^<^^^^i^/^ 
 
I UBRARY OF CONGRESS. | 
 
 Chap. ^'XjlhO^ 
 Shelf 
 
 %. 
 
 )t UNITED STATES OF AMERICA. 
 
/ 
 
THE 
 
 BOY ENGINEERS 
 
 WHAT THEY BID 
 
 HOW THEY DID IT 
 
 a ^oofe far Bops; 
 
 BY THK 
 
 REV. J. LUKIN 
 
 AUTHOR OF " THB YOUNG mechanic" "AMONGST MACHINES." ETC. ETC. 
 
 NEW YORK 
 G. P. PUTNAM'S SONS 
 
tr^ 
 
 V 
 
 Press of 
 
 G. P. Ptit nam's Sons 
 
 New York 
 
Content^. 
 
 CHAP. 
 
 I. IKTRODTTCTOBT ••«•••£« •! 
 
 n. OUR -WORK . . ♦ , , « « »•, • 29 
 
 ni. WORKSHOP APPLIANCES • « * •» , • ♦64 
 
 IV. OUR WOODEN CLOCK ••••••••83 
 
 V. SOME MORE AUTOMATA •••«•••• lOO 
 
 VI. OUR FIRST ORGAN *•••••••• 121 
 
 VII. OUR HOUSE .. ••••••• I47 
 
 Vm. OUR WORKSHOP AND ITS FITTINGS •»••,, I78 
 IX. ONE OR TWO ENGINES .*••*••. 20C 
 X. OUR CARVING-MACHINE . , • ' , « « « ♦ 26? 
 
 XI. OUR ELECTRICAL AND PNEUMATIC APPARATUS • • . • 306 
 
Preface. 
 
 T is perhaps of no great importance to tlie reader 
 
 to know how the outline of the following 
 
 J narrative came into my possession. Perhaps 
 
 the surgeon who is spoken of in the introductory 
 chapter placed it in my hands, and perhaps he did 
 not ; but it was in any case lawfully my own, to do with 
 as I pleased j and I therefore put it into book form for 
 the benefit of my old friends. The Boys. In doing so, I 
 found it necessary to add considerably to it, and so to 
 modify it that, while relating what the BoT Engineers 
 said and did, I might from personal knowledge of the 
 mechanical arts assist the youngsters in their work. The 
 
a PREFACE. 
 
 volume, therefore, will be found to contain something 
 more than a record of Boy Engineering, while, at the 
 same time, there is no work described in it which a per- 
 severing and industrious lad might not accomplish. I 
 therefore hope that not only will my young readers be- 
 come interested in the tale of what was done by these 
 youngsters, but themselves make trial of their skill in 
 
 the construction of similar works. 
 
 J. L. 
 
Chapter I. 
 
 INTRODUCTORY. 
 
 URING the time of my residence at the village 
 of Brampton, in the year 18—, I became ac- 
 quainted with two brothers who were being 
 educated at Huutingdou Grammar School, 
 about four miles distant. They were the sous of a re- 
 tired captain in the Eoyal Isavy, who, although by no 
 means rich, had sufficient means to live in comfort. His 
 name was Addison, and the boys Henry and Arthur were 
 better known as Harry and Tim, the latter name scarcely 
 agreeing with that which his godfathers and godmotbers 
 had given- him when he submitted, under somewhat noisy 
 protest, to the baptismal rite. For a long time I could not 
 divine the origin of his assumed name, but I subsequently 
 discovered that it was derived from one Timothy Potter, 
 an itinerant mender of pots, pans, and umbrellas, with 
 whom my young friend held frequent commercial inter- 
 
BOY ENGINEERS. 
 
 course as a vendor of divers articles needed in his trade. 
 It was old Tim wlio supplied solder, and wire, and odds 
 and ends of tin and brass wherewith Arthus' and his 
 elder brother jjractised various handicrafts after their own 
 fashion. For these and similar articles Henrj^ seldom 
 dealt personally with the tinker, not because he was too 
 proud, but because his colleague was a better hand at 
 driving a bargain, and did not object to any amount of 
 higgling, so that he obtained his object in the end. I'm 
 afraid, however, that, after all, old Tim beat young Tim 
 sadly at these transactions, and made a very handsome 
 profit, even when he declared that he was selling under 
 cost price ; especially as I had reason to think that the 
 old tinker sometimes obtained his wares without paying 
 for them at all. 
 
 My acquaintance with these lads originated in profes- 
 sional attendance rendered for a somewhat severe cut 
 which Harry had inflicted on himself with a chisel in some 
 carpentering operation. I found him not only a courage- 
 ous boy who could bear pain without flinching, but an 
 exti'cmely ingenious youngster at mechanical work, and 
 (which is not always the case) one exceedingly anxious to 
 acquire information both in the theory and practice of 
 engineering. His younger brother shared this predilec- 
 tion, and was in some respects the neatest hand of the two 
 in actual work, though somewhat behind Harry in theore- 
 
AT SCHOOL. 
 
 tical knowledge. Being myself fond of mechanics, and 
 the possessor of a lathe and other simple requisites, we 
 naturally struck up a friendship ; and perhaps the loss of 
 my own son, who was an only child, tended to draw my 
 affections towards two lads who were by no means 
 unlike him in disposition and tastes, and of whom, 
 moreover, the youngest was not very dissimilar in 
 personal appearance. Both the boys subsequently rose 
 to eminence in their profession, but the eldest died 
 comparatively young, having specially intrusted to my 
 care an autobiography of his school-days, which I shall 
 now present in a modified form to my readers. 
 
 *' We had," says the writer, " an old wooden outhouse, ad- 
 joining the school, which had once served as a fowlhouse, 
 but the feathery tenants had long since had notice to 
 quit, and their home had not been transferred to new oc- 
 cupants. Tim and I cast many a longing look at the old 
 shed, for it was little else, and had fancied that it might 
 be conveited into a very tolerable workshop by a moderate 
 outlay of hoarded pocket-money, if we could but persuade 
 our worthy schoolmaster to let us have it. For some time, 
 however, we coidd not make up our minds to prefer the 
 request, but contented ourselves with practising a little 
 diplomacy, by keeping out of all mischief, and working 
 zealously at our respective tasks. Having thus established 
 
BO Y ENGINEERS. 
 
 a good character, which we managed also to retain, we 
 determined on writing a joint petition, and we further 
 proposed to do this in choicest schoolboy Latin. Having 
 obtained a sheet of foolscap, as looking more official and 
 business-like than notepaper, we began, after much con- 
 sideration, as follows : — 
 
 " * Domine Reverende et Doctor prasstantissime, — Nos 
 tui alumni (vix adhuc scholares appellari digui) quibus 
 natura cacoethes studiorum attinet, qu^e ad machiuas 
 fabricandas pertinent,' 
 
 '"'■ ' Oh, hang it,' said I, ' we shall never get to the end 
 of the letter, Jim. I don't think 'tis bad grammar 
 exactly, so far ; but I am in a hurry to come to the point, 
 and for the life of me I can't find out the Latin for work- 
 shop, or fowlhouse, or padlock. " Gallinae domus," I 
 suppose, would do for henhouse; but I vote we chuck up 
 Latin and try English ; or, what is better than either, let 
 us write home and ask father to come and see us, and 
 ^then we can tell him to ask the Doctor.' 
 
 " And so it was settled, and the ultimate result was 
 that we got the shed made over to us, and an advance 
 of pocket-money to repair it ; and henceforth we had a 
 terrestrial paradise of our own under lock and key. 
 
 " Luckily for us the other boys could not get near our 
 workshop without going into the Doctor's garden, which 
 garden was tabooed, as it contained a good assortment of 
 
OUR WORKSHOP. 
 
 fruit-trees, wliicli would have been apt to shed their pro- 
 duce into the pockets of the pupils instead of those of the 
 owner^ if a right of way had once been established. As 
 for us two, we were put on our. honour, which boys as a 
 rule observe a deal better than garden walls and fences ; 
 and though we were not unconscious of raids by outsiders, 
 which at any rate tended to thin out the fruit, we our- 
 selves had no part in these predatory excursions, nor did 
 "we ever consent to receive any share of the plunder. 
 
 *' Let me describe our workshop and its contents before 
 I pass on to tell of the various works executed therein. 
 
 " Not, however, that all waS possessed at once, far from 
 it ; and m;iny a treat did we give up, in which the rest of 
 the boys participated, in order to obtain some much-coveted 
 tool or appliance to add to our stock-in-trade. The shed, 
 now weather-tight and clean, was about twelve feet long 
 and ten wide, and was of ample height, and comfortably 
 thatched. At one end was a window formed of an old 
 cucumber-light, which we had picked up a bargain, and 
 framed by laying it on its side, and securing it to a 
 convenient beam which formed our window-sill. A 
 similar window, formed of some neglected cottage case- 
 ments placed side by side, and newly leaded, was fitted in 
 one of the longer walls, and a padlocked door at the end 
 gave access to the interior. We thought it would Iook. 
 well to put a notice on this door of * no admittancb 
 
BO Y ENGINEERS. 
 
 EXCEPT ON BUSINESS,' to wliicli was Subsequently added, to 
 scare away passing tramps, ' beware of the bulldog,' 
 an invisible mytliic animal, supposed by a pleasing fiction 
 to be housed within. We tarred the whole of the out- 
 side of our workshop, dignitatis et honoris causd. A 
 roughly-made carpenter's bench occupied the space in 
 front of the side window, over which we fixed our rack for 
 carpenter's tools, the squared and saws, and similar in- 
 struments hanging on nails, and the planes being ranged 
 on a shelf above. 
 
