UC-NRLF 
 
 315 MID 
 
 :-MAKINC 
 
 J-, PQC-QC3L 
 
GIFT OF 
 
MODEL ENGINE-MAKING. 
 
MODEL ENGINE-MAKING 
 
 3n 
 
 ant> practice, 
 
 BY 
 
 J. POCOCK. 
 
 WITH OVER ONE HUNDRED ILLUSTRATIONS, 
 DRAWN BY THE AUTHOR. 
 
 
 LONDON: 
 
 SWAN SONNENSCHEIN CO., 
 PATERNOSTER SQUARE. 
 
 1888. 
 
f 
 
 BUTLER & TANNER, 
 
 THE SELWOOD PRINTING WORKS, 
 
 FROME, AND LONDON. 
 
MODEL STEAM ENGINES. 
 
 Every description, from tbe smallest to powerful Engines, of the very best 
 workmanship, at the lowest possible prices. LEE'S NEW ENLARGED 1 
 and REVISED ILLUSTRATED CATALOGUE contains Illustrations and 
 Descriptions of Engines from the smallest to 15 H.-P. Paddle and Screw 
 Steamboats from Is. to 37 guineas ; Sailing Yachts, Castings of Engines, 
 Tools, Lathes, Shaping Machines, Foot Motors, Chucks, Parts of Engines, 
 Anchors, Guns, Boiler Fittings, &c., Electric Machines, &c. , To Amateurs 
 the most useful book extant, and largest and best Catalogue in the Trade, 
 64 pages, 110 Illustrations, price 6d. post free. 
 
 ENGINE CASTINGS. 
 
 LEE'S WORLD -FAMED BRASS CASTINGS, with his improved 
 " Tenon " or Chuck Pieces, on all parts requiring to be turned, are supply- 
 ing a want long felt, being easily turned even by the most unskilled amateur. 
 Complete sets for Horizontal Slide-valve Engine, in. bore, 1 in. stroke, 2s., 
 post free, 2s. 3d. ; f in. bore, 1 in. stroke, 3s., post free, 3s. 6d. ; 1 in. bore, 
 2 in. stroke, 4s. 6d., post free, 5s. ; 1J in. bore, 2 in. stroke, 11s. 6d., post 
 free, 12s. 6d. ; by Parcels Post. All sizes up to 6 in. stroke at equally low 
 prices. Each Casting has Lee's improved " Tenon," without which model 
 Castings are practically useless. 
 
 TO AMATEURS. 
 
 R. A. LEE is now supplying all his best HORIZONTAL ENGINE CAST- 
 INGS, from 1 in. bore, with the Steam and Exhaust Ports accurately cast 
 in the Cylinders, free of charge, thus saving an immense amount of work in 
 fitting up and ensuring accuracy in one of the most important parts of the 
 Engine. 
 
 PHOTOGRAPHIC LENSES at Marvellously Low Prices. 
 
 Single Achromatic, 
 to cover 5 by 4, 7s. 6d. ; 
 ditto, half -plate, 10s. 6d. Rapid 
 Rectilinear Lens, with set of 
 Waterhouse Diaphragms for In^ 
 stantaneous work, to cover 5 by 
 4, 21s. ; half-plate, ditto, 30s. 
 Each of these rapid Rectilinear 
 Lenses will cover the size larger 
 than it is stated to be i.e., 
 -plate will cover 1-1 size. All 
 post-free. 
 
 These Lenses are guaranteed of 
 the highest quality, and cash will be 
 returned if not satisfactory. Illus- 
 trated Catalogue gratis on receipt of 
 addressed postal wrapper. 
 
 To be obtained only of ROBERT A. LEE, Manufacturing Optician. Works : 
 76, 77 and 78A High Holboin, London, W.C. (directly opposite Inns of Court Hotel). 
 Please state where you saw this advertisement. 
 
 AWARDED PRIZE MEDAL IN'llRft ATIONAL INVENTIONS IXHIBITION, 
 
 Lee's Patent Electro-Motor and Battery for Driving Lathes, &c. 
 
 Half H.P. for one-third the price of a Gas Engine. Batteries for Electric Lighting. 
 
 Send for Protpectus gratis on receipt of addressed postal Wrapper. 
 
 ROBiERT A. LEiE, ENGINEER, 
 
 76, 77 & 78a, High Holborn, London, W.C. 
 
WORKING MODEL STEAM ENGINES 
 
 Largest Stock in the World. 
 
 BATEMAN & 
 
 fEngttutrtng 
 
 Originators of Castings for the Construction of Model Steam Engines, 
 Lathes, &c., &c., by Amateurs. 
 
 BATEMAN & COMPANY'S " MUSEUM OF MODELS" pronounced 
 by the leading press of the day to be one of the most interesting sights in 
 London, comprises five houses, and has on view the Largest Stock of 
 Working Models in the World, from 2/- up to 500 each. 
 
 VERTICAL STEAM ENGINE MODEL. 
 
 (Works beautifully.) 
 
 Complete with Boiler, Furnace, Brass Cylinder, &c., &c., 2/-; 
 
 Post free, 2/3. 
 
 LOCOMOTIVE KAILWAY ENGINE. 
 
 (Works perfectly.) 
 
 7i in. long, 2 Brass Cylinders, &c., &c., 5/6 complete. 
 
 Postage 5d. extra. 
 
 Of every conceivable type of HORIZONTAL, BEAM and OTHER 
 MODELS in gradual running sizes from in. to 4 in. bore, from 
 
 2/6 P er complete set. 
 MARINE and LAUNCH ENGINES (single and double), \ to 4 in. bore. 
 
 CASTINGS FOR LOCOMOTIVE ENGINES, 
 
 Prom the simple Oscillating Cylinders to the most perfect Scale Models. 
 
 CASTINGS OF LATHES, 
 
 From 2| Centre Back and Single Geared up to 6 in. 
 
 Gkrj Rflprisiie for Amateur Engineers. 
 
 See J. BATEMAN & COMPANY'S interesting MECHANICAL 
 PAMPHLET and CATALOGUE, 100 Illustrations, giving fullest details 
 of the above, 6d., post free. Address : 
 
 JOHN BATEMAN & COMFY., 
 
 " Museum of Models," 
 
 Also at the 
 
 "ORIGINAL" MODEL DOCKYARD, 
 53, FLEET STREET, & 1O4, STRAND. 
 
 Model Steam and Sailing Ships, Yachts, Blocks arid Fittings. New 
 Pamphlet, fully illustrated, 4d., as above. 
 
PREFACE. 
 
 / T^ V HE Steam Engine in one or other of its 
 many forms is a sufficiently familiar ob- 
 ject ; not equally familiar, I venture to think, 
 the knowledge of its manner of working. Yet 
 surely in these days of scientific and technical 
 education it would be well that at least the 
 younger members of the community should 
 have some clear perception of the method in 
 which steam exerts the force which has become 
 so necessary to the exigencies of daily modern 
 life. 
 
 The want of some practical book on Model 
 Engine-Making has during the last few years 
 been made evident by the number of queries 
 upon this subject which have appeared in 
 various journals more or less devoted to the 
 interests of mechanical science. 
 
 Much of the desired information might no 
 doubt be gathered from the columns of these 
 papers, notably, for instance, from the back 
 
 V 
 
 464511 
 
vi Preface. 
 
 numbers of The English Mechanic ; but this 
 involves a troublesome search and a comparison 
 of sometimes diverse directions. 
 
 These and kindred considerations have in- 
 duced me to revise and enlarge a series of 
 papers on Model Engine-Making, which origin- 
 ally appeared in a magazine chiefly addressing 
 itself to the interests of amateur workers. 
 
 Wishing these papers to be useful to as 
 large a body of amateurs as possible, I have 
 thought it best to give many details for the 
 sake of beginners, which may not be needed 
 by those who have already become practised 
 workmen. 
 
 The patterns in which Model Engines are 
 made are very numerous, but they will usually 
 be found to be only varieties of one or other 
 of the types mentioned in this book ; and 
 any one who has constructed the models here 
 described will, I believe, find little difficulty 
 with any other pattern, whether it be that of 
 a model or a small power engine. 
 
 J. POCOCK. 
 
 HARLESDEN, N.W. 
 
CONTENTS. 
 
 CHAP. PAGE 
 
 I. TOOLS AND CASTINGS ! 
 
 II. OSCILLATING CYLINDER ENGINE ... 12 
 
 III. OSCILLATING CYLINDER LOCOMOTIVE . . 30 
 
 IV. HORIZONTAL SLIDE-VALVE ENGINE ... 42 
 
 V. HORIZONTAL SLIDE-VALVE ENGINE (continued'] 70 
 VI. VERTICAL SLIDE-VALVE ENGINE . 91 
 
 VII. LAUNCH ENGINE 99 
 
 VIII. MARINE ENGINE I0 o 
 
 IX. LOCOMOTIVE ENGINE I2 2 
 
 X. MODEL BOILERS 14 r 
 
 XI. BOILER FITTINGS, ETC 151 
 
 XII. NOTES .168 
 
 INDEX , 77 
 
MODEL ENGINE-MAKING. 
 
 CHAPTER I. 
 
 INTRODUCTION. 
 TOOLS AND CASTINGS. 
 
 THERE may be those who, never having tried 
 their hands at model engine-making, are ready 
 to maintain that such work is a mere waste of time; 
 but, as a matter of fact, there are few leisure occupa- 
 tions better calculated to train the hand, eye, and 
 mind all at one and the same time, and to such good 
 effect. Not only does it afford a most thorough 
 training in all such descriptions of mechanical work 
 as lie within the compass of an amateur's powers, 
 as filing, drilling, turning, fitting, screw-making, etc., 
 but a considerable amount of knowledge is also ac- 
 quired as to the theory and practical application of 
 steam the most important power of the present day. 
 Nor must it be forgotten that James Watt himself, 
 although he had previously by means of a Papin's 
 digester and a syringe made a few experiments, 
 
 B 
 
might nevertheless have failed to turn his attention 
 seriously to the improvement of the steam-engine, 
 had it not been for the model engine placed in his 
 hands for repairs by the authorities of the College of 
 Glasgow ; and while we continue to obtain from the 
 steam-engine as at present only a small proportion 
 of the energy theoretically contained in the fuel con- 
 sumed under the boiler, who can say but that the 
 model-maker of to-day may be a second James Watt 
 to-morrow ? 
 
 Although many of the so-called model engines 
 as, for example, those described in Chaps. II. and 
 III. have no large and useful archetypes, still the 
 construction of these will prove a valuable stepping- 
 stone to the more advanced models described in later 
 chapters ; and in order to impart as much interest as 
 possible to the work of Model Engine- Making, I have 
 in many cases given the proportions of the more 
 important parts as they would be in full-sized 
 engines. 
 
 Before however we take in hand the actual con- 
 struction of a model engine, it will be convenient 
 to devote a preliminary chapter to the consideration 
 of the tools required and the castings to be used. 
 
 First, as to the tools needed, these will be such as 
 are to be found in the workshop of any amateur who 
 has taken up metal-turning. It is sometimes stated 
 that, provided the cylinder is bought ready bored, 
 a lathe is not absolutely necessary. Perhaps not 
 
Introduction. 3 
 
 absolutely, but without it much additional time and 
 patience will be demanded, and the results both in 
 appearance and working will certainly be far less 
 satisfactory. I would therefore by no means recom- 
 mend any one to undertake model engine-making, 
 unless they are provided with a lathe. 
 
 FIG. 
 
 FIG. 2. 
 
 FIG. 3. 
 
 FIG. 4. 
 
 FIG. 5. 
 
 A chuck for holding small drills, and a grip-chuck 
 holding from ^-inch diameter upwards, will be found 
 useful adjuncts to the lathe ; and if the lathe is pro- 
 vided with a face-plate, so much the better. 
 
 A few small chisels of the shapes shown by Figs, i 
 to 5, must be made from good square cast steel : these 
 are for chipping out steam-ports and similar work. 
 
4 Introduction. 
 
 A few drills from T V-inch up to i-inch, of the 
 ordinary shape, will be necessary ; and D-bits of the 
 required sizes may be made as wanted. Fig. 6 is a 
 section of a D-bit at its cutting end, and Fig. 7 is a 
 section taken at a little distance down the shank. 
 
 O 
 
 FIG. 6. FIG. 7. 
 
 A rimer (Fig. 8) will be found useful. It is made 
 from a piece of small steel rod, filed up to a triangular 
 or five-sided shape, and tempered to straw colour. 
 
 FIG. 8. 
 
 The usual gravers, round-nosed and other turning 
 tools will be required, also one or two inside tools ; 
 and a few files, flat, half-round, and triangular, coarse, 
 medium, and fine. A bench vice is almost as indis- 
 pensable as a lathe ; and an Archimedean, or some 
 other form of hand-drill, for small drills will often be 
 found handy in addition to the drill-chuck already 
 named. 
 
 A small steel square, usually known as an "en- 
 gineer's square," must be included in the list of tools 
 required. 
 
 One or two scrapers will also be found useful. 
 These may be made from broken files, the teeth 
 being ground out for a short distance from the broken 
 
Introduction. 5 
 
 end of the file, and the end ground off straight across. 
 These scrapers are to be used for giving the finishing 
 touches to such work as cannot be got sufficiently 
 level by filing. 
 
 A surface-plate must be mentioned among the 
 tools it is very desirable to have, but it forms an 
 expensive item, costing twelve or fifteen shillings and 
 upwards according to size ; and small work, such as 
 slide-valves, etc., may often be got up with sufficient 
 accuracy by using the planed lathe-bed as a testing 
 surface 
 
 A screw-stock with dies and taps may occasionally 
 be useful, but is not indispensable provided there is a 
 good screw-plate among our tools. 
 
 Any other special tools required will be described 
 as they are mentioned. 
 
 It is not, as a rule, worth while for an amateur to 
 make his own screws, except when only one or two 
 of some particular size are wanted ; but, on the other 
 hand, it is not always easy to procure screws suited 
 to one's own screw-plate, unless the latter is standard 
 thread ; neither are screws of standard thread every- 
 where obtainable. Moreover, I must warn my readers 
 against ordering screws, say of different lengths and 
 the same diameter, under the belief that only one 
 pair of taps would be required. As a matter of fact, 
 one maker to whom I applied informed me that his 
 screws of -gVinch diameter and ^-inch length were 
 of a different thread, and consequently required a 
 
6 Introduction. 
 
 different set of taps to those screws which were -g 
 diameter and f-inch in length. I have also received 
 taps which, when measured with a micrometer, were 
 found to be very perceptibly smaller in diameter than 
 the screws for which they were supposed to be in- 
 tended. 
 
 Under these circumstances, the amateur will find it 
 far better to obtain screws of Whitworth standard 
 thread, and these may be had of Messrs. Davies & 
 Timmens, Screw Manufacturers, 24, Charles Street, 
 Hatton Garden, London, E.G. They are sold in 
 quantities of a quarter gross and upwards. Nos. 134, 
 144, and 147 will be found the most useful sizes to 
 keep in stock, and cost by the half- gross is. 6d., 
 is. 8d., and i.r. <^d. respectively, while the postage for 
 the gross and a half would be threepence. The 
 prices per quarter gross are rather higher, and per 
 whole gross rather lower in proportion to those given 
 above. 
 
 Now as to taps. A screw-plate which will suit the 
 above-quoted numbers of screws may be obtained 
 from Messrs. Buck & Hickman, 280, Whitechapel 
 Road, E., for *]s. This screw-plate is not sold as a 
 Whitworth, but will prove to be the same thread. It 
 has twenty-seven holes, and with it are sold a set of 
 taps. 
 
 Plug taps the amateur must make for himself. 
 They should not be like those usually sold, which are 
 made from steel the same size as the tap required. 
 
Introduction. 7 
 
 This plan will answer very well for taps of \ of an 
 inch and upwards, but all taps under of an inch 
 should be made from i-inch steel. The steel should 
 be turned or filed down to the required size over the 
 length that is to be screwed, but the thicker portion 
 must graduate into the threaded part, and there must 
 be no sharp angle. The other end of the steel 
 should be filed to form a tang, as seen in Fig. 9, and 
 
 FIG. 9. 
 
 after the tap has been hardened and tempered, it 
 should be fitted into a bradawl handle ; it will then 
 be found far more handy to use, and will last much 
 longer than the little pieces of screwed steel wire to 
 be purchased at the shops for $d. and 6d. apiece. 
 
 Having at different times experienced considerable 
 difficulty with the screws obtained from various 
 sources for the reasons indicated above, I have been 
 at some trouble to go fully into the matter for the 
 benefit of my readers, and the above remarks embody 
 the result of my investigations. 
 
 Now with regard to castings, the amateur may of 
 course make his own patterns and get them cast at 
 the nearest foundry. In such small castings the 
 shrinkage may practically be ignored, amounting as 
 it does to no more than | of an inch in nine or ten 
 inches. But in these days of cheap castings supplied 
 
8 Introduction. 
 
 ready to hand, I imagine there are few amateurs who 
 will care to make their own patterns and take the risk 
 of working up castings that have possibly been cast 
 at a foundry where the workmen are unaccustomed 
 to this class of work. For this reason I have not 
 included a chapter on pattern-making in this volume; 
 and indeed any amateur who feels a longing to make 
 his own engine from the very beginning will learn 
 more in half an hour from the inspection of a few 
 patterns which will be shown him by any good- 
 natured foreman of a foundry, than he would gather 
 from a whole bookful of descriptive writing. 
 
 Supposing then that the castings are to be pur- 
 . chased from some one of the numerous firms who 
 advertise these goods, the following points should be 
 especially considered in making a selection. The 
 castings should be even and free from holes, and 
 should not present too rough a surface ; also all the 
 parts should be of such size and weight that when 
 bored, turned, or filed down, as the case may be, they 
 will still be thoroughly substantial, both in appearance 
 and in fact. As amateurs (especially those living in 
 the country) often find a difficulty in obtaining such 
 things, I have written to several dealers, and am able 
 to append the following particulars of the castings 
 they supply. It must, however, be remembered that 
 these particulars, except where otherwise stated, have 
 been given me by the makers, and I cannot therefore 
 guarantee their correctness further than by naming 
 
Introduction. 9 
 
 the sources from which I obtained the information. 
 I subjoin the price asked by each maker for a certain 
 size of engine, in order that my readers may have 
 some idea of the various scales of charges. 
 
 Several of the engines described in this volume 
 were made from castings supplied by Messrs. Lucas 
 & Davies, of 21, Charles Street, Hatton Garden, who 
 are themselves practical model-makers, and they will 
 have much pleasure in showing to any amateur who 
 will call upon them engines made up from sets of 
 castings precisely similar to those they sell, so that 
 the purchaser can judge of the appearance of the 
 finished model before buying the castings. Messrs. 
 Lucas & Davies charge for a set of horizontal slide- 
 valve engine castings, one-inch bore and two-inch 
 stroke, 4^., the bed-plate and columns for this set 
 being 2s. 6d. extra. 
 
 Mr. R. A. Lee, of 76, High Holborn, supplies 
 castings for models of all descriptions, from those for 
 a single-action oscillating cylinder engine at 2s. the 
 set, to those for a Great Northern express locomotive 
 engine at 7 LOS. All the castings supplied by this 
 maker which require to be turned, are fitted with 
 tenon pieces, so that they may be easily held in a 
 grip-chuck for both turning and boring. Mr. Lee's 
 catalogue, price 6d., will prove very useful to any of 
 my readers who contemplate taking up the work in 
 question. They will find that he charges for a set of 
 horizontal slide-valve engine castings : 
 
I O Introduction. 
 
 Cylinder, one-inch bore, two-inch stroke 
 
 Best quality . . . .6s. set 
 Common . . . . 4s. 6d. 
 Cylinder, two-inch bore, four-inch stroke 
 
 Best quality .... 2Js. 
 
 Mr. A. A. Dorrington, West Gorton, Manchester, 
 has sent me his price list and some designs. He 
 charges for castings of an engine 
 
 Two-inch bore, three and a half-inch stroke 
 
 I2s. 6d. set 
 
 Three-inch bore, four-inch stroke 28^. ,, 
 Working drawings, 2s. and $s. respectively. 
 Mr. A. Wood, 15, Dalley Street, Lower Broughton, 
 Manchester, supplies castings with tenon pieces to 
 those parts requiring turning at the following rates : 
 One-inch bore, two-inch stroke . $s. iod. set 
 One and a quarter-inch bore,, two and a half-inch 
 
 stroke . . . . ?s. 6d. set 
 Mr. Wood's prices for boring cylinders and such 
 work appear to be exceptionally low. 
 
 Mr. J. Tomlin, 28, Highfield Terrace, Barnsley, 
 supplies castings and forgings of half-horse power, 
 horizontal and launch engines. 
 
 Cylinder, two and a half-inch bore, three and a half- 
 inch stroke . . . . 12s. 6d. set 
 Copper tube and sheet and copper rivets, are 
 supplied by Messrs. Stanton Bros., metal merchants 
 and workers, of 73, Shoe Lane, London, E.C. 
 
Introduction. 1 1 
 
 In case any of my readers should wish to obtain 
 sets of castings exactly similar to those described, I 
 may here mention that the castings for the engine 
 described in Chap. II. were obtained from Mr. R. A. 
 Lee, and the various sets mentioned in Chaps. VII. to 
 IX., together with the separate castings described in 
 Chapter XL, were supplied by Messrs. Lucas & Davies, 
 of Charles Street, Hatton Garden. 
 
CHAPTER II. 
 
 SINGLE-ACTION OSCILLATING CYLINDER 
 ENGINE. 
 
 A DESCRIPTION of the fitting up of a model 
 single- action oscillating cylinder engine is 
 placed first in the series of models described in this 
 volume, because, owing to its simplicity and to the 
 fact that it is not necessary to bore the cylinder, 
 few tools are required, and the beginner is more 
 likely to succeed in its construction ; while, at the 
 same time, the cost of the requisite materials is so 
 trifling that it is not a matter of great importance 
 should any part be spoilt and have to be replaced. 
 
 Thus, although the single-action model has no 
 useful archetype, it is itself useful as a stepping-stone 
 to the modelling and comprehension of more com- 
 plicated engines, especially those belonging to the 
 oscillating class ; and it may not be without interest 
 to note that James Watt himself constructed at least 
 one model of an oscillating engine, a drawing of 
 which is given in Fig. 10. 
 
 The castings, etc., required for the model in ques- 
 
FIG. 10. 
 
14 Single- Action Oscillating Cylinder Engine. 
 
 tion, together with a piece of brass from which to 
 form the bed-plate, cost about two shillings. The 
 castings consist of the fly-wheel, a pair of standards, 
 the crank, steam-block, cylinder bottom and top, and 
 piston ; and a small piece of brass tubing is supplied 
 with the castings for the body of the cylinder. 
 
 The cylinder being the most important part, we 
 will attack it first. 
 
 Such a cylinder as the one under consideration 
 viz., ^-inch bore, and i-inch stroke single action 
 will not require boring, but the interior must be 
 smoothed out. In order to accomplish this, turn 
 down a piece of soft wood about 5 inches in length 
 to a slightly taper form at one end, in such a man- 
 ner that the smallest part of the tapering end will 
 pass easily through the small piece of tube which 
 is to form the cylinder. From this end the piece of 
 wood should increase in size, till it is just so large 
 that it would require hammering to drive it through 
 the cylinder, and from this point to the other end it 
 should be cylindrical. 
 
 This piece of wood being turned, it is to be 
 mounted between the lathe centres, with the piece 
 of cylinder tubing upon the small end of it. Now 
 coat the wood with a little fine emery and oil, 
 and holding the bit of tube between the fingers, 
 set the lathe in motion, and grind the tube out 
 smooth. Before taking it out of the lathe, it may 
 be forced up to that end of the wood which has not 
 
Single-Action Oscillating Cylinder Engine. 15 
 
 been used in the grinding process. This part will 
 now be just large enough to hold it securely, while 
 the ends are turned off true, and the outside polished 
 with a piece of fine emery paper. 
 
 If the lathe be a good one, and the owner should 
 not care to use it for grinding purposes, this part of 
 the process may easily be carried out by hand. 
 
 The next part to be undertaken is the bottom of 
 the cylinder. This piece must be held in a grip- 
 chuck by the tenon attached to the under side of 
 the casting, and the interior of the piece is to be 
 turned out until the cylinder- tube will just slide 
 stiffly into it, the bottom being turned out square, 
 and the top edge neatly turned off either square or 
 to a bevel from the outside, according to fancy. Now 
 take the cylinder bottom out of the chuck, and 
 placing it in the vice file off the tenon, leaving the 
 bottom square and smooth. File up the outside all 
 round, leaving it as smooth and truly round as possi- 
 ble; and file also the bearing-face, that is, the circular 
 flat piece attached to one side of the casting, till it is 
 smooth and level and as square as possible to the 
 top, and consequently parallel with the inside. The 
 centre of this face should now be found, and a circle 
 struck from it as near the edge as can be managed ; 
 and then using this circle as a guide, the edge must 
 be filed up round ; or if the piece can be con- 
 veniently chucked for the purpose, it may be again 
 mounted in the lathe, properly centred (taking care 
 
1 6 Single- Action Oscillating Cylinder Engine. 
 
 that the bearing-face is exactly at right angles to 
 the mandrel), and the face and edge turned up. If 
 this is properly done, this important part will require 
 no further finishing. 
 
