOUNG MECHANIC. head flat on the under side, and the upper part, above the scre"w, is to be square for three-eighths of an inch, and the slot in the pieces of wood must just fit this squared part. Now, as this is three-eighths only, and the thickness of the wood is four-eighths or half an inch, it is plain that the nut will draw, and the head of the screw clamp this tightly. You Clin, if you like, however, make the hole in the poppit square also, and then let the squared part of the screw be long enough to reach almost entirely through both pieces. Then slip a washer (an iron plate with a hole in it like L) over the end of the screw, and fix all with the nut. Thus you have a boring collar with one hole, and this you can raise or lower the length of the slot so as to get it exactly the right height, and when it is so arranged, one turn of the nut at the back will fix it. This you will find a very simple form of boring-collar, easy to make, and of practical use. If you really take all the care you can, and follow the directions I have given, I do not see how you can possibly fail in constructing one. You should have a sliding-plate with a hole for each size of tool-handle ferule used, as you will frequently be making these. HOLLOWING OUT WORK. As I have spoken of boring, I will go on to treat now of the general practice of hollowing out chucks and boxes, and such like. K this is to be done in soft wood, such as HOLLOWING OUT WORK. 187 willow, no tool will answer so well as the hook- tools, of which I have given drawings. But these are very difficult indeed to use, owing to their tendency to catch in, or take suddenly a deeper cut than was intended. Nothing but practice will teach exactly how to use these tools; but then, when the difficulty of so doing is once mastered, nothing can be more rapid or more satisfactory than the work which they will do. Small bowls are hollowed almost instantaneously by their means in skilled hands ; whereas, with other tools, it becomes not only a tedious job, but if it is done at all, it is but roughly, the wood having to be rather scraped out than cut. Using, however, the back of the gouge as explained before, in the directions given for squaring up the end of a cylinder with this tool, it is possible to hollow out soft wood with it, but not very satisfactorily. In any case, other tools (generally a car- penter's chisel) must be used to work into the angle which neither the gouge nor hook-tool can, of course, reach. Hence it is generally so much easier to cut out boxes and such like articles in box or hard wood, that this is nearly always used by amateurs. The ordinary way to turn a box is as follows : — Prepare the wood as usual, turning it cylindrical, using any chuck you please for this work ; cut off with the parting-tool rather more than the box and its cover together will require, and drive the piece thus separated into a cup-chuck, [You i88 THE YOUNG MECHANIC. may, if you prefer it, screw upon the nose of the mandrel, or upon the taper screw-chuck, the rough piece of the proper length, instead of first turning a cylinder to cut from. If you have several boxes to make of one size, the cylinder method is to be preferred.] Turn it up again quite true, for although it was correct before you cut it off, it will not be so now. Square up the end, and turning round the rest so as to stand across the face of the wood, begin to hollow out the cover. Use either the round end or pointed tool at first, and then a carpenter's chisel or flat tool to finish. Be very careful that the sides (I must call it by this name, although a circle has not more sides than a plum-pudding) are turned square to the bottom, or else, when the cover is put on, it will perhaps fit just at the entry, and be quite loose when fairly on ; or, it may be that it will be easy at first, and when you press it on, it will be tighter and become split, — a very common but unpleasant occurrence. Do not, moreover, turn down these sides as thin as they will ultimately be; because, after the box is hollowed and the cover fitted on, both will have to be slightly turned together to finish them nicely. Moreover, you may not wish your box to have plain sides, but may prefer to mould them into a more elegant form. All these little questions have to be duly considered in turning, for a mistake is often made, and the work spoiled, for want of a little timely consideration. IfOlV TO MAKE A BOX, i^g The next point on which you have to be on your guard is this, — having turned out the cover, you have to cut it off, not with a saw, but with your parting-tool. Now, be sure to leave thickness enough for the top of the cover ; or, just as you think you have nearly severed the latter from the rest of the piece of wood, you will see a beautiful little ring tumble off, — sad relict of your box cover, which has come to an untimely end. The sliding square of the turner, of which I gave a description among the list of tools, will always enable you to gauge both the depth to which the work is hollowed out, and also the squareness of the inside to the bottom. But if you have no turner's square, you can easily gauge the depth inside, and thus see how much is necessary to be allowed for the thickness of the top. Keep the parting- tool edgewise on the rest, which should be raised to such a height that, when this tool is laid horizontally across it, it will point nearly to the centre of the work, i.e.,, the axis of it. After the parting-tool has cut into the wood a little way, widen the groove a little, and continue to give the tool a little play right and left, unless its end is so much wider than its blade generally that it will clear itself perfectly as it goes deeper and deeper into cut. If it should bind, it is almost certain to break, for it is a very thin tool ; and it is better to waste a little more of your material than to have to replace a spoiled tool. I90 THE YOUNG MECHANIC. I shall suppose that you have now succeeded in cutting off the cover ; jick it up and lay it near you. Directions are given generally to turn down next the flange upon which the cover of the box is to be fitted, but this is not to be wholly done yet, and you may proceed to hollow it out as soon as you have turned down just so much of this flange as will show you how much to leave in hollowing out the box. If jonjit the cover before you have hollowed out the box, you will have the mortification of finding it a great deal too loose when the box is finished, because the latter will contract in size as soon as ever the solid core is removed from it. After you have hollowed it out, you must gauge the inside of the cover, and the outside of the place that it is to occupy, with the in-and-out callipers, or with a common pair, and turn the flange till it is almost correct to this gauge, and only a very little larger than it ought to be. When this is the case, do not trust any longer to the callipers, but try on the cover again and again until you get a nice fit. You must finish the flange with a chisel, held flat ; and again I repeat the caution about keeping it truly square, so that the cover will hold equally tight in all positions. When this is the case, leave it on, and give a last touch to both box and cover together, when you ought barely to be able to see the joint. You have now only to cut oiF the box as you did the cover, using the same precautions. Before it is quite SCREWS AND TWISTS. 191 pevered, however, you should give it a polish. Pick up a handful of shavings, and while the work is revolving as rapidly as possible, hold them with some pressure against it. Every fibre will be at once laid smooth, and it will look nice and bright at once. You can varnish it afterwards if you like, or French-polish it. Yarnish is best for boxwood, and French-polishing requires special directions, which I shall give you separately in a future page. To be able to make a box well^ with its cover well fitted, is to be able to do all kinds of similar work. Yet in these may be special details deserving notice. Probably, there- fore, when speaking in a future page of particular objects which have to be turned, such special details will be more fitting than if given here. I shall therefore pass on to another part of the subject, namely, screwed and twisted work. SCREWS AND TWISTS.' Neither of these can be very accurately made without special and somewhat expensive apparatus ; but both can with practice be done tolerably well by the young mechanic with ordinary simple means. I need not describe a screw, for all boys know what it is ; and sporting boys, of which in these days there are many, know what sort of animal a screw is. Well, never mind. I am always riding, a screw, I believe, for it is my hobby, and there is a great deal of 192 THE YOUNG MECHANIC. science in a screw; and as for the variety of the manufactured article, there is plenty of it. There is the corkscrew, which is, after all, not a screw, but a twist, — and this is often the means of making men screwed ; and the miserly screw, who skins fleas for the sake of their fat ; and there is the mythical, invisible, moral (and im-moral) screw, which hard-fisted men inflict upon their weaker brethren ; and there is the gigantic screw of the Great Eastern steamship ; and the minute, microscopic screw of the lady's tiny jewelled watch. There are several modes of cutting screws, in the lathe and out of it. The small ones required for holding together the different parts of machinery, as well as larger ones for the same purpose, are always cut with stock and dies. The very small ones used by watchmakers, and all below one-eighth of an inch diameter, are made by the screw- plate. But when either large or small screws are required of great accuracy, they are invariably cut in the lathe, and with the aid of mechanical appliances of the most delicately accurate description. These are all metal screws. But the young mechanic will often wish to put screwed covers to his boxes, and to join various parts of his work by screwed connections instead of glue ; and all these may be cut in the lathe by simple hand-tools skilfully applied, although the operation is sufficiently fraught with difficulty to require a great deal of practice before it can be done with certainty SCREWS AND TWISTS. 193 of success. At tlie same time, my young friends cannot possibly do better than practise this operation, for there are numberless cases in which screws cannot be conveniently cut in any other way, and it is, further, an accomplishment that will at once stamp them as skilful workmen. The tools required are represented at A, B, Fig. 51. A is an outside, and B an inside screw chasing-tool. These Fig. 51. are always made in pairs, of exactly the same pitch, Le.y the outside tool being applied to the inside, the respectiva^ notches and points will exactly fit into each other. If you were to examine the under side of these tools, shown at C,. you wo aid notice that the notches do not run straight, but slanting. They are in fact parts of screw threads ; and you N 194 THE YOUNG MECHANIC. could make a tool of this kind out of a common screw nut. as I have shown you at D, only it would be too much hol- lowed out to make a good tool. Now, supposing you were to hold the tool A flat on the rest, while a cylindrical piece of wood revolved in contact with it, you would cut a series of rings only ; but if you were at the same time to slide the tool sideways upon the rest, so that by the time the wood had revolved once, the first point of the tool would have just reached the spot which was oc- cupied by the second when you started, you would have traced a screw thread of that particular pitch. This is what you have to learn to do always, and with certainty, no matter what pitch of tool you may be using, and it is easy to understand how difficult the operation must be to a beginner. Indeed, there are numbers of otherwise good turners who have never succeeded in mastering this work. Nevertheless it can be done, and, although difficult, it is not so much so as might be supposed. Indeed, at first sight it would hardly be believed possible^ because each different pitch of tool, and each different-sized piece of work, requires a different speed of traverse to be given to the tool. But a practised hand will strike thread after thread without failure, and those whose trade is to make all sorts of screw-covered boxes and similar articles, will execute the work with as much speed and apparent ease, as they would any ordinary operation of turning. I shall tell you SCREWS AND TWISTS. 