 " In order to ensure tidiness and order, which we 
 rightly believed of great importance, we agreed to fine each 
 other for leaving tools out of place, or unduly damaging 
 them ; and these fines, dropped fairly and faithfully into 
 a money-box, were always expended upon new tools and 
 materials. 
 
 " The first time we opened this box, which we did once 
 every six months, we found ourselves able to buy a grind- 
 stone which happened to be for sale in the village, and 
 had long been vainly coveted. It was a good stone, but 
 most decidedly of a very eccentric character, as it had been 
 badly used, and had a piece broken off one side, if a cir- 
 cular object has a side at any part of its circumference. 
 However, we determined that our grindstone should at 
 any rate not disgrace our workshop, and we therefore pro- 
 ceeded to correct it. 
 
GRINDSTOA^ES. 
 
 ^' Ktiocking- ont the already loosened wedges which kept 
 the axle in place, we laid it upon its side on the floor, and 
 drove also into the floor, through the square hole in its 
 centre, a peg of wood cut to fit it easily hut closely, into 
 the middle of which we inserted a bradawl, which was first 
 passed through the end of a lath. Having found, by 
 turning the lath round upon this bradawl as a centre, the 
 utmost size to which the stone could be trimmed, we com- 
 pleted our beam-compasses by inserting a nail at the re- 
 quired distance, with which we easily marked a circle upon 
 the upper part of the stone. We found we could still 
 save the greater part of it, and obtain a grindstone fifteen 
 inches in diameter ; the face, moreover, was rather more 
 than three inches wide, quite sufficient for grinding our 
 plane-irons, or even our light hand-axe. We then got a 
 mallet and chisel on loan, and with much patience and 
 care we managed to chip off little by little all that was 
 outside the marked circle, and thus reduced our stone to 
 shape, ready for mounting." 
 
 I may perhaps digress here to tell my young readers 
 how the grindstones are cut from the quarries, as it is just 
 one of those operations which the majority of those who 
 buy and use these articles know nothing about. At the 
 time of my young friends* purchase, in fact, I chanced to 
 be staying at the Eev. Doctor's, and having the run of 
 their workshop, I found them at work as above described. 
 
8 BOY ENGINEERS. 
 
 and gladly gave tliem the information which I now suhmit 
 to the eyes of the readers. 
 
 The stones ordinarily used by the carpenter are quarried 
 in Yorkshire, and are called by the generic name of grit- 
 stones. There are, however, many other localities which 
 produce them, notably Staffordshire, which supplies a 
 quality, called Bilston grit, of a harder and closer texture 
 than those of Yorkshire. The cutting powers of all these 
 depend upon the particles of silica contained in their sub- 
 stance in union with the softer sandstone. The greater 
 the proportion of silica, and the closer its particles, the 
 harder and finer is the stone, so that a selection is 
 generally made by the workman to suit his special 
 requirements. The stone is got out in solid blocks, which 
 are cut by chisels into cylinders of greater or less diameter, 
 and of varying lengths. Around these at intervals deep 
 grooves are cut, marking the several stones ultimately 
 required, and into these are driven wedges of wood — 
 generally willow, which bears a good deal of hammering, 
 as boys used to cricket-bats ought to know. These are 
 driven tightly into the grooves, and the whole is left 
 exposed to the dews of night, which swell the wedges, and 
 the several sections are in this way split asunder without 
 further treatment. The rough surfaces are, however, sub- 
 sequently worked to a more accurate face with the mallet 
 and chisel, by which the square hole to receive the iron 
 
OUR GRINDSTONE. 
 
 rtxle i? al.«o cut. The largest stones, made to revolve at a 
 terrific speed, are used by the Sheffield cutlers for grind- 
 ing large pit-saws and other tools, and also by stove and 
 grate manufacturers and others for brightening their iron 
 and steel work. When too small for this purpose, a bar 
 of iron is held against them as they revolve, so as to cut 
 a deep groove, and by means of wedges or chisels they are 
 split into narrower or thinner sections, and handed over 
 to the grinders of razors, scissors, and smaller articles. 
 
 Our young friends having to face up the stone which 
 they had trimmed to a correct shape in the way already 
 described, so as to give it a face sufficiently smooth for 
 use, I was able to give them a " wrinkle " which they 
 were not likely to have discovered for themselves. I shall, 
 however, state their difficulties and experiments in the 
 words of the manuscript from which I have already quoted 
 largely. 
 
 *' It did not take us very long to heat the old and bent 
 handle, which from bad usage and exposure had become 
 rusty and out of form, and to correct its shape ready for 
 use, but it took us a good deal of manoeuvring to wedge 
 it centrally in the square hole of the stone. After some 
 time, however, we arranged it to our satisfaction, our 
 carpenter's square assisting us very materially in getting 
 •it accurately fixed at right angles to the sides of the 
 etone. 
 
10 BOY ENGINEERS. 
 
 *' Our workshop having an earthen floor, we moniited 
 onr grindstone upon two posts driven into the ground, 
 driving two staples to keep it in place — a V2ry primitive 
 metliod, which we subsequently altered to a better ; but it 
 served our purpose for a long time, as it had no doubt 
 served that of many others previously. Driving two other 
 posts as a support, we placed a home-made water-trough 
 underneath it, which we could easily remove ; and we also 
 arranged a support for the tools, and to enable us to turu 
 up and true the face of the stone. 
 
 " For the latter purpose we begged an old file from a 
 friendly blacksmith, selecting the hardest tool we could 
 think of wherewith to attack our friend, who had already 
 proved to us that it was ' rale grit,' as the Yankees say, 
 during our preliminary operations upon its substance. 
 Although, however, we worked very patiently at our task, 
 the file seemed to get by far the worst of it ; and although 
 we turned it over and over as the edges in turn became 
 blunted, we did not appear to make much progress in our 
 work. 
 
 *' Whilst, however, we were thus engaged, our kind 
 friend the surgeon who attended the school, and who 
 had been called upon on one occasion to dress a very 
 severe cut of my brother's, paid us a visit. After watch- 
 ing us a few minutes, he proposed to take a turn at the 
 work himself, and rejecting the file, he picked up a bit 
 
OUR GRINDSTONE. 
 
 of small iron rod that lay near, and to our surprise 
 began to cut the stone at a far quicker rate than we had 
 done with the hard steel, and very soon reduced it to a 
 true cylinder." 
 
 This is worth recording for the reader's benefit, as no 
 good work can be done on an untrue grindstone ; and the 
 moment it is found to approach such a condition, it must 
 be corrected or it will get rapidly worse. The reason for 
 its untruth is sometimes that the stone is softer in one 
 part than another; but very often it is the result of 
 allowing it to remain partly sunk in the water in the 
 trough, which renders that part more easy of abrasion in 
 use than that which has been kept dry. The weight of 
 the cranked handle always causes the stone to stop in the 
 same position, so that the same part is invariably exposed 
 to this deterioration and is never completely dry. The 
 water-trough should therefore always be so arranged that 
 it can be either lowered or wholly removed when the 
 stone is not in use ; a still better plan, perhaps, is to have 
 a drip-can with a tap above it, and to allow the water 
 that runs from it upon the stone into the trough below 
 to escape from the latter at once into a bucket. Our 
 young friends learned all this in due time, but would 
 have saved themselves many an hour's work in truing up 
 their grindstone, if they had been told this and other trade 
 secrets at the commencement of their mechanical career. 
 
12 BOY ENGINEERS. 
 
 The reason that soft iron will answer for the purpose 
 named better than steel, is supposed to be that it contains 
 less carbon, and does not heat so quickly during the 
 operation. It is at any rate a proved fact, and the best 
 tool to use is a bit of small rod to turn down the stone, 
 followed by a bit of hoop iron to give the finishing touch 
 to the surface. The iron must be held firmly on a rest 
 fitted for the purpose, pointing downwards, and the bar 
 must be turned over and over as the upper edge gets 
 blunted. It is at best a somewhat tedious operation, but 
 absolutely necessary if the stone does not run truly ; and 
 the only way to lighten the task is never to allow of any 
 irregularity, but to correct at once the slightest tendency 
 to eccentricity. 
 
 We soon found, says the narrative, the benefit of the 
 hints given us by our good-natured friend, and hence- 
 forward we always kept a rod of iron and a bit of hoop on 
 purpose for this work. Moreover, we learned to save the 
 face of the stone by traversing the tool to and fro across 
 it when grinding it, especially if it were narrow or 
 pointed. The gouges gave us most trouble, but we 
 eventually found it better to lay these across the stone, 
 rolling them over and back again as the work proceeded, 
 instead of holding them in the position of chisels and 
 similar tools. Channels and grooves in the grindstone 
 were, however, among the list of finable offences, and 
 
TOOL-GRINDING. 13 
 
 until we got well used to the work, our money-box got 
 thereby many an odd copper added to its treasures. 
 
 Another secret of tool-grinding was explained to us on 
 a subsequent visit of our friend, who found us at work 
 with the stone running from instead of towards us. It 
 had appeared to us in our ignorance that this must of 
 necessity be the right mode of grinding, because we 
 fancied that if the stone were made to run as it were 
 against the edge of the tool, it would blunt instead of 
 sharpening it. We had, however, always noticed that a 
 wire edge or thin flexible filament of the steel formed when- 
 ever we used the grindstone, whicii we had to get rid of 
 by drawing it across a bit of wood before we could 
 produce a keen edge upon the oilstone; and sometimes 
 this would also form a second time upon the surface of the 
 latter, which then needed to be wiped and cleaned before 
 we could go on with our sharpening. 
 