 The piston, a small circular casting with a shallow 
 groove running round it, is now to be turned up. 
 The turning of the lower face and edge can be done 
 while the piece is held in the grip-chuck by its tenon, 
 a flat groove being turned in the edge to take the 
 packing ; and while still in the lathe, it should be 
 drilled for tapping with the screw for the piston-rod. 
 The piston is now to be reversed, the tenon cut off, 
 and the upper side turned. The centre hole may 
 then be tapped, and the piece placed on one side 
 for the present. 
 
 The top of the cylinder is formed from a casting 
 very similar to that used for the piston, but rather 
 larger. It is to be turned up in the same manner as 
 the piston, but the edge, instead of being grooved, 
 will be turned down on the lower side, leaving a 
 flange on the upper side; and the edge, where turned 
 down smaller, should be left very slightly conical, and 
 of such a diameter that it will be a stiff fit in the 
 cylinder tube. The top thus made forms a sort of 
 plug in the upper opening of the cylinder ; but 
 it might also be turned out hollow, and fitted on to 
 the cylinder as a cap. In either case the top must be 
 drilled through while in the lathe. The tenon, instead 
 of being cut off, may be turned up as shown in Fig. 
 
Single- Action Oscillating Cylinder Engine. 17 
 
 12. This will give the cylinder a more finished 
 appearance. 
 
 The steam-block (Fig. n) and the crank have only 
 at present to be filed up, and left as neat in shape 
 and as smooth as possible. 
 
 FIG. ii. 
 
 The fly-wheel must be centred, drilled, and mounted 
 on a temporary shaft for turning. This will be found 
 better in most cases than turning it on its own shaft, 
 there being in the latter mode considerable risk of 
 breaking the shaft, unless this latter is made so stout 
 as to look clumsy in the finished model. The fly- 
 wheel need only be turned upon its edge, the sides 
 being made smooth with a file. 
 
 The standards and the bed-plate may now be filed 
 up, the openings in the standards being worked out 
 smooth with round and half-round files. The bed- 
 plate must be squared up with the aid of the steel 
 square. 
 
 Some screws and nuts will be required in the fitting 
 together of the several parts, and these, if not pur- 
 chased, should now be made. The nuts may be 
 made of any piece of stout brass about one-tenth of 
 
 C 
 
1 8 Single- Action Oscillating Cylinder Engine. 
 
 an inch thick, as, for instance, an old clock-plate. 
 From some such piece cut off with a metal saw, or 
 otherwise, a strip 2\ inches long by f of an inch 
 wide ; mark this strip off into square pieces, and 
 file about half-way through at each mark. Centre- 
 punch each square, and drill through with a drill 
 suited to the tap which is to be used, which latter 
 should be about one-tenth of an inch in diameter. 
 Now tap each hole, when you will find yourself 
 supplied with a row of nuts which only require to 
 be broken off from the strip and filed up at the edges. 
 If preferred, the corners also may be filed off, and 
 the nuts thus made octagonal. 
 
 For the screws, take a piece of brass wire about 
 No. 6, New Standard Gauge, and file down half an 
 inch at one end, till it is the right size to take the 
 same gauge of screw-thread as that used for the nuts. 
 Cut the thread with the screw-plate, and cut off the 
 screw with a head about one-eighth of an inch deep. 
 File the head up flat in the vice, and notch with a 
 knife-file or saw ; or if preferred, rather larger wire 
 may be used in the first instance, and the heads 
 filed up either square or octagonal, in which case 
 they will not have to be notched. Of course, if a 
 proper chuck is available, it will be quicker to turn 
 down the wire for the screws in the lathe. 
 
 Now with the square mark on the bed-plate two 
 lines exactly parallel, the first about a quarter of an 
 inch from the edge of the bed-plate, the second 
 
Single- Action Oscillating Cylinder Engine. 19 
 
 about one inch distant from the first. Drill through 
 the two feet of each standard with a drill a trifle 
 larger than the screws you are using, so that the 
 holes when drilled will allow the screws to pass 
 through them. Place one of the standards on the 
 bed-plate with the outside of its feet against the first 
 line, and mark the bed-plate through the drilled 
 holes. The second standard should now be placed 
 with its feet just the further side of the second line ; 
 and again mark. This should leave about three- 
 quarters of an inch clear space between the standards. 
 It is as well to so mark the standards and bed-plate, 
 that the standards may, in fitting up, be again placed 
 without difficulty in their original position. 
 
 To mark the bed-plate it is a good plan to make 
 a small centre-punch of a piece of steel wire the 
 same size as the screws used, and about half an inch 
 in length. This should be filed at the end to rather 
 an obtuse but at the same time sharp point, and 
 hardened ; it is then to be placed in the hole in the 
 standard or other piece, the position of which we 
 desire to mark on the bedplate. It will stand upright 
 without being held, thus leaving the left hand free 
 to support the standard, and a sharp blow upon it 
 with a light hammer will centre-punch the bed-plate 
 ready for drilling. 
 
 The four holes for the standards may now be 
 drilled in the bed-plate. These must be the same 
 size as those already drilled in the standards ; and 
 
2O Single- Action Oscillating Cylinder Engine. 
 
 the standards may now be bolted to the bed-plate, 
 and tested with a square. They will probably be 
 found to stand considerably out of the perpendicular, 
 in which case they must be taken off the bed-plate, 
 and the feet must be filed and fitted until the stand- 
 ards, when bolted to the bed-plate, stand perfectly 
 perpendicular to it, and parallel with each other. 
 
 A centre mark is now to be made on each side in 
 the centre of the solid top piece of each standard, 
 and the standards being bolted to the bed-plate, and 
 a piece of wood placed between them to prevent 
 their giving under the pressure, the hole for the fly- 
 wheel shaft may be bored in the lathe through both 
 standards at one operation ; this hole may be from 
 an eighth to a tenth of an inch in diameter. 
 
 The standards can however, if preferred, be bored 
 for the fly-wheel shaft before their position is marked 
 upon the bed-plate. In this case the shaft also should 
 be turned and finished before the position of the 
 standards is determined, so that it can be placed in 
 its bearings while marking the bed-plate through 
 the feet of the standards. This is necessary in order 
 to ensure the coincidence of the two bearings. The 
 holes in the bed-plate may also take the form of 
 short slots, so as to allow a slight adjustment to be 
 made in the position of the standards. 
 
 The shaft may be rather larger than the bearings 
 bored for it in the standards, it being turned down at 
 the two ends to the necessary extent, thus leaving 
 
22 Single- Action 'Oscillating Cylinder Engine. 
 
 a shoulder to work against the inner side of each 
 standard ; or the shaft may be of the same diameter 
 throughout, with a shallow and narrow groove turned 
 in it where it passes through one of the standards, 
 and in this case a small set screw must be fitted into 
 the bearing from the side or top, and after the shaft 
 is in position, this set screw is screwed in till its 
 point just enters the groove in the shaft, thus prevent- 
 ing any motion of the latter from side to side. 
 
 The fly-wheel must fit the shaft perfectly. A key- 
 way must be filed in the fly-wheel with a small square 
 file, and a corresponding flat filed upon the shaft. 
 After the wheel is in place, a small and very slightly 
 tapered key or wedge must be driven into the space 
 thus provided. During this operation the shaft 
 should be held in the vice in an upright position, 
 with pieces of lead between it and the jaws of the 
 vice to preserve it from injury, and the fly-wheel 
 being placed in position, the key is gently tapped in 
 with a light hammer. 
 
 Before proceeding further, it will be found best to 
 make a full-sized working drawing of the engine, 
 as shown in Fig. 12, where A B is the perpendicular 
 centre line, C one of the standards, D the cylinder, 
 E the fly-wheel, F the crank, G the fly-wheel shaft, 
 H the crank-pin, I the steam-block, K the piston, 
 and L the piston-rod. 
 
 This drawing is made from an engine constructed 
 from castings supplied by Mr. Lee, and it will be 
 
Single- Action Oscillating Cylinder Engine. 23 
 
 seen that the cylinder might with advantage have 
 been cut shorter, the cylinder as sent out being 
 adapted for a ij-inch stroke, while the- crank only 
 allows a I -inch stroke. 
 
 Fig. 13 shows the same engine as seen from above. 
 
 FIG. 13. 
 
 C C are the standards, F is the fly-wheel, S the 
 steam-block, and T the top of cylinder. 
 
 Now, having our working drawing ready, we will 
 proceed with the fitting. The bearing surface of 
 the cylinder, if not turned up in a lathe, must now 
 
24 Single- Action Oscillating Cylinder Engine. 
 
 be finished off as level as possible. For this it should 
 be filed up with a fine file, and then rubbed with 
 water on a good flat stone. It is useful to have a 
 quick cutting stone, and to keep it for this sort of 
 work. One face of the steam-block must also be 
 finished in the same way, and the holes for the 
 screws by which the latter is to be bolted down to 
 the bed-plate may also be bored at this stage of the 
 proceedings. 
 
 A line should now be marked down the centre of 
 the bearing surface of the cylinder, and another 
 through the centre of the face of the steam-block, as 
 seen at A B, Figs. 14 and 15. Upon the former line 
 punch two centre-marks on the cylinder face, in about 
 the positions marked D and E in Fig. 15 ; also cen- 
 tre-punch the crank for the crank-pin and fly-wheel 
 shaft. 
 
 Now draw the diagram as shown in Fig. 16, as 
 follows : at right angles to the straight line A B draw 
 C D, equal in length to the distance between centre- 
 marks on crank, and draw D E equal to distance 
 between crank-pin H (Fig. 12) and centre-mark D 
 (Fig. 15), when the engine is in the middle of its 
 stroke. (This may be easily found by adding 
 dotted lines to Fig. 12, showing positions of cylinder, 
 piston, and crank at half-stroke, and of centre-mark 
 D.) Continue D E to F, equal to distance between 
 centre-marks D E (Fig. 15). 
 
 Now taking the steam-block (Fig. 14), centre-punch 
 
Single- Action Oscillating Cylinder Engine. 2$ 
 
 on the flattened side the mark F to correspond with 
 the mark D on cylinder face, and with the radius FK 
 equal to D E (Fig. 15) describe the arc H K. Turning 
 to the diagram Fig. 16, take the distance FH with 
 
 compass, and mark off this distance on Fig. 14 on 
 each side of the centre-line A B. The centre-marks 
 for the steam-ways must be made upon the arc H K, 
 and just within the distance marked off from the 
 centre-line, so that the steam-ways themselves, when 
 
26 Single-Action Oscillating Cylinder Engine. 
 
 drilled, may be just within the mark, as seen at H 
 and K (Fig. 14). The steam-ways are to be drilled 
 half-way through the steam- block with a T V-inch 
 drill ; a rather larger drill is then to be taken, and 
 with it a hole is to be drilled from each side of the 
 steam-block into the T V-inch steam-way just men- 
 tioned. This will be made quite clear by a glance at 
 Figs. 17 and 18, Fig. 18 being a section of the steam- 
 block on the line A B of Fig. 17, and H and K the 
 steam-ways. 
 
 
 F 
 
 
 
 
 
 
 
 
 \ 
 
 n 
 
 n 
 
 
 
 
 u. 
 
 
 
 FIG. 
 
 17- 
 
 
 
 
 is 
 
 I 
 
 O 
 
 FIG. 1 8. 
 
 Bore the holes D and E in cylinder-face with a 
 T V-inch drill, as marked in Fig. 15, and tap a screw 
 in D. Take a piece of brass wire one inch long, and 
 screw about J inch at one end to fit D, and J inch 
 at the other end ; this is to be screwed into the 
 hole D in the cylinder-face, and forms the pivot upon 
 which the cylinder will oscillate. Take a piece of 
 brass, rather under half an inch in diameter, and after 
 
Single- Action Oscillating Cylinder Engine. 27 
 
 boring it to take the same thread as that with which 
 the hole D (Fig. 15) has been screwed, turn it down, 
 partly cut off about one-eighth of an inch, mill the 
 edge, finish cutting it off with a parting-tool, and screw 
 the hole in the centre with the same tap as that used 
 for D. Now take a piece of wire a trifle larger than 
 the piece used for the cylinder pivot, and round it 
 twist a piece of cold-drawn brass wire to form a spiral 
 spring half an inch in length. 
 
 Bore the hole F in the steam-block (Fig. 17) a 
 trifle larger than D (Fig. 15), so that the cylinder 
 pivot will pass through it easily, yet without having 
 room for play. 
 
 Tap the ends of the steam-ways at the sides of 
 the steam-block for steam and exhaust pipes respec- 
 tively. 
 
 Give the cylinder-face and surface of steam-block 
 a final rub with a little oil upon a good flat oil-stone 
 to take off the burrs at the edges of the drilled holes, 
 etc. Probably no great difficulty will be experienced 
 in getting the surfaces true and flat. To ascertain 
 whether you have succeeded in obtaining a good fit, 
 smear one of the surfaces with a little red lead, and 
 then press the other against it. 
 
 Screw the pivot into its place in the bearing-face 
 of the cylinder, push it through the hole bored for 
 it through the steam-block, pass the spiral spring 
 over the end of the wire projecting on the other side 
 of the steam-block, and screw on the small milled 
 
28 Single-Action Oscillating Cylinder Engine. 
 
 nut. It will be seen that by means of this nut the 
 tension of the spiral spring can be altered, and the 
 surfaces of the cylinder-face and steam-block brought 
 together with more or less pressure as required. 
 
 The crank casting may now be bored and tapped, 
 and the shaft cut off to project f of an inch be- 
 yond its bearings, and one end screwed to take 
 the crank. The crank -pin is formed of a small 
 piece of steel wire, \ or f of an inch long, one 
 end being screwed to fit the casting. Bore a piece 
 of brass measuring about f by \ of an inch with 
 a hole a trifle larger than crank-pin. File up this 
 piece of brass square, or, if preferred, it may be 
 turned off a piece of rod in the same manner as the 
 tension nut was formed. Drill a hole in the edge, 
 and tap this to take the top of the piston-rod, which 
 must also be screwed to fit, after it has been cut off 
 to the right length ; this may be ascertained by a 
 reference to the working drawing. 
 
 The steam-block may now be placed in position 
 upon the bed-plate, with the crank upon the shaft, 
 and the head of the piston-rod upon the crank-pin ; 
 and taking care that the centre upon which the piston 
 works is directly under and parallel with the shaft of 
 the fly-wheel, mark the position for the holes in the 
 bed-plate which are to receive the screws by which 
 the steam-block is to be held in place. It will pro- 
 bably be found that the steam-block comes partly 
 between the legs of the front standard. 
 
Single- Action Oscillating Cylinder Engine. 29 
 
 The holes in the bed-plate are now to be drilled, 
 and the steam-block bolted down to it. It may 
 be found necessary to make the heads of the bolts 
 which secure the steam-block very shallow, so that 
 they may not interfere with the screwing in of the 
 steam and exhaust pipes. The piston must be 
 packed with a little tow, and oiled ; and now, with 
 a little oil upon the shaft of the fly-wheel and on 
 the cylinder bearings, our engine stands complete 
 and in working order. 
 
CHAPTER III. 
 
 SINGLE-ACTION OSCILLATING CYLINDER 
 LOCOMOTIVE. 
 
 THIS, the most simple form of steam locomotive, 
 must not be despised by the amateur worker ; 
 for although it is not like the slide-valve locomotive, 
 an actual model of a full-sized engine, its construc- 
 tion will give some good practice in fitting, while it 
 may be finished in a far shorter time than the more 
 complicated slide-valve locomotive. 
 
 The castings for the engine now in question cost 
 6s. 6d., and the following parts are comprised in it : 
 
 The bed-plate or frame, seen in Fig. 23, 
 
 Piece of brass tube to form the body of the boiler, 
 
 Two cast boiler ends, 
 
 Piece of brass tube for the chimney, 
 
 Casting for top of chimney, 
 
 Steam-dome, 
 
 Two number-plates, 
 
 Two buffers (cast in one piece), 
 
 Two driving-wheels, 
 
 Two small wheels, 
 
 Two cylinder blocks (cast in one piece, Fig. 19), 
 30 
 
FIG. 19. 
 
 FIG. 20. 
 
 f 
 
 FIG. 21. 
 
32 Single- Action Oscillating Cylinder Locomotive. 
 
 and a casting (Fig. 20), from which may be formed 
 the steam-tap, whistle, and gauge-tap. 
 
 An engine of this class can very well be made 
 without any castings except for the wheels ; in that 
 case the bed-plate is cut out of stout brass and 
 turned down as shown by the dotted lines in Fig. 21. 
 Steam-blocks are soldered on and connected by a 
 steam-pipe, into the centre of which the pipe from 
 the boiler is soldered. A prettier model, however, 
 and one that will prove in every way more satis- 
 factory, will be turned out if the proper castings are 
 purchased. 
 
 The first thing to be done is of course the filing 
 up of the separate parts, and we will commence with 
 the bed-plate. This should be filed up bright all 
 over, the grooves in the foot-plate being left as cast, 
 or filed out smooth with a triangular file, according 
 to taste. The steam-blocks on each side must be 
 filed smooth, flat, and perfectly square with the top 
 of the bed-plate. The four wheels must be turned 
 up ; these present no difficulty, only it must be re- 
 membered that each pair must be of exactly the 
 same outside diameter, otherwise the engine will not 
 run straight without rails. When the wheels have 
 been turned, the bed-plate may be bored for the 
 axles. The position of the bearings in the lugs cast 
 for them on the underside of the bed-plate may easily 
 be found in the following manner : 
 
 Make a full-sized drawing of one side of the bed- 
 
Single-Action Oscillating Cylinder Locomotive. 33 
 
 plate, and (parallel with the top of the bed-plate) 
 draw a line rather more than the diameter of the 
 small wheels below the bed-plate. Now draw two 
 circles to represent the wheels, just touching with 
 their circumference the lower parallel line,, and the 
 centres of these circles will mark the positions for the 
 axle-bearings. The axles will be made of steel 
 rather over \ of an inch in diameter, and the wheels 
 may be either keyed on or screwed, the latter method 
 being the more convenient, as the wheels can then 
 be easily taken off when required. The carriage 
 should at this point be put together and tested by 
 running it on a smooth and level surface,., to see if it 
 runs straight. 
 
 The boiler may now be taken in hand.. The top 
 must be soldered on to the funnel-tube, and this part 
 may then be put into the lathe and polished with 
 emery-paper ; the steam-dome must be.- turned up 
 and the under side filed to fit the curve of the boiler. 
 Two holes must be drilled exactly opposite to each 
 other at one end of the boiler-tube, to take the 
 funnel which may be at once soldered in. If the 
 steam-pipe is to be inserted into the dome, a hole i 
 of an inch in diameter must be made in the boiler, 
 and another T V of an inch in diameter in the centre 
 of the dome to receive the steam-pipe. These holes 
 must of course be made before the dome is soldered 
 on ; and when this is done, care must be taken to have 
 the dome in a line with the funnel. Between the 
 
 D 
 
34 Single- Action Oscillating Cylinder Locomotive. 
 
 dome and the end of the boiler-tube let there be 
 soldered on to the inside of the tube a piece of brass 
 as thick as the tube itself or somewhat thicker, and 
 half an inch or so square, then bore and tap the part 
 thus lined for a quarter-inch screw. This is the man- 
 hole, and although the size given here is smaller than 
 usual, the engine will have a neater appearance ; the 
 small man-hole is more easily kept steam-tight, and 
 with a short length of indiarubber tubing to act as a 
 siphon, there need be no difficulty about filling the 
 boiler. 
 
 The ends of the boiler must next be filed up and 
 soldered on. A little solder should be run round the 
 flange of each end-piece and round each end of the 
 boiler-tube itself. Now stand the boiler-tube in 
 position upon the end to be soldered, and a soldering- 
 iron or blow-pipe flame run round the joint will unite 
 the two parts. 
 
 The cylinder-tubes will next be ground out smooth, 
 as described in Chap. II. Two pieces of sheet brass 
 must be filed up to fit into the cylinder ends, and one 
 soldered into one end of each. 
 
 The steam-blocks (Fig. 19) must then be sawn 
 apart, and the groove in each block filed out to fit 
 the cylinder-tubes, which must then be soldered to 
 the blocks. A hole T V of an inch diameter is to be 
 drilled through the steam-block into the cylinder 
 close to its lower end ; and about T V of an inch above 
 it, a pin made of steel wire rather over T V of an inch 
 
Single- Action Oscillating Cylinder Locomotive. 35 
 
 in diameter and f of an inch in length, is to be 
 screwed into the cylinder face. This pin must also 
 be screwed at its free end to take a small nut. 
 
 The cylinder covers must be turned up, and should, 
 when finished, fit stiffly over the tops of the cylinders, 
 the hole for the piston rod being of course bored 
 while the cover is in the lathe. The pistons should 
 be turned up from a piece of brass rod, and bored 
 and tapped for the piston-rods ; the latter are made 
 of steel, T V to -aV of an inch in diameter and 2 
 inches in length. Heads for the piston-rods are 
 turned up from \ inch brass rod to the shape shown, 
 
 a hole being drilled through each to take the driving- 
 pins of the driving-wheels. 
 
 The driving-pins are made of pieces of steel wire 
 the same size as the piston-rods, and about half an 
 inch long. They must be screwed into the solid part 
 of the driving-wheels, at a distance of half the piston- 
 stroke from the centre of the wheels. 
 
 The steam-ways may now be made. It will be 
 found that, underneath the rear end of the bed-plate 
 casting, the metal is thick enough to allow of the 
 steam-ways being bored in it. A hole T V of an inch 
 in diameter is first bored from one steam-block half- 
 way through, and a similar hole from the other 
 steam-block joins it. These steam-ways should be 
 
36 Single- Action Oscillating Cylinder Locomotive. 
 
 bored as low down as they safely can. The hole for 
 the steam-pipe is made underneath, if the engine is 
 to be fitted up as shown in Fig. 24, or it may be 
 made from the top, and the steam-pipe brought to it 
 from the end of the boiler instead of coming from 
 the dome at the top. A line must now be drawn 
 through the centre of the steam-way and the driving- 
 pin, with the driving-wheel in the position it would 
 occupy with the piston at half-stroke. Upon this 
 line should be drilled the hole for the cylinder-pin, of 
 course at the same distance from the steam-way as 
 the pin itself is from the steam-port in the cylinder. 
 Grooves are cut in the steam-blocks for the exhaust 
 steam, as shown at A in Fig. 22. To find the posi- 
 
 FlG. 22. 
 
 tion of the exhaust, draw a line running through the 
 centres of cylinder-bearing and driving-wheel, and 
 the exhaust will be the same distance above such a 
 line as the steam-way is below it. 
 
 The cylinder face must be ground to the steam- 
 block with a little fine emery and oil, the cylinder 
 being worked backwards and forwards as it will ulti- 
 mately work under steam, and the surfaces may then 
 
Single- Action Oscillating Cylinder Locomotive. 37 
 
 be washed and finished off by working with a little 
 putty powder in place of the emery. The cylinder 
 faces are kept against the steam-blocks by means of 
 spiral springs and nuts, as explained in the chapter 
 on an oscillating cylinder engine. One of thes 
 springs may be seen in Fig. 23. 
 
 FIG. 23. 
 
 The engine may now be fitted together, the steam- 
 pipe being soldered into the boiler, and into the hole 
 made for it in the bed-plate. If a safety-valve is to 
 be added to the boiler, a steam-tap may also be 
 added ; but if no safety-valve is put in, it is better to 
 connect the boiler direct with the steam-ways. 
 
 The screw for the man-hole of the boiler should 
 be made with a rounded head milled at the edge ; 
 a little hemp or a leather washer will make it steam- 
 tight. The number-plates have each a flange by 
 which they are to be soldered on. 
 
 In putting on the driving-wheels, be careful to see 
 
38 Single- Action Oscillating Cylinder Locomotive. 
 
 that when the driving-pin of one wheel is at its high- 
 est point that of the other wheel is at its lowest. If 
 the wheels are screwed on to the axles, it may be 
 necessary to file a flat upon one of each pair, and 
 drive in a wedge when the wheels are in the correct 
 position. With only one wheel of each pair to screw 
 on, the wheels will still be easily taken off, should this 
 at any time be necessary. 
 
 A small slip of mahogany should be screwed on to 
 the front of the engine-frame, and the buffers having 
 been turned up and separated are fastened into two 
 holes in the wood. Fig. 24 shows the finished engine. 
 