195 by and by, however, of several ways to escape this diffi- culty of screw-cutting, — lathes being fitted in various ways to insure good work, in some cases by carrying forward the tool at exactly the right rate of traverse, and at others by moving along the work itself at the proper speed, while the cutting tool is held immovably fixed in one position, — and I will give one tool of great service which will guide you in starting the ordinary chasing- tool ; and a good start is here truly '' half the battle." The chasing-tool must run from right to left for an ordinary right-handed screw (and a left-handed one is very seldom required), so that the young mechanic need not trouble himself about it. Precise directions cannot be given further than to have a rest with a very smooth and even edge, which will not in the least hinder the traverse of the chasing-tool, and to get the lathe into steady, equable motion. Then hold the tool lightly, but firmly, keeping it at right angles with the work. Allow it only just to touch until you find you have got into the right swing. It is all a matter of knack and practice ; and if you succeed quickly, you may congratulate yourself. The inside chasing-tool is used in precisely the same way, running it from the outer edge of the hole inwards. To some this is an easier tool to use than the outside chaser. I cannot say that I find it so ; especially as one bas to work more in the dark ; unless the work is of large tg6 THE YOUNG MECHANIC. diameter like the cover of a box, and even then the work is gufificiently difficult owing to the shallowness of the lid, •which necessitates the instant stopping of the tool for a fresh cut. For you must understand that you have to deepen the screw-threads very gradually, and it will take several traverses of the tool to cut them to a sufficient depth. The chasers require to be very sharp to cut wooden screws neatly, but observe you must only rub the upper flat face upon the oilstone, or, if a notch has been made by using the tools upon metal (they will cut brass well with care), grind them in the same way ; the great secret being to hold the tool quite flat on the stone. You will thus, even by continual grinding, only thin the blade of the chaser, which will thus last for a long time. A practised hand will even cut a good thread with any flat piece of steel filed into equal notches, but a screw-chaser is the only tool really fit for the purpose. The most efiectual remedy for the screw-cutting diffi- culty, is unfortunately rather expensive in its best form. But in another, it is by no means costly ; and although it may not look so well as the first, it is equally effective, and extensively used by the turners at Tunbridge Wells, who make those beautiful little inlaid boxes and other articles. I shall explain this to you, therefore, first : — A, is a lathe-head, something like the one I have already CHASING SCREWS. 19) described, but you will notice that the mandrel is a much longer one, and has several short screws cut upon it, each one being of a different ''thread" or "pitch."* This Fi?. 52. mandrel runs through two collars, so that, besides turn- ing round, it can be pushed end-wise. Now, supposing • In the drawing, they are all accidentally drawn of the same pitch. 198 THE YOUNG MECHANIC. I was to hold the point of a tool firmly against either of the screws, and at the same time was to turn the pulley and mandrel, you will understand that it would run back- wards or forwards in its collars, at such a rate as the screw-thread compelled it to move. This is the plan of the traversing mandrel ; and now supposing that you had a box held as usual in a chuck, and while the mandrel was compelled to move end-wise as described, you were to hold a pointed tool against it, the tool would evidently cut a screw-thread of exactly the same pitch as that upon the mandrel against which the pointed tool first spoken of was applied. But in practice, a single-pointed tool held against the mandrel would not answer very well, and so the follow- ing plan is adopted instead, which answers perfectly. Fig. 52, C, is called a half-nut. It has a set of screw- threads, cut where the semicircular hollow is, which threads fit one of the screws on the mandrel. A whole row of these half-nuts are fitted to turn at one end upon a long bar, so that either one can be raised up at pleasure to touch the screw upon the mandrel, which has threads of the same pitch as itself, B. These, then, are ranged under the mandiel, and when it is desired to make It traverse in its collars, one of these half-nuts is raised and kept up by a wedge placed underneath it. When no screw is required, a somewhat similar half-nut, but with merely a sharp edge instead of a thread, is raised, and this edge falls into a CHASING SCREWS. 199 uotcli or groove turned upon the mandrel, or sometimes a back centre-screw is added like D, and when no screw has to be cut, this is run up against the mandrel like an ordinary lathe. In the more expensive traversing mandrels, although the principle is the same, there is a little difference in the ar- rangement of the different parts. The mandrel is not very- much longer than usual ; and it has no screw-threads cut upon it. But a number of ferules like K, are made each with a screw upon its edge, and one of these of the desired pitch is slid upon the end of the mandrel at ^, fig. P, and is there held by a nut or otherwise, so that it cannot move out of its place. The half-nut is seen at a. It con- sists of a piece of brass or steel of the form shown with a hole in the middle, and a screw cut upon each hollow, so that it is a circle or set of half-nuts of different pitches. This slips over a pin at a, and when the screw h is turned, it draws up this pin and the nut attached, until the latter comes in contact with the ferule upon the end of the mandrel. This is very neat but expensive. Now, by far the cheapest and best way for the young mechanic, is to set boldly to work to conquer the difficulty of chasing screws by hand. There are even disadvantages in the expensive form of a traversing mandrel, which render it by no means a desirable mode of fitting up a lathe, and after all, the length of screw which it enables one to cut is very limited, 200 THE YOUNG MECHANIC. and in addition, it is not every day, nor probably once a month, that screw-cutting will be necessary at all. My advice, therefore, is, do not get a traversing mandrel until you can cut screws well with the chaser. When you can do this, you will be able to judge of the advantage or dis- advantage of one. By far the greater number of common screws are cut without the lathe, by screw-plates, or stocks and dies, and the nut, or hole into which such screws are to fit, is cut with a tap. A screw-plate is a simple affair, — a mere flat plate of steel, in which several holes are drilled, which are afterwards threaded by screwing into them taps, or hard cutting steel screws of the size re- quired; the plate is then hardened by being heated red- hot and suddenly cooled, after which being much harder than brass, iron, or steel which has not gone through such process, it will in turn cut a thread upon any of these by simply screwing them into it. But although this will answer for small and common screws, it is not at all suit- able for better ones, because the thread is burred up, not cut cleanly as it would be with a proper tool. A far better plan is a stock and dies ; the latter being practically a hardened steel nut sawn in half, and fitted so that the two halves can be pressed nearer and nearer together as the screw thread becomes deeper. The dies are screwed up by means of a thumbscrew opposite to the handle. A SCREW-BOX. 20I To use it, a piece of iron is filed up or turned to the required size, which must be exactly that of the finished screw. The dies are then loosened and slipped on to the end of this screw-blank as it is called, and are then slightly- tightened upon it. All that is now required is to keep turning the tool round and round upon the pin, which it will soon cut into a screw thread. When the stock is at the bottom or top, you may tighten the dies, and so work up or down ; but never tighten them in any other part. If iron or steel is to be cut, use oil with the tool, but brass may be dry. If the screw is of steel, heat it red-hot and let it cool very gradually, to make it as soft as possible. The hole or nut, into which the screw is to fit, is to be drilled so as just to allow the taper tap to enter about a couple of threads ; a wrench, or, if small, a hand-vice is then applied to twist it forcibly into the hole, when the thread will be completed. Take great care to hold the tap upright, or else, if it is a screw with a flat head which has to fit into it, it will not lie correctly, but one side of the head will touch while the other is more or less raised. There are other modes of screw cutting, but at present I need only mention one, which is used for wooden screws alone. It is called a screw-box, and is only made to cut one size, a tap being always sold to match. You can, how- ever, purchase any size you like, from a quarter of an inch to 2 or 3 inches ? but the latter are only intended for very 902 THE YOUNG MECHANIC. large screws, sucli as are used for carpenters' benches and various kinds of presses. A screw-box looks like a small block of wood with a hole in it, but if you take out two screws you will find a blade of a peculiar shape, which forms the thread by cutting the wood as it is screwed inro the hole in the box. Chapter )i\. HARD-WOOD TURNING. E now discard almost entirely tlie gouge and chisel used for soft woods, and fall back upon an entirely different set of tools, similar to those used for metal, but ground to rather more acute angles. These tools are held horizontally upon the rest, because depressing the handles causes the bevel below the edge to rub upon the work ; and in addition, the gi-ain of hard foreign woods is such that it cannot well be cut by placing the tool at a more acute angle, as would theoreti- cally be required. Hence we can only regard these as scraping tools ; but as such they will do excellent work in skilful hands. I have said that we discard the gouge, but there are some woods that will bear this tool, to take off the roughest parts of the work, before the application of others. The roughing-tool, however, may now be considered to be the point-tool, and the round-end tool, or " round " as it is 204 THE YOUNG MECHANIC. often called; a narrow one makes a good tool for this purpose. Hard wood is easier on tlie wliole to work tlian soft, because we have for the purpose a large stock of tools ol all . shapes, suitable to the various mouldings required. Hollows, round-beading tools, compound and simple moulding tools of various sizes, to say nothing of those which are made for use with ornamental apparatus, such as are required for fluting, beading, and eccentric work, spirals, and so forth. It is indeed in hard wood that most amateurs are accustomed to work ; ebony and ivory, singly or in combination, being more extensively used than any other. To turn a cylinder, or any work requiring to be held at both ends, you will invariably find the cross-chuck the best to use, — the fork or prong not taking hold in the hard material. Rough down to shape as before, using the gouge if it will work, but keeping the rest as close as possible, and only taking a light cut. Then finish roughing with a round-tool, and proceed generally as in soft wood turning, except inasmuch as you have to scrape instead of cutting the work into form. In addition to the tools already described, you will have to obtain a few beading-tools, if you want to do very good work, for these give far more beautiful mouldings than you can cut in any other manner. Fig. 53, A to C, represent SIDE-PARTING TOOL 205 these. The bevel is on the under side, and it is better to interfere with it as little as possible, by always sharpening the flat face only. If it should be necessary^ however, to touch the bevil, it must be rubbed by a slip of oilstone, rounded on the edge, as used for sharpening gouges. Conical grinders, revolving in the lathe, are also used, especially for small beading-tools, to be fixed in the slide- rest. In the same figure, D and E represent another useful hard-wood and ivory tool. It is called the side-parting tool ; and it is usual to have several of these, the hooks increasing in length. The edge is only on the extreme end of the hook. These tools are used for economy's sake to cut solid blocks of ivory and hard-wood from the inside of boxes, instead of cutting the material into a heap of useless shavings. Similar tools, G, H, curved instead of rectan- gular, serve to cut out a solid piece from the inside of 2 howl. In ivory work it is essential to use these tools, because such material is very costly ; $2.50 a lb., and up- wards, being a common price. K is given to show what are meant by headings. If these are exactly semicircular in section, they are far more beautiful in appearance than if of such curves as can be roughly cut by a chisel. The bead-tools are beautifully formed for this very purpose. To use the same side-parting tool, you must proceed as follows, which j^ou will under- stand by the fig. L : — A common straight parting -tool or 206 THE YOUNG MECHANIC, THE RING-TOOL. 207 narrow chisel is first applied to the face of the work to cut a deep circular groove or channel, as shown by the white space at N, and in section at L. This allows the narrowest of the hooked tools to b6 applied to under-cut the solid core X. This being withdrawn, a rather longer hook is applied, the hook being held downwards as at 0, until it reaches the spot where it is to work, when it is gradually turned up (bevel