 Our friend, however, told us that this wire edge was 
 but the result of our mode of grinding, the stone tearino- 
 away the steel when it got very thin, whereas if we turned 
 it towards the edge, the particles would be driven inwards 
 towards the solid metal, and as it were compressed. This 
 we found to be really the case, and thus we made a step 
 forward towards a workman-like mode of sfrindino- our 
 tools, and gradually learned the art of producing upon 
 them a good and evenly-levelled edge. 
 
H 
 
 BO Y ENGINEERS. 
 
 It must not, however, be supposed that the subsequent 
 operation of setting them on the oilstone was acquired 
 without a long series of failures ; for at first we rather 
 blunted than sharpened them, and for any special work 
 were only too glad to call in the aid of the village carpenter 
 
 Jraterion. 
 Pig. I.— Our Fii-st Latha. 
 
 or his apprentice to put our planes and chisels in working 
 order. After long and careful practice, however, we 
 triumphed over this difficulty, as we did over others of a 
 more serious character. 
 
POLE-LATHE. 15 
 
 Our great ambition was to possess a lathe, which we 
 intended to stand under the window at the farthest end 
 of the workshop. There were not at that period the same 
 chances that subsequently existed of obtaining articles of 
 this kind ; there were, indeed, a few firms in London 
 ready and willing to supply them, but only at such a 
 price as there was no chance of our being able to afford for 
 many a long year. No " English Mechanic " or ^' Bazaar" 
 or other periodical existed whose columns might offer to us 
 a second-hand tool, and it became evident to us that we 
 must contrive to make a lathe ourselves with such appli- 
 ances as we could muster, and with the help of the black- 
 smith or old Tim. 
 
 The only advantage we had was the power of inspecting 
 two lathes possessed by a chairmaker and by the carpenter. 
 The former was what is called a pole-lathe, a very simple 
 affair, but in the hands of Bill Birch the owner capable 
 of a great deal of good work. 
 
 The rough sketch given in fig. i will sufficiently explain 
 its construction as arranged in our own workshop, for it was 
 this lathe which we ultimately decided to make, postponing 
 to a future day the construction of a more serviceable one, 
 after the pattern of Bob Chip's the carpenter. It will be 
 seen that the bed of this lathe consisted of a pair of beams 
 placed parallel to each other, and resting upon a frame 
 at each end. We planed the upper surface of these ag 
 
i6 BOY ENGINEERS. 
 
 well as we could, and the front of the foremost one for 
 appe<arance' sake, leaving the rest rough. As the pieces 
 were of beech, this was to us boys a formidable undertak- 
 ing. We quickly discovered that beech was far more 
 difficult to face up than deal, to which we had hitherto 
 been accustomed. Oar long or "jack plane" sufficed to 
 take off the rougher outside of the wood, but the grain 
 did not run straight from end to end, but seemed to delight 
 in curls and knots, which defied our efforts to reduce them 
 to a smooth surface. 
 
 But here again our medical friend came to the rescue 
 and showed us how to conquer the enemy. He pointed 
 out to us that the mouth of our jack-plane being worn 
 was too wide, and that the second iron, called the break- 
 iron, which was fixed upon the cutting iron of the plane, 
 was too far from the edge of the latter. To plane knotty 
 wood, he explained to us that the mouth of a plane should be 
 very narrow, the break-iron not more than one-sixteenth of 
 an inch from the level of the cutting edge, and the latter set 
 very fine — Le.^ only allowed to project a very minute de- 
 tance beyond the sole. With a plane thus arranged very 
 thin shavings are taken, which are fairly cut, and not split 
 off from the surface of the wood ; but it is also necessary 
 to work the plane in all directions where the grain is 
 curly and uneven, so as to cause it to cut them lengthwise 
 instead of across, After the surface has been levelled 
 
LATHE DETAILS. 17 
 
 M'ith such a plane, called a tryiug-plaue, it is often 
 necessary to go over it again with a smoothing-planej 
 which is a very short one, carefully sharpened and set, as 
 it is easier to work this in various directions than it is to 
 do so with a longer plane. The latter, however, insures 
 a more truly level surface. 
 
 On or rather between the pieces forming the bed we 
 placed a pair of poppits, of which a spare one is seen upon 
 the floor, showing, more accurately than tliose above, the 
 tenoned part, with the mortise-hole by which they were 
 secured in any desired position by wedges underneath the 
 bed. Through each of these was a pointed screw, turned 
 up to form a winch-handle by which to move it, and 
 advance or withdraw the point. Between these was 
 mounted the wood to be turned. Throuirh a hole about 
 half-way up the poppits a square iron rod passed, whicli 
 was bent to form a hook, and upon these rested a long 
 board of beech to support the tools during the operation 
 of turning. The upper Q.d<.gQi of this was level with the 
 centre-points, and we could push in or draw out the hooks 
 according to the size of our work. We afterwards found 
 that this board troubled us by falling forward when in 
 use, so we bored a hole in each poppit with an auger 
 above that through which the hooked irons passed, and 
 fitted in these a couple of bed-screws, which we got for 
 fourpence ; and by screwing them to bear on the inside 
 
i8 BOY ENGINEERS. 
 
 of the board, we kept it firnily pressed against the hooks 
 and made it very steady. 
 
 The next consideration was the treadle and its fittings 
 The treadle itself was only a board an inch thick, under which, 
 at the part resting on the floor, we fixed two short spike? to 
 prevent it slipping about when in use. From the farthest 
 end a cord ascended, taking a turn round the work, and was 
 fastened to the end of a strong ash pole, of which one end 
 was fixed to the beams overhead, and the other was arranged 
 to come over any part of the lathe. This we managed by 
 putting a round pin through the pole about eighteen inches 
 from its larger end, and driving this pin into a convenient 
 beam, thus allowing the pole a horizontal motion on the 
 pin. Then we nailed a stout bar just over the end of the 
 pole, under which it was free to move, but which held it 
 down securely against the tendency to rise from the strain 
 of the cord at the other end. This pole, therefore, formed 
 a strong spring, which raised the treadle off the floor when 
 the pressure of the foot was relaxed, but yielded to that 
 pressure when the treadle was i)ressed downwards. During 
 the latter motion the cord caused the work to rotate 
 several times towards the workman, so that a tool held 
 against it would cut it freely, but as the pole sprang 
 upward again this motion was reversed, and during that 
 time the tool had to be withdrawn slightly, so as to clear 
 the work. 
 
INDIA. 19 
 
 Many an hour had we watched the old chairmaker 
 turning at a lathe like this, and he certainly worked very 
 fast, and with apparent ease; but it must be confessed 
 that for some time we could do very little, for the roug-h 
 pieces of wood caused the tools to hop about upon the 
 bar which formed the rest, and we could not manage to 
 advance and withdraw it at exactly the proper moment, so 
 that our work was done but slowly, and was at best very 
 rough. 
 
 Soon after we had finished this somewhat unique piece 
 of machinery, our friend the surgeon paid us a visit, and 
 gave us a very interesting account of the way in which 
 turned work is managed by the natives of India, and also 
 by the Africans and others. I give the account in his 
 own words as nearly as I can recollect them. 
 
 " Soon after my arrival in India, where I was to act as 
 an army surgeon, I had occasion for several turned articles ; 
 for though I liad practised carpentry, I had never tried 
 my hand at the lathe. I wanted some legs to complete a 
 small table, and some rounds for a chair back ; a leg of 
 my pocket camp-stool was also broken, and needed to be 
 replaced by a new one. At first I proposed to round my 
 pieces as well as I could with a spokeshave, as I had 
 no idea where to obtain turned ones; but Captain Fellows, 
 an old friend, seeing me thus employed, suggested sending 
 for a turner, who, he told me, would do all I wanted for a 
 
BOY ENGINEERS. 
 
 sum amounting in English money to fourpence. ' But, my 
 dear fellow,' I replied, ' I have no lathe, and there is not 
 one, I believe, in the place ; so that it is no use to send 
 for the turner, even if such could he found amongst 
 these woolly-headed black-skins.' ' Wait a bit,' he replied, 
 ' {ind you'll soon have lathe and workman too ; ' and 
 addressing a few words in Hindostanee to one of his 
 native servants, the fellow salaamed and hastened off. 
 
 " Returning in about twenty minutes, he was accom- 
 panied by a native carrying a small adze in one hand, and 
 a bag of matting in the other, containing all requisites, as 
 I soon found, for his work. Taking a couple of long wooden 
 tent-pegs, he bored a hole through each with a native 
 drill in a few seconds, and drove into them a couple of 
 pointed nails or spikes. He then with a mallet hammered 
 them a short distance apart into the ground, placing them 
 just so far asunder as the length of the table leg he pro- 
 l)Osed to turn. The pegs stuck out of the ground perhaps 
 nine inches. These were the poppits, and the solid 
 ground, which was dry and hard, as it generally is in hot 
 countries, was the lathe-bed. Two more tent-pegs were 
 driven, and a straight-edged board nailed to them at the 
 proper height to form the rest, and the lathe was so far 
 complete, the whole having been arranged within ten or 
 twelve minutes. I had seen a pole or chairmaker's lathe 
 similar to that which you boys have now made, but I. v/as 
 
EASTERN WORKMEN. 21 
 
 sorely puzzled how the spring pole could be fixed, as there 
 were not only no workshop beams overhead — the roof of the 
 shop being the clear sky above — but no overhanging tree 
 to which a spring of any kind could be fixed. The 
 mystery was presently solved. A strip of raw hide was 
 the cord, which was passed round the work, and the ends 
 given to two natives, who sat on the ground, one in front 
 and one behind the lathe. Each of these pulled alter- 
 nately, and set the work in rapid rotation, singing a sort 
 of monotonous chant the while, which had the effect of 
 keeping time. It was a regular case of ' Seesaw, 
 Margery Daw ; ' and I was told that the natives will con- 
 tinue this apparently back-aching work all day without 
 complaint. As soon as the work had made a few revolu- 
 tions, the pointed spikes were driven into the ends a 
 little farther to render it more secure, and a little grease 
 was added to prevent undue wear, and make the wood 
 revolve easilj'. The turner then took up his tools, which 
 were of a very rough description, and no English workman 
 could have done better work, or done it more rapidly. In 
 a few minutes the rough wood was shaped to its intended 
 form, measured in length and size from time to time with 
 a bit of Indian grass, and finally polished with a bit of 
 some kind of native rush or reed, like what is known to 
 turners as Dutch rush. When several pieces were needed 
 of the same size and length, they were all roughed over 
 