 Fig. 25 shows the lamp ; this is made in the fol- 
 lowing manner. Make first a tin box about 2 by \\ 
 by I inch, for material a piece of an empty meat-tin 
 will do as well as anything. Then a piece of f inch 
 brass tubing, 2f inches long, is bent as shown in the 
 illustration, and a short piece half an inch long is 
 soldered into it about an inch from the curved end. 
 This branched tube is now soldered into the tin-box, 
 and to the other end of the box is soldered a hook 
 made of a piece of wire doubled and bent, by which 
 the lamp may be hooked on to the foot-plate of the 
 engine, while another piece of wire soldered to the 
 front of the lamp rests upon the axle of the front 
 wheels. The hole in the top of the lamp for filling 
 may be closed either with a cork or a screw. A 
 small pinhole should be made in the top of the lamp 
 to allow air to enter as the spirit is burnt away. 
 
4O Single-Action Oscillating Cylinder Locomotive. 
 
 The casting for the taps and whistle (Fig. 20), is 
 given here, because being supplied with the set the 
 reader might otherwise be puzzled as to its use ; but 
 these adjuncts are not necessary to this engine, and 
 the method of making them will be fully described 
 in another chapter. 
 
 A double-action oscillating cylinder locomotive 
 may be made by using the double-action cylinders 
 described in the chapter dealing with the marine 
 engine ; in this case the cylinders may be placed on 
 the outside of the frame, and kept up to the steam- 
 block by means of spiral springs as in the engine just 
 described, or they may be placed inside the frame 
 and kept in place by means of set-screws as in the 
 marine engine; in the latter case the driving axle 
 must of course be provided with two cranks. The 
 method of making a double crank is described in 
 another place. 
 
CHAPTER IV. 
 
 HORIZONTAL SLIDE-VALVE ENGINE. 
 
 THE CYLINDER. CYLINDER COVERS. STEAM-CHEST 
 AND STUFFING-BOXES. 
 
 THIS engine will present considerably greater 
 difficulties in construction than those described 
 in previous chapters ; indeed, it will tax to the utmost 
 the amateur's capabilities, whether in turning, drilling, 
 filing, or fitting. Still, with careful attention to the 
 smoothness, flatness, squareness, and straightness of 
 the working parts, all obstacles may be overcome, 
 and the result will not only be a model of handsome 
 appearance, but one which works upon exactly the 
 same principles as the half and one-horse power 
 engines in every-day use in many small workshops ; 
 and indeed the mechanism of the most powerful loco- 
 motive is but an adaptation with additions of the 
 model we are now about to construct. 
 
 It is not advisable to take too small a size for the 
 first model made ; perhaps the most easily managed 
 size is a model having a cylinder of one-inch bore 
 and two-inch stroke. In a smaller size, the minute- 
 
o 
 
 o 
 
 o 
 
 o 
 
44 Horizontal Slide- Valve Engine. 
 
 ness of the details and the delicacy of some of the 
 parts might lead to difficulties ; while, on the other 
 hand, in the larger sizes we find that the greater 
 extent of some of the surfaces requiring to be made 
 level and steam-tight renders it less easy to obtain 
 the needful accuracy in fitting and smoothness in 
 working. 
 
 When purchasing the castings, the cylinder may be 
 had ready bored at an additional cost of about 2s. ; 
 and I recommend all who are not possessed of a good 
 lathe, and are not also very certain of their own 
 powers, to get this important part of the work done 
 for them. For the benefit, however, of those who 
 prefer doing everything for themselves at all risks, I 
 shall describe several methods of boring the cylinder, 
 depending upon the apparatus available. 
 
 Fig. 26 shows the bed-plate, and Figs. 27 to 41 
 show most of the castings usually supplied in what 
 is called a set ; to those shown in the engravings 
 must be added a fly-wheel, which requires no illustra- 
 tion. It may here be mentioned that Figs. 31, 32, 
 and 33 are supplied in pairs, and that several of the 
 smaller parts in these sets are often cast in one piece ; 
 thus, Fig. 34 is really a casting of four small pillars 
 in one length, Fig. 29 will form the two guide-blocks, 
 and Fig. 41 the glands for the stuffing-boxes of the 
 cylinder and steam-chest respectively. Fig. 40 is 
 sometimes omitted from the set ; in this case it must 
 be worked up from a forging, which any blacksmith 
 
FIG. 27. 
 
 FIG. 29. 
 
 FIG. 28. 
 
 FIG. 30. 
 
46 Horizontal Slide- Valve Engine. 
 
 will turn out if supplied with a full-size drawing of 
 what is required. The crank (Fig. 42) is worked up 
 from a forging. 
 
 THE CYLINDER. This is by far the most important 
 part of the engine, for it is in the cylinder that the 
 steam exerts its expansive power ; or, in other words, 
 it is here that the heat generated in the furnace is 
 turned into work ; and upon the accuracy with which 
 the cylinder is bored and fitted, largely depends the 
 effectiveness of the engine. Even in a model, where 
 the highest degree of effectiveness is not a consider- 
 ation, it will be impossible to get our engine to work 
 evenly and well unless the most careful attention has 
 been given to this part of the construction. Those 
 of my readers who reside in the neighbourhood of 
 London, and who, after procuring their castings, find 
 themselves unable to get over the boring of the 
 cylinder to their satisfaction, will find Mr. Smelt, of 
 7, Goldsmith's Row, Gough Square, very attentive to 
 their requirements. Mr. Smelt will undertake any 
 machine work, either small or large, at a moderate 
 price, and will, I think, be glad to render any assist- 
 ance in his power to amateurs in difficulty. However, 
 there is no insuperable difficulty in boring the cylinder 
 at home. 
 
 The first step of course is to chuck the cylinder, 
 and this may be done in two or three ways. First, 
 it may be attached to the face-plate thus : take a 
 circular piece of wood about a quarter of an inch thick 
 
FIG. 33. 
 
 FIG. 34- 
 
 FIG. 35. FIG. 36. 
 
 47 
 
48 Horizontal Slide-Valve Engine. 
 
 and of rather greater diameter than the cylinder end, 
 including the flange. If this piece of wood is turned 
 up, and a few concentric circles marked upon its face, 
 it will facilitate the centring of the cylinder. Now 
 place the piece of wood upon the face-plate, and then 
 after filing one end of the cylinder as flat and square 
 as possible, place it filed end downwards upon the 
 wood. Next take three dogs, i.e., pieces of iron or 
 steel about two inches long and three-eighths to half 
 an inch thick, with a hole in the middle of each to take 
 a bolt. Place these with one end of each resting on 
 the flange of the cylinder, and directly over three of 
 the slots in the face-plate. Now place a small piece 
 of wood about half an inch thick under the other end 
 of each dog, and finally pass a bolt up through the 
 slot in the face-plate and through the hole in each 
 dog, and screw the nuts down so that the cylinder is 
 firmly held in place, but do not yet tighten the nuts 
 ready for action. Screw the face-plate with cylinder 
 attached on to the lathe mandrel, and see whether the 
 cylinder runs true. Probably it won't, so we first 
 centre the back flange by holding a piece of chalk 
 against the cylinder, as near the flange as possible, 
 and giving a slight tap where required with a light 
 hammer or mallet, till the back flange appears 
 properly centred. We now test the front flange, and 
 if the back flange, besides being truly centred, has been 
 filed square and flat, the front will run true ; other- 
 wise we must get it right by loosening slightly the 
 
FIG. 37. 
 
 FIG. 38. 
 
5O Horizontal Slide- Valve Engine. 
 
 nuts as required, but only one at a time, and packing 
 up whichever side requires it with thin pieces of 
 metal, taking care in the meantime that the position 
 of the cylinder upon the face-plate is left unaltered. 
 The arrangement just described is shown by Fig. 43 ; 
 and when it is completed and the cylinder satisfac- 
 torily centred, the nuts must be carefully tightened 
 up, so that there may be no danger of the work shift- 
 ing during the operation of boring. 
 
 Another method of chucking the cylinder, one 
 which may be adopted by those who do not possess 
 a face-plate, is by turning up a piece of beech or 
 box-wood, and turning in it a recess into which the 
 cylinder-flange will fit exactly. To prevent accidents, 
 it is well to secure the cylinder in this recess by the 
 same sort of dogs as those used in the method first 
 described, ordinary wood screws being passed through 
 the holes in the dogs into the wooden chuck ; or 
 three pieces of iron or wood having a hole at each 
 end may be fastened across the flange of cylinder by 
 screws, as shown in Fig. 44. 
 
 Yet another way of securing the cylinder is by 
 means of angle-plates used with the face-plate ; but 
 this method is more useful for cylinders of larger size 
 than the one now under consideration. 
 
 If the cylinder is to be bored with a boring bar the 
 first two methods will have to be slightly modified, as 
 thicker wood will have to be used ; and a recess, the 
 diameter of bore of cylinder when finished, must be 
 
52 Horizontal Slide- Valve Engine. 
 
 turned in it to a depth of three-quarters of an inch, 
 in order that the boring tool may pass completely 
 through the cylinder. 
 
 This last method will probably suit most amateurs, 
 and I shall therefore describe a simple and easily 
 made boring bar with which the boring may be done. 
 
 Another way I may mention, in passing, is to fix 
 the cylinder to the saddle of lathe instead of to 
 mandrel, and use a boring bar ; but those who possess 
 the necessary apparatus for this are not likely to 
 require any instructions as to how it is to be used. 
 I shall therefore confine myself to such methods 
 as may be of use to amateurs less practised than 
 we should suppose those to be who are thus fully 
 equipped. 
 
 Whichever plan of chucking has been adopted, we 
 will suppose the cylinder to be firmly fixed and 
 properly centred, and the next operation will be the 
 actual boring ; and if the lathe is provided with a 
 slide-rest, this may be done with an inside tool held 
 in the slide-rest. Two cuts will be necessary. The 
 slide-rest must be in good condition, and great care 
 must be taken to set it parallel with the work, other- 
 wise the cylinder will turn out taper and be useless 
 until it has been rebored, supposing there is enough 
 metal remaining for that operation. 
 
 However, it does not fall to the lot of every amateur 
 model- engine maker to be the happy possessor of a 
 good slide-rest ; therefore such of my readers as are 
 
FIG. 43. 
 
54 
 
 Horizontal Slide- Valve Engine. 
 
 minus this useful adjunct to the lathe will be glad to 
 hear that they may bore their cylinders in the follow- 
 ing manner : Take a piece of beech- wood about twice 
 the length of the cylinder to be bored, and turn it 
 down to the inside diameter of the cylinder casting. 
 Now take two pieces of thin steel ; a piece of an old 
 saw will do very well. These may if necessary be 
 softened, and must then be filed to a rectangular 
 shape three-quarters of an inch in length ; for about 
 half of this length, one piece must be exactly one inch 
 and the other a shade under one inch in breadth ; for 
 the other three-eighths of an inch, the width is to be 
 gradually and very slightly narrowed, as at A (Fig. 45). 
 A saw-cut is now to be made in the end of the piece 
 of turned beech-wood, so that the pieces of steel will 
 just fit tightly into it. When these are placed in 
 position, first one and afterwards the other piece of 
 steel (if only one piece of beech is used, but it is 
 better to make use of a separate piece of wood for 
 each cutter), a hole must be drilled through both wood 
 and steel for the reception of an ordinary wood screw, 
 the purpose of which is to prevent the steel from 
 
 FIG. 45A. 
 
 FIG. 45B. 
 
Horizontal Slide- Valve Engine. 5 5 
 
 shifting or the wood from splitting. This hole must 
 of course be countersunk at one end to take the head 
 of the screw (see B, Fig. 45). A slip of wood must 
 be taken away with a chisel on each side, as shown in 
 Fig. 46, to give clearance to the borings. The steel 
 cutters should now be hardened, tempered, and 
 pushed into their places, and a screw put through as 
 already explained. 
 
 The mouth of the cylinder must now be turned up, 
 so that the borer may start true ; the borer is then 
 placed in position, and the moving head-stock brought 
 up to the back end of it. The lathe must be driven 
 at a moderate speed, and the cutter sent through the 
 cylinder, if possible, without stopping, at a uniform 
 speed by means of the screw in the moving head- 
 stock. After the first rough cut, the cutter is to be 
 
 46. 
 
 changed, and the boring finished by sending the full- 
 sized cutter through in the same manner. The first 
 cut may also be taken with a cutter filed up from a 
 piece of square steel of the shape shown in Fig. 47. 
 This cutter is to be driven through a hole bored in a 
 piece of beech similar to that previously used. 
 
56 Horizontal Slide- Valve Engine. 
 
 Another method of boring the cylinder, similar to 
 the last described, is with a D-bit ; sections of this 
 
 FIG. 47. 
 
 tool are shown in Figs. 6 and 7. A bit of the proper 
 diameter may be obtained from any engineering shop, 
 made to order, or from Messrs. Buck & Hickman, 
 Whitechapel Road, the cost being about is. for every 
 eighth of an inch diameter. The D-bit might also be 
 made at home, as follows : A piece of cast-steel bar 
 of the proper size is softened and one end slightly 
 bent over, and then filed so that its surface may be 
 again brought to a right angle with the length of the 
 bar ; this end is centre-punched close to the edge 
 which, owing to the bending over of the end, projects 
 beyond the rest of the bar. At the other end the 
 centre-mark is punched in the centre of the bar. 
 Now drill for the lathe-centres, and mount the bar in 
 the lathe ; if the bar has been properly bent over and 
 centre-punched, one end will revolve upon its centre ; 
 but at a short distance from the other end, where 
 the bend is, in fact, the whole thickness of the bar 
 
Horizontal Slide- Valve Engine. 57 
 
 will be just on one side of a line joining the lathe- 
 centres, and as a consequence will revolve round that 
 line ; and if the bar be now turned down with the 
 slide-rest, the part near the end will be semi-circular 
 in section, and will, when the bent portion is cut off, 
 form the cutting edge of the bit. The bit will, of 
 course, require to be hardened and tempered before it 
 is used. The amateur who is unacquainted with the 
 D-bit should purchase one in the first place, and will 
 thenceforth, with the aid of the above description, 
 find no difficulty in making his own. 
 
 A mandrel, upon which the cylinder is to be 
 chucked while the two flanges are turned up, must 
 now be turned from a piece of box or beech-wood, 
 and the cylinder-ends finished upon it, unless the 
 boring has been done with the slide-rest, for in this 
 case one flange can be turned up at the time of 
 boring, and the cylinder may then be reversed and 
 chucked as before, and the other flange turned up. 
 
 The cylinder-face must be filed down smooth, and 
 the cylinder then stood up on end on a surface-plate, 
 or lacking that implement, upon the bed of the lathe, 
 and the face tested with a square. File and scraper 
 must be used until the face is perfectly square with 
 the ends of the cylinder. A little red-lead and oil 
 should now be smeared over the surface-plate or 
 other flat surface used as a test, and the surface of 
 the cylinder-face tried upon it. The red-lead will 
 show which are the high parts, and these must be 
 
5 8 Horizontal Slide- Valve Engine. 
 
 filed or scraped down until the surface is perfectly 
 flat. While thus getting the cylinder-face flat, we 
 must not, however, forget to test it occasionally with 
 the square, otherwise by the time it is flat we may 
 find that it has been filed and scraped out of square. 
 Finally, to take out any scratches left by the file, the 
 cylinder-face may be lightly rubbed on a flat stone. 
 The lugs or feet of the cylinder must be filed up 
 square with the face. 
 
 STEAM-PORTS. The next operation to be under- 
 taken is the marking out of the steam and exhaust- 
 ports. The usual practice in large engines is to 
 make the area of the steam-ports '057 (or about one- 
 twentieth of the area of the cylinder), and the length 
 of the ports is taken as seven-tenths of the diameter 
 of the cylinder. In this small engine the nearest 
 approach to theoretical correctness is to make the 
 steam-ports -/-^ by of an inch. 
 
 To mark out the steam-ports it is best to use a 
 scribing-block and surface-plate, but failing these 
 tools a pair of dividers or calipers may be used. 
 Before commencing to set out the ports, and especi- 
 ally if dividers or calipers are used, make sure that 
 the cylinder-face is itself square. Now stand the 
 cylinder on end on the surface-plate, and set the 
 point of the scriber as near the centre as possible ; 
 mark the cylinder-face very lightly with the point 
 of the scriber, and then, without moving the latter, 
 reverse the cylinder, standing it on its other end, and 
 
Horizontal Slide- Valve Engine. 59 
 
 again mark the face. The centre of the face will 
 of course be a point midway between the two marks. 
 Now place the cylinder horizontally on its feet, which 
 should have been previously filed up square with its 
 face, and again set the scriber-point as near the 
 centre as possible and mark ; reverse the cylinder, 
 placing small blocks of wood under the face to keep 
 it steady and square with the surface-plate, mark 
 once more with the scriber-point, and rule centre-line 
 between the two points marked. The first or vertical 
 centre-line should, when drawn, be continued across 
 the face of the cylinder and the boss for exhaust-pipe, 
 while the horizontal centre-line must be continued 
 along the metal left for the steam-ways and across 
 the flange of the cylinder at each end. 
 
 Should the feet of the cylinder stand out beyond 
 the flanges, or the flanges themselves be partly filed 
 away during the process of filing the feet square with 
 the cylinder- face, allowance for such difference must 
 of course be made when marking the horizontal 
 centre-line. This precaution will not be necessary 
 if the face is marked out with the dividers, as the 
 horizontal centre-line will then be marked from the 
 edge of the cylinder-face, the vertical centre-line 
 being taken from the flanges of the cylinder. Now 
 with the scriber or by means of the dividers draw 
 six lines, three on each side of the vertical centre- 
 line, the first pair being each a full yV of an inch 
 from centre-line, and the second and third pair & of 
 
6o 
 
 Horizontal Slide- Valve Engine. 
 
 an inch from the first and second pair respectively. 
 Now mark two lines, each T V of an inch from the 
 horizontal centre-line ; the ports will now be all 
 marked out, and the cylinder-face will exhibit the 
 
 FIG. 48. 
 
 appearance shown in Fig. 48.* Now with a punch 
 make three centre-marks in each of the spaces 
 marked out for the ports, one mark being made in 
 each case in the centre of the space marked out, and 
 the other two each \ of an inch from this centre, one 
 on each side. These centre-marks are also shown 
 in the figure to which we have just referred. We 
 next centre-mark for the steam-ways on each flange. 
 These centre-marks must of course be made upon 
 the continuation of the horizontal centre-line already 
 
 * Owing to a valve casting belonging to another set having 
 been accidentally sent by the manufacturers, and Figs. 48 and 
 49 drawn therefrom, these figures do not in all their measure- 
 ments answer to the description given in the text. 
 
Horizontal Slide- Valve Engine. 
 
 61 
 
 marked, and must be made on about the middle line 
 of the thickness of the metal in which the steam- 
 ways are to be bored, but if anything rather nearer 
 to the inner than the outer side. 
 
 With a i-inch drill the steam-ways should be 
 drilled down to within \ of an inch of the centre of 
 cylinder-face, the drill being inclined slightly out- 
 wards, so that the steam-ways may run towards the 
 surface of the cylinder-face. With the same drill 
 make the three holes for the exhaust-port, as already 
 marked. These holes should be rather under \ of an 
 inch in depth ; and next, using still the same |-inch 
 drill, or one slightly larger, make the exhaust-way 
 through the boss into the three holes just drilled. 
 With a -^2-inch drill make three holes in each steam- 
 port as marked. These holes should be drilled out- 
 wards towards the ends of the cylinder, to avoid any 
 risk of their running into the exhaust-port ; the two 
 
 FIG. 49. 
 
62 Horizontal Slide- Valve Engine. 
 
 sets of holes must of course be drilled .down into 
 their respective steam-ways. The ports and steam- 
 ways are shown in section in Fig. 49. 
 
 The ports may be left as they now are ; but they 
 will look more workmanlike, and the engine will also 
 work better, if they are squared out to the lines 
 marked with a small chisel. If it is intended to 
 square out the ports, it may be advantageous to drill 
 two steam-ways, each -/% of an inch in diameter 
 (instead of the one |-inch) at each end of the 
 cylinder, for the two -gV-inch ways will have a rather 
 larger total area than the square-cut port, while the 
 -|-inch steam-way will have an area rather less than 
 the square ports. 
 
 The side of the cylinder must be chipped down a 
 little, so as to make a clear way between the end of 
 the steam-ways and the interior of the cylinder when 
 the cylinder-covers are on ; or a way may be made 
 with a drill, and the end of the steam-way showing 
 in the cylinder-flange may be stopped up with a 
 small piece of brass wire. 
 
 CYLINDER-COVERS. The bottom cover should be 
 turned before the top one, since it is not so necessary 
 that the former should fit the cylinder exactly as it is 
 that the latter should be a perfect fit. If a chucking- 
 tenon has been cast on the cylinder-bottom, the 
 chucking will of course present no difficulty. It may 
 be held in a self-centreing or grip-chuck, or a chuck 
 may be made once for all by boring out a gun-metal 
 
Horizontal Slide- Valve Engine. 63 
 
 chuck to the proper size and tapping it with a screw, 
 which need not be a very fine one ; the tenons may 
 then be all screwed to fit this chuck, so that if the 
 said tenons have been properly cast, most of the turn- 
 ing work may be done with the one chuck. If there 
 is no tenon piece the chucking of the cylinder-bottom 
 will be a less easy matter ; but here, as is often the 
 
 FIG. 50. 
 
 case, the simplest method will be found the best. 
 Care must, however, be taken to perfectly fit the cover 
 to the chuck before beginning, for there are few things 
 more annoying than for a piece to work loose in the 
 chuck just as it is half turned, and to keep coming 
 out during the remainder of the operation. 
 
 To chuck the cover, take a piece of suitable wood 
 beech is good, boxwood preferable ; but when 
 
64 Horizontal Slide- Valve Engine. 
 
 nothing better was at hand, the writer has often used 
 deal, and made it serve the purpose well enough ; in 
 fact, Fig. 50 is an exact representation of a cylinder- 
 cover at the present moment before the writer's eyes, 
 chucked in an odd piece of -inch deal board, screwed 
 to the face-place by two ordinary wood screws passed 
 through holes in the face-plate and into the wood. 
 However, to return to the chuck we are about to 
 make, the piece of wood chosen need not be over 
 of an inch thick and 2\ inches in diameter ; it should be 
 screwed to the face-plate with two or three ordinary 
 screws, and if the face-plate is not already provided 
 with the necessary holes, it will be found very con- 
 venient to drill half a dozen at different distances 
 from its centre, these holes being about T \ of an inch 
 in diameter, and slightly countersunk at the back of 
 the face-plate to take the heads of the screws. 
 
 The wood for the chuck being firmly attached to 
 the face-plate and the latter screwed on to the lathe- 
 mandrel, a recess of T Vmch depth should be turned 
 in the centre, and this recess must be gradually 
 enlarged until it is nearly of the same diameter as 
 the cylinder-cover. The edges may be very slightly 
 undercut. When the cover will all but go into the 
 recess turned in the wood, the face-plate with chuck 
 attached is to be taken from the lathe and laid on 
 the bench, and the cylinder-cover driven into the 
 recess by a few light blows from a mallet, taking care 
 to place the cover with its outside towards the wood, 
 
Horizontal Slide- Valve Engine. 65 
 
 so that the inside may first be turned. As to the 
 process of turning, light cuts only should be taken, 
 and the centre of the cover should be left projecting 
 about T V of an inch, the projection being of such a 
 diameter as to fit the bore of the cylinder exactly. 
 
 When this side is finished, the cover must be taken 
 out of the chuck, and a recess turned in the latter for 
 the reception of the projection in the centre of the 
 inside of the cover ; the cover is now to be replaced 
 in the wooden chuck in the same manner as before, 
 but in a reversed position, for the turning up of the 
 outer surface. 
 
 To do this, turn up the flat part first, and slightly 
 mark upon it with the graver a circle, li- inch in 
 diameter. Without removing the piece from the 
 chuck, draw a line through its centre, and where this 
 line cuts the circle just mentioned, centre-punch and 
 drill two holes, -gV-mch in diameter. Now pass two 
 1-inch wood screws through these holes, and screw 
 
 firmly down to the wooden chuck, after which the 
 centre and hollow portion of the cover may be turned. 
 When the surface is finished, the chuck itself must 
 
 F 
 
66 Horizontal Slide- Valve Engine, 
 
 be turned away until the edge of the cover is free, 
 and then, the cover being still held to the chuck by 
 the two screws, the edge is to be turned down until 
 it exactly fits the cylinder-flange. Fig. 5 1 shows the 
 inner surface of the finished cover. 
 
 The top cover is to be turned up in much the 
 same manner, the under side being turned first. Of 
 course a deep recess to hold the stuffing-box (which 
 is cast on to the top of this cover) must be turned 
 in the chuck in the first instance. The top being 
 reversed in the chuck, the stuffing-box will be turned 
 up after the flat part has been turned and the piece 
 screwed down to the chuck. 
 