below). Eventually, it is plain that the solid core or centre block x will fall out entire, which may be used for other purposes. M shows how a similar but curved block can be removed from the inside of a cup or bowl, the curved tool not requiring an entry to be made for it, as it cuts its own way entirely from first to last. P and Q show a ring-tool and the method of using it. A recess is turned in the face of a piece of wood as il it was intended to hollow out a box. The ring-tool is then applied bevel downwards, and with the left cutting edge a bead is cut half-through from the inside. The right edge is then applied to the outside, and when the cuts meet the ring neatly finished, will fall ofi". With this tool you can turn them very rapidly, and they will require only a rub of sand-paper to finish them. R, S, T are three more tools for hard wood. The first two cut on the outside of the curved part all round. Thess would be used to hollow out humming-tops and all similar 2o8 THE YOUNG MECHANIC. articles, and to finish the insides of howls, for which T is also designed. Indeed, I might go on to describe all pos- sible shapes of curved tools, each intended for some special work ; but you will not do better than to go to Fenn, Buck, or any tool-maker in London, or elsewhere, and pick out at 7s., or so, per dozen, all shapes and sizes, or if you live at a distance and write to either of the above, they will select you the most useful ; and you can trust these tradesmen and all first-class ones to send you no tools which are not of the best quality. In finishing best work in hard wood, be very careful of all sharp edges of mouldings. Sand and glass paper round off these, and spoil the beauty of the work. If you are obliged to use such substances, touch off again the edges with .very keen tools, which ought to leave brighter and more beautiful surfaces than any sand-paper can produce. Indeed, the secret oi finished ^ov'k in hard wood is to have tools whose edges and bevels are polished. In ornamental eccentric and rose-engine turning, where to use sand-paper would be to ruin the appearance of it, the little drills and cutters pass through three stages of sharpening, being ground on the oilstone, finished on a slab of brass, fed with oil and oilstone powder, and polished on a slab of iron with oil alone or oil and rouge. After this every cut that is made with them reflects the light; and as the surface is otherwise purposelv srrailed or dulled by cutting a series of fine light TURNING IN METALS. 209 rings with a point tool, the pattern itself shows out clearly and lustrously. TUENING BRASS AND OTHER METALS, I shall now teach you how to turn iron and brass, which, though harder than wood, are not very difficult to cut, if you go to work in a proper manner and understand how to use your tools. What these are like I have already told you, and also how to mount a bar in the lathe by using the driver or point-chuck with a carrier. If the piece to be turned is not a bar, you will have to drive it into a chuck of wood, or clamp it upon a face-plate, or in a self-centring chuck if you have one. I shall suppose, first of all, a mere straight bar of iron, centred at the ends, as I have shown you. Take off the lathe- cord that you use for wood, and fit one to go upon the largest part of the mandrel pulley, and the smallest upon the fly- wheel. When you now put your foot upon the treadle to work at your usual speed, you will find the mandrel turn quite slowly ; but I may at once tell you, that what you lose in speed you gain in power. Set your rest for iron (which is not that used for wood, but one with a broad, flat top) so that it stands a little below the central line of the lathe mandrel and work, which will bring the edge of the tool exactly wpon that line. This is always the position of the tool for metal-turning, at any rate for iron. O 2 10 2 HE YOUNG MECHANIC. Beo^in by trimming the end of the bar next to the back centre. Use a graver, held as I directed you; that is, with the bevel flat upon the^a^^ of the iron, which is in this case the end of it. Only let the point cut, and a very little of the edge beyond it, and do not expect to take a deep cut so as to bring off a thick shaving. In metal work you will always have to proceed slowly, but nothing is more pleasant when once you can do it well. You will at first have to experimentalise a little as to the exact angle at which to hold the tool, but you will soon find out this ; and the advantage of hand-tools is, that you can always feel as well as see how they are working, and can ease them here and there to suit the material. It is rather difficult at first to hold the tool still in metal-working, but, like all else, it becomes easy by practice ; so much so, that to hold the tool steadily in one hand is not only possible, but is the mode always followed by watchmakers. While you are about it, you should turn the graver over and try it in other positions ; for although the two sides of the bevel nearest to the point are the only ones to be used, these may be applied in either direction, because they are both sharpened to angles of 60°, and so long as you present them at the correct angle (the smallest possible in respect of the work), it matters not which face of the tool lies uppermost. After squaring off one end, the approved plan is to remove the carrier, reverse the bar, and do the same to the other end. Then begin to TURNING IN METALS. turn from the right hand. Place the graver as before, with the point overlapping the end very slightly (so as only to use the extremity of the cutting edge close to the point), and take off a light shaving along the bar for a distance of about half an inch, or even a quarter, keeping the edge of the graver which is on the rest in one position, and moving the tool, not by sliding it along the rest, but by using the point upon which it lies as a pivot. It is very difficult to describe this exactly, but Fig. 52, 0, will help to explain it. The tool is to rest upon one spot, and the point to move in short curves like the dotted lines, being shifted to a new position as you feel it get out of cut. The left hand should grasp the blade and hold it tightly down upon the rest, while the right moves the handle to and fro as required. The curved dotted lines are necessarily ex- aggerated, but the principle of the work is this, whether you use a graver or a heel-tool. You should turn about half an inch quite round, and then go on to the next, by which you will always have a little shoulder upon the work for the tool to start upon, and this will be nice, clean, bright metal, and will not blunt the tool. But if you go to work differently, so that the edge of the tool comes continually in contact with the rough outside of the iron caused by the heat of the fire, and which is exceedingly hard, the point of the tool will be quickly ground down, while the iron will not be cut into at all. 212 THE YOUNG MECHANIC. I need tell you no more about turning a bar of iron in the lathe, because the above directions apply in all cases ; but if you have to turn ^\Q,face of a piece of metal that is carried in a chuck of some kind, you should always work from the middle towards the edge, and if the graver is used, its bevelled face will lie towards you during the pro- cess. Take care to chuck the metal very firmly, for it is most annoying to have it suddenly leave the chuck or shift its position after you have been at the trouble of turning part of it truly. In such case it is very difficult to replace it exactly as it was before, and all your work has in con- sequence to be gone over again. When taking the final cut, or before, if you like, dip the end of the tool into water, or soap and water, and see the effect. The surface turned in this way will be highly polished at once, and the tool will cut with much greater ease, so that a large, clean shaving will come off. When using a slide-rest, you will find it always better to keep water just dripping upon the work and point of the tool ; but there is a drawback, never- theless, to this plan, for, as might be expected, it makes a mess and rusts the lathe, and sometimes the work as well, so the water must be constantly wiped off it. THE SLIDE-REST. I shall now pass on to describe a mechanical arrangement called a slide-rest, of which there are two separate and dis- THE SLIDE-REST. 213 tinct forms, one for metal and one for ornamental turning in ivory and hard wood. The ornamental work that can be done 1 shall pass by for the present, because few boys are provided with the costly apparatus required, and I am rather addressing those young mechanics whose tastes in- cline them to model machinery and to practise the various operations of mechanical engineering on a small scale. To such a slide-rest is an almost necessary addition to the lathe, for there is a great deal of work which, I may say, cannot be done without it ; for instance, boring the cylinders of engines (except small ones of brass), turning the piston- rods and various pieces which require to be accurately cylindrical and of equal size, perhaps for the length of a foot or more. Hand-work has accomplished something in this way in olden days, but the inability of workmen to advance beyond a certain standard of perfection with hand- tools alone, became such a hindrance to the manufacture of the steam-engine, as improved by Watt and others, that had not Maudsley, Naysmith, and others developed the principle of the slide-rest and planing machine, we should not yet have lived to see those gigantic engines which tear along like demon horses with breath of fire, at the rate of eixty miles or more in as many minutes. So likewise ' would various other machines, which now appear absolutely necessary to supply our various wants, have stood in their primitive and imperfectly developed forms ; for it is necessary, 214 THE YOUNG MECHANIC, before constructing a machine, to have the means of turning cylindrical parts truly, and producing perfectly level plates where required. The object of a slide-rest is to provide means for holding a tool firmly, and giving it a power to traverse to and fra and from side to side, so that by the first we may be able to cause such tool to approach or recede from the work, and by the second we may cause it to move in a perfectly straight line along its surface from end to end. This is accomplished in the following manner : — The drawing being a representation of one of the first machines con- structed for the purpose. A rectangular frame, A, of iron is carried by a pair of strong uprights, B B, fixed to the sole-j^late, C, by which it is attached by a bolt to the bed of the lathe. Lengthwise of this frame runs a screw, pre- vented by collars from moving endwise, but which can be turned round by the winch-handle, D. Thus a nut through which this screw passes, and which only has endwise motion, will, when the latter is turned by its handle, traverse it from end to end in either direction, ac cording as the screw may be turned from right to left or the contrary. This nut is attached to the under part of a sliding-plate, E, which has a part projecting between the sides of the frame, and also two others on its outside, by which it grasps the same with great accuracy, and is prevented from any shake or play as the whole THE SLIDE-REST. 215 witli the nut is made to traverse to and fro along the frame. Lengthwise of this sliding-plate, that is, in a direction the opposite to that of its own traverse, are two bars bevelled underneath, fixed exactly parallel to each other, which are so arranged to guide the cross traverse of another plate with chamfered edges to fit the bevels of the guide bars. This second plate has on its upper surface two clamps which secure the tool. It is plain, then, that by this ar- rangement the two required movements are attained, the lower plate sliding along in one direction parallel witli the lathe-bed, and the other across it. In the original rests, this upper plate with the tool was moved by hand, and in the modern rest for ornamental turning (which this was also constructed for) the same is done, but a hand-lever is added for the purpose. But although a similar arrangement is needed for metal, it is plain that the top plate should have a more easily regulated motion, and that we should be able to advance the tool as near the work as may be desired, and then to retain it securely at that distance while giving the necessary move ment in the direction of the length of the object to be turned. The method of efiecting this is at once suggested by the screw and nut of the lower part, and by merely adding to the top a similar arrangement, the desired end is at once attained. 