22 £0y ENGINEERS. 
 
 by the hand adze, or bassoolah, before any one of them 
 was put in the lathe to be turned; and nothing surprised 
 me more as a new-comer than the skill with which this 
 heavy but keen-edged tool was wielded by the native work- 
 men. It appeared to me that they could do any sort of 
 work with it, heavy or light, from roughing out the stem 
 of a pipe to trimming the timbers of a ship. All natives 
 sit on the ground upon or between their heels, in what 
 to us would be a most uncomfortable position, and they 
 hold the work or the tools partly by means of the great 
 toe. which, never having been confined in hard leather 
 boots, is as pliable and useful as the fingers. If a native 
 drops a tool, he will generally pick it up with his foot — an 
 action peculiarly ridiculous and grotesque to unaccustomed 
 spectators. I have even heard that a native tailor can 
 hold his needle in one foot, and thread it with the other, 
 and from what I have myself seen I am disposed to be- 
 lieve the report. 
 
 " In describing the formation of a native Indian lathe, 
 I spoke of drilling the holes for the two pointed screws. 
 The Indian and Eastern carpenters never use gimlets, as 
 we do, but a home-made and very efiective drill, with 
 which they bore holes with great rapidity, and without 
 any fear of splitting the wood, 
 
 " The drill is made almost wholly of hard wood, and in 
 two parts, of which the upper is held in the hand, while 
 
INDIAN DRIIL-STOCK. 23 
 
 the lower is made to rotate by means of a drill bow, 
 similar in principle to those used in England by watch- 
 makers and others. The bow is made of one of the 
 native hard woods of a springy character. I saw one of 
 these drills constructed on one occasion as follows : — 
 
 *' A bit of wood was selected about a foot long, which 
 was turned in the lathe, smooth and rounded off at the 
 end intended for the handle, but with a few grooves at 
 or about the middle of its length, below which it was 
 made cylindrical. This was sawn across to divide it into 
 two pieces, of which the shortest was to form the handle, 
 the rest the body of the drill-stock. At each end of the 
 latter a hole was bored, one for holding the actual drill, 
 the other for a spindle of very hard wood, which was 
 driven firmly into it, and I believe secured by some native 
 glue or cement. This pivot was like a large-headed pin, 
 the head being made as round and smooth as a small 
 marble, and the shank nicely rounded. This I did 
 not see made, but I should say it was done in the lathe, 
 as it was very nicely formed, and could hardly have been 
 accomplished by hand alone. This part had to be fitted 
 accurately into the head-piece or handle in which it was 
 to work, and the cavity to receive it was made as 
 follows : — 
 
 " First, a hole was drilled in the centre of the piece, tb*^ 
 size of the neck of the hardwood spindle, and then the 
 
24 BOY ENGINEERS. 
 
 whole piece was carefully sawn down lengthwise, so that 
 half of this hole was in each. The distance from the end 
 of the spindle to the knot was then measured, and a 
 cavitj' for the latter was made with a gouge — half in 
 each piece — and these cavities were made as smooth as 
 possible, so tlmt they resembled the two halves of a bullet 
 mould. A hole was then drilled in one of these pieces 
 to form an oil-hole sloping downwards into the cavity; 
 after which the spindle was put in its plnce, and the 
 two halves of the handle tied together with Indian grass, 
 to see whether the work was sufficiently accurate. At 
 first it appeared that the lower part had too much play, 
 but a tap on the end, by driving the spindle a little 
 farther into the lower part, brought the ends of the two 
 parts closely together, after which there was no undue 
 freedom of motion, and the fit was perfect. 
 
 " Before untying the grass bands which kept the two 
 halves of the handle together, two holes were drilled for 
 rivets, which were of stout brass wire, and when these 
 were in place and headed up, the ties were removed, and 
 the drill-stock nearly completed. The hole at the 
 bottom, however, to receive the drills, was ingeniously 
 * bushed' with a bit of bone or ivory, into which a 
 somewhat smaller hole was made, tapering to receive 
 the end of the bits of wire out of which the drills 
 were formed. These, in the present case, were apparently 
 
NATIVE DEXTERITY. 25 
 
 made of some umbrella ribs picked up in camp, as they 
 were of a small size ; and these steel ribs sufficed well 
 enough for the purpose. They were merely broken off, 
 heated, and flattened upon a stone anvil, and then 
 ground into the required shape by help of a bit of whet- 
 stone or native hone, upon which also the other end was 
 slightly tapered to fit the hole in the drill-stock. Some of 
 the larger drills are squared at the end like the " bits " of 
 our own carpenters, and then the hole in the stock is first 
 drilled and afterwards burnt out square with an old nail 
 or other implement. For the natives never find fault with 
 their tools," added our friend, '' as small boys are wont to 
 do ; but they make good use of all sorts of odds and ends 
 of iron and steel, from the rusty hoop of a barrel to the 
 broken blade of a knife. In fact, nothing in the way of 
 metal comes amiss to them, but their natural ingenuity 
 and acquired dexterity of hand enable them to turn to 
 practical use various broken articles which we ourselves 
 would most probably consign to the dust-heap as abso- 
 lutely worthless." 
 
 Naturally enough, after hearing this account, we became 
 far more sanguine about our own lathe ; for, we argued, if 
 those nigger fellows can do good work with their rough- 
 and-ready contrivances, we can do the same with ours, 
 which is, at any rate, one degree better, because we don't 
 want two people to work it besides the turner. Moreover, 
 
26 BOY ENGINEERS. 
 
 nothing would now content ns but an Indian drill-stock, 
 which we determined to make for our own use, although 
 we were, at the same time, perfectly well aware that, with 
 the same principle of construction, much more efficient 
 tools could be and were actually made and sold at the 
 shops. Our kind instructor nevertheless encouraged and 
 personally assisted us in the accomplishment of our task; 
 because, he said, it would give us the opportunity not 
 only of putting our lathe to some use, but also of 
 exercising our patience and skill in the production of work 
 which needed accuracy. We therefore tried our best, and 
 succeeded, but not until one or two failures had been in- 
 curred, the first arising from our having sawn the stock 
 across not quite at right angles to its length, so that the 
 ends would not work accurately together. We had con- 
 sequently to turn another ; and this time, by our friend's 
 advice, we made a mark rciund it with the chisel while in 
 the lathe as a guide for the saw, and another a little way 
 on each side of the first, so that, if we should fail to cut 
 exactly on the line at first trial, we could still saw off 
 each piece again at the other marks, and thus stand 
 another chance of success. 
 
 Our first attempt, however, this time proved satisfactory, 
 and we completed our drilling apparatus very much to 
 our satisfaction. We also found the tool an exceedingly 
 useful one, and frequently preferred it to any other. For 
 
OUR DRILL-STOCK. 
 
 27 
 
 holes in thin stuff, which hitherto we had split at divers 
 times with our ordinary gimlets, we always used our Indian 
 drill-stock ; and we found that for hard wood, which it was 
 a difficult task to bore with a gimlet at all, the drill was 
 exactly the tool required. We used it with a sixpennj' 
 bow of laucewood, fitted with a bit of catgut clock-line as 
 a string ; for we found a hempen cord would not 
 stand the work, as it quickly frayed and broke. 
 The greatest difficulty we had to contend with 
 in the manufacture of this drill-stock was the 
 spindle and knob. We tried boxwood and ebony, 
 and one or two other kinds, but all to no 
 purpose, as they proved too brittle for our 
 requirement, unless, we made the 
 spindle much larger than was other- 
 wise necessary. At last, however, we 
 got hold of a bit of ironwood, and 
 by dint of rasp and file — for we had 
 no tool that would cut it — we even- 
 tually succeeded in giving it the 
 necessary bullet-headed shape. It 
 was nevertheless a long job ; and even 
 at last — although when in place it 
 seemed to work very well — the 
 globular head was not, it is to be confessed, of very 
 accurate form. For its bed we got hold of an iron bit 
 
 //X3/4 
 
 4i9 
 
 Pig. 2 — Indian Drill-stock. 
 
28 BOY ENGINEERS. 
 
 called " a cherrj'," and made to fit a carpenter's brace. 
 They can be had at the London tool-shops, and are used, 
 in fact, to recess the cavities of bullet moulds, beings made 
 of hard steel, and channelled so as to have many cutting 
 edges. 
 
 Our friend kindly lent us a drawing of one of these 
 native drill-stocks, which, however, was lost with some 
 other mechanical sketches. 
 
 The writer has had the good fortune to find another 
 recently engraJ^ed, in the ^' English Mechanic," and by 
 the editor's permission it is now copied into this little 
 work. This will make its construction quite clear, with 
 the help of the description already given. 
 
Chapter II. 
 
 OUR WORK, 
 
 MUST now relate what we contrived to accom- 
 plish with our imperfect appliances ; and it may 
 encourage other boys of mechanical tastes to 
 state that some of our early work is still in 
 existence after the wear and tear of ten or fifteen years, 
 and is almost as serviceable as ever. This, I have no 
 hesitation in saying, would not have been the case had we 
 yielded to the usual temptation to do such things care- 
 lessly ; but, from the commencement of our career, we 
 determined to act in the spirit of the old proverb which 
 tells us that " what is worth doing is worth doing well." 
 Our first attempt at regular carpentry was a set of 
 steps for our own use in putting up shelves, and other 
 such jobs as needed longer legs than we were possessed of. 
 