 Now while the cover is still in the lathe, drill a 
 hole ^V-inch in diameter through the centre of the 
 stuffing-box, and enlarge this to -^--inch down to 
 within about |-inch of its inner end. Tap the 
 stuffing-box with a tolerably fine screw-thread by 
 means of a chaser, if the reader has had sufficient 
 practice in the use of this tool, otherwise the thread 
 must be cut with taper, medium, and plug taps. 
 The top cover will now be finished, with the excep- 
 tion of the screw-holes. To drill these, hold the 
 cover in place upon the cylinder, and mark upon the 
 latter the position of the two screw-holes already 
 drilled through the cylinder-cover ; centre-punch and 
 dril them through the flange with a T V-inch drill, 
 tap them, and screw the cover on with -aV-mch screws. 
 Now divide the circle marked on the cover into three 
 
Horizontal Slide-Valve Engine. 67 
 
 equal parts on each side of the two screws ; centre- 
 punch at the four points of division thus found, and 
 drill right through both cover and flange with the 
 T V-inch drill ; unscrew the cover and tap the four 
 holes in flange, and enlarge those in cover to T Vmch, 
 and the cover will then be ready to screw on. These 
 instructions apply equally to both top and bottom 
 covers. 
 
 STEAM-CHEST. In the set of castings now under 
 consideration, the gland for the cylinder stuffing-box 
 is cast in one piece with the gland for the slide-valve 
 chest, and I shall therefore leave the fitting of it 
 until after the valve-chest has been finished ; and 
 this will be our next care. The edges of the flange 
 should first be filed up square to fit the cylinder- 
 face. If the valve-chest has no chucking tenon (and 
 it has none in the set of castings now before me), 
 the centre of the stuffing-box must be found and 
 marked, and then the chest being laid on the surface- 
 plate or lathe-bed, a scriber must be set to this mark, 
 and the chest being reversed, a line is to be drawn 
 across the back of it with the scriber. The chest is 
 now to be set up on the edge of its flange, first on 
 one side and then on the other, each time setting 
 the scriber to the centre of the stuffing-box, and 
 marking the back of chest. Centre-punch the posi- 
 tion thus found upon the back, and mount the chest 
 between the lathe-centres. The stuffing-box is now 
 to be turned up, and the chest being then taken from 
 
68 Horizontal Slide- Valve Engine. 
 
 the lathe, a gVmch hole is to be bored through the 
 stuffing-box, enlarged to ^-inch diameter to within 
 i-inch of the inside of the valve-chest, and screwed 
 in the same manner as the cylinder stuffing-box. 
 
 STUFFING-BOXES. Now take the piece from 
 which the two glands are to be formed, and centre- 
 mark and drill a -^--inch hole right through it. This 
 hole may at once be enlarged to ^V-iiich through 
 that portion of the piece which is to form the gland 
 for cylinder-top. Mount the piece between centres 
 with a carrier upon one end, and turn up the other 
 end to the full diameter of the bottoms of the threads 
 of stuffing-box it is to fit ; now reverse the piece in 
 the lathe, so that the carrier may be placed upon the 
 end already turned, and turn the other end to fit 
 the other stuffing-box. The flanges of the glands 
 should be turned to a diameter about i-inch larger 
 than their respective stuffing-boxes, and a portion of 
 the metal between the two glands may at the same 
 time be turned away, but care must be taken not to 
 separate the glands which must next be screwed to 
 fit the stuffing-boxes. Now screw the valve-gland 
 into its stuffing-box as far as it will go, and mount 
 valve-chest and glands between lathe-centres, the 
 valve-chest acting as a carrier ; mill the flanges with 
 a milling tool, and cut off the cylinder-cover gland, 
 turning up its face at the same time. When this 
 gland has been cut off, bring the back centre up 
 again, and cut off the superfluous piece of metal left 
 
Horizontal Slide- Valve Engine. 69 
 
 on the top of the valve-chest gland, and the glands 
 will then be finished, appearing as in Fig. 52. 
 
 FIG. 52] 
 
 The steam-chest may now be filed up square and 
 smooth all over ; the holes for the screws should be 
 drilled |-inch from the edge of the flange, and T V to 
 i of an inch from each end. One hole -gV-inch in 
 diameter should first be drilled through the flange of 
 the chest, the position of this hole marked upon the 
 cylinder-face, and a hole drilled therein with a -3*8 -inch 
 drill ; this hole is to be tapped, and the valve-chest 
 screwed to the cylinder-face and carefully set square 
 with the cylinder, so that the piston-rod and valve- 
 rod when in place may be exactly parallel. The other 
 three holes are now to be drilled with a T V-inch drill 
 through both valve-chest and cylinder-face, being 
 afterwards enlarged to -^-inch in the former, and 
 tapped with screw-thread in the latter, as in the case 
 of the cylinder-covers. 
 
CHAPTER V. 
 
 HORIZONTAL SLIDE-VALVE ENGINE (continued']. 
 
 PISTON SLIDE-VALVE ECCENTRIC BED-PLATE 
 CRANK-SHAFT CONNECTING-ROD GUIDE-BARS 
 STANDARDS FITTING. 
 
 THE PISTON. This part may now be turned, as 
 it might have been at any former stage after 
 the boring of the cylinder was finished. If there is a 
 chucking tenon on the piston, it may be turned up 
 and bored and screwed for piston-rod while in the 
 lathe. For the piston-rod, a piece of straight steel 
 about sV of an inch in diameter and 5 inches long 
 may be used, and this should be screwed into the 
 piston while the latter is still in the lathe, so that we 
 may be sure it is screwed in straight and square. 
 
 If, however, the piston has no tenon-piece, it may 
 be bored, the piston-rod screwed in, and the end of 
 the rod centre-punched, when the piston may be turned 
 up between the lathe-centres, the driving carrier being 
 placed on the piston-rod. The piston when finished 
 should be a good fit in the cylinder. It should be 
 \ of an inch thick, and a groove -^ of an inch wide 
 
 70 
 
Plorizontal Slide-Valve Engine. 71 
 
 and gV deep should be turned in it to take the pack- 
 ing. 
 
 Another method of making the piston will now be 
 described a method which requires that the piston 
 should be made in two parts : one part as shown at 
 A > Fig. 53, the other part forming the bottom plate 
 shown at B in the same figure. A cast gun-metal 
 ring will be required, having an inside diameter rather 
 less than the diameter of the groove in the piston, 
 and an outside diameter rather larger than the dia- 
 meter of the cylinder. (In larger engines two rings 
 are used, these being bored eccentrically ; and when 
 the cylinder is of brass or gun-metal, the rings are 
 
 FIG. 53. 
 
 of cast iron.) The two parts of the piston must be 
 screwed together with three small screws through 
 the bottom plate. Of course screws with bevelled 
 heads should be used, so that they may be driven in 
 flush with the surface of plate ; the piston-rod is then 
 to be screwed in, and the piston turned up as already 
 described. 
 
 The ring must be chucked in a recess turned in a 
 
/ 2 Horizontal Slide- Valve Engine. 
 
 piece of wood screwed on to the face-plate, in the 
 manner adopted for chucking the cylinder-covers. 
 The inside of the ring is to be turned out to the same 
 diameter as that of the groove in the piston. The 
 sides must also be turned up square, the ring being 
 reversed in its wooden chuck so as to get at the other 
 side. Thus far finished, the ring should be of just such 
 a width that when tried in its place on the piston, 
 with the bottom plate screwed on, it will be a good 
 fit, not jammed immovably, and not having any shake. 
 Now put the ring on the piston and screw on the bot- 
 tom plate, with a ring of paper between it and the pis- 
 ton ring, so that the latter may be tightly held. Place 
 the whole between the lathe-centres, and turn down 
 piston and ring, leaving the former a good fit to cylin- 
 der, and the latter a tight fit to same. Now take out 
 the ring, and saw through it at an angle of 45. 
 Replace the ring on the piston and screw up again, 
 
 FIG. 54. 
 
 and the piston is finished, the spring of the ring keep- 
 ing it pressed against the sides of the cylinder, and 
 
Horizontal Slide- Valve Engine. 73 
 
 thus obviating the necessity for any other packing. 
 Fig. 54 shows this form of piston complete. When 
 two rings are used, the saw-cuts are placed upon op- 
 posite sides of the piston, thus preventing any loss 
 of steam through either division. 
 
 A further development of this sort of piston is 
 one in which steam is admitted to a groove in the 
 piston under the rings, the pressure of the steam 
 thus helping to make the piston steam-tight. This 
 form is valuable where the piston goes on working 
 when the steam is shut off, as in a tram engine 
 descending an incline ; for the friction of the piston 
 against the sides of the cylinder is thus diminished 
 directly the steam is shut off, and any unnecessary 
 wear of these parts is consequently avoided. 
 
 Before leaving this subject, I may mention that 
 the following proportions are given by Molesworth 
 for the piston and piston-rod of a high-pressure en- 
 gine : depth of piston, '25 of diameter of piston ; 
 diameter of piston-rod, "15 of diameter of cylinder. 
 
 THE SLIDE-VALVE. This part must be filed up 
 square and smooth on the outside, and the width 
 reduced until it will work easily in the slide-valve 
 chest. The interior of the valve should be cut out 
 with a small chisel until it measures nearly the same 
 in length as the distance between the inner edges of 
 the steam-ports. The metal must of course be left 
 of equal thickness at both ends when the valve is 
 finished, and the total length of the valve should be 
 
74 Horizontal Slide- Valve Engine. 
 
 such that when the valve is placed over the ports 
 it will extend a very little beyond the steam-ports at 
 each end. This extension beyond the steam-ports is 
 technically called "the lap of the valve," and serves to 
 cut off the supply of steam rather earlier in the stroke 
 of the piston than would otherwise be the case. The 
 valve-face should be rubbed down flat on the stone 
 already used for the cylinder-face, and a slit rather 
 less than T V of an inch wide, and ^\ of an inch deep, 
 sawn in the back of the valve lengthwise, as shown 
 
 FIG. 55. 
 
 in Fig. 5 5. Fig. 56, giving a sectional view of the valve 
 in position over the steam-ports, will make the fore- 
 going description quite clear. 
 
 THE ECCENTRIC AND ITS STRAP. The eccentric 
 must be chucked by the tenon, which should always 
 be cast upon this piece ; the edge is to be turned 
 down smooth, and a groove, -gV of an inch wide and 
 T V of an inch deep, turned in it. While still in the 
 lathe the true centre of the eccentric should be 
 marked, and the chucking tenon may then be cut off. 
 
 A moment's reflection will make it apparent that 
 when the slide-valve is in action, the port in it must 
 
Horizontal Slide- Valve Engine. 75 
 
 cover the opening of the exhaust-port in the cylinder- 
 face during the whole of each stroke, while, during 
 each half-stroke, one or other of the steam-ports must 
 also open into the valve-port, the two steam-ports 
 each in turn becoming an exhaust-way; while, on the 
 other hand, one or other of the steam-ports must 
 each half- stroke be left uncovered by the valve, and 
 this will be accomplished by making the whole travel 
 of the valve equal to twice the width of one steam- 
 port added to twice the lap given to the valve. 
 
 FIG. 56. 
 
 Returning now to the eccentric, a distance equal 
 to half the travel of the valve must be marked off 
 from the centre of the eccentric, and as nearly as 
 possible in the centre of the boss cast on the eccen- 
 
76 Horizontal Slide- Valve Engine. 
 
 trie ; this mark must be centre-punched, and a hole 
 drilled through it of any convenient size, not ex- 
 ceeding the diameter of the shaft upon which the 
 eccentric is ultimately to be mounted. The piece can 
 now be mounted on a temporary shaft, and the boss 
 neatly turned up. 
 
 The strap of the eccentric should now be either 
 filed up smooth, or it may be bored first and then 
 turned up in the lathe, being mounted for the latter 
 purpoae upon a wooden mandrel ; in either case it 
 must be finished to just the thickness that will make 
 it a good fit in the groove of the eccentric. The band 
 is to be bored out the same diameter as the eccentric, 
 the diameter of the latter being of course callipered 
 
 FIG. 57. 
 
 at the bottom of the groove. The outside edge of 
 the band must be smoothed off with the file, and 
 -iV mc h holes bored in the two projections or lugs, 
 and tapped for screws. The band is now to be sawn 
 
Horizontal Slide- Valve Engine. 77 
 
 in two, as shown in Fig. 57, and the holes in the 
 upper half slightly enlarged to allow the screws to 
 pass through. 
 
 THE BED- PLATE. If this has not been purchased, 
 it may now be cut out ; a convenient size will be 
 found to be io| inches long and 3! inches broad. 
 Half an inch from one end a rectangular hole i| by 
 \\ inch must be cut out, as shown in Fig. 26, in order 
 to allow the crank to revolve. As to the thickness of 
 the bed-plate, the metal used should be \ or V of an 
 inch thick. 
 
 THE CRANK-SHAFT. This part is made from a 
 forging, which may be obtained at any of the shops 
 that supply castings, for the sum of 4^., or from 
 any country blacksmith for about 6d. ; in fact, the 
 latter will turn out the forging " while you wait." 
 All that is necessary is to get him to weld a piece of 
 f-inch iron ii inch square on to a piece of |-inch bar, 
 
 - - , 
 
 i 1 
 
 yi 
 
 1 
 
 I 
 
 i 
 
 
 , r 
 
 I 
 
 I 
 
 ! R 
 
 
 FIG. 58. 
 
 and your 4^. forging is ready, as shown in Fig. 58. 
 The dotted lines C C in this figure indicate that part of 
 the forging which must be filed away a piece of work 
 which, it may be remarked, is not to be accomplished 
 
78 Horizontal Slide- Valve Engine. 
 
 in a few minutes. As some amateurs with more 
 money at command and less time than others ob- 
 ject to this labour, Messrs. Lucas & Davies have 
 thought it best in these days when most things are 
 made easy, to bring out a bent crank which only re- 
 quires turning and finishing off. However, the task 
 of filing away the solid crank forging may be rendered 
 less tedious by drilling two or three holes through the 
 part to be removed, which reduces considerably the 
 amount of labour. To turn the crank-shaft it must be 
 placed between the lathe-centres, with a piece of hard 
 wood in the gap, and turned down to i-inch diameter, 
 the proper proportion being '33 of the diameter of 
 the cylinder. The bearing-pin of the crank will be 
 more difficult to turn up. When the shaft is a short 
 one, and the lathe-centres are sufficiently long, the 
 pin may be centre-punched and mounted between 
 the centres, and the pin turned down. 
 
 The following is also a simple method of turning 
 the crank-pin : To the ends A A of the shaft solder 
 two flat pieces of iron rather longer than the throw 
 of the crank ; now insert between the ends of these 
 pieces of iron and the crank B B, two pieces of hard 
 wood to take the thrust of the lathe-centres, in the 
 same manner as was done by the piece of wood in 
 the gap of the crank while the shaft itself was being 
 turned. On the pieces of iron mark off the distance 
 from the centre of the shaft equal to the throw of the 
 crank, centre-punch and mount between the lathe- 
 
8o Horizontal Slide- Valve Engine. 
 
 centres, when, if the irons have been soldered on in a 
 line with the crank, the crank-pin will be between the 
 lathe-centres, and may easily be turned up. 
 
 The pin when finished should be about T a g- of an 
 inch in diameter, or -23 of the diameter of the cylin- 
 der. The flat part of the crank should be finished 
 with the file. 
 
 Before proceeding further, it will be best to make 
 full-size working drawings from which to fit the 
 several parts of the engine together. 
 
 Figs. 59 and 60 are working drawings on a scale 
 of 6 inches to the foot. It will be seen that the 
 parts are so arranged that the length of the connect- 
 ing rod is just double the stroke of the piston. 
 
 THE CONNECTING-ROD will therefore be 4 
 inches in length, in the case of a 2-inch stroke en- 
 gine ; if it is not provided in the set of castings, it 
 may be made from a round bar of iron, the ends 
 being forged out flat, or a flat piece of iron half an 
 inch wide and a quarter thick may be taken, the 
 middle part filed roughly to shape, and then turned 
 down, as shown in Fig. 61. Drill the top end of the 
 
 FIG. oi. 
 
 connecting-rod for the crank bearing, and also drill 
 two screw-holes in the top ; now saw across, as shown 
 by the dotted line in Fig. 61, and enlarge the screw- 
 
G 
 
82 Horizontal Slide- Valre Engine. 
 
 holes in the top piece and tap those in the rod itself 
 for the screws which are to fasten the two parts of the 
 bearing together. Another way of making the bear- 
 ing in the connecting-rod is shown in Fig. 62 ; the 
 
 FIG. 62. 
 
 top piece A may be filed up from a piece of steel, and 
 then fitted to the connecting-rod, and a -gVmch hole 
 drilled through as shown by the dotted lines in B. 
 A pin is to be filed to size and run through the 
 hole, and the two parts being thus firmly held to- 
 gether, the hole seen in B is to be drilled to fit the 
 crank. 
 
 The different parts of the engine should now be 
 fitted together, each piece being finished and fitted 
 as required. If the bed-plate has been bought with 
 the castings, the positions of the various parts will 
 be found marked upon it ; but if the bed-plate is a 
 home-made one, it will be necessary to set out the 
 positions of the cylinder, guide-bars, etc., from the 
 working drawings. 
 
 The lugs on the cylinder must be bored, and two 
 pieces of |-inch steel about f-inch long must be 
 screwed into them. The position of these bolts rela- 
 tively to the top and bottom of the cylinder must be 
 
Horizontal Slide- Valve Engine. 83 
 
 taken with the compasses and marked on the bed-plate, 
 and a couple of holes drilled through the latter to allow 
 the bolts to pass through. A couple of nuts screwed 
 on to the bolts will hold the cylinder firmly down in 
 its place. Should it prove to be not perfectly level 
 on the bed-plate, it must be removed, and the lug 
 at the high end filed away until it is found that the 
 piston-rod is perfectly parallel with the bed-plate 
 when drawn out to its full extent. The pillars to 
 go between the guide-bars should now be turned up ; 
 this is done while they are all in one piece. They 
 are afterwards sawn apart, when their height should 
 be just a shade over the thickness of the guide-blocks, 
 which are in the present instance i-inch thick. They 
 must be bored with a i-inch hole, and this may be 
 done to each pillar separately, or to all four at once 
 while they are in one casting. 
 
 THE GUIDE- BARS. These having been filed up 
 smooth, and the upper surface of the lower bars and 
 the under surface of the top bars worked perfectly 
 level, the top guide-bars must be centre-punched at 
 each end and drilled with a i-inch hole. They are 
 then to be placed upon the lower bars, and the 
 position of the holes in the top bars marked, centre- 
 punched and drilled in the lower bars. These latter 
 must now be placed in position upon the bed-plate, 
 and the position of the holes again marked and 
 drilled in this latter. Both bed-plate and bars should 
 be marked so that they may always be put together 
 
84 Horizontal Slide-Valve Engine. 
 
 in the way in which they were marked for drilling. 
 Before putting the guide-bars together the lower 
 ones may be roughly filed down to near the correct 
 height ; and as the distance between the guide-bars 
 will be i-inch, and the piston-rod will work in the 
 centre of them, it is obvious that the top surface of 
 the lower guide-bars must be -inch nearer the bed- 
 plate than the centre of the piston-rod. Four bolts 
 about if-inch long, with small steel nuts, will be re- 
 quired to bolt the guide-bars to the bed-plate. These 
 bolts are passed through the guide-bars with the 
 pillars between them, and the whole thus secured in 
 position. 
 
 ' THECRANK-SHAFT BEARINGS OR STANDARDS may 
 next be finished off. A fV-inch hole is to be bored 
 in each standard, and two screw-holes drilled in the 
 top of each to the depth of half an inch, and tapped 
 for -inch screws. Then the tops are to be sawn off 
 at the lines marked on the castings, and the holes in 
 the top pieces enlarged to allow the screws to pass 
 through them. The feet of the standards must also 
 be drilled to take -g-inch bolts or screws, the former 
 being preferable. The crank-shaft may now again 
 be put in the lathe, and the parts which are to rest 
 in the bearings turned down to fit the holes in the 
 latter. The fly-wheel end will only be turned down 
 for a length equal to the thickness of the bearing ; 
 at the other end, however, it will be a good plan to 
 turn the shaft down to the same diameter to within 
 
Horizontal Slide-Valve Engine. 85 
 
 half an inch of the crank, as the hole in the eccentric 
 will not then need to be larger than those in the 
 standards, and the small eccentric supplied with 
 model castings scarcely admits of a larger one. 
 
 The eccentric should be bored out to be a good 
 fit in its place on the shaft, and a small hole is to be 
 bored through the boss upon it sloping inwards into 
 the larger one ; this is for the set-screw, and should 
 be tapped for -inch screw. The set-screw itself is to 
 be made from a piece of steel wire |-inch long, and 
 screwed and finished with a nick in the top for the 
 screw-driver, no head being necessary. 
 
 The crank-shaft is now to be placed in the bear- 
 ings, and the whole placed upon the bed-plate. Now 
 see that the shaft is directly at right angles with 
 the piston-rod, and then mark the positions of the 
 holes in the feet of the standards upon the bed-plate. 
 Drill the latter and bolt the standards down. 
 
 THE PISTON-ROD HEAD is to be bored and tapped 
 with a screw, so that it may be screwed on to the 
 piston-rod when the proper thread has been cut upon 
 this latter. A T Vinch hole must be bored through 
 this piece to take the cross-head. The piston-rod 
 should be cut off to the right length, which length 
 may easily be taken from the working drawing, and 
 screwed with the same thread as that of the piston- 
 rod head, which should now be fitted on to it. 
 
 Attach the connecting-rod to the crank, and after 
 pushing the piston down to about i of an inch from the 
 
86 Horizontal Slide- Valve Engine. 
 
 bottom of the cylinder, and bringing the crank round 
 until it is at its nearest to the cylinder, mark on the 
 free end of the connecting-rod the position of the 
 cross-head holes in the piston-rod head. Take the 
 connecting-rod off the crank and drill a T Vinch hole 
 for the cross-head in the place marked. 
 
 Take a piece of -^-inch steel if inches long, and 
 turn half an inch at each end down to J-inch. Drill 
 a J-inch hole through the centre of each guide-block. 
 Now take the top guide-bars off the bed-plate and 
 pass the steel cross-head through the piston-rod head 
 and connecting-rod, placing the guide-blocks on the 
 end of the cross-head. 
 
 The height of the guide-bars with respect to the pis- 
 ton-rod and of the pillars between the upper and lower 
 bars must be carefully adjusted, a very little being 
 taken off the feet of the lower bars till these latter are 
 low enough, or if they are accidentally made too low, 
 the lugs by which the cylinder is bolted down must 
 be slightly reduced ; for it is obvious that unless the 
 guide-bars are perfectly horizontal and of exactly the 
 correct height, a strain will be put upon the piston- 
 rod and much unnecessary friction caused, even if the 
 piston can be got to move at all under such circum- 
 stances. At the same time the thickness of the guide- 
 blocks must be adjusted so that the blocks will run 
 smoothly and easily, and without any shake, between 
 the guide-bars. 
 
 THE SLIDE-VALVE ROD is to be made of steel 
 
Horizontal Slide- Valve Engine. 87 
 
 wire, say Vinch thick, rather under than over. The 
 eccentric band must be drilled and screwed to re- 
 ceive one end of the rod, and a joint must be 
 made in the rod about one inch from the steam- 
 chest stuffing-box. The short piece is to be filed flat 
 on two sides T V of an inch from its end for a distance 
 corresponding with the length of the valve, so that it 
 will drop into the slit in the latter, and will move it 
 backwards and forwards over the ports without allow- 
 ing any end-play. The joint in the valve-rod may be 
 made from two pieces of brass-wire T Vinch thick ; 
 these are each drilled and screwed at one end, to re- 
 ceive the ends of the two parts of the rod ; in the other 
 end of one piece a saw-cut is to be made, and a flat 
 filed on the other piece to fit the saw-cut. These two 
 pieces are now to be put together, the flat of the one 
 into the saw-cut of the other, a small hole drilled 
 through the joint, and a piece of wire put through as 
 a pivot, and rivetted with one or two light taps of 
 the hammer. 
 
 The eccentric must now be put in place on the 
 shaft, and the length of the rod so adjusted that when 
 the strap is at its farthest from the steam-chest, 
 the lower port shall be just as much open as the 
 upper port is when the strap is at its nearest to the 
 steam-chest ; of course for this purpose the steam- 
 chest must be taken off, and the engine turned on its 
 side with the cylinder-face uppermost, so that the 
 valve may lie upon this latter. 
 
88 Horizontal Slide-Valve Engine. 
 
 The fly-wheel may be turned and bored upon the 
 face-plate of the lathe, or it may be keyed on to the 
 crank-shaft and turned up in position. The shaft 
 must be filed away a little on one side, and a corre- 
 sponding flat filed in the fly-wheel ; a small key very 
 slightly wedge-shaped is then to be driven into the 
 space thus made between the wheel and shaft, bear- 
 ing in mind however the caution given in Chap. II. 
 
 An exhaust-pipe may be screwed into the exhaust- 
 port of the cylinder, brought through a hole in the 
 bed-plate and bent outwards, and a steam-pipe 
 should be screwed into the steam-chest. 
 
 If it has not already been done, the burrs left at 
 the edges of the screw-holes in the cylinder-covers, 
 steam-chest, etc., must be rubbed off, and a little white 
 and red lead put between such parts as are required 
 to be steam-tight before they are finally screwed to- 
 gether. Before the steam-chest is screwed on, how- 
 ever, the eccentric must be fixed by means of its set- 
 screw in such a position upon the shaft that the valve 
 will open the lower port just as the piston is at the 
 bottom of the cylinder, and the upper port just as 
 the piston is at the top of the cylinder. 
 