2l6 7 HE YOUNG MECHANIC. The actual construction of sucli rest varies somewliat, but Fig. 54, H, shows it in its most ordinary form. The lower part is, of course, to be clamped down securely to the rig. 64. lathe-hed, there being a projection below which is made to fit accurately between the bearers similar to that beneath the poppits. This projection secures the correct position of the rest, of which one frame or plate will travel length THE SLIDE-REST. 217 wise of the bed, while the other will move exactly at right angles to it. Bat in the compound slide-rest, which is very general, there is also a third circular motion, by which the upper part can be set at any angle with the lower, instead of being permanently fixed at right angles to it. By this the tool can be made to approach the work more and more as it passes along it ; and it will therefore cut deeper at one end of its traverse than at the other. The result will be that what is thus turned will not be a true cylinder, but a cone, i.e.^ it will be larger at one end than the other, although otherwise smooth and even. We are thus provided with the most valuable addition to the lathe ever devised by mechanics, and it is no longer a question of the strength and skill of the workman whether we can produce a perfect piece of work, but simply of the accuracy with which the lathe and rest are constructed, and of the form and condition of the tools to be used. The latter are not exactly like those ordinarily used, although the principle of the cutting angles already laid down needs to be adhered to even with more unfailing attention than that required for the correct formation of hand-tools. Moreover, it is plain that — here we shall no longer feel whether the tool is working as it ought to do — we shall be unconscious of the precise amount of strain that is being brought to bear against its edge, and if it is by chance working in a bad position, at a wrong angle, we cannot re-adjust it in a 2i8 THE YOUNG MECHANIC. moment as we could a hand-tool by a slight movement of the fingers or wrist. Hence you will see at once how very important it is that tools for the slide-rest should be shaped with the most rigid adherence to correct principles ; and, further, that they should be so fixed in the slide-rest as to meet the work at the precise angle, and at the height exactly suited to the material of which it is composed. As regards the latter point, it may be taken as an almost invariable rule that the work should be attacked on its axial line (that is, a line that would run from end to end of it dividing it lengthwise into equal parts, or, as it would commonly be named, its middle line). If the tool meets it above this, it is most likely that it will rub against it, and the point will be out of cut. If it meets it below, there will be a tendency for the point to catch in, and the work to roll up upon the face of the tool, which, in fact, it very often does with careless workmen, and then there comes a smash of some kind — lathe centres snapped off, the tool broken, the bar bent beyond remedy, and possibly the operator's toes made un- pleasantly tender. The most common slide-rest tool for outside work is that given at H^. It is made straight, as shown, or bent sideways to right or left to cut shoulders on the work, or enter hollows, or creep sneakingly round corners, or any other of those crooked ways in which man delights ; but THE SLIDE-REST. 21 g wliether straight or not, these tools have all most com- monly the cranked form shown here. This gives the tools a slight degree of elasticity — not very much, because that would only injure the perfection of the work ; therefore they are not very considerably cranked. The angles are ground as directed in the table of tool-angles, and if the point is too low, slips of iron are placed below the shank upon the tool-plate of the slide-rest ; if too high, the grind- stone must be resorted to; and the advantage of these cranked tools is, that they can be ground down several times without being brought too low to be packed up with iron slips to the right level. Thus a cranked tool is by far more advantageous for the slide-rest than one made straight like those used for hand-turning. For inside work, how- ever, or " holing," the crank form is not possible, unless the hole is of large size, and so, for this purpose, straight side-tools are used, like K. If the tool is well placed, as well as correctly made, nothing can be more easy and delightful than slide-rest work. You merely advance the tool to take the required cut (beginning generally at the right-hand end of the bar), and then gently turning the other handle, you will see it traverse along, as if work was a pleasure to it, as it ought to be to all young mechanics. Not infrequently, however, instead of this even, steady work, the tool jumps and catches, or rubs and shrieks : it is out of temper, I sup- 2 20 THE YOUNG MECHANIC, pose ; at any rate, in some one or more particulars it needs correction. Although with the slide-rest you can generally venture upon taking a deeper cut than you could with hand-tools, it is by no means well to hurry the work. At first, especially before it has become cylindrical, the tool will only cut partly round its surface, and the work is done in an uncomfortable, jerking, dissatisfied sort of way, and the deeper you drive the tool the worse it is ; but as soon as the outer skin is ofi*, and the work has become cylindrical, a long, clear, bright shaving curls o£f pleasantly from end to end, and the surface ought, if the tool is wetted, to become at once of a finished appearance. You should always, with a slide-rest, take the whole run of the piece from end to end to a certain depth, and then, commencing again at the end, repeat the same process, and so on until the required size is almost attained. When it is, take out the tool with the pointed end which has been in use, and insert one freshly sharpened with a broad point, getting it so placed as to cut the shaving both from the surface below, and from the shoulder to which it is attached at the side, as I explained to you in the chapter on grind' ing and setting tools, and which must be well understood before you can hope to make good work with tools rigidly fixed in a slide-rest. With this tool, kept wet with soap and water (or soda water, which is better for this than for THE SLIDE-REST. your stomacli), take a very light shaving from end to end, taking especial care to turn the handle which gives the traverse slowly and evenly. If you stop, or almost stop, the tool will be sure to draw, a little deeper into cut, which will make a scratch upon the work, or, it may be, plough a groove, and so far spoil the appearance of it. Whenever you finish turning any bar that has been centred at each end, be careful to leave the centre marks just as they were when the work was in the lathe. The ends will have been otherwise trimmed off at the very com- mencement, and it may happen that at some future day it may be desired to re-mount the piece for repair, when, it these marks are gone, and new centres have to be drilled, the whole will run so much out of truth that it will have to be entirely re-turned from the commencement. Do not, therefore, fancy that these centre marks are unsightly, and forthwith file them out, but be content to leave them. Slide-rest tools, made in the ordinary way, are so far troublesome in use that if they get broken you must have them re-forged, and few country smiths know anything about such matters. I have a tool now lying by me made by a smith (true, it was a Welsh smith), and although I stood by and explained how it should be done, and cut one out of a piece of wood, it never arrived at a proper shape, and was never even placed upon the rest. I keep it as old Izaak Walton kept the Londoner's artificial fly, viz., " to THE YOUNG MECHANIC. laugh at," and as a caution to all concerned, never to go to a country blacksmith for slide-rest tools. The following plan answers very well for many kinds of outside work, and is on the whole a plan that may be satisfactorily fol- lowed by the young mechanic. Instead of having the tools constructed from a large bar of steel half an inch or so in the square, they are made of short pieces about an inch long, fitted into a peculiar holder. The advantage of this arrangement consists in the ease with which you can make your own tools out of broken round, triangular, or square pillar files, small chisels and such like. These can be shaped by the grindstone alone, and the blacksmith will not have to be called into requisi- tion. I shall give you two forms of tool-holders, more or less simple, because I may suppose my young mechanic to be fast growing into an old hand, and able to appreciate differences in these arrangements. Fig. 55, A, B, represents two of such holders, one for round, the other for flat steel cutters. Yon can see at once that when these are upon the bed of the rest, they form a tool with cranked end, as previously described, and can therefore be used in precisely the same manner. I shall give no directions for mailing these tool-holders, which are, nevertheless, very simple affairs, and can be readily under- etood from the drawings here given. SLIDE-REST TOOL-HOLDERS. 223 Another form is shown at C. The part d e \^ fa clamp, which is separately drawn at/. This, like the last, enables one to use all sorts of odds and ends for tools. There are X Fig. 55. several other patterns of tool-holders, arranged either to use the little pieces of square, round, or triangular steel bars, so that one side, at least, of these may remain without grinding, and others in which two entirely new faces must be given to the tool by the grindstone. The latter are, perhaps, generally the best, because you can then, with the 2 24 ^HE YOUNG MECHANIC. *• . — aid of the table of tool-angles, shape your cutters very accurately to the work required of them. Although such tool-holders and cutters are generally used for metals, there are others intended for wood ; and constructed to hold miniature gouges and chisels, which perform their work admirably. A capital tool for outside work, Fig. 55, E, which was used extensively at Portsmouth dockyard for brass turning, is made simply by filing off at an angle of about 45° a round short bar of steel. This angle, however, is unusually small for brass and gun-metal, 80° being better. For iron it will answer better, because though filed, or rather ground at 45°, the cutting edge, a little way from what may be called the point of the tool, is nearer 60°. Similar to these last are the tube gouges, short bits of steel tube ground off and sharpened. These fixed in a holder answer beautifully for soft wood, and do not "catch in." If the holder is bent so as to bring the tool into proper position, inside work can be rapidly effected by these, such as hollowing out large bowls and similar heavy work. All this can, of course, be done rapidly with the slide-rest, so far as regards the removal of the greater part of the wood. But in the case of a bowl, in which a curve predominates over a straight line, hand-tools must be used to finish it (generally the inside hook-tool). This last is, in fact, almost identical with the tube gouge ; for the SLIDE-REST, ,25 slide-rest, and that whicli makes it so difficult a tool to use, is that, being a hand-tool, and subject to slight un- intentional changes of position upon the part of the work- man, it catches in, and is either wrenched out of the hand or a piece is chopped off the wood. Rigidly held in the Blide-rest, the exact angle, once found, is of course maiu- Hiued. Chapter XII. NOW propose to assist the young mechanic in special work, instead of continuing general directions. This will enable me to explain to him various lathe appliances, and other details of mechanical work hitherto passed by. Of all models which boys (and very big boys too) are desirous to construct, the steam-engine holds the chief place, and deservedly so ; for every boy calling himself mechauical, ought to know how this is made, and the general principles of its construction as well. However, I am aware, from experience, that many a youngster, who is even in possession of a model engine, is utterly ignorant of the cause of its motion; although it is a great delight to them to see the steam puffing out, and the wheel revolving " nineteen to the dozen," as schoolboys say. Now, an engine is a very simple affair, and can be easily explained ; and, as I wish my readers to work rationally, irOW TO MAKE A STEAM-ENGINE. 227 I shall show them what they have to do before I tell them how to do it. / iir^\ Pig 6a. A, Fig. 56, represents a cubical yes«el of tin or any 228 THE YOUNG MECHANIC. other substance. By cubical, I mean that all its sides are squares, and all exactly equal ; each side in the present case is to be 1 inch wide and long, or a square inch. B is a similar vessel, 1 foot cube. It contains, therefore, 1728 cubic inches, or is 1728 times as large in capacity as the first. Now, if I were to fill the little vessel with water and tip it into the second, and put a lamp under it, the water would all soon boil away, as it is called. It would be converted into steam ; and the quantity of steam it would produce would exactly fill the larger vessel, without excit- ing any particular pressure upon its sides. Steam, thus allowed plenty of elbow room, is like a lazy boy ; it will play and curl about very prettily, but will do no work. "We must put some sort of pressure, therefore, upon it — confine it, and we shall soon see that, by strug- gling to escape, it will serve our purpose, and become a most obedient workman. "We have, therefore, only to put double the quantity of water into our larger vessel, that is, two cubic inches. We will put on a cover tightly, adding a pipe through which to pour in the water. Soon we shall have the steam formed as before; but it has no longer room enougb, and out it comes fizzing and roaring, very savage at having been shut up in so small a cage. And we can make it work too, for if we set up a little fan-wheel of tin right in its way, we shall see it spin round merrily enough; or if we cork tire tube lightly, we shall find this cork soon FORCE OF STEAM. 