30 BOY ENGINEERS. 
 
 They were not required to be very high, and we had in om 
 possession a hoard or two of deal an inch thick and nine 
 inches wide, that appeared well suited to our need. 
 
 We found, on measuring these, that we could make the 
 side pieces five feet long, which we fancied would result 
 in a set of steps four feet high when placed in the usual 
 sloping position for use. As this was a first attempt, 
 we did not propose to make them with a hinged frame at 
 the hack to shut up, hut with fixed supports, especially as 
 we could then contrive to put braces to stiffen the whole if 
 there should seem to be any grogginess in their condition. 
 
 The first point was to see to the state of our planes. 
 The jack-plane, having been used upon the lathe-bed to 
 take off" the rough outside of the beech bearers, was 
 evidently in a very blunt condition, though not damaged 
 by notches, and we had to try our hand at grinding and 
 setting it. This, I think, rather pleased us than otherwise, 
 as it would put our new grindstone to the test. After 
 what our friend had told us about wire-edges, we did not 
 fall into the error of turning the stone away from the 
 work, but we had some difficulty in holding the plane- 
 iron steadily, and preventing it from an occasional dig in, 
 thereby cutting into the stone, and damaging its edge 
 instead of improving it. Being the eldest, I asserted my 
 privilege to be head-carpenter, and Tim, as carpenter's 
 apprentice, had the task of working at the handle. I 
 
OII^S TONES. 31 
 
 should not like to say how often he had to change hands, 
 nor how unduly his labours were extended owing to my 
 cwn inefficiency. First I found that I was grinding the 
 tool more at one corner than the other; then the bevel 
 was rounded instead of being quite flat, as I knew it 
 should be; but at last matters appeared more satisfactory. 
 Trying it with our carpenter's square, we found the 
 edge fairly at right angles to the sides of the iron, and 
 the bevel tolerably flat and even ; and glad enough was 
 poor Tim to let go the handle and give his arms a rest. 
 
 Then I set about the difficult task of finishing the cut- 
 ting edge upon the oil-stone. We had bought one of these 
 out of the stock of a bankrupt carpenter, arguing in our 
 minds that we were far more certain in this way to get the 
 genuine article than if we went to a tool-shop ; and no 
 doubt we were perfectly right in our supposition. It 
 turned out eventually that we had thus secured not only a 
 real Turkey stone, but one of good cutting powers, and even 
 hardness — qualities of great value and importance, in which, 
 however, many of the Turkey stones fail. Had our boy- 
 hood been of later date, we should have found other and 
 cheaper stones in the market, especially Washita oil-stone, 
 which is excellent for carpenter's tools, and Arkansas, also 
 from America, some of which is very fine and hard ; but 
 in our day the ones most readily obtainable were Turkey 
 and Chorley Forest oil-stones, both, however, very service' 
 
32 BOY ENGINEERS. 
 
 able, and fit for our purpose. It was with a good deal of 
 anxiety that I set about the job in hand, which indeed 
 looks easy, but requires a good deal of knack and some 
 practice for its proper performance. However, I set to 
 work, and diligently rubbed the iron a few times up and 
 down the stone, as I had seen Bob Chips do with so 
 satisfactory a result. I then stopped to look at the edge, 
 Tim also being at my elbow to assist in criticising the 
 work. Feeling the edge, we both agreed that it was 
 tolerably smooth and sharp, but somehow it did not look 
 exactly right. We had, in fact, rounded off the first- 
 made bevel, instead of making a fresh one on the oil-stone, 
 which gave it what Tim called a doubtful look, as if 
 we did not precisely know at what angle we wished to 
 grind it. 
 
 We, nevertheless, determined to use it in its present 
 state, lest we should make bad worse in further attempts 
 to improve it. We accordingly put it back into its stock, 
 and set it, after one or two trials, at the right distance 
 below the sole. Although it proved fairly satisfactory in 
 cutting powers, we were very warm, and weary too, before 
 we had finished the broad surfaces of our two boards, and, 
 in addition, we had not exactly satisfied our expectations 
 as to the squareness of the edges to the faces. We had 
 not, as we afterwards learned, gone about the process in 
 the right way ; and as other boys may some time or other 
 
PLANING. 33 
 
 read of our difficulties and failures, I will here add the 
 proper order of carrying out this work, and squaring up 
 such boards or pieces of wood. 
 
 The first process is to level one of the broad 
 faces. The eye alone will not be a sufficient guide 
 in testing the correctness of the planed surface, which 
 must be tried by the edge of a square, or b}' a 
 straight-edge such as the edge of a carpenter's rule. 
 But it is much more satisfactory, and often absolutely 
 necessary, to have two strips of wood, very truly planed 
 upon their edges, which can be stood upon the board at 
 opposite ends. If the board is '' out of winding," i.e.^ 
 has not a twisted surface, the tops of these straight- 
 edges will coincide, if the eye is brought to a level with 
 them; but if it is otherwise, they will of course not agree. 
 The board must be tested in this way as the process of 
 planing it proceeds, moving the straight-edges to various 
 parts of it, and noticing what particular places require to 
 be lowered to reduce the whole surface to a uniform 
 level. Then must be planed one of the edges ; and this 
 is where we made the mistake, as we planed first of all 
 the two opposite sides of the board. This first edge 
 must be tried with the square at all points, and, if very 
 narrow, it will prove rather a severe test of a young 
 workman's skill. Even in the case of a board an 
 
 inch thick, such as that upon which we were operating, 
 
 
 
34 J^OY ENGINEERS. 
 
 much care will be required, and probably some time will be 
 expended before it becomes accurately square to the sides. 
 Then from this the third side must be worked, and lastly, 
 the second edge, always testing from the last finished sur- 
 face. This lesson, however, we had not at the time learnt, 
 and the consequence was, we worked in a hap-hazard 
 way, and our pieces were not very accurately planed. 
 We did not recognise this until we came to fit the steps, 
 when we were somewhat astonished to discover that they 
 required to be forced into place in one part, while in 
 another they fitted too loosely, although we had taken 
 great care to cut them all accurately to the same length. 
 The sides were, in fact, " winding," and, consequently, 
 were not parallel to each other at all points, and the 
 tendency of the steps was to take up a position like those 
 of a winding staircase. To correct this we had to sac- 
 rifice closeness of fit between some of the pieces, and to 
 cut others out of square, and this rendered our steps so 
 rickety, that we were obliged to add braces to keep 
 them together, much to our disappointment ; for, so far 
 as our knowledge went at the time, we had taken much 
 pains with our work. 
 
 After planing the side pieces, as stated, to what we 
 at the time believed true surfaces, we set ofi" the difierent 
 distances for the steps. This necessarily puzzled us con- 
 siderably, as we could not think how to mark the places 
 
OUR STEPS. 35 
 
 for the ends of the steps, so that when the sides were 
 placed in a slanting position in use, they would be 
 horizontal. Moreover, we saw that the ends of the side 
 pieces must be so cut as to be parallel with the steps. 
 At Tim's suggestion, however, we set up one of these 
 edgewise, leaning it against the wall at about the required 
 slope, and then, while it was in this position, drew by 
 hand a line across it from the top corner, which touched 
 the wall as nearly horizontal as we could, and then laying 
 the board again upon the bench, we made this line true 
 by ruling it. We then took this as our starting-point, 
 and from each end measured equal distances to represent 
 the top of each step, finishing by a similar line to show 
 us where to cut off the bottom piece, so that the steps 
 would have a firm bearing upon the ground. We then 
 sawed it off correctly at each end, and used it as a gauge 
 by which to mark the other side piece. Now w^e found 
 that if we set our five-feet plank with its edge against 
 the wall at the height of four feet from the ground, as 
 we intended it to be when finished, we were workins: 
 out that well-known mathematical fact, that the square 
 of the base of a right-angled triangle equals the sum 
 of the squares of the two sides which contained the right 
 angle ; for when we measured the distance from the wall 
 to the lower corner of our board, we found it to be 
 exactly three feet. The square of five feet we knew to 
 
36 BO Y ENGINEERS. 
 
 be twenty-five, which was just equal to the square of 
 four feet, or sixteen added to the square of three feet or 
 nine, equalling twenty-five. The base of the triangle was 
 of course the inner edge of the plank which touched the 
 wall and the floor, and was practically only a straight 
 line. After cutting away the triangular pieces at each 
 end, which reduced the board to what we knew was 
 called a rhomboid, we found that we had about four feet 
 five inches to divide equally for the steps. We called it 
 in the rough four feet six, and agreed to put five steps, 
 the upper surfaces of which should be nine inches apart ; 
 then there would be the top step of all, nailed to lap 
 over somewhat, and the lowest division — i.e.., the space 
 from the last step to the floor — would take up the odd 
 inches, namely, eight, making up the fifty-three which we 
 had altogether at our disposal. 
 
 In order to make the above description quite clear, an 
 outline sketch is appended, representiug what has been 
 stated above. A is the board leaning against the wall ; 
 its upper corner, D, resting at four feet from the floor ; and 
 its bottom corner, E, resting upon the floor at a distance 
 of three feet from the wall. Tlie triangular bit E, which 
 had to be cut off, lowered the whole six inches, so 
 that when completed, the steps were just three feet six 
 inches, just six inches shorter than we had proposed, but 
 we could not foresee this as a regular carpenter would 
 
OUR STEPS. 
 