 Oil-holes may be drilled in the centre of the top 
 guide-bars, the plummer-blocks, and anywhere else 
 where it may be thought necessary. 
 
 The engine may now be mounted upon a solid block 
 of wood, the same size as the bed-plate and 2\ inches 
 thick, holes being made in the top of the block to 
 
Sg 
 
QO Plorizontal Slide- Valve Engine. 
 
 make room for the various nuts under the bed-plate, 
 and a slot cut for the exhaust-pipe ; and the bed-plate 
 being screwed down to this block, we may consider 
 our model finished. 
 
 Fig. 63 shows the engine in its complete state, but 
 mounted upon standards instead of upon a solid block 
 of wood. From this diagram the relative disposition 
 of the different parts of which it is composed will 
 be easily recognised. 
 
 The amateur who has successfully made this 
 model may safely take in hand a small power engine 
 of the class recently introduced by Messrs. Lucas & 
 Davies ; these engines are very suitable for driving a 
 lathe, working a pump or a small circular saw, or 
 other machinery likely to be found in the amateur's 
 workshop. 
 
 The cylinder is of iron, and if the cylinder and guide 
 are bored before the castings are sent out, the engine 
 will be an easy one to put together. The set, includ- 
 ing governor and force-pump castings of the No. I 
 engine, cylinder i|-inch diameter and 3-inch stroke, 
 costs 3cxr. ; while the set for the No. 2 size, cylinder 
 2-inch diameter and 4-inch stroke, costs 50^. The 
 nuts and studs for No. I are sold at 12s. 6d., and for 
 No. 2 at 15^-. per set. Tubular boilers suitable for 
 these engines, fitted with pressure-gauge and all 
 necessary taps, etc., are supplied by the same firm 
 at 10 IDS. and 13 respectively. The finished 
 engines complete with boiler, etc., cost 20 and 25. 
 
CHAPTER VI. 
 
 VERTICAL SLIDE-VALVE ENGINE. 
 
 THIS engine is the same in all essential respects 
 as the one last described, the only difference 
 being in the arrangement of the working parts 
 vertically instead of horizontally ; this type of engine 
 consequently occupying less floor space than that last 
 described. 
 
 The castings required for this engine consist of the 
 following pieces : 
 
 Two A-standards, 
 
 Two bearings, 
 
 Cylinder, 
 
 Two cylinder-covers, 
 
 Piston, 
 
 Steam-chest, 
 
 Slide-valve, 
 
 Gland for steam-chest, 
 
 Gland for top of cylinder, 
 
 Eccentric and eccentric-strap, 
 
 Support for guide-bars, 
 
 Cross-head, 
 
 Crank, 
 
 Fly-wheel. 
 
92 Vertical Slide- Valve Engine. 
 
 Some makers will also supply the connecting-rod 
 as a casting. 
 
 Of these castings, the cylinder, steam-chest, pis- 
 ton, glands, connecting-rod, slide-valve, eccentric and 
 eccentric-strap, and fly-wheel, will be in all respects 
 similar to the castings of those parts used for the 
 horizontal engine ; and as they are to be treated 
 in the same manner up to the point of fitting the 
 engine together, we shall leave them on one side for 
 the present, and proceed to speak of the pieces which 
 vary in this engine from the analogous parts in the 
 horizontal type. 
 
 These pieces are the guide-bar stay, shown in Fig. 
 64 ; the cross-head, Fig. 65 ; the crank, which will be of 
 the same design as that of the oscillating engine first 
 described ; and the cylinder-cover, which differs from 
 the horizontal cylinder-cover in having two small 
 projections on its rim into which the guide-bars are 
 fixed. 
 
 The bed-plate is shown in Fig. 66. 
 
 This engine makes a very pretty model, and with 
 very little extra trouble it may be brought out highly 
 finished, all the parts being filed smooth and bur- 
 nished, with the exception of the body of the cylinder, 
 which may be coloured with bright green enamel 
 paint. 
 
 The surface of the bed-plate should be filed up 
 flat and smooth ; the position of the centre of the 
 cylinder must be marked upon it ; and when the 
 
FIG. 64. 
 
 Fio. 65. 
 
 Fie. 66. 
 
 93 
 
94 Vertical Slide- Valve Engine. 
 
 circle for the screw-holes has been marked upon the 
 cylinder-bottom, a circle of the same radius should be 
 struck upon the bed-plate from the centre marked, 
 and two holes of a size to allow the screws to pass 
 through them should be drilled diametrically opposite 
 each other upon the circumference so struck. The 
 cylinder-bottom must then be placed upon the bed- 
 plate, and while it is held in place, mark upon it the 
 position of these two holes just mentioned ; the 
 position of the other four holes for screwing on the 
 cover being marked off as usual. When the bottom 
 cover is screwed on to the cylinder, the two holes 
 coinciding with those in the bed-plate are to be left 
 without screws, to be used in finally attaching the 
 cylinder to the bed-plate. It will give a neater ap- 
 pearance to the engine, when finished, if screws with 
 conical heads are used for screwing on the cylinder- 
 bottom, the screw-holes being countersunk for the 
 reception of the heads of the screws, or all the six 
 screws may be put through both bed-plate and 
 cylinder-cover. 
 
 The two projections on the cylinder-top will prevent 
 its edge being turned up in the lathe ; therefore when 
 each surface has been turned up, and before the top 
 is taken from the lathe, a circle should be marked 
 with the graver of the same diameter as the outside 
 of the cylinder-flange, and the edge must afterwards 
 be carefully filed away to this mark, save where the 
 aforesaid lugs are left projecting. In marking the 
 
Vertical Slide- Valve Engine. 95 
 
 screw-holes upon the top flange of the cylinder, it 
 must be remembered that when the engine comes to 
 be finally fitted up, a line drawn through the lugs on 
 the cylinder-top must be at right angles with the 
 shaft of the engine. 
 
 The standards should be filed up smooth and the 
 tops left level ; the ornamental grooves may either be 
 scraped out bright or left as they are, or they may be 
 painted over with enamel paint after the engine is 
 finished. 
 
 The bearings may next be filed smooth, centre- 
 punched, and drilled for screws ; they must then be 
 put in place upon the standards, and the position 
 of the screw-holes marked on these latter, and drilled 
 and tapped for i-inch screws. The bearings should 
 then be screwed firmly to the standards and filed 
 down to the same level at the sides and ends while 
 in situ. If properly done, the joint should be in- 
 visible except upon looking closely for it. A groove 
 is left in the castings for the bearings, and in the tops 
 of the standards, so that when the two parts are 
 screwed together the hole for the crank-shaft will be 
 formed between them. To bore this hole out to the 
 right size, a small D-bit is the best tool. The finished 
 diameter of the hole should be i-inch. 
 
 Before the bearings are taken off the standards, 
 they should be marked at the back, so that they may 
 always be placed in their proper position without 
 trouble. The feet of the standards may now be 
 
96 Vertical Slide- Valve Engine. 
 
 drilled for the bolts which are to hold them down 
 upon the bed-plate. 
 
 The crank may be simply filed up smooth, or the 
 bosses for the end of the crank-shaft and for the 
 crank-pin may be finished off in the lathe. 
 
 The support for the guide-rods will be fixed in the 
 position shown in Fig. 68. A hole must be drilled 
 in each of the two legs of the front standard, and the 
 guide-bar- support being drilled and tapped in corre- 
 spondence with these holes, is held in place by screws 
 passed through from the back of the standards. 
 
 The centres of the two bosses shown in Fig. 64 
 should now be found and punched. The exact dis- 
 tances between these centres must be taken with 
 the compasses and marked off upon the cross-head 
 (Fig. 65), and upon the cylinder-top. These pieces 
 are then to be drilled as marked, the holes in the 
 cover must be tapped to take a piece of screwed steel 
 rod about -inch in diameter, the cross-head should 
 be an easy fit upon the same rod, so that it will slide 
 up and down without shake, and the holes in the 
 support must be the least trifle smaller than those 
 in the cross-head, so that they will be a tight fit 
 upon the same rods. The holes in the support may 
 be drilled right through or not, according to fancy ; 
 in the former case, the guide-rods will of course be 
 made rather longer, their tops being neatly rounded 
 off. The cross-head must be drilled and tapped for 
 the end of the piston-rod, and fitted to the connect- 
 
98 Vertical Slide- Valve Engine. 
 
 ing-rod, the joint being made by a steel pin passed 
 through the connecting-rod and the cross-head, the 
 other end of the connecting-rod being treated in the 
 manner described in the case of the horizontal engine. 
 
 The shaft will be of the same diameter as that used 
 for the horizontal engine ; it will be made of a straight 
 piece of round steel bar turned down to fit the bear- 
 ings, and f of an inch at the cylinder-end must be 
 turned down to \ of an inch diameter and screwed, 
 the larger boss on the crank being drilled and tapped 
 to correspond. The smaller boss on the crank is to 
 be drilled and tapped to take a T Vmch screw, a steel 
 pin one inch long being screwed into the same. 
 
 The engine may now be put together. Let the 
 feet of the standards be filed down, if necessary, until 
 the shaft-bearings are perfectly level with one another 
 and the shaft runs easily. The position of the 
 eccentric will of course be inside the front standard, 
 and the cylinder, connecting-rod, fly-wheel, etc., being 
 all in place, the position of the holes in the feet of the 
 standards must be marked upon the bed-plate, and 
 the cylinder being unscrewed, the bed-plate is to be 
 drilled where marked ; the standards can then be 
 bolted down, and the engine permanently fixed up. 
 
 Figs. 67 and 68 are working drawings on a scale 
 of six inches to the foot, Fig. 67 showing the engine 
 partly in elevation and partly in section. In this 
 figure, however, the distance between the steam-ports 
 and the exhaust is greater than it should be. 
 
CHAPTER VII. 
 DOUBLE-CYLINDER LAUNCH ENGINE. 
 
 E engine described in this chapter is a double- 
 J- cylinder launch engine, the castings for which 
 cost lAfS. 
 
 The set consists of thirty-three pieces, as follows : 
 
 I Bed-plate (Fig. 71), 
 
 1 Top-plate (Fig. 72), 
 4 Standards, 
 
 2 Cylinders, 
 
 2 Cylinder-tops, 
 
 2 Cylinder-bottoms, 
 
 2 Pistons, 
 
 2 Steam-chests, 
 
 2 Slide-valves, 
 
 2 Connecting-rods, 
 
 2 Eccentrics, 
 
 2 Eccentric bands and rods (Fig. 69), 
 
 2 Cross-heads, 
 
 3 Shaft-bearings, 
 i Balance-wheel, 
 i Screw, 
 
 99 
 
100 
 
 Double-Cylinder Launch Engine. 
 
 and two pieces, each of which forms a cylinder and 
 steam-chest stuffing-box gland. 
 
 FIG. 69. 
 
 The cylinders are I inch in diameter, and ij inch 
 stroke. 
 
 The steam-chests, cylinder-bottoms, and eccentrics, 
 all have chucking tenons cast upon them for con- 
 venience in turning. 
 
 The cylinders, with their steam-chests and slide- 
 valves, will of course be finished off in the same 
 
IO2 Double-Cylinder Launch Engine. 
 
 manner as in the other engines described, except that 
 the cylinders will have to be bolted down upon the 
 top-plate. This may be done by making screw-holes 
 in the plate to coincide with those in the cylinder- 
 tops and cylinder-flanges, and screwing plate and 
 covers to the cylinders with the same screws. Three 
 marks will be found on the top-plate, one showing 
 the centre of the plate, and the other two indicating 
 the position of the centre of each cylinder. Taking 
 these two latter marks as centres, two half-inch holes 
 must be bored in the top-plate for the stuffing-boxes 
 of the cylinder-covers to pass through. 
 
 The standards are best bolted to the bed-plate 
 with small bolts and nuts, using two for each standard. 
 The positions of the standards are shown at A (Fig. 71). 
 The top-plate is placed symmetrically upon the tops 
 of the standards, and secured in the same manner. 
 
 The crank forging is made as described in a 
 previous article, except that in this instance there 
 must be two crank-pieces welded on to the bar, and 
 these pieces should be at right angles to each other, 
 as seen in Fig. 70. 
 
 The cross-heads must be filed up, and a slight 
 groove filed in each end to fit the guiding part of the 
 standards. 
 
 The fitting of the connecting-rods to the cross- 
 heads and cranks will present no difficulty, the cross- 
 head and connecting-rod being held together by a 
 -inch steel pin ; and the crank end of the connecting- 
 
n 
 
 A 
 
 D 
 
 en 
 
 B- 
 
 FIG. 71. 
 
 FIG. 72. 
 103 
 
IO4 Double- Cylinder LauncJt Engine 
 
 rod being sawn across where marked, the two parts 
 are screwed together and drilled to take the crank. 
 
 The position for the three supports for the shaft is 
 shown at B (Fig. 71). They must be sawn across, 
 and drilled with a J-inch drill for the shaft, the 
 latter being turned down to the same diameter at 
 the parts which are to rest in the bearings. 
 
 The eccentrics and eccentric-bands are to be fitted 
 as in the other engines already described ; half the 
 band will, however, be in one piece with the eccentric- 
 rod. In the top of the eccentric-rod, a slot must be 
 filed to receive the head of the slide-valve rod, which 
 latter is formed from a piece of brass rod filed flat 
 at one end ; the two parts are then put together as 
 a hinge, and held by means of a small pin. 
 
 The bed-plate must, if necessary, be filed away to 
 make room for the revolution of the eccentrics. 
 
 The balance-wheel, answering to the fly-wheel of 
 other engines, must be screwed or keyed on to the 
 end of the shaft. 
 
 The screw must be filed up and mounted on a 
 separate shaft, the length of which will depend upon 
 the boat in which the engine is to be placed. The 
 shaft is made from a piece of steel wire ; the screw 
 is drilled, and a set-screw fitted into it upon one 
 side to fix it in its place upon the shaft ; upon 
 the other end of the shaft is screwed a piece of 
 brass, through which a pin passes, which engages 
 two pins projecting from the disc of the balance- 
 
Double- Cylinder Launch Engine. 105 
 
 wheel of the engine. The shaft passes through a 
 long stuffing-box (as shown in Fig. 76) ; this latter, 
 being firmly fixed in the hull of the vessel for which 
 
 FIG. 73. 
 
 the engine is intended, acts also as a bearing for the 
 shaft. 
 
 In order to keep the driving-pin up to the balance- 
 
io6 
 
 Double- Cylinder Launch Engine. 
 
 wheel, a small brass collar is fixed upon the shaft ; 
 for the sake of clearness, this collar is shown in the 
 drawing pulled forward, but in action it is fixed to 
 
 FIG. 74. 
 
 the shaft by means of a set-screw, and revolves with 
 it against the forward end of the stuffing-box. 
 
 Fig. 73 shows the complete engine as seen from 
 one side ; Fig. 74 is an end view showing one cylinder, 
 
Double-Cylinder Launch Engine. 
 
 107 
 
 with its guide and connecting-rod ; and Fig. 75 is the 
 same view, with the eccentric and eccentric-rod, and 
 slide-valve rod added. 
 
 FIG. 75. 
 
 Reversing gear may easily be added to this engine ; 
 two small brackets attached to the standards carry 
 the rocking-bar, and the reversing lever may be 
 pivoted to a bracket attached to one of the standards 
 
loS Double-Cylinder Launch Engine. 
 
 on the opposite side to those carrying the rocking- 
 bar. A full description of reversing gear is given in 
 another chapter. 
 
CHAPTER VIII. 
 
 DOUBLE-ACTION OSCILLATING CYLINDER 
 MARINE ENGINE. 
 
 THE design of the marine engine in actual use in 
 steam-ships is rather too complicated to form 
 an easily made model, neither would a model so 
 made be likely to prove so effective as the more 
 simple pattern generally put into model steamers. 
 
 The full-sized marine engine is usually of the com- 
 pound high-pressure type ; that is, it contains within 
 itself the essential parts of a high-pressure and of a 
 low-pressure condensing engine, the steam being first 
 used in a small high-pressure cylinder, and after 
 doing a portion of its work therein it is conducted 
 into a larger cylinder with condenser and air-pump 
 attached, where it completes its work expansively. 
 
 In these engines the steam is admitted into the 
 cylinders by means of slide-valves ; and where the 
 cylinders oscillate, as is often the case, the slide-valve 
 chest is bolted to the cylinder and rocks with it, and 
 various arrangements are used for the purpose of 
 connecting the eccentric with the oscillating valve. 
 In the case of oscillating cylinders the steam is 
 
 admitted to the valve-chest through one of the 
 
 109 
 
no Oscillating Cylinder Marine Engine. 
 
 trunnions, which are hollow and connected with the 
 steam and exhaust pipes respectively by means of 
 steam-tight joints. 
 
 The model I am now about to describe is similar 
 to one large class of marine engines in that it has 
 oscillating cylinders ; and in outward appearance it 
 will certainly pass to the unprofessional eye as a 
 model of the real thing. Moreover, it is easy and 
 interesting to construct, as it differs considerably from 
 the forms previously described, and forms a handsome 
 little engine when finished. 
 
 A set of castings for a marine engine of this descrip- 
 tion costs C)s. 6d., and should include the following 
 items : 
 
 Two plates, one forming the bed-plate and the 
 other the top-plate of the engine ; 
 
 Two cylinders, differing from the cylinders of the 
 engines described in previous chapters in having a 
 round plate on one side and a trunnion on the other ; 
 
 Four pillars to support the top-plate, 
 
 Four cylinder-covers, 
 
 Two pistons, 
 
 Two stuffing-boxes, 
 
 Two piston-rod heads cast in one piece, 
 
 One steam-block, 
 
 Two standards, 
 
 Three bearings, 
 
 Four paddle-wheel sides, 
 making twenty-seven separate castings in all. 
 
Oscillating Cylinder Marine Engine. 1 1 1 
 
 We will suppose that the cylinders are bored, and 
 the piston, piston-rod, covers, and stuffing-boxes are 
 all fitted, these parts being precisely the same as in 
 the other engines described. We shall therefore com- 
 mence with the steam-block (Fig. 79). This must be 
 filed up bright and smooth, care being taken to get 
 the two faces square with the bottom of the block, 
 and parallel with each other. Now mark off the 
 centre on each side of the block, centre-punch, and 
 drill a ^V-inch hole from each side, the holes meeting 
 in the middle. The next thing will be to make the 
 steam-ways, and for this we shall require a special 
 tool. A pin-drill, with the part between the pin and 
 the outside cutting edge cut away, would do ; but in 
 Fig. 77 is shown a tool which may be made in ten 
 
 FIG. 77. ~ 
 
 minutes, and with it both steam-ways may be cut out 
 in another five. The writer having recently made 
 this use of the tool from which the drawing is made, 
 
1 1 2 Oscillating Cylinder Marine Engine. 
 
 can guarantee both its speed and its efficiency. The 
 tool is prepared in this way : A block of box or other 
 hard wood is to be screwed to the face-plate of the 
 lathe, and the face of this block turned down smooth; 
 then, while it is still in the lathe, a hole under V of 
 an inch in diameter is to be drilled in the centre. 
 The face-plate must now be taken off the lathe, and 
 a saw-cut i of an inch deep is to be made, passing 
 exactly through the centre of the face of the block. 
 
 A piece of straight -^--inch steel wire must be ham- 
 mered into the hole, and a cutter of the shape shown 
 in Fig. 78 is to be filed up from a piece of sheet steel 
 
 FIG. 78. 
 
 (for example, a bit of an old saw), and after it has been 
 hardened and tempered, this also must be hammered 
 into the saw-cut in the block of wood, the inside edge 
 of the cutter being -- of an inch distant from the 
 centre-pin. In use the centre-pin of the tool works 
 in the centre-hole in the steam-block, and the latter 
 being fed up to the cutter by the screw of the lathe, 
 a circular groove about ^V of an inch deep will soon 
 be scraped out. 
 
 This groove having been cut in both sides of the 
 steam-block, a line is to be marked across each side of 
 the block at right angles to its base, as seen in Fig. 79, 
 and holes of the same diameter as the annular groove 
 
Oscillating Cylinder Marine Engine. 1 1 3 
 
 must be drilled through the block at the points where 
 the line cuts the groove. Now heat a piece of brass 
 wire of the right size for the purpose, coat it with 
 solder, and put it through the holes just drilled ; heat 
 the block until the solder runs, and when cool, file the 
 ends of the wire down smooth with the faces of the 
 block. 
 
 FIG. 79. 
 
 Drill a -|-inch hole into each end of the steam- 
 block, i of an inch deep, and two T yinch holes lead- 
 ing from each groove into the |-inch hole upon its 
 own side of the block. Fig. 80 is a section of Fig. 79 
 
 FIG. 80. 
 
 on the line A B, the dotted lines showing the steam- 
 ways and exhaust. 
 
 After the faces of the block have been filed smooth 
 again, a piece of -aVinch steel is to be fitted into 
 
 I 
 
H4 Oscillating Cylinder Marine Engine. 
 
 the centre hole, and filed off to such a length that 
 it will project about | of an inch upon each side of 
 the block, and the lugs of the latter must be drilled 
 to allow the passage of the |-inch screws by which it 
 will be attached to the bed-plate. 
 
 The steam-block being now complete, we will turn 
 our attention to the cylinders. The steam-face and 
 end of trunnion must be filed up smooth and square 
 with the ends of cylinder ; mark and centre-punch 
 the centre of the steam-face, and draw a line from 
 end to end of the cylinder passing through this 
 centre mark ; upon the line so drawn mark off a 
 distance above and below the centre equal to the 
 distance from the centre of the steam-block to the 
 centre of the groove in the same. Centre-punch at 
 these points, and drill three -gV-inch holes \ of an 
 inch deep, one in the centre of the steam-face, and 
 the other two at the points marked. Into these two 
 latter holes drill steam-ways from the two ends of 
 the cylinder, as in the case of an ordinary slide-valve 
 cylinder. Fig. 81 shows the cylinder-face finished. 
 
 Now stand the cylinder on end upon a level sur- 
 face, and mark off on the trunnion the height of 
 the centre of the steam-face, and drill a T V to gVinch 
 hole a little way into the trunnion. Take the two 
 standards, and having carefully filed them up square 
 and smooth, stand them upon a level surface and 
 mark across them with the scriber the exact height 
 of the centre of the steam-block. Centre-punch and 
 
Oscillating Cylinder Marine Engine. 115 
 
 drill, and tap for |-inch screws, also drill the feet of 
 the standards to clear ^\-mch screws. 
 
 FIG. 81. 
 
 The ^-inch screws for the standards must be filed 
 to a smooth round point, and either lock-nuts should 
 be fitted to the screws, or set-screws should be fitted 
 into the top or at one side of the standards, other- 
 wise the bearing screws will work loose with the 
 motion of the cylinders. 
 
 The four pillars, seen in Figs. 83 and 84, may next 
 be turned up, the top and bottom of each being 
 screwed and nuts fitted to the bottom-pins. The 
 top and bottom plates must be filed up quite 
 smooth and drilled at the corners. It is best to 
 clamp them together in the same position with re- 
 spect to each other as they will occupy when finished, 
 and drill through both at once. Use in the first 
 place a i-inch drill, and screw the holes in the top 
 plate to suit the top screws of the pillars ; the holes 
 
n6 Oscillating Cylinder Marine Engine. 
 
 in the bottom plate are to be enlarged to allow the 
 lower pins of the pillars to pass through them. 
 
 Draw centre-lines across the upper surface of the 
 foundation-plate, and placing the steam-block so 
 that its centre coincides with the centre of the plate, 
 mark upon the latter the position of the holes in the 
 lugs of the block, and drill and screw the plate for 
 -inch screws. 
 
 Mark and drill the holes for the -gV-inch screws 
 which are to fasten the standards to the bed-plate, 
 taking care that they are in perfect line, and square 
 with the steam-block, and also set near enough to 
 the ends of the bed-plate to allow the cylinders to 
 work between them and the steam-block. 
 
 The crank-shaft may now have our attention ; 
 this may be made in the manner already described, 
 or as shown in Fig. 82, the latter form having the 
 advantages that no special forging is required for it, 
 and of giving a more equable motion to the paddle- 
 wheels. The shaft itself consists of three straight 
 pieces of steel, upon which are keyed four discs of 
 iron or brass about & of an inch thick ; these discs 
 are connected in pairs by pins upon which work the 
 heads of the piston-rods. The drawing Fig. 82, 
 which however is not to scale, will make this quite 
 clear. The crank-shaft should be left of ample 
 length, say nine or ten inches, until the width of 
 the boat in which the engine is to work is known. 
 
 The three crank-bearings must be screwed upon 
 
n8 Oscillating Cylinder Marine Engine. 
 
 the top-plate so that the centre line of the shaft will 
 be directly over the line running through the centres 
 of the steam-block and the cylinder-standards, the 
 bearings being first sawn apart and drilled for the 
 shaft as explained in Chap. V. 
 