1^29 come out with a bang. We have, in fact, already con- Btriicted a steam-engine and a steam-gun on a small scale. The pressure in this case is, indeed, not great, but what it is I must now try to explain. The air or atmosphere, which surrounds us on all sides, exercises a pressure upon everything of 15 lbs. on every square inch of surface. If our little cubical inch box of tin had no air inside it, and no steam, but was absolutely empty, each side, and top, and bottom would have 15 lbs. pressure upon it ; which would be evident if it were not very strong, for it would sink in on all sides directly, just as much as if you were to add a weight of 15 lbs. when it was full of air, as it would ordinarily be. When I spoke of the larger box being exactly filled with steam from the evaporation of the cubic inch of water poured from the smaller box, I supposed it empty of air. The steam from that quantity of water, occupying the place of the air, would also be of the same pressure, 15 lbs. per square inch of surface ; and as this only balances the pres- sure of the atmosphere, which would be, in such a case, pressing in on all sides, the steam would not show any pressure : just as, if you put equal weights into each scale of a balance, the beam of it would remain horizontal, neither scale showing to the outward senses that it had any pres- sure upon it. But in the second case, we have doubled the quantity of steam, but compelled it to occupy the same 230 THE YOUNG MECHANIC. space; therefore we have now real, visible pressure of 15 lbs. upon each square inch ; and if we again halve the space which the steam has to occupy, or double the quantity of water, we shall obtain a pressure of 30 lbs. beyond the pressure of the atmosphere. Let us now disregard atmospheric pressure, and fit up such an apparatus as Fig. 56, D. Here we have first our small box, closed on all sides, and from it a small tube rising and entering into the bottom of a larger one, which is very smooth in the inside ; in this is a round plate or disc, called a piston, which fits the tube nicely, but not so tight as to prevent it from moving up and down easily ; and let a weight of 15 lbs. be laid upon it. Let us suppose this large tube or cylinder to be 1700 times larger than the cubic inch box, into which water is to be poured till full. Now we heat it as before, and when 212° of heat are attained by the water (which is its boiling-point) when it begins to be converted into steam, the piston will be seen to rise, and will gradually ascend, until quite at the top of the tube, because the steam required exactly that amount of room. Now we have arrived at the same conclusion which we came to before ; for you see that not only has the cubic inch of water become a cubic foot of steam {about 1700 to 1 728 of its former volume), but it is supporting 15 lbs. weight, which represents that of the atmosphere, and if we could get rid FORCE OF STEAM. 231 of the latter, a solid weight of 15 lbs. would be thus sup- ported. Now, still neglecting the atmospheric pressure, suppose instead of 15 lbs. we add another 15 lbs., making the weight 30 lbs., down goes our piston again, and stands at about half the height it did before. "We have thus, as we had previously, a cubic foot of steam made to occupy half a cubic foot of space, giving a pressure (which is the same as supporting a weight) of 30 lbs. I ought, perhaps, to add in this place, however, that under 30 lbs. pressure, or atmospheric weight and 15 lbs. additional, the water would not become steam at a tempera- ture of 212°, but it would have to be made much hotter, until a thermometer placed in it would show 252**. So far we have seen what a cubic inch of water will do when heated to a certain degree, and at first sight it may not seem a great deal. Far from being light work, how- ever, this is actually equal to the work of raising a weight of 1 ton a foot high. Let us prove the fact. Suppose the tube or cylinder to be square instead of round, and that its surface is exactly 1 square inch, how can we give 1700 times the room which is occupied by the water ? It is plain that the piston must rise 1700 inches in the 1-inch cylinder or tube, carrying with it, as before, its weight of 15 lbs. — that is, it has raised 15 lbs. 1700 inches, or about 142^^^^. But this is the same as 15. times 142 feet raised 1 foot, which, is 2130 lbs. raised 1 foot, very nearly a ton, the latter 232 THE YOUNG MECHANIC. being 2240 lbs. So, after all, you see that our little cubic inch of water is a very good labourer, doing a great deal ol work if we supply him with suflScient warmth. Now this is exactly the principle of the ordinary steam- engine : we have a cylinder in which a piston is very nicely fitted, and we put this cylinder in connection with a boiler, the steam from which drives the piston from one end of the cylinder to the other. In the first engine that was made, the cylinder actually occupied the very position it does in our sketch ; it was made to stand upon the top of the boiler, a tap being added in the short pipe below the cylinder, so that the steam could be admitted or shut off at pleasure. But it is plain that although our little engine has done some work, it has stopped at a certain point ; there is the piston at the top, and it cannot go any farther ; we must get it down again before it can repeat its labour. How would you do this, boys ? Push it down, eh ? If you did, you would find it spring up again when you removed your hand, just as if there were underneath it a coiled steel spring ; by which, however, you would learn practically what is meant by the elasticity of steam. Besides this, if you push it down, you become the workman, and the engine is only the passive recipient of your own labour. Try another plan ; remove the lamp, and see the result — gradually, very gradually, the. piston begins to des(;end. Take a squirt or syringe, and squirt cold water against THE FIRST ENGINE CONSTRUCTED. 233 the apparatus. Presto! down it goes, now very quickly iu- deecl, and is soon at the bottom of the cylinder. But we may as well try to get useful work done by the descent of the piston as well as by its ascent. Set it up like Fig. 5G, E. Here is a rod or beam, h a c^ the middle of which is supported like that of a pair of scales. From one end we hang a scale, and place in it 15 lbs. ; and as the piston sinks the weight is raised, and exactly the same work is done as before. Thus was the first engine constructed; but instead of the scale-pan and weight, a pump-rod was attached, and as the piston descended in the cylinder this rod was raised, and the water drawn from the well. This, however, was not called a steam-engine, because the work is not really the effect of the steam, which is only used to produce what is called a vacuum (2.^., an empty space, devoid of air) under the piston. In fact, the up-stroke of the piston was only partly caused by steam, and the rod of the pump was weighted, which helped to draw it up. I must get you to understand this clearly, so that the principle may become plain — " clear as mud," as Paddy would say. I told you that the air pressed on every square inch of surface with a force of about 15 lbs. "We do not feel it, because we are equally pressed on all sides — from within as well as from without — so that atmospheric pres- sure is balanced. Sometimes this is a very good thing. We should, I think, hardly like to carry about the huge 234 THE YOUNG MECHANIC. weight pressing upon our shoulders, if something did not counteract it for us, so that we cannot feel it. Indeed, if it were otherwise, we should become flat as pancakes in no time — ''totally chawed up.'* But sometimes we should prefer to get rid of the ait altogether — and I can tell you it is not easy to do so, unless we put something into its place; and we want perhaps simply to get rid of it, and make use of the room it occu- pied. We require to do this in the present instance, and in fact we have just done it. If the whole space below the piston, when we begin to work, is filled with water, it is plain there can be no air below it ; and when the steam has raised it, there is still no air below it, but only steam. We then apply cold to the cylinder by removing the lamp and squirting cold water against it, which has the effect of reducing the steam to water again, which will occupy 1 inch of space only. We, therefore, now have a space of 1600 cubic inches with neither air nor water in it; and so, if the piston is 1 inch in size, there will be the 15 lb. pressure of the atmosphere upon it, and nothing below to balance it, for we have formed a vacuum below it, and of course this 15 lb. weight will press it rapidly down. It did so; and we therefore were enabled to raise 15 lb. in the scale-pan. You will know, therefore, henceforth, exactly what I mean by a vacuum and atmospheric pressure. It is, you see, the latter which does the work when a vacuum is ATMOSPHERIC ENGINE. 235 formed as above; but you can easily understand that it might be possible to use both the atmospheric pressure and the pressure of steam as well, which is done in the con- densing steam-engine. In the earliest engine, called the Atmospheric for the reason above stated, the top of the cylinder was left entirely open, as in our sketch; but the condensing water was not applied outside the cylinder, but descended from a cistern above, and formed a little jet or fountain in the bottom of the cylinder at the very moment that the piston reached its highest point. Down it, therefore, came, draw- ing up the pump-rod. When at the bottom the jet of water ceased. Steam was again formed below the piston, which raised it as before ; and the process being repeated, the required work was done. A boy, to turn a couple of taps, to let on or off the water or steam, was all the attend- ance required. For some time the atmospheric engine, the invention of Newcomen, was the only one in general use ; and even this was, in those days (1705-1720), so difficult to construct that its great power was comparatively f eldom resorted to, even for pumping, for which it was nevertheless admu'ably suited. The huge cylinder required to be accurately bored, while there were no adequate means of doing such work ; and although the piston was " packed," by being wound round with hemp, it was difficult to keep it sufficiently «36 THE YOUNG MECHANIC. tight, yet at the same time to give it adequate " play.'* Then, another drawback appeared, which, though of less importance in some districts, absolutely prevented the introduction of this engine into many parts of tbe country. The consumption of coal was enormous in proportion to tlie power gained. "We can easily understand the reason oi this, when we consider the means used for producing a vacuum in the cylinder below tlie piston. The Water intro- duced for the purpose, chilled, not only the steam, but cylinder and piston also ; and therefore, before a second stroke could be made, these had to be again heated to the temperature of boiling water. The coal required for the latter purpose was therefore wasted, causing a dead loss to the proprietor. So matters continued for some time, until a mathematical instrument-maker of Glasgow, named Watt, about the year 1760, began to turn his attention to the subject ; and having to repair a model of Newcomen's engine belonging to the University of Griasgow, the idea seems to have first struck him of condensing the steam in a separate vessel, so as to avoid cooling the cylinder after each upward stroke of the piston. This was the grand secret which gave the first impetus to the use of steam-engines ; and from that day to this these mighty workmen, whose muscles and sinews never become weary, have been gradually attaining perfec- tion. Yet it may be fairly stated that the most modern JAMES WATT'S INVENTION. 