 37 
 
 have done, and practically it was not of much import- 
 ance. 
 
 Having set off on each edge the position of the upper 
 surface of the steps, and ruled lines from one mark to the 
 other, we made similar lines an inch below each, to mark 
 the thickness of the several steps, and we intended then, 
 
 
 / 
 
 A 
 
 / /^ 
 
 "s-i 
 
 / * / 
 
 / 
 
 "-y^ 
 A^ 
 
 
 // 
 
 / / 
 
 
 ; 
 
 i^. .3_^!?_ci^. „.3y 
 
 Fig. 3.— Our Steps. 
 
 with a tenon saw, to cut a little way into these marks, 
 and with a narrow chisel to remove the intervening wood, 
 so as to let the steps into the sides, as we had seen them in 
 a set made by the carpenter. But we did not want this 
 to show upon the front edge, and we therefore, with our 
 square placed as in the figure, set off the end of each 
 groove, which thus ended slightly within the edge of the 
 side pieces. I think a glance at the sketch will render 
 
38 BOY ENGINEERS. 
 
 all this perfectly clear, and indeed it is all simple enough, 
 but takes a good many words to describe it accurately. A 
 perspective view of the finished article is also added, in 
 order to show the back and sides. 
 
 We made a frame like H of strips two inches wide and 
 three-quarters thick, fitted with tenoned and morticed joints; 
 and here, being forewarned by experience, we were addi- 
 tionally careful to plane up the pieces truly, so that the frame 
 should be flat and not twisted. We left one side higher 
 than the other to form a stay or handle to steady the climber 
 whenu^^iugit. Having glued and pinned this frame together, 
 we then braced it across with two half-inch strips, nailed on, 
 and notched into each other where they crossed. When 
 finished, we attached it by side strips, KL, to the strips 
 on each side with screws, the heads of which we let in by 
 a countersink. 
 
 Thus our set of steps was finished, and when we had 
 painted them stone colour, and also painted our name 
 in black letters, carefully ruled, which we traced first 
 of all from letters on some handbills, our performance 
 was by no means discreditable to young apprentices like 
 ourselves. True, there was a little putty here and there 
 to fill up open places in some of the joints, and the steps 
 required at last a little secret adjustment before they 
 would stand quite steady ; but the paint concealed the 
 first, and as to the last, we had little to complain of after 
 
BILL BIRCH. 
 
 39 
 
 finally adjusting the length of the legs; so that this set of 
 home-made steps proved extremely useful, and, to our 
 pride and satisfaction, were actually borrowed on several 
 occasions by the inmates of the schoolhouse. Even the 
 head-master used them sometimes to reach a book from 
 his top shelves, and ultimately gave us an order, to our 
 great delight, for a similar set, for which, I now think, he 
 paid us about double their real value. 
 
 We had not as yet done much with our lathe, on 
 which, nevertheless, our ambition chiefly centred. We 
 therefore agreed to set bravely to work to conquer once 
 for all the difficulties we had hitherto met with in its use. 
 I doubt, however, whether we should have done this for a 
 very long time, if we had not succeeded in bribing Bill 
 Birch to give us a few lessons. Nothing, however, 
 would induce him to try our own lathe, or hardly to look 
 at it. " He knew," he said, without examining it, " that 
 it would not answer for real work ; but if we could get the 
 Doctor to allow us to come to him the first half-holiday, 
 and would give him half-a-crown to pay for his time and 
 trouble, he would show us how to go to work in the right 
 way." 
 
 Although our pockets were not very well lined, we 
 agreed to these rather hard terms, and as a lucky birth- 
 day had given us a tip from home, which had not yet 
 gone the way of tips in general, we obtained leave from 
 
40 BOY ENGINEERS. 
 
 the Doctor on the ensuing Saturday, and presented our- 
 selves at Bill's workshop, money in hand. 
 
 *' Well, young gents," said Bill, " I am just going to 
 do a Lit of turning, and you can stand by and look on, 
 but don't you be talking unless I speak to you, 'cause 
 that only bothers me and don't help you. But old Bill 
 Birch can turn, mind you. Why, lads, before I were your 
 age, I could turn all the parts of a chair, and put it 
 together too ; but then d'ye see. Bill had a feyther, and 
 he had a stick, and that stick were a good deal used 
 instead of words in teaching me my trade. 'Twas — 
 * Hulloa, Bill, here's a notch in my chisel I ' ' Hulloa, Bill, 
 here's a good chair leg spoilt ! ' and then down came the 
 stick pretty sharp. So I soon learned to do my work as 
 it ought to be done, and when feyther grew old and 
 rheumatic, he would hobble into the shop and look on, 
 and say, ' Bill Birch, lad, you're a turner, and a rare 
 good 'un too; and lookee here, lad, 'twas thy feyther 
 taught 'ee, and he's proud of 'ee. Bill, he is, for there's 
 not a man this side of Lunuun as can beat 'ee now.' 
 So, young gemmen, you be come to the right shop to 
 larn, only ye'll never turn like old Bill, so ye needn't 
 expect it. There's plenty of talk in these here days, and 
 no taching. Why, I never had but one prentice, and he 
 ran away — he did." 
 
 We had heard of this prentice of Bill's before, and, 
 
THE 'PRENTICE. 41 
 
 knowing, as we did, that the ash stick had been considered 
 in liis case also the only able instructor, we rather 
 applauded the lad, who, to avoid a too frequent application 
 of it, had " made tracks " out of the village, and was now, 
 under a new master, already a very fair hand at the lathe. 
 This latter fact, however, old Bill persistently ignored, 
 and if we asked him (as we often did), where his old 
 apprentice was now, all he would say was, " Ah ! he\ no 
 good ; he should ha' stayed with old Bill, but he run away 
 — lie did ; M'^ no good." We fancied old Bill would have 
 preferred teaching us lads in his own way too, for he was 
 a grumpy old chap, but the half-crowns and sundry words 
 of flattery and praise of his skill kept him in tolerably 
 good humour. 
 
 We soon found, however, that the old man became so 
 busied iu his task, that he actually forgot our presence 
 altogether after a few minutes, and was only recalled to 
 a sense of our proximity by a sneeze from Tim, who was 
 nearest to his elbow, and who was consequently imbibing 
 a certain amount of fine dust from a bit of worm-eaten 
 beech which was being converted into the rail of a chair 
 or stool. 
 
 Being thus made conscious of the fact that two 
 lads awaited his instructions, old Bill tossed down the 
 now finished rail, settled his spectacles, took a pinch 
 of snuff, and then selected a bit of wood, which was 
 
42 £0V ENGINEERS. 
 
 to be submitted to our tender mercies under his 
 directions. 
 
 " Now, look ye here, young gemmen," said he. 
 " You've got to make this rail like the one I've just 
 finished, and ye can't do it," he aSded, as I suppose, by 
 way of encouragement! "Now, first of all, as ye're 
 young hands, ye'd better take a gimlet, and bore a hole 
 at each end for the lathe-points, 'cause ye'll be sure to 
 make the tools catch in; and then, if the centres aren't 
 pretty deep, out comes the bit of wood, and maybe ye 
 gets a rap in the face at the same time. Why, lads, I've 
 seen a lathe with a strong ash pole overhead fling a bit 
 of wood right across the shop and through the window; 
 ay ! and I seed one chap knocked over, with his eye 
 bunged up for a week after. So, as I said, ye'd better 
 bore a hole at each end like this. And now ye see, 
 nothing's easier than to put it in the lathe, and screw up 
 the points pretty tight ; only, ye see, I just take a turn 
 of the cord round it first ; and this cord, mind, is a bit of 
 raw horse's hide, nothing but raw hide properly dressed, 
 as old Bill knows how, will stand the work. And, 
 mind," he continued, '" that you give the turn in the 
 right direction, so that when you press down the treadle, 
 the work shall run towards you, because then you'll get 
 into the way of putting the tool forward into cut at 
 the very same moment that you press down your foot. 
 
SPIVERS. 43 
 
 After a bit ye won't need to think about it, but it'll 
 all come as nat'ral as spiders catch flies ; and there's a 
 pretty many spiders up and about this here shop, and I 
 expects they knows old Bill won't hurt 'em, and maybe 
 they like the sound of the lathe too, but that's neither 
 here nor there, only there's hundreds of 'em under the 
 old thatch up there." 
 
 All this time the old man kept running the wood 
 backwards and forwards while lightly grasped in his 
 right hand, and was evidently relapsing into a state of 
 forgetfulness about the proposed lesson. I therefore 
 ventured to remark upon the accuracy with which the 
 wood was centred, and also to suggest that I supposed 
 he always began work with a gouge. "There, there! 
 I told ye not to talk," was the answer. " Gouge, of 
 course, before chisel ; but bless ye, lad, ye won't want 
 no chisel yet a bit. Here," he added, to ray great joy, 
 " you catch hold of this here gouge, and let's see what ye 
 can do." Taking up the tool at his bidding, and at the 
 same time putting my foot on the treadle, I was just 
 going to begin, but in a nervous sort of way, when Bill 
 roared out, " Not so, lad — not so , that won't do. Grip 
 the tool by the handle in the right hand, and seize it 
 with the left close to the rest, and hold on like grim 
 death. And don't hold it so level " (horizontally), 
 ** but slope the point upwards. Don't ye see, if you hold 
 
44 BO Y ENGINEERS. 
 
 it level, all the rough parts of the wood, as they come 
 against the edge, only hammer it, and, sooner or later, 
 knock out a very pretty lot of notches, 'cause, ye see, 'tis 
 but thin stuif at best, and good steel is very brittle. 
 But if you hold it pointing upwards, the edge will cut the 
 chips clean off, as it ought to do." We both saw at once 
 that old Bill was right, and that, like most beginners, 
 we had held the gouge so that it could only scrape, and 
 we now perceived how it had happened that we notched 
 and blunted our own tools so frequently. 
 