 The piston-rod heads must be sawn apart and 
 drilled and screwed for the piston-rods ; each head 
 must then be sawn across, screwed together, and 
 bored for the crank-bearing, in the same manner as 
 the head of the connecting-rod in the other engines 
 described. 
 
 Now the final adjustment of the cylinders should 
 be made, the cylinder-faces being ground to the faces 
 of the steam-block, and it is best during this process 
 to stop up the steam-ports in the cylinder-face, 
 otherwise the abrading material used may find its 
 way to the interior of the cylinder, which it will in 
 no way improve. 
 
 The engine being now finished, with the exception 
 of the paddle-wheels, it may be screwed together, 
 and the tops of the supporting pillars filed off level 
 with the upper surface of the top plate. 
 
 The floats for the paddle-wheels should be about 
 i inch in length by i-inch wide. The length 
 here given is not in the proportion used for large 
 steamers, for Molesworth gives the following as the 
 dimensions of the paddles of one of Maudslay & 
 Sons' marine engines: " Diameter of paddle-wheels 
 to centre of floats, 19 ft. Length of floats, 8 ft. 6 in. 
 
I2O Oscillating Cylinder Marine Engine. 
 
 Breadth of floats, 3 ft. 4 in. ;" and the same propor- 
 tion would give a length of over 2 inches to the floats 
 of our small paddle-wheels. The floats should be 
 made of thin sheet brass or other metal cut to size. 
 
 The sides of the wheel in hand being clamped 
 together, the centres must be drilled to take a piece 
 of stout tubing of a size that will just fit over the 
 ends of the shaft ; this piece of tubing should be 
 fitted with a set-screw in the centre. 
 
 The sides must now be clamped with some small 
 pieces of wood between them to keep them just ij 
 inch apart all the way round ; the centre-tube is 
 first soldered in, care being taken that the set-screw 
 will come between two of the floats so that it may 
 be reached with a screw-driver. 
 
 The floats must rest upon the bars provided for 
 them, and will project slightly upon each side of the 
 wheel. 
 
 A finish may now be given to the engine by paint- 
 ing the bodies of the cylinders green and the paddle- 
 wheels the orthodox bright red ; and if the rest of 
 the engine has been worked up bright, one of the 
 prettiest models we have yet constructed will be the 
 result. 
 
 By fitting up this engine as shown in Fig. 84, 
 instead of according to the foregoing description and 
 illustration (Fig. 83), it may be adapted to working 
 a screw instead of paddle-wheels. 
 
FIG. 84. 
 
CHAPTER IX. 
 
 SLIDE-VALVE LOCOMOTIVE ENGINE. 
 
 r I "HE locomotive, the last model to be described, 
 -L will tax to the utmost the amateur's skill in 
 fitting ; but when finished, the result will be a com- 
 plete and handsome model of which the maker may 
 well feel proud. 
 
 The castings for the engine described in this 
 chapter cost 28^. the set, and comprise : 
 
 Bed-plate, 
 
 Front and back of smoke-box, 
 
 Front and back of fire-box, 
 
 Boiler, 
 
 Tubes for boiler, 
 
 Furnace-door (Fig. 95), 
 
 Two cylinders (Fig. 85) and their covers, 
 
 Two steam-chests, 
 
 Two slide-valves, 
 
 Two cross-heads, 
 
 Six axle-blocks (Fig. 87), 
 
 Two parallel bar supports (Fig. 88), 
 
 Four eccentrics, 
 
 Four eccentric rods and bands, 
 
Slide- Valve Locomotive Engine. 123 
 
 One reversing quadrant (Figs. 89 and 90), 
 
 One starting lever, 
 
 One starting quadrant, 
 
 One steam-tap casting (Fig. 92), 
 
 Two name-plates, 
 
 Man-hole and plug, 
 
 Steam-tap, stuffing-box, and gland, 
 
 Four buffers (Fig. 93), 
 
 Lower part of chimney (Fig. 94), 
 
 Top of chimney, 
 
 Chimney-tube, 
 
 Steam-dome, 
 
 Pair of leading- wheels, 
 
 Two pair of driving-wheels, 
 
 T-joint for steam-pipe. 
 
 THE BOILER. This is made with six f-inch tubes. 
 The two ends should be clamped together and drilled 
 for the tubes, two below and four immediately above 
 them, all six being kept as low down in the boiler 
 as possible. The tubes, which will be rather longer 
 than the boiler, must be placed in position in the 
 front and back of the latter, and their ends spread 
 well out and hammered over, after which a little 
 solder is to be run round the end of each tube to 
 close the joint. 
 
 The front end of the boiler will consist of a 
 flanged circular plate, but at the foot-plate end the 
 lower part of the boiler is cut away for a length of 
 
124 Slide-Valve Locomotive Engine. 
 
 2f inches to form the fire-box, and the back plate 
 must be of a shape to fit this opening. A plate 4 
 inches wide and 7 inches long will allow of a suffici- 
 ently wide flange ; it must be bent twice at right 
 angles in opposite directions to fit the boiler, and the 
 top and bottom must then be rounded and the piece 
 flanged all round. 
 
 The ends with the tubes in situ are now to be 
 placed in the body of the boiler, and it will be best 
 to rivet in the fire-box end even if the front end is only 
 soldered. After the rivetting is finished, solder should 
 be run into the joints. Further details respecting 
 flanging and rivetting will be found in Chap. X. 
 
 The dome should be turned up, and the valve fitted 
 to the top of it. [As to the fitting of this latter, 
 see Chap. XL] It may then be soldered on to the 
 boiler, but before this is done, the steam-tap (Fig. 92) 
 must be put in. Directions for making this part and 
 the rest of the boiler-fittings will also be found in 
 Chap. XI. The inlet pipe from the dome should 
 be supported by a strip of metal fastened across the 
 dome-hole in the boiler. 
 
 Any firm supplying castings will also supply the 
 boiler already finished with steam-tap and other 
 fittings, and I certainly recommend the purchase of 
 it in this complete form to all but the most experi- 
 enced amateurs. 
 
 THE SMOKE- AND FIRE-BOXES. The ends of the 
 smoke- and fire-boxes are flanged, and the sides of 
 
Slide- Valve Locomotive Engine. 125 
 
 both parts are made of sheet brass rivetted or brazed 
 inside the flanges of the ends. One end of the 
 smoke-box, as also one end of the fire-box, has a hole 
 in it the size of the boiler, and the two ends of this 
 latter are supported in these holes ; the other end of 
 the smoke-box has a rather smaller hole to which the 
 smoke-box door is fitted, while the other end of the 
 fire-box has a small hole to be closed by the furnace 
 door (Fig. 95). The lower part of the fire-box is left 
 open for the lamp. 
 
 THE FURNACE DOOR. The half-hinge seen at the 
 lower part of this piece in Fig. 95 must be cut off, 
 and after it has been drilled to take the hinge-pin 
 and three rivets, it is to be rivetted on to the back of 
 the fire-box. The door itself is to be polished up, 
 and the hinge drilled and attached to the half-hinge 
 on the fire-box by means of a pin run through both 
 parts. The door may be finished off with a small 
 knob or handle attached to a latch. 
 
 THE SMOKE-BOX DOOR is formed from a piece of 
 tin or thin brass, which is either spun in the lathe or 
 hammered into shape. [Directions for spinning will 
 be found in the chapter on Boiler-Making.] The form 
 of the handle seen in Figs. 96 and 98 will be familiar 
 to all who have noticed the front of a real locomotive. 
 On the inside of the door this handle works the latch ; 
 a piece of iron about half an inch wide is fastened 
 across the front of the smoke-box, and the latch 
 catches into a slot cut in the iron. 
 
126 Slide-Valve Locomotive Engine. 
 
 When finished, the parts just described should 
 measure : 
 
 The smoke-box if in. long x 4 in. diameter. 
 
 The fire-box 3 x 3! wide and 5 in. 
 
 deep. 
 The boiler 8f x 3^ diameter. 
 
 THE FUNNEL. The base (Fig. 94) and the top of 
 the funnel should be brazed to the funnel tube, and 
 the funnel is then to be rivetted, bolted, or brazed to 
 the top of the smoke-box, in which of course a hole 
 must be made rather smaller than the diameter of the 
 lower part of the funnel. 
 
 The fire- and smoke-boxes are to be bolted to the 
 bed-plate later on by means of small angle-plates. 
 
 We may now place the boiler and the smoke- and 
 fire-boxes on one side, and proceed to the mechanical 
 portion of the engine. In the working drawings, two 
 of which (Figs. 96 and 98) are on a scale of 3 inches 
 to the foot, and one (Fig. 97) on a scale of 4 inches to 
 the foot, the same letters are applied to the same 
 parts in each drawing. Fig. 98 shows the engine 
 in elevation, Fig. 96 in section, and Fig. 97 shows 
 the working parts as seen from underneath : A is 
 the fire-box ; B, the boiler ; c C, the tubes, of which 
 there are six ; D, the smoke-box ; E, the smoke-box 
 door ; F, the steam-tap ; and G, the handle to the 
 same. 
 
 The form of the bed-plate will be seen in Figs. 96, 
 
Slide- Valve Locomotive Engine. 127 
 
 97, and 98 ; the front or leading pair of wheels run 
 under the bed-plate, but for the larger wheels there 
 are four slots in the plate, as seen in Fig. 97. 
 
 FIG. 85. 
 
 THE CYLINDER {Fig. 85) has two lugs cast upon it 
 which are to be drilled and tapped for screws. These 
 screws fasten the cylinder firmly to the bed-plate, 
 passing through the latter from above. The cylinder 
 
 FIG. 86. 
 
 cover (Fig. 86) will be found somewhat different in 
 construction from those which have been previously 
 described, a piece being cast on it which serves to 
 support the guide-bars. While the cover is in the 
 lathe, a hole for the piston-rod must be bored, and 
 where this passes through the oblong casting on the 
 
128 Slide- Valve Locomotive Engine. 
 
 top of the cover, it must be enlarged and threaded to 
 form the stuffing-box. 
 
 The castings for the slide-valve and chest, and for 
 the glands of the stuffing-boxes, are similar in all 
 respects to those for the engines already described. 
 
 The two steam-chests are joined by the T-piece 
 included in the castings ; the steam-pipe from the 
 boiler is joined to the long arm of the T, and the two 
 short arms are bored and screwed on the inside, as 
 are also the steam-chests ; then for each side a short 
 piece of pipe is to have a screw cut upon it throughout 
 its length, and to have two small nuts fitted upon it. 
 This pipe must first be screwed into the arm of the 
 T-joint for half an inch, then the other end is to be 
 screwed into the steam-chest, but not so far as to 
 withdraw it entirely from the T-joint or jamb the 
 slide-valve. The two nuts are then screwed up 
 against the T-piece and the steam-chest respectively, 
 with a little packing of hemp between. 
 
 FIG. 87. 
 
 Fig. 87 shows the form of the casting for the cross- 
 head, and also for the axle-blocks, and Fig. 88 shows 
 the support for the back ends of the guide-bars; 
 these latter may be screwed into the top of the 
 
Slide- Valve Locomotive Engine. 129 
 
 cylinder-cover, and the support drilled for the other 
 end ; but a better method is to file up the guide-bars 
 from square pieces of iron or steel 3 inches in length, 
 as seen in the engine represented on the cover of this 
 
 FIG. 
 
 book. Each bar must of course be perfectly straight 
 and flat upon its inner or guiding surface, but the op- 
 posite surface that is, the top of the upper bar and 
 the bottom of the lower bar may taper towards each 
 end, the bar being T 3 of an inch thick in the middle, 
 and i of an inch thick at either end, the width being fV 
 of an inch throughout. If the bars are made in this 
 way, they must be drilled at each end and screwed 
 to the ends of the projections on the cylinder-cover 
 and the guide-bar support ; and the length of these 
 projections, coming between the guide-bars and thus 
 determining their distance apart, must of course be 
 carefully matched, care being also taken that the 
 middle point in their length coincides with the centre 
 of the piston-rod. The guide-bar support is shown 
 in situ at H (Fig. 98). 
 
 K 
 
130 Slide- Valve Locomotive Engine. 
 
 THE CROSS-HEAD is to be fitted to the guides and, 
 piston-rod, and the top drilled to take the pin by 
 which the connecting-rod is attached to it. 
 
 THE CONNECTING-ROD is a forging and is forked. 
 At its top end it works upon a pin screwed into the 
 driving-wheel ; and outside the connecting-rod, the 
 coupling-rod works upon the same pin, both rods 
 being kept in place by the head of the pin. The 
 connecting-rod measures 3^ inches in length from 
 centre to centre. 
 
 THE COUPLING-BAR is made of steel, and should be 
 i-inch wide by -inch thick, with a head |-inch long 
 at each end, measuring -f x J-inch ; that is to say, a 
 piece of flat steel f x x 5-1 is to be reduced T V of an 
 inch upon each surface, except the f-inch at each end. 
 The coupling-bar may be bent as shown in Fig. 97, 
 but it is preferable to keep it straight, and either place 
 a distance piece over the pin of the trailing wheel, or 
 make the pin with a shoulder against which the con- 
 necting-rod will work. 
 
 The pin by which the cross-head and connecting- 
 rod are connected should be fV of an inch in 
 diameter, with a i-inch head at one end, and a -inch 
 screw at the other. If a corresponding thread is cut 
 on one side of the fork of the connecting-rod, a nut 
 will not be necessary. 
 
 The driving-pin should be of the same diameter, 
 but the two pins will of course not be of the same 
 length. 
 
Slide- Valve Locomotive Engine. 131 
 
 THE AXLE-BLOCKS. These must be filed up to 
 fit the spaces provided for them in the bed-plate ; 
 the lower edge of this latter must be drilled, and a 
 ^V-inch pin inserted in the centre of each axle-block 
 space ; a corresponding hole is to be drilled in the 
 top of each axle-block, and when the engine is com- 
 pleted a spiral spring must be slipped over each of 
 these pins, and these bearing upon the top of the 
 axle-blocks will take the weight of the engine. 
 
 A piece of metal is screwed on across each of the 
 openings for the axle-blocks, to prevent these latter 
 from falling out when the engine is lifted up. The 
 blocks must be drilled for the wheel-axles, which 
 latter should be cut from -g-inch steel bar. 
 
 At I (Fig. 96) is seen the guide to the slide-valve 
 rod ; this is a small casting screwed on to the bed- 
 plate as shown. 
 
 The wheels will of course be turned up and keyed 
 on as usual, great care being taken that the two 
 wheels of each pair are of exactly the same diameter. 
 
 There are two eccentrics to each valve, each 
 eccentric strap and rod being cast in one piece. The 
 eccentrics are to be centred and turned up and bored, 
 and the straps fitted to them as already described 
 in former chapters ; but at this point we come to 
 an important difference, for the engines hitherto 
 described have been constructed for forward motion 
 only, whereas the engine now under consideration 
 
132 Slide- Valve Locomotive Engine. 
 
 has reversing gear, which not only enables the driver 
 to run the engine the reverse way, but also enables 
 him to give the slide-valve any desired shortness of 
 stroke, thus admitting steam to the cylinder for only 
 part instead of for nearly the whole of the stroke. 
 This is technically called working expansively ; some- 
 times another valve, called an " expansion valve," is 
 added to large engines, in addition to the slide-valve, 
 for the purpose of cutting off the steam at an earlier 
 period in the stroke of the piston than could con- 
 veniently be done with the slide-valve alone. How- 
 ever, to return to construction. 
 
 REVERSING GEAR. Instead of being attached 
 direct to the slide-valve rod, the eccentric-rods are 
 attached to either end of a link. The links, which 
 are cut out from flat pieces of iron, must be marked 
 out with a pair of compasses, taking the distance 
 from centre of shaft to the end of eccentric-rod as 
 the radius for the curve of the slot. A number of 
 holes are then drilled where the slot is to be, and the 
 links are roughly cut out, leaving a lug at top and 
 bottom for the attachment of the eccentric-rods, and 
 another at the extreme lower end for the attachment 
 of the lifting rod, as seen at K (Fig. 96). The links 
 should now be fastened together, and the slots filed 
 out, and both finished off before they are separated. 
 Their length when finished should be if inch, their 
 width in the centre f of an inch ; the slot should 
 be li inch long, by i-inch wide, and the distance 
 
Slide- Valve Locomotive Engine. 
 
 133 
 
 between the centres of attachment of the eccentric- 
 rods should be of an inch. The valve-rod head is 
 really a short fork which clasps the outer side of the 
 link, and is bolted to a piece of brass which slides in 
 the slot of the latter. 
 
 The rocking bar, L, will present no difficulty. It 
 may be made to work between the points of two 
 screws, screwed through the bed-plate on either side, 
 or in small brass blocks screwed to the inner side 
 of the bed-plate. On the rocking bar are three 
 levers, to two of which the lifting rods are attached ; 
 and to the centre one is jointed the reversing-rod, 
 a flat bar, fVinch wide, -gVinch thick, seen at M. 
 In Fig. 96 the rocking bar itself is at the end of the 
 lever nearest to the letter L. The levers are fixed 
 at this point ; the other joints shown are hinge-joints. 
 
 FIG. 80. 
 
 FIG. 90. 
 
 Figs. 89 and 90 show the quadrant in which the 
 reversing lever works ; the lever itself being shown 
 at Fig. 91. As will be seen, it consists of the main 
 lever, i-inch wide by tY-inch thick, and a catch-bar 
 
134 
 
 Slide- Valve Locomotive Engine. 
 
 lifted by a small handle at the top. The handle 
 is bent as shown, and is attached to the catch-bar 
 by a short link, the bar working in two bands which 
 are rivetted on the reversing lever. The catch-bar 
 
 FIG. 91. 
 
 is kept down in the niches in the quadrant by the 
 spring at the top. Another quadrant with longer 
 legs is supplied for the starting lever ; this should be 
 engraved with the words " on " and " off," either by 
 means of a graver, if the worker have sufficient skill 
 in the use of this tool, or etched in with acid. 
 
 The starting lever is also supplied as a casting, 
 but a small iron or brass handle must be turned for 
 it. The starting lever is shown at G (Fig. 98) ; the 
 quadrant has been omitted from the drawing. 
 
 There are two name-plates which may be soldered 
 on to the boiler, see Fig. 98. 
 
Slide- Valve Locomotive Engine. 
 
 135 
 
 Fig. 93 shows one of the buffers ; the rounded 
 portion is to be cut off, and the pillar then left at the 
 back of the square piece should be threaded, so that 
 
 FIG. 92. FIG. 93. 
 
 the buffer when finished can be screwed into the 
 buffer beam. A hole T V of an inch in diameter must 
 be bored right through the portion of the buffer last 
 mentioned ; that is to say, from the front through the 
 
 FIG. 94. 
 
 screw at the back. This hole is to be enlarged to f 
 of an inch for the first half-inch of its depth. The 
 front portion of the buffer must be turned and made 
 to slide one quarter of an inch into the f-inch hole 
 in the back ; into the back of the front part of 
 the buffer is screwed a piece of T Vinch steel \\ 
 inch long ; round this a spiral spring i-inch long 
 is put immediately behind the buffer, and the two 
 parts being put together, a small nut is screwed on 
 to the end of the piece of -jVinch steel projecting 
 at the back of the buffer box. This part is now 
 finished. 
 
'36 
 
 Slide- Valve Locomotive Engine. 
 
 The " cow-catchers " are made from pieces of flat 
 bar iron, and are bolted to the front of the bed-plate, 
 a recess being cut for them in the buffer beam which 
 
 FIG. 95. 
 
 is screwed on over them. They will measure i-inch 
 thick and f-inch wide at the top, tapering to ^-inch 
 at the lower end. 
 
 The driving-wheels are provided with covers or 
 boxes ; the trailing-wheels have no boxes, being 
 covered by the tanks at the side of the foot-plates. 
 These tanks, together with the side-plates, are cut 
 out of stout tin-plate ; and where there is so much 
 heat, rivets are better than solder for joining the 
 edges of the pieces from which the tanks are to be 
 formed, to the side-plates. A bright steel hand-rail 
 supported by small brass pillars screwed into the 
 boiler will add to the finished appearance of the 
 engine. 
 
137 
 
138 Slide- Valve Locomotive Engine. 
 
 The spring seen over the leading wheels is only a 
 sham one, and may either be made from separate 
 pieces of spring steel bound together by a brass 
 strap, or in one solid piece. In putting the engine 
 together, the exhaust-pipes from the cylinders must 
 be brought up through the bottom of the smoke-box, 
 and cut off just below the funnel. 
 
 The lamp is in the form of an oblong box, the 
 shape of the foot-plate of the engine, under which it 
 hangs ; six curved brass wick tubes project from it 
 into the fire-box. 
 

 140 
 
CHAPTER X. 
 
 BOILER-MAKING. 
 
 A LTHOUGH I do not altogether recommend 
 *"* amateurs to make their own boilers, there is no 
 reason why they should not do so, provided they get 
 them properly tested by a trustworthy firm. Boilers 
 are tested by hydraulic pressure, and a pressure-gauge 
 and force-pump are the necessary apparatus. I need 
 hardly say that no boiler, whether made at home or 
 bought, should be used without a safety-valve duly 
 proportioned to the size of the boiler and its proper 
 working pressure. 
 
 There are three ways of making a model boiler : 
 (i.) soft soldering ; (ii.) brazing, or, as it is sometimes 
 called, hard soldering ; and (iii.) rivetting. 
 
 The first method will answer well enough in cases 
 where the pressure required is very slight, as, for 
 instance, in engines with single-action oscillating 
 cylinders. 
 
 Brazing very frequently proves a stumbling-block 
 in the path of the amateur. The solder, usually 
 called spelter, is mixed with borax and water, and 
 spread along the inside of the joint. A forge is 
 
I4 2 Boiler-Making. 
 
 required, and with a clear fire and just the right heat, 
 above all, with plenty of practice, a good joint 
 will be the result. I cannot, however, recommend 
 the process to any but a practised hand. 
 
 Rivetting is far easier than would appear at first 
 sight, and this is the process I would recommend to 
 those who must try their hand at boiler-making. 
 Let us, therefore, assume this to be the method 
 adopted by the reader. 
 
 The tools required are not many : a pair of metal 
 shears for cutting thin sheets of metal, or a cold 
 chisel for thicker sheets ; a light hammer and a rivet- 
 heading punch. This latter tool is for forming the 
 heads of the rivets ; it is made from a piece of steel 
 about \ of an inch in diameter and 3 inches in length, 
 which is centre-punched and slightly drilled with a, 
 say, -inch drill. The small conical hole thus made 
 must be rounded either by finishing with a drill of 
 the same section as the rivet heads are required to 
 be, or by making the steel red-hot and hammering 
 into the hole a piece of cold steel similarly rounded. 
 The hole having thus been formed of the right shape, 
 this end of the steel heading-punch is to be hardened 
 in the usual way. 
 
 The most easily constructed boilers are those 
 shown in Figs. 99 and 100. In the vertical boiler, 
 shown in Fig. 99, the two ends are flanged either by 
 hammering or by spinning in the lathe. The latter 
 process will produce neater ends, and to effect it 
 
Boiler-Making; 
 
 143 
 
 the disc of copper should be cut to the right size 
 and placed between two discs of wood of the inside 
 diameter of the flange. The whole is now to be put 
 into the lathe, which is to be driven at a quick speed, 
 while the edge of the copper is turned down with a 
 burnisher. Should the metal appear to get thinner 
 
 FIG. 99. 
 
 in any part, the burnisher must be worked towards 
 that part to bring the metal back. The tool should 
 be provided with a long handle, and the rest should 
 have a series of holes along the top of it, in one of 
 which is placed a pin to act as a fulcrum to the tool ; 
 and a little grease or soap and water should be used 
 as a lubricant between the work and the tool. 
 
 By using a pattern of the shape required, the ends 
 
144 Boiler- Making. 
 
 may be spun up to a rounded form ; in this case the 
 piece of wood between the back centre and the work 
 must be of small diameter to allow the tool to be 
 worked over the surface of the disc of metal. Should 
 the metal slip, a little powdered resin may be put on 
 the pattern. The metal will require to be annealed 
 once or twice in the course of spinning it up. Only 
 thin metal for small boilers can be spun up in this 
 manner. 
 
 The body of the boiler may be formed from sheet 
 copper or from a piece of copper tubing. In case 
 the former is chosen, the sheet must be bent round ; 
 its two edges, overlapping f to \ an inch, should be 
 drilled at each end for a rivet which may be put in 
 and finished off at one end, but at the other end it 
 should have only a tap or two with the hammer, as 
 it is only meant to keep the two edges properly over- 
 lapping while the rest of the rivets are put in, and 
 should therefore be finished off last of all. The 
 rivets suitable for the smaller boilers are i of an 
 inch long, and rather over T V of an inch in diameter, 
 with a flat head T 3 of an inch in diameter. The 
 price of a pound of these rivets, containing several 
 hundreds, is 2s. 6d. The larger-sized boilers will 
 require rather larger rivets, which will cost somewhat 
 less per pound. 
 