237 form of condensing engine in nse is but an improyement upon Watt's in details of construction and accuracy of workmanship. For Watt did not stand still in his work ; but after having devised a separate condenser, he further suggested the idea of closing the top of the cylinder, which had hitherto been left open to the influence of the atmos- phere; and rejecting the latter as the means of giving motion to the piston, he made use of the expansive power of steam on each side of the piston alternately, while a vacuum was also alternately produced on either side of it by the condensation of the steam. The atmospheric engine was thus wholly displaced. The saving of fuel in the working of the machine was so great, that the stipulation of the inventor, that one-third of the money so saved should be his, raised him from comparative poverty to affluence in a very short time. Watt, however, had still to contend with great difficulties in the actual construction of his engines. He was in the same "fix" as some of my young readers, who are very desirous to make some small model, but have little else than a pocket-knife and gimblet to do it with. For there were no large steam-lathes, slide-rests, planing and boring machines, procurable in those days, and even the heaviest work had to be done by hand, if indeed those can be called hand-tools which had frequently to be sat upon to keep them up to cut. It was therefore impossible for Watt to 238 THE YOUNG MECHANIC. carry out his designs with anything like accuracy of work- manship, else it is probable that he would have advanced the steam-engine even further towards perfection than he did. In spite of these drawbacks, however, this great inventor lived to see his merits universally acknowledged, and to witness the actual working of very many of these wonderful and useful machines. The first necessity which occurred from closing the cylinder at both ends was the devising some means to allow the piston-rod to pass and repass through one end without permitting the steam to escape. This was effected by a stuffing-box, which is represented in Fig. 57, A, B, — the first being a sectional drawing, which you must learn to understand, as it is the only way to show the working details of any piece of machinery. We have here a cylinder cover, a, which bolts firmly to the top of the cylinder, there being a similar one (generally without any stuffing-box) at the other end or bottom of the same. On the top of this you will observe another piece, which is marked h, and which is indeed part of the first and cast in one piece with it. Through the cylinder cover, a, is bored a hole of the exact size of the rod attached to the piston, which has to pass through it, but which hole, however well made, would allow the steam to leak considerably during the working of the piston-rod. To obviate this, the part h is bored out larger, and has THE STUFFING-BOX. 239 a cnp-sliaped cavity formed in it, as you will see by in- specting tlie drawings. Into this cavity fits the gland, c, which also has a hole in it, to allow of the passage of ^o. piston-rod. This gland is made to fit into the cavity in h Fig. 57. as accurately as possible ; and it can be held by bolts as in the fig. A, or be screwed on the surface as shown at B, in which latter case the greater part of the interior of b is screwed with a similar thread. The piston-rod being in place, hemp is wound round it (or india-rubber packing- 240 THE YOUNG MECHANIC. rings are fitted over it), and the gland is tlien fitted in upon it, and screwed down, thus squeezing the hemp or rubber tightly, and compelling it to embrace the piston- rod so closely, that leakage of steam is wholly prevented. Whenever you have, therefore, to prevent steam or water escaping round a similar moving-rod in modelling pumps or engines, you will have to effect it in this way. The piston was also packed with hemp or tow, either loosely- plaited or simply wound round the metal in a groove formed for the purpose. In Fig. 57, C and D, I have added drawings of a piston, so made, partly for the purpose of again explaining the nature of sectional drawings. In this one, C, you are shown the end of the piston-rod passing through the piston, and fastened by a screwed nut below, a shoulder preventing the rod from being drawn through by the iction of this nut. The hemp packing is also shown \\. section, but in the drawing D the groove is left for the sake of clearness. In all your smaller models you will have to pack your piston in this way, except in those where you entirely give np all idea of jpower. The little engines, for example, sold at $1 and upwards, with oscillating cylinders, have neither packed pistons nor stuffing-boxes; the friction of those would stop them, and escape of steam is of no great consequence. It will, however, be found advantageous to turn a few shallow grooves round these unpacked pistons NE WCOMEN 'S ENGINE, 24 . after they have been made to fit their cylinders as accu- rately as possible, like fig. C. These fill with water from the condensation of steam, which always occurs at first until the engine gets hot ; and thus a kind of packing is made which is fairly effectual. In Fig. 58 I have given a drawing of Newcomen's engine, in case you would like to make a model of one ; but I do not think it will repay you as well for your labour as some others. There is the difficulty of the cistern of cold water and the waste- well ; and the condensation of the steam is a troublesome affair in a small model , so that, on the whole, I should not recommend you to begin your attempts at model-making with the construction of one of these. I shall, however, add a few directions for this work, because what I have to say about boring, screwing, and so forth, will apply to all other models you may desire to construct. The cylinder, in this case, will be more easily made by obtaining a piece of brass tubing, which can be had of any size, from 3 or 4 inches diameter to the size of a small quill. The first you will often use for boilers, the latter for steam or water pipes. You can also obtain at the model makers — Bateman, for instance, of High Holborn — small taps and screws, and cocks for the admission of water and steam, and all kinds of little requisites which you would find great difficulty in making, and which would cost you more :|'- y '///. '////// • - '-''. : O. ■ -■--: >( y /'/'////.'.' ■.'/ ///.'//y -yy/,: y////7TTY//////////////////77yy HOJF TO MAKE A BOILER, 243 in spoiling and muddling tlian you would spend in buying them ready made. The drawing is given on purpose to show the best and easiest arrangement for a model. It has all parts, there- fore, arranged with a view to simplicity. A is the boiler made of a piece of 3-inch brass tubing, as far as a, 5, c, «?, the bottom being either of brass or copper at the level ot a, h ; the upper domed part may be made by hammering a piece of sheet brass, copper, or even tin, with a round- ended boxwood mallet upon a hollowed boxwood block, of which T, T is a section. You should make one of these if it is your intention to make models your hobby, as it will enable you to do several jobs of the same kind as the pre- sent. Probably you will not be able to make the dome semi- circular, or rather hemispherical ; but at all events, make it as deeply cupped as you can — after which, turn down the extreme edge one-sixteenth of an inch all round to fit the cupped part exactly. This requh-es a good deal of care and some skill. If you find that you cannot manage it, make your boiler with a flat top instead. Whichever way you make it, a very good joint to connect the parts is that shown in section at V.* The edge of the lower part is turned outwards all round ; that of the upper part is also turned outwards, first of all to double the width of the other, and is then bent over again, first with a pair of pliers * The parts so jointed are highly exaggerated ; when hammered down, the joint only forms a light beading. 244 THE YOUNG MECHANIC. and afterwards with a hammer, a hlock or support being placed underneath it. All this is done by the manufac- turer with a stamping machine on purpose, and would be completed by the Birmingham brass-workers before I could write the description. It can, however, be done without any more toals than shown. You will often need a tinman's boxwood mallet with one rounded end and one flat one, which, of course, you can now turn for yourself, as it is an easy bit of work. With the rounded end you can cup any round piece of tin ; but it requires gentle work ; do it gradually by hammering the centre more than the edges. I will show you presently how to do similar work by spinning in the lathe, which is a curious but tolerably easy method of making hollow articles of many kinds from round discs of metal without any seam. After you have hammered the joint of the upper and middle parts together, you must solder them all round with tinman's solder. For this purpose you require a soldering- iron represented at W. This is a rod of iron, flattened and split at the end, holding between the forked part a piece of copper, which is secured to the iron by rivets. I should not recommend a heavy one, not so heavy nearly as what you may see at any blacksmith's or tinman's shop, because your work will be generally l-ight, and such irons are all top heavy to use. The end, which may be curved over as shown, will require to be tinned^ for without this it will not work al all THE ART OF SOLDERING. 245 well. File the end bright, and heat it in the fire nearly red hot. Get a common brick, and with an old knife or anything else, make a hollow place in it — a kind of long-cupped recess like a mussel shell, if you know what that is, and put a little rosin into it. Take your iron from the fire, and holding it down close to the brick, touch it with a strip of -solder, which will melt and run into the cavity. Now rub the iron well in the solder and rosin, rub it pretty hard upon the brick, and presently you will see it covered with bright solder, from which wipe what remains in drops with a piece of tow. The iron is now fit for immediate use ; but remember, the first time you heat it red-hot, you will burn off the tinning, and you must file it bright again, and repeat the process. So when you want to solder, heat the iron in a clean fire, until, when you hold it a foot from your nose, you find it pretty warm; and avoid a red heat. You will now find that when the soldering-iron is hot, it will not only melt but pick up the drop of solder ; and as you draw it slowly along a joint (previously sprinkled with powdered rosin, or wetted with chloride of zinc, or with Baker's soldering fluid), the solder will gradually leave the iron, and attach itself to the work in a thinly-spread, even coat. The secret of soldering is to have the iron well-heated, and wiped clean with a bit of tow, and to apply it along the joint so slowly and steadily that the tin or other metal will become hot enough just to melt solder. Try to solder, 246 THE YOUNG MECHANIC. for instance, a thick lump of brass ; file it bright if at all tarnished — for this must invariably be done with all metals. You will be unable to do it at first, for the moment the solder touches it, it will be chilled, and rest in lumps, which you can knock off directly when cold. Now place the brass on the fire for a few seconds until hot, and try again ; the solder will flow readily as the iron passes along it, for it is kept up to the melting-point until it has fairly adhered. This is why in heavy work a large iron is required ; it retains heat longer, and imparts more of it to the metal to be soldered. But you will find it often better to use a light soldering-iron, and to place the brass-casting upon the bar of the grate for a short time. You may, indeed, often work without any soldering-iron as follows : — Heat the pieces to be soldered (suppose them castings and not thin sheets of metal) until they will melt solder. Take a stick of the latter, and just dip it in one of the solder- ing solutions named, and rub it upon the work previously brightened. The solder will adhere to both such pieces. Now, while still hot, put them together and screw in a vice, or keep them pinched in any way for a few minutes, and you will find them perfectly secured. In making chucks for the lathe, and in forming many parts of your models, you will find it advantageous to work in this way ; but, notwithstanding, you will often require a light soldering- iron, and sometimes also a blowpipe, which I shall likewise THE STOP-COCK. 247 teacli you to use, as also how to make a neat little fire-place or furnace to stand on your bencli by which to heat the iron. I must now suppose that you have carefully soldered the dome to the middle of your boiler ; and as the solder will be underneath, the joint will be concealed even if (as is likely) you should not have made a very neat piece of work. Before you put on the bottom of the boiler, you will have to make two holes in the top — one for the steam-pipe three-eighths of an inch in diameter, the other for the safety-valve also three-eighths — because this will require a plug of brass to be soldered in, which plug will have a hole drilled through it of a quarter of an inch diameter. These may be punched through from the inside, or drilled ; they are easily made, but should be as round and even as possible. Take a piece of three-eighths-inch tubing, with a stop- cock soldered into the middle of it. I shall suppose you have bought this. It need not be over an inch in length altogether ; and you must put it through the hole in the top of the boiler, and solder it round on the inside of the same. The nearer you can get the stop-cock to the bottom of the cylinder the better the engine will work, because the steam will have to rise through whatever water is left in this pipe from the jet used to cool the steam. You will see that it cannot run off by the pipe C into the pump well, like that which collects in the cylinder itself. In a real engine the steam-tap was a flat plate which slid to and fro sideways, 248 THE YOUNG MECHANIC. level with the bottom of the cylinder ; but this you would ^not make easily at present. The plug for the safety-valve you must turn out of a little lump of brass. It must be about three-eighths of ai: inch long ; and you must drill a quarter-inch hole through it, and countersink one end of the hole (that is, make it wider and conical by turning a rose-bit or larger drill round in it a few times), to make a nice seat, as it is called, for the valve itself, which need not be now attended to. Remem- ber you can buy at Bateman's, or any model-maker's in London, beautiful safety-valves ready-made, as well as any part of a model engine that you cannot make yourself; and indeed it is so far a good plan at first that it saves you from becoming tired and disgusted with your work, owing to repeated failures. If you buy them, therefore, you must do so before you make the holes above alluded to, but in some respects it will be more to your advantage to try and make all the details for yourself. I cannot call it making an engine, if, like many, you buy all the parts and have little left to do but screw them, or solder them, together. Don't do this, or you will never become a modeller. Your boiler from c iQ a is, in height, maybe 2 inches, the dome 1^ or thereabout. This will slip inside the part that you see in the drawing, and which I here sketch again separately.