 With a pole-lathe, we found it impossible to run the 
 tool along the rest as the work revolved, although we 
 managed, this at a later period. For the present, we had 
 to be content with reducing it by a series of separate 
 grooves to the required size, running these into one 
 another, however, as well as we could afterwards. For 
 final smoothing, we had to let Bill himself go over 
 it with a chisel, for our attempts to use this tool were 
 decided failures. First one point caught in, and then 
 the other ; and we could (as Bill had forewarned us) do 
 nothing with it. Still an hour's steady perseverance was 
 not without its effect, and so well pleased was old Bill 
 with our determined and zealous attempts to get over our 
 difficulties, that before we left, he condescended not only 
 again to put the turning chisel into our hands, but to 
 give us the following accurate instructions for using it. 
 
THE CHISEL. 45 
 
 " You see, lads, the chisel is not like old Bob Chips's 
 the carpenter's, but is ground off sloping, so that it has 
 one very sharp point and one blunt ; and Chips's is onl}'' 
 ground from one side, while this is ground on both, so 
 that the edge is in the middle of the tool. And, you 
 see," he continued, " we grind very long flats or bevels, 
 and gets 'em as true and level as we can ; and then, just 
 a rub on the stone on both sides, and the tool is ready. 
 Then," he continued, " we lays the tool so as to rest 
 almost flat against the bit of wood, but at the same time 
 keeping the upper point quite clear of it. This, ye see, is 
 the secret. The lower point — and ye may put either the 
 sharp or the blunt one below — can't catch in, but if ye 
 only let the upper one touch the wood, in it goes as sure 
 as them spiders eats flies, and then ye ploughs as pretty 
 a furrow as old Tom Wurzel ever made in his life, and 
 your work is spoilt right off, and most likely the point " 
 (or pint, as he called it) " of the chisel is left sticking fast 
 in the wood, and then there's a pretty long job at the 
 grindstone." 
 
 We had now to bid farewell to our instructor, but we 
 had really gained a good deal of instruction, which we 
 could at our leisure put in practice at our own workshop. 
 Indeed, we found that, after clearly understanding the 
 principles of the art, and the mode of using the two most 
 important tools, we had to encounter comparatively few 
 
46 BOY ENGINEERS. 
 
 difSculties, and these were due simply to our present 
 lack of manual dexterity, which further practice supplied. 
 As to our own lathe, we found, in spite of old Bill's 
 contempt, that it was practically almost as good a tool as 
 his own. We had made it very firm by driviag the 
 upright timbers into the solid ground, and nailing the 
 others to the beams of our workshop. We found, indeed, 
 that these timbers of the old shed were of great value to 
 us in fixing our bench and shelves and a tail vice, which 
 we picked up at an old iron store, and similar workshop 
 necessaries; and although we both lived to occupy pre- 
 mises of far handsomer and more pretentious appear- 
 ance, we never found any workshop more fit for the pur- 
 poses of the carpenter and turner than that dear old shed 
 at Brampton. A photograph of it, both of its exterior 
 and interior, with our primitive lathe and apparatus, 
 hangs now in our study. 
 
 From first to last the chisel gave us the most trouble ; 
 for although, after some practice, we avoided lowering 
 the upper point so as to allow it to catch in, we could not 
 succeed in giving a perfectly level surface to the work. 
 On the whole, we found it easier to work with the 
 sharpest angle below ; but old Bill never seemed to care 
 much which was uppermost. He would lay the tool flat 
 upon the work, and run it along with one hand, and use 
 it with equal facility from right to left or the contrary 
 
MANUAL DEXTERITY. 47 
 
 way. We, however, found that it was more difficult to 
 use it running from left to right, and only persevering 
 determination to succeed gave us the victory at last. 
 
 When, however, in after years, we were enabled to 
 discard the pole-lathe in favour of a better, we found 
 ample cause to rejoice that this inefficient machine had 
 given us our first lessons in the art, for it had afibrded us 
 a great deal more practice of the right kind than usually 
 falls to the lot of amateurs. The gouge and chisel are 
 par excellence the tools of the wood-turner, but their use 
 is generally considerably neglected by those who can affi^rd 
 expensive lathes fitted with a slide-rest. This article is 
 made to serve instead of skilful handling of the more 
 ordinary tools, and the gouge proper, with its ally the 
 chisel, only appear in the form of short bits of steel 
 fitted into a holder, and run to and fro by means of the 
 slide-rest screw — an operation which demands no skill on 
 the part of the turner, but which renders the surface of 
 the work absolutely true. 
 
 Lads who are fond of mechanical work should make 
 up their minds not to resort to these by eways of the 
 turner's art, but learn to do all that is possible with 
 simple tools, and only fall back upon these mechanical 
 aids under the pressure of necessity. 
 
 After we had attained what at any rate appeared to 
 ourselves a fair amount of skill in turning such small 
 
48 BOY ENGINEERS. 
 
 pieces as are used by the chair-makers, that is to say, chair 
 rails, legs of tables, tool handles, and such-like articles of 
 comparatively small diameter, our ambition centred on a 
 bread platter. We had not before attempted anything of 
 the kind, and we did not see how it would be possible to 
 arrange the cord, even if we began by sawing out a piece 
 of board, and rounding it off before putting it in the lathe. 
 We rather doubted, in fact, whether ou^ friend Bill could 
 manage an article of this kind ; but on passing his window 
 one day, we saw three platters exposed for sale, besides 
 circular stands for tea-urns, lamps, and such-like, and 
 also, in addition to these, a stand of rather pretentious 
 character, fitted with an inverted bell-glass for an 
 aquarium. It was evident, therefore, that articles of this 
 nature were within the scope of the pole-lathe. 
 
 We at last told Bill of our dilemma, but the old fellow 
 would not help us. All we got for the present by way of 
 reply was, " Turn platters in a pole lathe ! o' course ye 
 can, if ye know how, and can handle the jfcools ; old Bill 
 turns scores of 'em, but he can turn, he can." 
 
 Determined not to be beat, we set our wits to work 
 again, with the following result. We first of all trimmed 
 a piece like a large, very large cotton reel, but short in 
 proportion to its size. We took care to make it as true as 
 possible at each flange or end, where it was about three 
 inches in diameter. This we set on one side. We then 
 
BREAD PLATTER. 49 
 
 cut out with a keyhole saw, for want of a compass saw, a 
 round bit of sycamore previously planed on both sides to 
 three-quarters of an inch thick, its diameter in the rough 
 being ten inches. We made one mistake in our work, 
 which we record for the reader's benefit. In our undue 
 haste to get our bit of wood into shape, we cut it out 
 before we had planed it. The result Avas greatly increased 
 difficulty in performing the latter operation. It was well 
 enough so far as the central line — the parts immediately 
 about its diameter — were concerned ; hut when we tried 
 to plane on each side farther from the centre, the wood 
 insisted on revolving the moment the plane began to cut. 
 We only succeeded by sawing a wide notch in a bit of 
 half-inch board laid against the planing stop, which, by 
 embracing, as it did, a good part of the circumference, 
 kept the work steady. 
 
 After this experience we avoided the difficulty in future 
 by planing the board before cutting out of it the cir- 
 cular piece required. 
 
 We had marked out the circle with a large pair of com- 
 passes, and from-thesame centre we marked also a three- 
 inch circle. We now took our big reel, and glued it care- 
 fully down upon this part, and further secured it by two 
 short screws, which passed through the flange, and reached 
 a quarter or three- eighths of an inch into the board, as 
 
 D 
 
5© BOY ENGINEERS. 
 
 we rightly conjectured that we could easily fill up and 
 conceal such holes after the work was finished. 
 
 When the whole was dry, we mounted it in the lathe. 
 We found the impetus, however, much greater than we 
 had expected, and every time the rotation was checked 
 before it commenced in the opposite direction, there was a 
 suddeu jerk which seemed to threaten to throw the concern 
 out of the lathe — probably to the detriment of the turner's 
 nose. 
 
 But steady determination will do wonders, and although 
 we had not yet ventured to apply a gouge to the work, we 
 found that, by turning more slowly, and slightly easing 
 the foot at the end of the up and down motion, we could 
 in a great measure diminish the impetus and reduce the 
 danger. 
 
 The first application of the tool brought the work to a 
 standstill, and buried the point of the gouge somewhat 
 deeply in the wood. Luckily, however, it did not take 
 out a piece of the edge, nor did it remove a chip. We 
 now found that it was a very different and far more 
 difiicult matter to turn an article of this kind than a 
 simple bar or tool handle, and that it was necessary to 
 place the rest as close to the work as it would go without 
 touching it, and to make very slight cuts indeed. We 
 also learnt another fact, namely, that it was much harder 
 vvc-rk for the leg, because a bit of wood of large diameter 
 
LEVERAGE. 51 
 
 represented a lever equal in length to tlie radius, which, 
 as soon as the tool was applied, became a resisting power, 
 which we had to overcome. But this fact we had im- 
 pressed on our minds more thorough!)'- after our pole-lathe 
 had been replaced by one of the more generally known 
 form, in which the work is driven through the medium of 
 a fly-wheel. In the pole-lathe, the power of the foot 
 acting directly upon the work gives an advantage which 
 the other lathes do not possess, and the whole weight of 
 the body being thrown, when necessary, upon the treadle, 
 gives the turner very great power in causing the work to 
 rotate against the tool. There is, of course, the spring of 
 the pole to be overcome, but this is not so great as would 
 be supposed, and does not add very greatly to the labour. 
 When this class of lathe was more general than it is now, 
 the pole was sometimes replaced by a bow of lancewood 
 or yew, or other elastic wood, which was strung exactly 
 like that used by archers, and from the middle of its string 
 descended the cord to the treadle. This was, however, 
 more general on the Continent than in England; and in 
 an old French work by Plumier, which has become very 
 scarce, there are drawings of these lathes, with steel 
 spring bows mounted on an upright pedestal fixed to the 
 lathe itself; and the latter was not the clumsy contrivance 
 of the old chairmaker, but fitted very cleverly, and 
 capable of being applied to the general purposes of the 
 
52 BOY ENGINEERS. 
 
 watch aud clock maker, and to that of the general 
 turner. 
 