 For rivetting the body of the boiler, a stout bar of 
 iron, rather longer than the boiler and supported at 
 its two ends, will be necessary. It will be best to 
 
Boiler- Making. 145 
 
 drill only two or three holes at a time, rivet them, 
 and then drill two or three more, and so on. The 
 rivets are put through from inside the boiler, which 
 is then placed so that the flat heads of the rivets rest 
 upon the iron bar ; now give each rivet a tap or two 
 with the hammer, and then, placing the heading- 
 punch upon the rivet, give the punch a few blows, 
 and a neatly rounded rivet head will be the result. 
 The rivets should be placed from f to an inch 
 apart. 
 
 The top of the boiler must be drilled or punched 
 for the chimney ring before it is rivetted to the body. 
 For the rivetting of this part, the bar of iron must be 
 held by one end in a vice. 
 
 Before the bottom is put in, the chimney may be 
 soldered into it ; as will be seen in Fig. 99, the lower 
 end of the chimney is spread out or flanged, and is 
 soldered to the bottom of the boiler with ordinary 
 plumbers' solder. The chimney should be of copper 
 or brass tube, J an inch in diameter and upwards, 
 according to the size of the boiler. The lower end of 
 the boiler is rivetted with the flange downwards, as 
 shown in the figure. 
 
 The chimney ring is turned up from a casting and 
 soldered to the top of the boiler and to the chimney, 
 and this latter is finished off by soldering or rivetting 
 on to the top of it an ornamental cap, either turned 
 up from a casting or spun in the lathe. 
 
 Last of all, soft solder is to be sweated into all the 
 
 L 
 
146 
 
 Bo Her- Making. 
 
 seams, and to do this a little chloride of zinc should 
 be run along the seam, and a little solder dropped 
 on ; a blow-pipe flame is then applied to the seam, 
 and the solder will run into it as the flame is moved 
 along. Some care should be taken not to use too 
 much solder, as any surplus on the outside of the 
 boiler will have to be removed, if a neat finish is 
 desired. 
 
 The lower part, or fire-box, may be cut away on 
 two sides to allow the air free access to the lamp- 
 flame, or the same object may be accomplished by 
 rivetting three short iron legs to the fire-box. 
 
 The boiler shown in Fig. 100 is more easily 
 
 FIG. loo. 
 
 rivetted ; but the body of the boiler must be flanged 
 either by spinning or hammering, and it is not so 
 easy to flange the body as it is to flange the two 
 ends. Boiler tube already flanged may, however, be 
 had from any copper worker's, and should cost about 
 
. Boiler- Making. 147 
 
 is. per Ib. for the tube, and 2s. and upwards, accord- 
 ing to size, for the two flanges. If copper tube be 
 used for the body, the rivetting in this boiler will be 
 all on the outside, so that perhaps this is the most 
 simple boiler an amateur can take in hand. The 
 chimney will, of course, be put in before the ends are 
 attached. 
 
 Boilers of over 8 or 9 inches in length should 
 always be stayed, especially if they are intended to 
 carry more than a few pounds pressure. The stays 
 may be made of i-inch wire reduced a little at each 
 end for -i of an inch or so to form a shoulder. They 
 must be placed across the boiler and rivetted over 
 before the ends are rivetted on. 
 
 Either of these methods of construction may be 
 used for either a horizontal or a vertical boiler. In 
 the case of a horizontal boiler, the furnace must be 
 separately made from thin sheet iron, or stout tin 
 plate may be used. 
 
 Fig. 101 shows in section a simple form of marine 
 boiler ; as will be seen, the fire-box is made within 
 the body of the boiler, a flanged plate being rivetted 
 in the latter to form the bottom of the water space. 
 The funnel end of the boiler and furnace may be 
 completely closed, but at the other end the fire-box 
 should be left open to admit the air to the lamp- 
 flame. 
 
 In order to economize room by making the boiler 
 more the shape of the boat, when it is to be put 
 
148 
 
 Boiler- Making. 
 
 entirely under deck, marine boilers are often made 
 with flat tops instead of round. In this case they are 
 best made from sheet copper, and the bottom of the 
 boiler should be rivetted in before the seam (which 
 
 FIG. 101. 
 
 
 
 will come at the bottom of the fire-box) is closed up 
 and rivetted. In boilers with flat tops it is better to 
 put a few stays ; these must also be rivetted over 
 and soldered before the bottom seam is closed. 
 
 For large-sized models of marine and locomotive 
 engines, tubular boilers are preferable. The tubes 
 are usually brazed in ; and so few amateurs can take 
 this work in hand, that it is unnecessary to occupy 
 space with further details. 
 
 The copper used for model boilers varies from 
 No. 15, Birmingham wire gauge, for the larger sizes, 
 
Boiler- Making. 149 
 
 down to No. 20 or 22 for the smallest. An easy rule 
 is to divide the diameter of the boiler in inches by 
 100 ; this will give in decimals the thickness of the 
 metal suitable for a pressure of 15 or 16 Ibs. to the 
 square inch, which is more than sufficient for any 
 model. 
 
 The following are the minimum sizes of boilers suit- 
 able for the engines described in previous chapters : 
 
 CYLINDER. BOILER. 
 
 Horizontal or Vertical Engine : 
 
 1 in. stroke, \ in. bore . . . 2jx 5|- in. 
 
 * 2 TV " ' * * J ^ / 
 
 2 i ... six ro 
 2i ij . . . 5 xi3 
 
 3 ,. J i <> 6txi5 , 
 
 Single Cylinder Slide-Valve Launch, or Double 
 Oscillating Cylinder Marine Engine : 
 
 | in. stroke, in. bore . . 6x3^x4 in. 
 i i . . 7x4 x4* 
 
 ij i , - - 9 X 5 X 5i 
 
 Double Cylinder Slide-Valve Launch Engine : 
 | in. stroke, J in. bore . . 9x5 X5| in. 
 i f . . 11x6x7 
 
 ii i> i ,, v .- - I3 X 7 X 9 
 
 It is not, however, advisable to use the minimum 
 size as supplied at the shops ; but for any given size 
 
150 Boiler- Making. 
 
 of cylinder, the boiler given above for the size larger 
 should be used, while if a horizontal or vertical engine 
 of 2| or 3-inch stroke is required to do any real 
 work such as driving a sewing-machine, for instance 
 the boiler should be about 9 x 20 inches or larger, 
 instead of 6\ x 15. The minimum diameter for tubes 
 in model engine boilers is half an inch. 
 
 LAMPS. A lamp suitable for most model boilers 
 is shown in Fig. 25, but for marine engines it is 
 advisable to have the reservoir of spirit away from 
 the heat of the boiler and furnace ; the reservoir in 
 this case may be above the level of the furnace. 
 The tube leading to the furnace enters the reservoir 
 close to the top, or it may be carried through the 
 bottom of the reservoir nearly to the top. A wick 
 from this tube hangs down into the spirit, and acts 
 as a siphon in keeping the lamp supplied. The 
 number of flames required will of course depend 
 upon the size of the boiler and the amount of work 
 expected from it. 
 
- CHAPTER XL 
 BOILER AND OTHER FITTINGS. 
 
 THIS chapter will be devoted to a description of 
 taps, valves, and similar odds and ends, which, 
 although required in fitting up an engine, have found 
 no place in the foregoing pages. 
 
 STEAM-TAPS. Fig. 20, page 31, shows the casting 
 for a steam-tap, although it may easily be turned 
 out of any round piece of brass that is thick enough 
 for the purpose. The piece should be first bored 
 through from end to end ; the drill used must 
 depend upon the size of the tap. The piece may now 
 be turned up between the lathe-centres and bored 
 for the plug ; after boring, the plug-hole should be 
 made slightly conical with a rimer. The plug may 
 be made in two ways ; either it may be turned up as 
 
 FIG. 102. 
 
 shown in Fig. 102, a hole being bored through the top, 
 in which the handle is afterwards fitted ; or it may be 
 
152 Boiler and other Fittings. 
 
 formed from a piece of brass wire, which, after the 
 plug has been ground in, is bent over and filed up 
 square to form the handle, as shown in Fig. 103. In 
 
 FIG. 103. 
 
 either case, the plug having been turned to fit the 
 hole in the tap, it is put into the lathe and ground 
 into place with a little fine grindstone or coke dust, 
 or pumice-stone powder and water, finishing off with 
 a little putty powder. 
 
 When the plug has been fairly ground into place, 
 the steam-way must be bored through it, and in 
 small taps the plug may then be rivetted over at the 
 lower end, or the plug hole in the tap may be slightly 
 enlarged at the lower end, and the plug having been 
 put in place may be filed off flush and then spread a 
 little by punching in the centre with a centre-punch ; 
 but in larger taps it will be found best to drill and 
 tap the lower end of the plug and put a screw into it, 
 while in the largest size the plug may project below 
 the tap and be fitted with a nut. 
 
 If a curved tap should be required, it is most easily 
 made by inserting a piece of bent tube into a straight 
 tap, reducing the latter at the junction so that the 
 join may not be perceptible. 
 
Boiler and other Fittings. 153 
 
 The steam-tap shown in the drawing of the loco- 
 motive engine (Fig. 96) is made in rather a different 
 manner. The casting for the tap (Fig. 92) is bored 
 with a conical hole, and a straight hole is drilled 
 through the projection on one side; into this latter is 
 soldered or screwed the pipe going up into the dome. 
 To the small end of the conical casting a pipe leading 
 into the smoke-box is attached, and this pipe is joined 
 by means of a forked junction or T-piece to the two 
 pipes leading to the steam-chests. To the other end 
 of the cone another tube is attached ; and fastened to 
 the foot-plate end of this is a nut screwed on the 
 inside, and fixed into the back-plate of the boiler, as 
 seen in Fig. 96. 
 
 The plug for this tap is to be bored half-way up 
 through its length and half-way through from one 
 side, as seen in the illustration. Attached to the 
 larger end of the plug is a long bar carrying at its 
 other end the starting handle. The bar works 
 through a nut, which screws into the one attached 
 to the back plate of the boiler, and also screws up 
 against a small collar which must be shrunk on to 
 the bar. 
 
 It will now be seen that by screwing up the inner 
 nut which works against the collar on the steam-tap 
 rod, the plug of this latter is forced home and kept 
 steam-tight, and also by unscrewing the nut the plug 
 may be pulled out, should it at any time require 
 attention. 
 
154 Boiler and other Fittings. 
 
 The steam-tap is supported by a stay across the 
 dome, not shown in the engraving. 
 
 STEAM-WHISTLES. The ordinary steam-whistle, 
 shown in Fig. 104, is simply a tap upon one end of 
 
 FIG. 104. 
 
 which a piece of closed brass tubing of suitable size 
 has been soldered ; before the tube is soldered on, 
 however, it must be partially blocked up at the open 
 end by soldering in a short piece of round brass fitting 
 the tube but having a flat filed upon one side. The 
 position of this piece of brass is shown in the draw- 
 ing, and the mouth of the whistle is made with a file 
 just above the block and upon that side of the tube 
 to which the flat part of the block is turned. 
 
 In the drawing the tap is shown turned off, and the 
 handle is thus hidden behind the whistle. Unlike the 
 handles of steam-taps, the handles of these steam- 
 whistles should be at right angles to the whistle when 
 turned on, otherwise the fingers may be brought into 
 unpleasant proximity to the steam escaping from the 
 mouth of the whistle when the latter is being turned 
 on or off. 
 
 The bell whistle shown in the locomotive (Figs. 96 
 and 98) is given in section in an enlarged drawing in 
 Fig. 105. As will be seen, it consists, besides the bell, 
 of a tap with a cup at the top. Into this cup is 
 
Boiler and other Fittings. 
 
 155 
 
 screwed a piece of brass bearing a disc at the top, a 
 hole is drilled a little way up this piece and another 
 hole is drilled through it crossing the first one, thus 
 forming a T-shaped steam-way with two outlets. 
 
 FIG. 105. 
 
 The disc almost fills the cup, leaving a very narrow 
 opening all round ; so that when the tap is turned 
 on the steam fills the chamber below the disc, and 
 escaping all round this latter, strikes against the edge 
 of the bell, thus producing a shrill whistle. 
 
 UNIONS. Fig. 106 shows a union. The nut and 
 
 FIG. 106. 
 
 union-piece are cast in one ; the former is to be cut 
 off and bored out to within T 3 7r of an inch of one 
 
156 Boiler and other Fittings. 
 
 end, which is to be drilled to receive the pipe for 
 which the junction is intended. The larger part of 
 the union and the nut are to be screwed to fit one 
 another, the union-piece being drilled, and, if desired, 
 fitted as a tap. A collar must be brazed on about 
 | of an inch from the end of the tube with which the 
 union is to be used. 
 
 SAFETY-VALVES. Figs. 107 and 108 show the cast- 
 
 FIG. 107. FIG. 108. 
 
 ings for a lever safety-valve. The main casting, shown 
 in Fig. 1 07, must be turned up between the lathe-centres, 
 and a hole drilled through it, say a fV-inch hole for 
 the size shown in the drawing. At the top end the 
 edge of this hole must be taken off so as to leave a 
 very short conical bearing-surface. 
 
 To make the valve, take a piece of brass about \ of 
 an inch larger than the hole drilled in the casting, and 
 turn \ to f of an inch of it down to fit this latter ex- 
 
Boiler and other Fittings. 157 
 
 actly ; then turn down the next -i of an inch to nearly 
 fit the conical bearing in the casting, but it is to be 
 noted that the surfaces actually in contact must be 
 something under y'g- of an inch in width. The valve 
 is now to be ground into its seat in the casting 
 with a little grindstone dust and water, and three 
 flats are then to be filed upon the spindle which has 
 been left below the valve. These flats will form the 
 steam-ways, while the three rounded edges left be- 
 tween them, fitting the central hole in the casting, will 
 cause the valve to fall back truly into its place after 
 it has been lifted. The top of the valve may now 
 have a groove filed in it, as shown in Fig. 109 at A, 
 which is an enlarged drawing of this piece. 
 
 Another piece of brass must be turned up and 
 slotted and screwed into the rim of Fig. 107; and a 
 piece of flat steel bar, drilled at the end, is to be 
 pivoted in the slot of this last piece by a pin, rivet, or 
 screw. 
 
 The weight (Fig. 108) must be turned up, the top 
 end being held in a grip- chuck, and the other end 
 supported by the back centre, or it may be turned 
 up between the two centres. The top of the weight 
 must have a slot cut through it, so that it may slide 
 on the valve lever ; two or three holes should first be 
 drilled through, and the slot afterwards finished by 
 filing. The valve piece must be screwed at the 
 bottom, and it will then be finished and appear as 
 shown in Fig. 109. 
 
158 
 
 Boiler and other Fittings. 
 
 Several variations may be made in this valve ; for 
 instance, instead of making a guiding groove in the 
 top of the valve piece, this latter may be filed off flat, 
 and another piece of brass with a guiding slot in it 
 
 FIG. 109. 
 
 FIG. 1 09 A. 
 
 may be screwed into the rim of the main casting in 
 front of the valve ; also the lever may be a bent one 
 attached to a projection upon the rim of the main 
 casting. 
 
 The pressure at which a lever safety-valve will let 
 off steam is approximately found by multiplying the 
 weight in pounds by the length of the lever from its 
 point of support to the point at which the weight 
 is suspended, and dividing by the area of the valve 
 in inches multiplied by the distance between point 
 
Boiler and other Fittings. 159 
 
 of suspension of the lever and centre of the valve ; 
 the result giving the pressure in pounds per square 
 inch. To get the exact pressure, an allowance must 
 also be made for the weight of the lever and of the 
 valve itself. 
 
 In full-sized engines the area of the safety-valve 
 is made '006 the area of the fire-grate, and the mitre 
 is made not exceeding ^ of an inch. 
 
 Spring-valves may be made either with or without 
 a lever. If made with a lever, the valve itself is con- 
 structed in the same manner as the valve already 
 described, excepting that the free end of the lever is 
 forged out flat and pierced with a hole or slot The 
 spring acts upon a piston working in a tube, the 
 upper end of the piston-rod being screwed and pro- 
 vided with a nut. If the end of the lever is not 
 slotted, the spring-barrel must be pivoted at its lower 
 end. The whole arrangement will be made quite 
 clear by a reference to Figs. 96 and 98. 
 
 In the case of a spring-valve without a lever, the 
 spring will act directly upon the valve, the escape 
 of steam taking place through the tube containing 
 the spring. Such a valve may also be made adjust- 
 able by placing a piston upon the top of the spring, 
 a nut kept down by the cap of the spring-barrel being 
 used to screw the piston-rod up and down. Fig. no A 
 shows the cap and nut in an arrangement of this 
 sort ; the lower part and centre of the nut are in one 
 piece, but the top is filed up square, and the milled 
 
i6o 
 
 Boiler and other Fittings. 
 
 head by which it is worked is made with a square 
 hole to fit the top of the nut. 
 
 FIG. no. 
 
 A variation of this last valve is shown at B in the 
 same figure, where several pieces of watch-spring are 
 substituted for the spiral spring. 
 
 By cutting a slot down the spring-barrel and 
 attaching a pointer to the piston, either of these 
 forms of valve may be made to show the pressure 
 at which .they are set. 
 
 Valves with weights are sometimes used for station- 
 ary engines, but some form of spring-valve is in- 
 variably used for locomotive and marine boilers, as 
 the oscillations and vibrations to which such boilers 
 are subjected would interfere with the action of the 
 weight. 
 
 GOVERNORS. Figs, in and 112 show two forms 
 of governors ; the first adapted to small models and 
 the second suitable for small workshop engines. The 
 castings for Fig. 112 cost from 2s. and upwards, 
 
Boiler and other Fittings. 
 
 161 
 
 according to size. Fig. 112 is half-size, and the 
 position of the throttle-valve in relation to the 
 governor is regulated by the small set-screw seen at A. 
 
 FIG. in. 
 
 In Fig. ill the forked lever, links, and throttle- valve 
 have been omitted, being precisely similar to those 
 shown in Fig. 112. The method of construction is 
 
 M 
 
1 62 
 
 Boiler and other Fittings. 
 
 made so clear in the drawings that no further de- 
 scription will be necessary. 
 
 FIG. 112. 
 
 FORCE-PUMP. Fig. 113 shows in section a small 
 force-pump for supplying the boiler. It is worked 
 by an eccentric on the main shaft of the engine. 
 The barrel and valve-box of the pump are all in one 
 casting. 
 
 The barrel is first bored out, then a hole is bored 
 through the valve-box of the same size as the intake 
 
Boiler and other Fittings. 
 
 163 
 
 pipe. This hole must be enlarged for about two- 
 thirds of the way down for the lower valve, and again 
 enlarged for the first third of its length for the upper 
 valve. The outlet hole is also to be bored ; the 
 valves should be made in the same manner as the 
 
 FIG. 113. 
 
 safety-valve already described, and must be ground 
 into place while they form part of a long piece of 
 metal, and afterwards cut off. It will be noticed 
 that the lower part of the top valve must be the 
 same size as the largest part of the lower valve. A 
 plate is screwed on to the top of the valve-box, and 
 the plunger barrel is fitted with a gland as shown in 
 the drawing. 
 
 STEAM PRESSURE-GAUGES. The ordinary Bour- 
 don gauge is beyond the powers of an amateur ; 
 it consists of a flattened tube which is constructed 
 by special machinery. It is curved, and firmly fixed 
 
1 64 Boiler and other Fittings. 
 
 at one end, the free end being connected by a series 
 of levers with the index hand ; the interior of the 
 flat tube is connected with a siphon containing 
 water, and this in turn is connected with the boiler. 
 The tendency of the curved tube is to straighten 
 itself in proportion to the pressure within it ; the ex- 
 tent of this movement, and consequently the amount 
 of the pressure, is shown by the index hand. 
 
 Another form of pressure-gauge, however, which 
 lies well within the capabilities of an amateur, has 
 been twice illustrated in the English Mechanic, 
 and is shown in Fig. 114. It consists of two small 
 
 FIG. 114. 
 
 castings, the upper one bored out true, and the lower 
 one having a flat surface and a screwed hole for 
 attaching the siphon pipe. In the upper casting a 
 tubular piston works against the pressure of a spiral 
 spring ; connected to the piston-rod by a hinge joint 
 is another rod with a short rack at the top, which 
 
Boiler and other Fittings. 165 
 
 is kept by a spring against a pinion carrying an 
 index hand. The upper casting also carries a ring 
 into the back of which a dial is fixed, the front being 
 closed with glass. Before the two castings are 
 screwed together, a sheet of rubber is placed between 
 them to prevent the water from the siphon tube 
 being forced beyond the piston. The gauge is gradu- 
 ated by comparison with a standard instrument. 
 
 LOOSE ECCENTRIC. One way of making an engine 
 reversible has already been described in Chap. IX. 
 An easier method, and one which may be applied 
 to any engine, is by means of a loose eccentric. The 
 eccentric itself is of the usual form, but it is not 
 fixed upon the shaft, being kept in place on one 
 side by a small collar on the shaft, while on the 
 other side it works against a collar of the shape 
 shown in Fig. 115. As will be apparent from this 
 
 FIG. 115. 
 
 drawing of the collar, half the thickness of rather 
 more than half its surface (half the surface plus twice 
 the angle of lead) is cut away, and the collar itself is 
 fixed in its proper position on the shaft by means 
 of a set-screw. Its abutments catch a short pin screwed 
 into the side of the eccentric, and the collar thus 
 
1 66 Boiler and other Fittings. 
 
 carries the eccentric with it, and the engine will run 
 whichever way it is started. 
 
 TAPPETS. There are other ways of moving the 
 slide-valve, as well as by means of an eccentric ; for 
 instance, an arm projecting from the piston-rod head 
 and forked at its free end may be made to slide 
 up and down the valve rod, but without touching 
 it. Two small collars are then fixed to the slide- 
 valve rod by means of set screws, so that the fork 
 of the travelling arm coming into contact with one 
 or other of these collars knocks the slide-valve up 
 or down, as the case may be. The part of the slide- 
 valve rod which carries these tappet collars must not 
 however be connected directly with the valve, but 
 a rocking-bar must be interposed, carrying a short 
 lever on each side to which the two parts of the 
 rod are attached ; otherwise the valve will cover the 
 upper port of the cylinder when the piston is at the 
 top of its stroke, whereas the upper port is at that 
 time required to be open, and vice versa. 
 
 Another method of moving the slide-valve is by 
 means of a cam on the shaft ; in this case, the slide- 
 valve rod has a slotted head, and at each end of 
 this head and at right angles to its length is a plate 
 of metal ; the shaft passes through the slotted head 
 and the cam acts first on one plate, then on the 
 other, thus pushing the valve alternately up and 
 down. The motion of a valve moved by a cam will 
 vary from the sudden movement of the tappet action 
 
Boiler and other Fittings. 167 
 
 to the gradual motion of the eccentric, according to 
 the shape of the cam, this latter being in fact an 
 exaggerated form of the ordinary eccentric, the plates 
 on the valve-rod taking the place of the eccentric 
 strap. 
 
 In turning up some of the small pieces described 
 in this chapter, it will be often found useful to have 
 a brass or gun-metal chuck with a flat face to which 
 the part requiring to be turned may be attached by 
 means of a little solder ; this method of chucking 
 will also be convenient for cylinder-covers and other 
 parts having flat surfaces by which they may be 
 attached. 
 
CHAPTER XII. 
 
 NOTES. 
 
 THE following notes may prove useful to some of 
 my readers. 
 
 BURNISHING. This process gives a highly finished 
 appearance to all brass articles. Burnishers of various 
 shapes may be purchased at the tool shops at from 
 6d. to 2s. 6d. each ; half-round, flat, and oval curved 
 are perhaps the most useful shapes for the amateur. 
 
 Previous to burnishing, the article should, if pos- 
 sible, be annealed by heating it and quenching it in 
 water ; it must then be pickled in dilute nitric acid, 
 washed in clean water, and dried in hot boxwood 
 sawdust without the parts to be burnished being 
 touched by the hands. 
 
 The burnisher must now be worked over all the 
 parts that are to be burnished, using a little stale ale 
 as a lubricant ; some workers use soap and water 
 instead of the ale, and others prefer ox-gall with 
 cream of tartar and water. When the burnishing is 
 finished, wash again and dry in boxwood dust, then 
 lacquer. 
 
 LACQUERING. The articles to be lacquered should, 
 
 168 
 
Notes. 169 
 
 IF not burnished, be pickled in caustic soda or potash 
 and water, to remove all grease, washed and dipped 
 for a moment in nitric acid, washed again and dried 
 in boxwood dust. Now make the pieces as hot as 
 the hand can comfortably bear, and give each a thin 
 coat of the lacquer with a brush. 
 
 Lacquer may be bought almost as cheaply as it 
 can be made ; but for the information of those who 
 prefer to make their own, I here give a few recipes. 
 
 To one pint of alcohol or methylated spirit add 
 one ounce of good pale shellac ; this will form the 
 body of the lacquer, and may be coloured to taste as 
 follows : 
 
 For a pale lacquer, add 3 parts of Cape aloes and 
 I part turmeric. 
 