* * The bottom joint must therefore be hammered close ; the upper one will become a ledge for the boiler to rest on. THE BOILER DISSECTED. 249 Fii:. 59. 25© THE YOUNG MECHANIC. A is the boiler lifted out of B, the outer case or stand, which you cau make out of tin, and paint to imitate brichs. It is almost a pity to waste sheet-brass upon it, because it is not very important, its object being only to carry the boiler. It is like D before being folded round and fastened (not with solder, which would soon melt, but) by a double fold of the joint, similar to that which you made round the boiler itself, but turned over once more and hammered down. The holes are punched with any round or square punch with a flat end, and are intended to give more air to the lamp C, which should have three wicks, or two at the least, to keep up a good supply of steam. I have shown the flat piece of tin with three legs only, which is as well as if it were made with four ; but you can please yourself in this matter. The lamp I need hardly tell you how to make, for it is easier than the boiler, being merely a round tin box, in the top of which are soldered three little bits of brass tube for the wicks, and a fourth for the oil to be poured in — the latter being stopped with a cork. You should remember that no soldered work, like the iu- side of the boiler, must come in contact with the heat of the lamp, unless it has water about it, because if the water should at any time entirely boil away, the boiler will leak and be spoiled. A little care in this respect will insure the preservation of a model engine for a long t ime ; but HO IV TO MAKE A CYLINDER. 251 bo3-8 generally destroy them quickly by careless treat- ment. Let us now turn our attention to the cylinder. Cut oft a piece of three-quarter-inch brass tube, 2\ inches in length — you can do this with a three-square file — mount it in the lathe by making a chuck like Fig. 59, E, of wood, the flange of which is just able to go tightly into one end of the tube. The other end will probably centre upon the conical point of the back poppit, over which it will go for only a certain distance. If your back centre will not answer on account of its small size, you must make a similar flange to go into the other end ; but take care that when the back centre is placed against it, it runs truly. If the chuck is well made, it will do so. You can now with any pointed tool turn off the ends of the tube quite squarely to the side; but you should only waste one-quarter of an inch altogether, leaving it 2J inches long. When, this is done, take it out of the lathe, and in place of it, mount a disc of brass rather more than one-eighth of an inch thick, or if you have none at hand, take an old half- penny or penny piece, which is of copper, and lay it upon the flat face of a wooden chuck, driving four nails round its edge to hold it, and with a point-tool cut out neatly the- centre, of a size to fit inside your tube. You will scarcely, however, effect this perfectly without further turning ; so- take care to cut it too large ; but before you cut it com- 252 THE YOUNG MECHANIC. pletely through, make the hole for the tube which you soldered into the top of the boiler, which is three-eighths diameter. This you can do beautifully in the lathe with a pointed tool, or with a drill, centred against the point of the back poppit, as I showed you before. Cut the disc quite out (too large, mind) and then turn a spindle like Gr, mount the disc upon it as shown, by its central hole, and turn the edge with a graver or flat tool, Buch as is used for brass, until it will exactly fit the brass tube. You can cut out round discs of one-eighth or one- fourth sheet-brass by mounting any square piece on a wooden face chuck, keeping it down by four nails or screws, and then with a point-tool cutting a circle in it until the disc falls out. You will often save time by so doing. You now have a disc of brass or copper with a hole three-eighths of an inch wide in it; and as the disc is three-fourths of an inch in diameter {i.e.^ six-eighths), you will have three-eighths remaining, or three-sixteenths, each way on the diameter between the edge of the hole and that of the disc. This will just give room for the two small holes required, one on each side of the central one, for the pipes from the cold-water cistern and to the well below the pump. These must both be of brass ; and the first should be turned up and end in a jet, like a blowpipe, so as to make the water rise in a spray under the piston ; the other should be as long as can be conveniently arranged. THE PISTON-ROD. 253 The bottom of the cold-water cistern is drawn a little above the top of the cylinder, which is 2^ inches high. K jet would theoretically rise in the cylinder to nearly the height of the level of water in the cistern ; but with a small pipe, and other drawbacks inseparable from a model, you must not reckon on more than about half that height, which should be sufficient to condense the steam. The piston had better be nicely fitted, but not packed. You cut a disc of brass as before, drill the hole for the piston, make a spindle, or put in the piston-rod, and centre this as a spindle, which is the he8t plan, and then with a flat brass tool tu'rn the piston accurately to fit the tube. Or, if you think it easier, or wish to fasten the piston with a nut, as drawn, you can, if you like, turn it on a separate spindle ; and thirdly, you may tap the hole in the piston, and screw the end of the piston-rod. The great thing to attend to is, to turn the edge of the piston square to the sides. For the piston-rod, a steel knitting needle or piece of straight iron wire will do very well ; but it will have to be flattened at the upper end, or screwed into a little piece of brass, which must be sawn across to make a fork by which the chain can be attached which goes over the beam. Do not solder the cistern pipes in just yet, but go on to other parts. The cistern itself can be made out of any tin box. A geidlitz -powder box will answer well, or you can make one 254 THE YOUNG MECHANIC. about that size, say 4 inclies long, 2| wide, and 2 deep. The cistern for the pump will, of course, require to be the same size or a little larger ; it may stand on legs or be fastened to the bed-plate direct. This bed-plate is shown below the picture of the engine. It is merely an oblong plate of iron one-sixteenth inch thick, or in this particular engine may be of tin neatly fastened to a half-inch mahogany board, which will keep all firm. The white places show the position of the boiler and of the pump cistern, the inner rounds indicating the lamp, and pump, and cylinder. The square is merely made to show a boiler of that shape, which some prefer; — it is not so good as a cylindrical one. Whenever you have to make an engine, you should draw upon the bed-plate the position of each part, as I have done here, because it will serve you as a guide for measurement of the several pieces. The four small circles at S S show the positions of the legs of the support C, which carries the beam. In the drawing only two are given, but there would be a similar triangular frame upon this side. This may be made very well of stout brass wire, but in a bought engine it would be a casting of brass, painted or filed bright. The beam itself should be of mahogany, 6 inches long, half an inch wide (on the side)^ and a quarter of an inch thick. The curved pieces you will turn as a ring 3 inches THE SAFETY-VALVE. 255 diameter with a square groove cut in the edge for the chain. You can then saw into four, and use two of these, morticing the strip of mahogany neatly into them. Then finish with four brass wires, as shown, which will keep the curved ends stiff and give a finished appearance. The pin in the centre should be also of brass, as a few bright bars and studs of this metal upon the mahogany give a hand- some look to the engine. The pump will be of brass tube, made like the cylinder, but the bucket may be of boxwood, and so may the lower valve, each being merely a disc with a hole in it, and a leather flap to rise upwards. The bucket, however, should have a groove turned in its edge, to receive a ring of india- rubber, or a light packing of tow. The end of the pump- rod must be split to make a fork like Y, to allow the valve to rise. You can get just such a fork ready to hand out of an umbrella, if you can find an old one ; if not, and vou cannot split the wire, make the rod rather stouter, and bend it, as shown, so as to form only one side of a fork, which will probably answer the same purpose in so light a pump. The valve in both of these may be made of a flap of leather — bookbinder's calf, or something not too thick — and it may be fastened at one edge by any cement that will not be affected by water, or by a small pin, — cut off the head of a pin with half an inch of its shank, and point 256 THE YOUNG MECHANIC. it up to form a small tack. If the valve-box is of box- wood, you must drill a bole ; — ^you may make it, if pre- ferred, of softer wood. There is no support shown in the drawing for the cold- water cistern; but you must stand it on four stout wires, or on a wooden (mahogany) frame, which can be attached to the bed-plate. As this last is always of some importance, I shall add it again in this place (Fig. 60), to a scale of three-quarters of an inch to the foot, showing the position of each part. Always begin with a centre line and take each measure from it, and draw another across for the same purpose, at right angles to the first. You will quickly see the use of this. We draw two lines as described A, B, C, D, crossing in 0. The longest is the centre line of beam, cylinder, and pump. The beam is to be 6 inches long to the outside of the middle of each arc, whence the chain is to hang. We, therefore, from the centre point, set off 3 inches each way. At the exact 3 inches will be the centres of the cylinder and pump ; — set these off, therefore, on the plan. The end of the tank we must have near the cylinder, because we have to bring a pipe from it into the bottom of the cylinder. Set off, therefore, the end of the tank 2^ inches — i.e^ \\ on each side of the central line, and draw it 4 inches in length. N shows the position of the pipe close to the end and on the line. The centre of the boiler is the o, '■o -o ' (^ ^ n 2 \ -A ^ XTVcTie^T 2 / c> 0- ; a D V X c ) z ^s z fC "^ /^ A V ^ (/ ^ W ^ ;;^ X a: «M CD 258 THE YOUNG MECHANIC. same as that of tlie cylinder, so we draw a circle round it with a radius of \\ inches, which gives us the 3-inch circle of the boiler. Then we may set off equal distances, N, N, for the extremeties of the legs of the frame which is to support the beam, and we complete our plan. M is the waste pipe, and K is the opening for the water to flow into the tank. We now find, therefore, that the bed-plate must be 13 inches long and 6 inches wide to take the engine of the proposed size, and we may, of course, extend this a little, if thought desirable. Mark off on the bed all the lines of the plan as here given, and always start any measurement from one of the two foundation lines, or else, if you make one false measure, you will carry it on, pro- bably increasing the amount of error at every fresh measurement. Let this be with you a rule without ex- ception. It is plain that if you work all parts of your engine to size, you can set it up on the marked bed-plate with perfect accuracy. The description I have given will not only enable you to make a Newcomen engine with very little difficulty, but will give you an insight generally into this kind of work ; and you will learn, too, a practical lesson in soldering, turn- ing, and fitting. I must, nevertheless, help you a little in putting your work together. You had better begin by soldering into the bottom of the cylinder the end of the steam-pipe^ which you have already PUTTING TOGETHER. 259 fixed upright in the middle of the dome of the boiler, taking care that it stand _ .qiiarely across the pipe, or your cylinder will not be upright. Then place the boiler in position, and you may fix it by turning out slightly the ends of the legs, and putting a tack through, or screwing, if the bed-plate is of iron, — or with help of Baker's fluid you can solder; but this is hardly safe work, and you had better have a wooden plate, covered with tin, and tack down the legs. I have drawn you a circular lamp, and given three and four legs to the boiler-stand; but take care that you so arrange size of lamp and openings of the stand as to enable you to withdraw the former for trimming and filling. Now fit in the two small pipes, previously bent as required. To bend them, if hard soldered or brazed, fill with melted lead, and then bend ; after which melt out the lead again. If soft soldered, you must fill with a more fusible metal. There is a composition called " fusible metal," very convenient for this work, and well worth making, because you will often need to bend small pipes into various forms. Melt zinc, 1 oz. ; bismuth and lead, of each the same quantity — this will melt in hot water ; 8 parts bismuth, 5 lead, and 3 tin, will melt in boiling water. You can buy these at any operative chemist's, either mixed, ready for use, or separately. Rosin and sand are also u&ed for bending tin pipes, the sole object being so to fill them that they will become like a solid strip of metal, and 2fio THE YOUNG MECHANIC. thus bend slowly and equally, witli rounded and not sliarp angles. Pass tlie two pipes through from beneath the bottom of the cylinder, and solder them on the upper side of it, so that when the cylinder itself is added these two joints will not be visible. Then set up the cold-water cistern ; block it up with anything you like so as to keep it in position, and, inserting the pipe from below, solder this also from abo\'e, i.e.^ on the inside of the cistern. Now, arrange the frame that is to support it, either stout wire or wood, and set it up so as finally to secure it in its place. Now, you had better set up the pump cistern, so as to secure the other small pipe in position, and prevent it from becoming dis- placed by any accidental blow. Fix this cistern therefore also, but leave the cover off for the present, that you may be able to solder the small pipe inside it. You will now, at all events, have secured the position of the most important parts, and you may drop the cylinder into place, and solder this also round the bottom. This would be facilitated by turning a slight rebate. Fig. 60, S, round the disc which forms the bottom of the cylinder, so that the smaller part of it will just fit inside it; but you will be able to manage it without. Let the cylinder project a very little beyond the bottom, just to allow a kind of corner for the solder to run in ; it will not show when all is fixed. Do this as quickly as you can, so as not to melt PUTTING TOGETHER. 26 \ off the solder rouDcI the small pipes. Now, make the pair of A-shaped supports for the beam. Measm'e the height Q>i your cylinder top, above the bed-plate, and allow about another inch, and you will get the perpendicular height to the axis of the beam. Allow 3 inches more for each side, that is, in all for each side, 3 inches longer than if it was to be perpendicular instead of spreading. Take enough brass wire, about as thick as a small quill, to make two such legs. Bend it in the middle, like T, Fig. 60, and flatten the bent part by hammering, so as to allow you to drill a hole to take the pivot on which the beam is to oscillate. If you like to flatten all of it, and then touch it up with a file, so as to get quite straight edges, it will look much more handsome. Make two such pieces exactly alike, and, at distances alike in each, put cross-bars. File a little way into each, making square, flat notches, which will just take two flattened bars of the same wire ; heat them, and solder very neatly, so that no solder appears on the outside ; file all flat and true. In this way you can make almost as neat supports as if they were of cast brass, and you are saved all the trouble of making patterns. By and by, nevertheless, you must do better. As I have directed you in this instance to put a wooden bed-plate to your engine, you may point the ends of the wires, and, making holes sloping at the same angle in the wooden stand, drive the wires into them. You have an 262 THE YOUNG MECHANIC. advantage here, inasmuch as you can raise or lower your stand until the position of the beam comes exactly right, and you find the ends drop over the centre of the cylinder and pump-barrel as it ought to do. When this is the case, you can cut off any wire that projects below the stand and file it level, for it will not be likely to need more secure fixing. The pump may now be soldered into the cover oi the cistern (before the cover itself is fastened on), and a hole must be then cut to receive the water that will flow from the spout, and then the cover can be fitted on. There is no need to solder it, if it is made to^^ over- tightly ; and you may wish, perhaps, to get at the lower valve of the pump now and then. The only thing left to do is to arrange the safety-valve of the boiler, which is in many cases the place through which the water is poured to charge it. In this engine it is, however, plain that you can fill the boiler by turning both the taps at the same time. A little will run off by the waste-pipe, but not enough to signify, because the tube below the cylinder is so much the larger of the two. The safety-valve is a little bit of brass turned conical to fit the •' eieat," made by counter-sinking the hole. It is shown at K, Fig. 59, N being the seat, P the dome of the boiler, and close to is the gauge-tap for ascertaining the height of water in the boiler. L M is a lever of flattened wire, pivoted to turn on a pin at L, — L being an upright wire PUTTING TOGETHER. 263 soldered to the boiler. A notcli is filed across the top of the valve, on which the lever, L M, rests. The weight is at M. One, as large as a big pea, hung at the end of a lever 2 inches long, the valve at half an inch from the other end, will probably suffice for this engine. Chapter Xni watt's engine. HAVE already told you that Watt suggested the use of steam alternately on each side of the piston ; and carried it out by closing the top of the cylinder, and allowing the rod of the piston to pass through a stuffing-box or gland. I now have to explain to you how this alternate admission of the steam may be effected. You evidently require first an opening at the top and bottom of the cylinder, communicating with the boiler, one only being open at a time ; but in this case, where is the steam to escape that was on one side of the piston when the opposite side was being acted upon ? It must go somewhere, but evidently must not return to the boiler. Hence, some method has to be contrived by which, when one end of the cylinder is open to the boiler, the other may be open to the air or to the condenser (in which the TV A TT'S ENGINE. 265 Fig. 61. 266 THE YOUNG MECHANIC. steatn is cooled under Watt's plan). Fig, 61 will, I think j render clear one or two of these arrangements. The first is the four-way cock, a very simple contriv- ance, easily and frequently used in models. You must first understand how a common water or beer tap is made, Fig. 61, A, represents one in section, turned so as to open the passage along the pipe to which it is attached ; C is the pipe in which is the tap, a conical tube of brass set upright, and with a hole right and left made through it, fixed into a short horizontal tube (generally cast with it in one piece). Into this fits very exactly the conical plug B, also with a hole through it sideways. When this is put into place, no water or other liquid can pass, unless the hole in the plug is in the same direction with the hollow tube forming an open passage. If a key is put on the square part of the plug, and it is turned half round, the passage through the pipe will be closed. A steam tap would be made in a similar manner, if its only office were to open and close a passage in a tube. But we now want two passages closed and two opened, and then the alternate pair closed and opened. This is cleverly effected bj a four- way cock. At D is shown a section of the steam cylinder and piston, with the stuffing-box and all complete. A pipe enters this at the top and bottom, and another crosses it in the middle, making four passages. Shaded black is the four-way cock, THE FO UR- WA Y COCK. 269 tlie white places showing the open channels through the plug. When this plug stands as at D, steam can pass from the boiler to the top of the cylinder only, above the piston, which it drives downward ; the steam below the piston escapes through the other open-curved channel into the air, or to the condenser. Just as the piston reaches the bottom of the cylinder, the tap is turned, and the passage stands as seen at E. Steam now passes to the bottom below the piston, driving it upward, and the steam above it, which has done its work, passes outward through the other open channel of the tap. You must understand that when Newcomen first set up his engine, a man had to turn the taps at the proper moment ; and it is said that one Humphrey Potter, a boy, being left in charge, and getting tired of this work, first devised means to make the engine itself do this, by con- necting strings tied to the handles of the taps to the beam that moved up and down above his head. Beighton and others improved on this, and very soon it became unneces- sary for the attendant to do anything but keep up a good fire, and attend to the quantity of water in the boiler, and the pressure of the steam. In the model I gave you of Newcomen's engine, I pur- posely left the taps to be moved by hand ; but F of the present figure shows how, by bringing them near together, and adding cogged wheels or pulleys, you would make one c68 THE YOUNG MECHANIC. handle answer for both ; and I shall leave you to" devise an easy method of making the engine work this one handle fol itsalf. When "Watt made his first engine, therefore, this work had been already done, and he only had io improve upon it, and to make it work more accurately to suit the engine designed by himself. If you should chance to pay a visit to the Museum at South Kensington, you may see, I believe. Watt's original engine, if not Newcomen's. The cylinders are so large and cumbrous, that the wonder is they were ever bored by the inefficient means then in use; and the beam is a most unwieldy mass of timber and iron, that looks as if no power of steam could ever have made it oscillate. Yet it was in its day a successful engine, the wonder of the age ; and did good work for its inventor and purchaser. I strongly advise my readers to try and visit Kensington, for there are many interesting models there, besides engines and appliances of older days. They will thus learn what rapid progress has been made since the days of Savery, Newcomen, and Watt ; not only in the improvement of the arrangement of the parts, but in the workmanship, which last is mainly due to the invention of the slide-rest and planing-machine. We must now return to the double-acting or real steam engine, and consider a second means whereby the Kteam can be alternately admitted and exhausted. THE LONG SLIDE-VALVE. 269 The four- way cock, already explained, was found to wear very considerably in practice, and hence work loose, and a new contrivance, called the slide-valve, soon took its place. Of this there are two patterns, the long D-valve and the short one, which latter is used for locomotives. There is also a form called a tappet-valve, often used for arge stationary engines, but which is noisy and subject to rapid wear. I shall describe the long D first, in the form in which it would be most easily made for a model engine. The two ports by which steam passes to the cylinder are shown at J, e, of H, Fig. 61. C is the passage to the boiler, K is that to the condenser. These are openings in a tube smoothly bored within, and having at the top a stuffing-box like that on the cylinder. Within this tube works an inner one, h^ having rings or projections at the ends fitting perfectly, and which are packed with india- rubber, hemp (or, in modern days, with metal), to make a close fit. In a model, two bosses of brass, K, soldered on the tube and then turned, make the best packing. These packed portions of the inner tube form the stoppers to the steam ports, e e, alternately, at the top and bottom The upper part of the inner tube has a cross arm, 3, affixed, from the centre of which rises the valve-rod by which it is moved up and down. In the position 1, the steam can pass from c round the tube to