 For a golden lacquer, add 4 parts of dragon's 
 blood and I part of turmeric. 
 
 For red lacquer, add 32 parts of annatto and 8 
 parts of dragon's blood. 
 
 Another method is to make saturated solutions of 
 each of the above-named colours in spirit, and a 
 small quantity of lacquer of any desired colour may 
 then be easily made by adding more or less of any 
 of the solutions to a little of the varnish. 
 
 PAINTING. Enamel paints for painting the cylin- 
 ders, etc., of engines may be bought at the model- 
 shops, or may be made by adding copal varnish to 
 ordinary paint. 
 
 SOLDERS. A good soft solder may be made of 
 
170 Notes. 
 
 equal parts of lead and tin; or a finer solder may be 
 made by doubling the quantity of tin. 
 
 Hard solder, or spelter for brazing, if required to 
 stand a high temperature, should contain three parts 
 of copper to one of zinc ; and these proportions may 
 be varied down to equal parts of each metal for ordi- 
 nary work, while a still softer solder for brazing may 
 be made by adding one part of tin to four of copper 
 and three of zinc. 
 
 Silver solder, two parts silver to one of brass 
 (ordinary pins), will be found useful for brazing small 
 work. 
 
 FLUXES FOR SOLDERING. For brass, copper, 
 tinned iron, or zinc : chloride of zinc, made by drop- 
 ping pieces of zinc into hydrochloric acid (spirits of 
 salts) until there is no further effervescence. The 
 fumes which arise during the process should not be 
 inhaled. For tin or copper : rosin ; and for lead : 
 tallow or rosin may be used. 
 
 For brazing, the flux borax should be made into a 
 paste with water and mixed with the spelter. 
 
 SETTING SLIDE-VALVES. The eccentric-rod should 
 first be adjusted to such a length that when the ec- 
 centric is at its farthest from the cylinder, the lower 
 port is opened to exactly the same extent as the 
 upper port is when the eccentric is at its nearest to 
 the cylinder. After the length of the eccentric-rod 
 has been thus adjusted, the eccentric must be fixed to 
 the shaft in such a position that the upper or lower 
 
Notes. 1 7 1 
 
 steam-ports will be just open when the piston is at 
 the top or bottom of the cylinder. 
 
 The following explanation of one or two terms of 
 frequent occurrence in descriptions of engines and 
 their efficiency may also prove useful. 
 
 LAP. The lap of the slide is the extent to which 
 the valve overlaps the edges of the ports which it 
 covers. If the face of the slide-valve exactly corre- 
 sponded with the width of the steam-ports, steam 
 would be admitted to the cylinder during the whole 
 of each stroke, but by making the valve of such 
 length that at the middle of its stroke it more than 
 covers the ports, the steam is cut off b.efore the 
 stroke is finished, the rest of the work for that stroke 
 being performed by the expansion of the steam 
 already admitted to the cylinder. 
 
 LEAD. This term is used to express the distance 
 which the slide-valve stroke is in advance of the 
 piston stroke. If the slide-valve were required to be 
 in its middle position at the moment the piston is at 
 the top or bottom of the cylinder, it is obvious that 
 the eccentric would be set at right angles to the 
 crank. It is found, however, that an engine works 
 best when the ports begin to open for the next stroke 
 just before the completion of the previous stroke ; 
 and in order to accomplish this, the eccentric is set 
 at rather more than a right angle in front of the 
 crank ; and the difference between the angle at which 
 the eccentric is set and that position which would 
 
i;2 Notes. 
 
 bring the slide-valve to the middle of its stroke with 
 the piston at the top or bottom of the cylinder, is 
 called the angle of lead. 
 
 SUPERHEATED STEAM. This is a term applied to 
 steam which has been heated above the boiling point 
 corresponding to its pressure. For instance, the 
 normal temperature of steam under a pressure of 15 
 Ibs. above the pressure of the atmosphere is 250 
 Fahrenheit. Now, if that steam be heated beyond 
 that temperature while the pressure remains the 
 same, or if it be maintained at that temperature 
 while the pressure is reduced, as when it is expand- 
 ing in the cylinder after the induction port is closed, 
 it will be superheated. 
 
 UNIT OF HEAT. This is the amount of heat 
 necessary to raise one pound of water by one degree 
 of Fahrenheit, and is represented mechanically by 
 772 foot-pounds. 
 
 One cubic inch of water will produce a cubic foot 
 of steam. 
 
 HORSE- POWER. In calculating the power of steam 
 and other engines, 33,000 Ibs. raised one foot in one 
 minute is taken as equal to the power of one horse. 
 
 NOMINAL HORSE-POWER. This is rather an in- 
 dication of the size of an engine than of its power ; in 
 calculating the nominal horse-power of an engine the 
 velocity of the piston is assumed to be 128 feet per 
 minute multiplied by the cube root of the length of 
 stroke in feet, and the steam pressure in the cylinder 
 
Notes. 173 
 
 is assumed to be 7 Ibs. per square inch, then the nomi- 
 nal horse-power equals 7 x 128 x $ stroke in feet 
 x area of piston in square inches -J- 33,000. 
 
 INDICATED OR ACTUAL HORSE-POWER. This is 
 calculated from the actual pressure in the cylinder 
 and speed of the piston as follows : Let A = area 
 of piston in square inches, P = the average pressure 
 of the steam in the cylinder in pounds per square 
 inch, R = the number of revolutions per minute, and 
 S = the length of stroke in feet, then the actual horse- 
 
 2 AP R S 
 power will be 33>QQa - 
 
 AVERAGE PRESSURE. If an engine is working 
 expansively, and the pressure in the boiler is 5 Ibs. 
 per square inch, and if the steam is cut off at half- 
 stroke, the average pressure in the cylinder will be 
 4 Ibs., and with a cut off at three-quarter stroke, 4f 
 Ibs. per square inch. The average pressure increases 
 in the same ratio as the boiler pressure ; thus, with 15 
 Ibs. pressure in the boiler, the average pressure under 
 the above circumstances will be about I2| and 141 
 Ibs. per square inch. 
 
 ROUND STEEL for making drills, etc., is usually 
 sold in one foot lengths. If ordered by the Birming- 
 ham wire gauge numbers, the name of the gauge 
 must be specified, as it is also sold by what is known 
 as the Lancashire gauge. This gauge runs from No. I, 
 which is about of an inch in diameter, to No. 60, 
 which is about the size of a stout sewing needle. The 
 
174 
 
 Notes. 
 
 price varies with the market; but supposing Nos. I 
 to 12 to be 2s. 6d. per lb., then Nos. 13 to 18 would 
 be 3^., and the price would increase about 6d. for 
 every four to six numbers, going up to fs. for Nos. 
 58 to 60. 
 
 SQUARE STEEL is made J and -f^ inch square and 
 i x i inch. With No. I round steel at 2s. 6d. y this 
 square hammered steel would cost 4*. per lb. 
 
 The following tables will be found useful for 
 reference, but it is to be noted that authorities differ 
 as to the exact weight, in some cases to the extent 
 of 8 or 10 per cent, of wire and sheet metal : 
 
 ROUND AND SQUARE WROUGHT-IRON WEIGHTS 
 PER FOOT. 
 
 Side of 
 Sq. or 
 Diam. 
 
 Square 
 Lbs. 
 
 Round 
 Lbs. 
 
 Side of 
 Sq. or 
 Diam. 
 
 Square 
 Lbs. 
 
 Round 
 Lbs. 
 
 TV 
 
 013 
 
 '010 
 
 i* 
 
 3'763 
 
 2'955 
 
 i 
 
 052 
 
 '041 
 
 4 
 
 4-2I9 
 
 3-313 
 
 
 117 
 
 9 2 
 
 1 T& 
 
 4701 
 
 3-692 
 
 i 
 
 208 
 
 '164 
 
 4 
 
 5-208 
 
 4-091 
 
 TV 
 
 326 
 
 2 5 6 
 
 
 5-742 
 
 4-510 
 
 1 
 
 469 
 
 368 
 
 If 
 
 6-302 
 
 4-950 
 
 T ? 6 
 
 638 
 
 501 
 
 I T 7 6 
 
 6-888 
 
 5-I90 
 
 * 
 
 833 
 
 '654 
 
 ? 
 
 7-500 
 
 5-410 
 
 
 1-055 
 
 828 
 
 
 8-138 
 
 6-322 
 
 I 
 
 I-302 
 
 1-023 
 
 4" 
 
 8-802 
 
 6-913 
 
 fi 
 
 1-576 
 
 1-237 
 
 
 9-492 
 
 7-455 
 
 3. 
 
 4 
 
 1-875 
 
 i'473 
 
 1^ 
 
 IO'2I 
 
 8-018 
 
 u 
 
 2*201 
 
 1728 
 
 'It 
 
 10-95 
 
 8'60I 
 
 L 
 
 2*552 
 
 2-004 
 
 4 
 
 1172 
 
 9-204 
 
 
 2-930 
 
 2-301 
 
 
 I2-5I 
 
 9-828 
 
 1 
 
 3-333 
 
 2-618 
 
 2 
 
 
 IO-47 
 
Notes. 175 
 
 TABLE SHOWING THE WEIGHT OF 100 FEET OF WIRE. 
 
 Descrip- 
 tive 
 
 Number. 
 
 Diameter 
 in Parts 
 of 
 an Inch. 
 
 Diameter 
 in Metric 
 Millimetres. 
 
 Copper Wire 
 in Lbs. 
 
 Brass Wire 
 in Lbs. 
 
 Iron Wire 
 in Lbs. 
 
 7/0 
 
 500 
 
 12700 
 
 76-576 
 
 72-006 
 
 65-45 
 
 6/0 
 
 464 
 
 II785 
 
 65-947 
 
 62*OIO 
 
 56-235 
 
 5/o 
 
 432 
 
 10793 
 
 57-I04 
 
 53752 
 
 48*858 
 
 4/0 
 
 400 
 
 10*160 
 
 49-009 
 
 46*083 
 
 41-888 
 
 3/o 
 
 370 
 
 9-449 
 
 42-388 
 
 39^58 
 
 36*229 
 
 2/0 
 
 348 
 
 8-839 
 
 37^95 
 
 34-88 
 
 31705 
 
 I/O 
 
 324 
 
 8-229 
 
 32-I55 
 
 30-235 
 
 27-482 
 
 I 
 
 300 
 
 7-620 
 
 27-5445 
 
 25-922 
 
 23-562 
 
 2 
 
 2 7 6 
 
 7-010 
 
 23-333 
 
 2 1 '940 
 
 I9-942 
 
 3 
 
 252 
 
 6-401 
 
 I9-45I 
 
 18*290 
 
 l6-5 9 8 
 
 4 
 
 232 
 
 5-893 
 
 16486 
 
 I5-502 
 
 I4-09I 
 
 5 
 
 212 
 
 5-385 
 
 13768 
 
 12-948 
 
 11*766 
 
 6 
 
 192 
 
 4-877 
 
 II792 
 
 IO-6I7 
 
 9-651 
 
 7 
 
 176 
 
 4-470 
 
 9-4882 
 
 8-921 
 
 8*1095 
 
 8 
 
 160 
 
 4-064 
 
 7-8414 
 
 7373 
 
 6*702 
 
 9 
 
 144 
 
 3-658 
 
 6-35I6 
 
 5-972 
 
 5*4287 
 
 10 
 
 128 
 
 3-251 
 
 5-0185 
 
 47189 
 
 4-2893 
 
 ii 
 
 116 
 
 2-946 
 
 4-I2I7 
 
 3^756 
 
 3-5228 
 
 12 
 
 '104 
 
 2-642 
 
 3-3I3 
 
 3T1IS3 
 
 2*8316 
 
 13 
 
 092 
 
 2-337 
 
 2-5926 
 
 2-4378 
 
 2-2I58 
 
 H 
 
 080 
 
 2-032 
 
 1-9603 
 
 1-8433 
 
 1-6755 
 
 15 
 
 072 
 
 1-829 
 
 1-5879 
 
 I-493I 
 
 1-3572 
 
 16 
 
 '064 
 
 1-626 
 
 1-2546 
 
 1*1767 
 
 I 0723 
 
 17 
 
 056 
 
 1-422 
 
 0-96058 
 
 0-9324 
 
 0-821 
 
 18 
 
 '048 
 
 1-219 
 
 70573 
 
 6636 
 
 60319 
 
 19 
 
 '040 
 
 roi6 
 
 49000 
 
 46083 
 
 41888 
 
 20 
 
 036 
 
 0-914 
 
 39698 
 
 37 3 28 
 
 33929 
 
 21 
 
 032 
 
 813 
 
 31366 
 
 -29493 
 
 26808 
 
 22 
 
 028 
 
 711 
 
 24014 
 
 22529 
 
 20525 
 
 23 
 
 024 
 
 610 
 
 -17643 
 
 1659 
 
 15079 
 
 24 
 
 '022 
 
 '559 
 
 14826 
 
 1394 
 
 I267I 
 
 25 
 
 '020 
 
 508 
 
 12252 
 
 1152 
 
 10472 
 
 26 
 
 018 
 
 '457 
 
 099243 
 
 093318 
 
 084824 
 
 27 
 
 '0164 
 
 4166 
 
 082384 
 
 077466 
 
 '070414 
 
 28 
 
 '0148 
 
 '3759 
 
 067093 
 
 06308 
 
 -057345 
 
 29 
 
 0136 
 
 '3454 
 
 056654 
 
 -053273 
 
 '048422 
 
 30 
 
 0124 
 
 3150 
 
 "047097 
 
 044286 
 
 -040255 
 
Notes. 
 
 TABLE SHOWING THE WEIGHT OF ONE SQUARE FOOT OF 
 ROLLED METAL. 
 
 Descrip- 
 tive 
 Number. 
 
 Thickness 
 in Parts 
 of 
 an Inch. 
 
 Thickness 
 in Metric 
 Millimetres. 
 
 Copper in Lbs. 
 (Sp. Gr. 
 8-986). 
 
 Brass 
 in Lbs. 
 (Sp. Gr. 
 8-448). 
 
 Iron 
 in Lbs. 
 (Sp. Gr. 
 7-680). 
 
 7/0 
 
 0^00 
 
 12*700 
 
 23'4 
 
 22'0 
 
 20"0 
 
 6/0 
 
 464 
 
 II785 
 
 2I-7I5 
 
 20*4l6 
 
 18-56 
 
 5/o 
 
 432 
 
 10-973 
 
 20'22 
 
 I9*008 
 
 I7-28 
 
 4/0 
 
 400 
 
 io'i6o 
 
 18 72 
 
 I 7 -6 
 
 1 6*0 
 
 3/o 
 
 372 
 
 9'449 
 
 I4-44I 
 
 16-368 
 
 14*88 
 
 2/0 
 
 348 
 
 8-839 
 
 16-285 
 
 I5*3I2 
 
 13-92 
 
 I/O 
 
 324 
 
 8*229 
 
 15-163 
 
 14*256 
 
 12-96 
 
 I 
 
 3 00 
 
 7-620 
 
 14-04 
 
 I3-2 
 
 I2'0 
 
 2 
 
 2 7 6 
 
 7-010 
 
 12-917 
 
 12*144 
 
 1 1 '04 
 
 3 
 
 252 
 
 6-401 
 
 II794 
 
 1 1 *o88 
 
 10 -08 
 
 4 
 
 232 
 
 5-893 
 
 10-858 
 
 IO'208 
 
 9-28 
 
 5 
 
 "212 
 
 5385 
 
 9-9217 
 
 9-328 
 
 8-48 
 
 6 
 
 192 
 
 4-877 
 
 8-9856 
 
 8-448 
 
 7-68 
 
 7 
 
 I 7 6 
 
 4-470 
 
 8-2368 
 
 7744 
 
 7-04 
 
 8 
 
 160 
 
 4-064 
 
 7-488 
 
 7*04 
 
 6-4 
 
 9 
 
 144 
 
 3-658 
 
 6-552 
 
 6*16 
 
 5'6 
 
 10 
 
 128 
 
 3-251 
 
 5-9904 
 
 5-632 
 
 50965 
 
 ii 
 
 116 
 
 2-946 
 
 5-4288 
 
 5-104 
 
 4-68 
 
 12 
 
 104 
 
 2-642 
 
 4-8672 
 
 4'576 
 
 4-16 
 
 13 
 
 092 
 
 2-337 
 
 4-3056 
 
 4*048 
 
 3'68 
 
 14 
 
 080 
 
 2*032 
 
 3-744 
 
 3-52 
 
 3'2 
 
 15 
 
 072 
 
 1-829 
 
 3-3696 
 
 3*168 
 
 2-88 
 
 16 
 
 064 
 
 1-626 
 
 2'9952 
 
 2*816 
 
 2-56 
 
 17 
 
 056 
 
 1-422 
 
 2-6208 
 
 2*464 
 
 2-24 
 
 18 
 
 048 
 
 1-219 
 
 2-2464 
 
 2'II2 
 
 92 
 
 '9 
 
 040 
 
 roi6 
 
 I-872 
 
 76 
 
 6 
 
 20 
 
 036 
 
 0-914 
 
 1-6149 
 
 584 
 
 '44 
 
 21 
 
 032 
 
 813 
 
 I'4976 
 
 408 
 
 28 
 
 22 
 
 028 
 
 711 
 
 I-3I04 
 
 232 
 
 12 
 
 2 3 
 
 024 
 
 610 
 
 1*1232 
 
 '056 
 
 0-96 
 
 24 
 
 022 
 
 '559 
 
 I "0296 
 
 0-968 
 
 88 
 
 25 
 
 '020 
 
 508 
 
 0-936 
 
 88 
 
 8 
 
 26 
 
 018 
 
 '457 
 
 8424 
 
 792 
 
 72 
 
 27 
 
 0164 
 
 4166 
 
 76752 
 
 7216 
 
 656 
 
 28 
 
 0148 
 
 '3759 
 
 "69264 
 
 65118 
 
 592 
 
 2 9 
 
 0136 
 
 '3454 
 
 63648 
 
 5984 
 
 "544 
 
 30 
 
 0124 
 
 3150 
 
 58032 
 
 54-56 
 
 496 
 
INDEX. 
 
 Axle blocks, 128, 131. 
 
 Bearings, 84, 95. 
 Bed-plate, 77, 92. 
 Boiler fittings, 151. 
 
 Horizontal, 146. 
 
 Locomotive, 33, 123. 
 
 making, 141. 
 
 Marine, 147. 
 
 Size of, 149. 
 
 Vertical, 143. 
 Boring bar, 54. 
 Brazing, 141. 
 Buffers, 93. 
 Burnishing, 168. 
 
 Castings, 8. 
 Centre punch, 19. 
 Connecting rod, 80. 
 Coupling bars, 130. 
 Cowcatchers, 136. 
 Crank, 28, 96. 
 
 Double, 102, 1 1 6. 
 
 pin, 78. 
 Crank-shaft, 77, 84, 98. 
 
 Bent, 78. 
 Crosshead, 86, 96, 102, 128. 
 
 Cylinder, Boring, 52-. 
 Chucking, 46. 
 covers, 16, 35, 62, 
 94, 127. 
 Cylinder, Locomotive, 127. 
 
 Oscillating, 14, 34, 
 114. 
 Cylinder, Slide-valve, 46. 
 
 Eccentric, 77, 104. 
 
 Adjusting, 88. 
 Loose, 164. 
 strap, 76. 
 
 Fire-box, 124. 
 Fluxes, 170. 
 Fly-wheel, 22, 88. 
 Force pump, 162. 
 Furnace door, 125. 
 
 Gauge, 163. 
 Glands, 68. 
 Governors, 160. 
 Guide bars, 83, 86, 96, 129. 
 blocks, 86. 
 
 Horizontal engine, 42. 
 
 '77 
 
Index. 
 
 Horse power, 172. 
 
 Actual, 173. 
 Nominal, 172. 
 
 Lacquering, 169. 
 
 Lamp, 38, 150. 
 
 Lap, 171. 
 
 Launch engine, 99. 
 
 Lead, 171; 
 
 Links, 132. 
 
 Locomotive engine, 122. 
 
 Marine engine, 109. 
 
 Nuts, 17. 
 
 Oscillating cylinder engine, 12. 
 
 Paddle wheels, 118. 
 Painting, 169. 
 Piston, 1 6, 35, 70. 
 
 Dimensions of, 73. 
 
 rod head, 85. 
 Pressure, Average, 173. 
 
 gauge, 163. 
 Pump, 162. 
 
 Quadrant, 133. 
 
 Reversing gear, 132. 
 lever, 134. 
 Rivetting, 142, 145- 
 Rocking bar, 133. 
 
 Safety valves, 1 56. 
 Screws, 5, 18. 
 Screw-shaft, 104. 
 
 Slide valve, 73. 
 
 rod, 86. 
 
 Setting, 170. 
 Small power engines, 90. 
 Smoke box, 124. 
 
 door, 125. 
 Solders, 169. 
 Spinning me-tal, 143. 
 Standards, 95. 
 Starting lever, 134. 
 Steam block, 17, 34, m. 
 
 chest, 67. 
 
 ports, 58. 
 
 taps, 151. 
 
 ways, 24, 35, in. 
 Steam whistles, 154. 
 Steel, round, 173. 
 
 square, 174. 
 Stuffing-box (Cylinder), 66, 68. 
 (Steam chest), 68. 
 (Screw shaft), 104. 
 glands, 68. 
 Super-heated steam, 172. 
 
 Tables, 174. 
 Tappets, 1 66. 
 Taps, Screw, 6. 
 
 Steam, 151. 
 Tools, 2. 
 
 Unions, 154. 
 Unit of heat, 172. 
 
 Valves, 156. 
 Vertical engine, 91. 
 
 .Whistles, 154. 
 
MODEL STEAM ENGINES & BOILERS 
 
 OF ALL KINDS. 
 
 BRASS AND IRON CASTINGS, SETS OR PARTS. 
 
 (As supplied to the Author of this work.) 1U 
 
 SEPARATE FINISHED PARTS. 
 
 OF EVERY DESCRIPTION. 
 
 MESSRS. LUCAS & DAVIES, having had 
 over 2O years practical experience in the 
 manufacturing of the above, can con- 
 fidently recommend their goods to Amateurs 
 and others. The Patterns are of the newest 
 designs (not copies of other makers) and care- 
 fully proportioned, so that the castings, which 
 are of the best metal, make up easily, and with 
 as little work as possible. 
 
 Mr. POCOCK, who has had castings from 
 every firm in the trade, said, " Those supplied 
 by us were superior to any others he had 
 obtained, as to correctness of design, quality 
 of metal, and ease of construction." 
 
 These Castings have been sent to all parts 
 of the world, and have given universal satis- 
 faction. 
 
 PRICE LIST, with Illustrations from 
 photographs of the finished Engines, &e., post 
 free, 4d. 
 
 LUCAS & DAVIES, 
 
 21, CHARLES STREET, HATTON GARDEN, 
 
 LONDON, E.C. 
 
MODEL STEAM ENGINES, 
 
 CYLINDERS, PUMPS, STEAM & WATER GAUGES, 
 
 SAFETY VALVES, ECCENTRICS, TAPS, ETC., 
 
 fflodel Yachts and $team Boats, 
 
 Blocks, Deadeyes, Skylight, Companions, Stanchions, Flags, 
 
 CANNON, ETC. 
 
 FITTINGS FOR MODEL SHIPS 
 
 (LIST FREE). 
 
 MODEL SHIPS' FITTINGS MADE TO SCALE OR TRACING; 
 FIRST-CLASS WORKMANSHIP. 
 
 STEVENS' MODEL DOCKYARD, 
 
 22, ALDGATE, LONDON. 
 Send 3d. for Illustrated Catalogue. 100 Engravings. 
 
 POST/YNS & COMPY., 
 
 AND 
 
 SCIENTIFIC MODEL MAKERS, 
 
 75a QUEEN VICTORIA STREET, LONDON, E.C. 
 
 Factories : 25, Bread Street Hill, E.C. 
 
 Fourth Edition, numerous Cuts, Crown &vo., Cloth. 
 2s. 6d. 
 
 TUP nVNAMR HOW MADE> 
 
 I fit UllmlVIU i And HOW USED. 
 
 By 8. A. BOTTONE. 
 
 " Exceedingly plain, clear instructions for the manufacture of small dynamos." 
 Journal of Science. 
 
 " Gives minute instructions to amateurs, by following which they may be able to- 
 make, at trifling cost, a dynamo for themselves." Scotsman. 
 
 SWAN SONNENSCHEIN & CO., PATERNOSTER SQUARE, E.C, 
 
14 DA\ USE 
 
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 Renewed books are subject to immediate recall. 
 
 
 REC'D LD 
 
 
 
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 APR 27 
 
 :c. CIR. nps 2 8 1971 
 
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 72 -11 AM 
 
 ODORC MAR 7 1986 
 
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 AUG 1 9 1986 
 
 LD 2lA-60m-2,'67 
 (H241slO)476B 
 
 General Library 
 
 University of California 
 
 Berkeley 
 
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 UNIVERSITY OF CALIFOWIA LIBRARY