 The pole-lathe is certainly becoming a tning of the 
 past, being mostly superseded by its more elegant and more 
 serviceable brother, but it is still employed by preference for 
 certain purposes. In the soft-wood districts, where wooden 
 spoons are made, it still has a place in the workshop ; and 
 I was told by a turner that it is preferred on account of the 
 ease and rapidity with which such work can be mounted — 
 no chuck being needed. Nevertheless, I have seen a steam- 
 power lathe of the usual construction used for a similar pur- 
 pose ; and although the mandrel must have revolved two 
 thousand times in a minute, I saw a lad mount his work, 
 and remove it when finished, without even stopping the 
 lathe. Moreover, I am inclined to think that even 
 old cantankerous Bill Birch, if he had seen the dexterity 
 with which the lad in question used gouge and chisel, 
 would have been obliged to confess that one other person 
 besides himself could turn. 
 
 It is not necessary to tell the reader all the further 
 particulars of our work on that wondrous specimen of the 
 turner's art, the bread platter. We succeeded, by 
 careful manipulation, in bevelling off the edge and pro- 
 ducing something like a decent moulding round it ; aud 
 by dint of tolerably free application of glass paper, we 
 put a sufficient finish upon it to satisfy our youthful 
 
PLEASURABLE STUDIES. 53 
 
 aspirations. To detach the reel from the back, and, by a 
 little rubbing with a tool handle, erase the marks of the 
 screws, and clear off all trace of the glue, was not a very 
 difficult or prolonged task, and we then determined to go 
 over to old Bill the following Saturday, and to submit to 
 his critical eye this specimen of his pupils' handiwork. 
 
 To obtain permission to do this was not a matter of 
 difficulty. We never abused the liberty which the Doctor 
 gave us, and therefore it was extended to us freely at 
 all times, when it did not interfere with the school-work, 
 to which we continued to apply ourselves as steadily as 
 we could. In fact, we considered it a point of honour to 
 study hard, and it soon grew into a real pleasure. Our 
 mathematical work especially gave us an interest which 
 we did not feel equally in the classical, as it enabled us 
 to understand, to a great extent, the principles of 
 machinery as well as of mechanical work, and we were 
 often pleasantly surprised to find that we were but 
 carrying out in the workshop principles which we had 
 been learning in our school hours, and that the more 
 closely we studied these principles, and the more 
 carefully we worked out the problems given us, the 
 more clearly we understood the wliy and wherefore of 
 many details of practical mechanics. It was thus we were 
 led to perceive the reason that works of large diameter 
 required more labour than those of a smaller size j tha». 
 
54 BO Y ENGINEERS. 
 
 the latter gained less impetus as it revolved, aud that its 
 motion could be suddenly arrested without much diffi- 
 culty, and without producing any great shock ; that the 
 smaller the work, the greater might be the rapidity 
 of rotation ; and why, on one memorable occasion, so 
 severe a blow was given by a piece of wood which 
 suddenly escaped from the lathe-centres when at full 
 speed. These mechanical laws, as we gained more and 
 more sound information respecting them, interested us 
 very deeply, and gave great zest to our self-imposed 
 labours. 
 
 When we presented ourselves at Bill's workshop, 
 platter in hand, we saw a shade of disappointment over- 
 spread his features. Pushiug up his spectacles into the 
 roots of his hair, he deliberately and closely examined our 
 work ; then pulling down the glasses again, and settling 
 them comfortably on his nose, he laid down the platter 
 on the lathe-bed and resumed his work. We could not 
 help feeling highly amused at his evident perplexity. 
 He did not expect, nor intend us to succeed, without 
 leceiving a special lesson, aud for this lesson he luid 
 reckoned on another coin out of our pockets. For Bill 
 was a grasping, close-fisted, and churlish old fellow as 
 ever held a gouge, envious of his fellow-craftsmen, 
 whose work he delighted to depreciate, and a regular 
 tyrant in his own house. But no equally clever hand 
 
BILES CRITICISM. 55 
 
 was within onr reach, the nearest craftsman living .out 
 beyond St. Ives. We knew that we should best 
 propitiate Bill by depreciating our performance, and 
 expressing our regret that he had not been at our elbow 
 when we were at work. Tim was a greater favourite than 
 I was, being a better hand at this sort of (perhaps 
 pardonable) humbug ; he therefore commenced the 
 assault. 
 
 '* I wish we could turn like you, Bill," said he. '* I 
 thought we should never get through this job, and I dare 
 say you could have done it in five minutes, and somehow, 
 now it is done, the platter doesn't look like a work- 
 man's. Any one could tell it was a boy's work, eh, 
 Bill?" 
 
 " Boy's work I " answered Bill, '^ tisn't work at all ; 
 you might cut out a better one with a pocket-knife." 
 
 We knew that was an exaggeration, but said nothing ; 
 and Bill resumed. 
 
 " Look here now — where's all the sharp, clean-cut 
 work ye see in Bill's platters ? This here one isn't cut 
 at all ; 'tis just muddled and rubbed into shape with sand- 
 paper; and this here edge you calls a moulding ain't no 
 sort of form. All that is tidy about it is the planed 
 part, and that is half spoilt too by the sandpaper." 
 
 Then Bill began another bit of work, and was silent 
 till he had finished it, which took him about three 
 
S6 BO Y ENGINEERS. 
 
 minutes, after which he suddenly asked, " How did ye 
 do it ? " 
 
 We knew now that the ice was thawed, and began to 
 enter into a detailed account of how we had made the 
 big reel, and glued it on for the cord to work upon, and 
 what difficulties we found in turning up the edge, not 
 omitting to repeat the fact of our regret at not having had 
 Bill's assistance. 
 
 Thus further mollified, the old fellow condescended to 
 converse more freely, especially when Tim pulled out a 
 packet of snuflF, of which Bill was insatiably fond, and 
 presented it to him. I can't say, however, that he evinced 
 any gratitude for the present — he never did — nor do I 
 think there was a spark of gratitude ever present under 
 that gaudy but faded old waistcoat, which had been bought 
 cheap at a pawnbroker's. The snuff, however, had an 
 effect, as we soon perceived. Taking out of a cupboard 
 near the lathe a bit of wood cut out with a sweep saw 
 and nicely planed. Bill proceeded to mount it in the lathe. 
 For this purpose, however, he did not glue on a bobbin, 
 as we had done, but produced two pieces made thus : — 
 One was like our big reel, only one flange was much 
 larger than the other — about six inches diameter, the reel 
 itself between the flanges being about three ; and from 
 the larger face projected near its outer edge four sharp 
 but short spikes, being the points of screws driven from 
 
OLD BlZrS WORK. 57 
 
 behind, and afterwards sharpened with a file. The other 
 bit was merely a round flat piece, also having spikes pro- 
 jecting- on one side, and on the opposite side of each was 
 a central hole to receive the lathe-point. 
 
 The platter was pinched between these, which were 
 placed on each side accurately by a circle drawn on the 
 wood with compasses, as we had done. Thus, without 
 glueing, these bits of wood served to turn from three to 
 half-a-dozen platters, after which the holes for the centre- 
 points of the lathe became. Bill told us, too much worn 
 to hold the work safely, and the pieces were replaced by 
 new ones. Besides sycamore. Bill used, as we found, 
 willow, plane, and beech, and indeed any tolerably soft 
 wood of even and close grain, any wood not naturally prone 
 to splinter and chip easily. He turned the moulding at 
 the edge chiefly with the gouge, but afterwards, with the 
 sharpest corner of the chisel, he cut out a shallow angular 
 grove, w'hich gave a finish to the work by making a well- 
 defined edge to the moulding. He afterwards showed us 
 a very useful tool for this and similar purposes, viz., a 
 V tool, which was similar to a gouge, except that instead 
 of being round like the half of a tube, it was like a bit of 
 paper folded sharply lengthwise. It was then ground 
 from the outside, and made very keen upon the oil-stone. 
 This tool, we were also graciously informed, was used for 
 cutting screws in soft wood, an art requiring much practice, 
 
5 8 £0V ENGINEERS. 
 
 but which Bill did very well in his old lathe by dint of 
 bringing down the treadle very slowly and following a 
 pencil-line carefully drawn beforehand. This he rightly con- 
 sidered rather a feat, as few turners could do this, or make 
 Elizabethan twist, or roped- work, as it was called, for 
 which we received instructions at a much later date, 
 which will be recorded for the reader's benefit. As to 
 sand or glass paper, Bill warned us never if possible to 
 use it, but to use sharp tools, and use them in a workman- 
 like manner, because abrasive materials always rubbed off 
 the sharp edges of the work, and gave it a very poor, 
 'prentice-like appearance. But if at any time such means 
 were absolutely necessary, he told us always to take up 
 a very sharp chisel or V tool, and make a final cut after 
 the sandpapering, to restore the sharp edges which the 
 paper had obliterated. 
 
 Before our acquaintance with this queer old fellow 
 commenced, we had read about the chairmaker's pole- 
 lathe, but never could have believed the extent of its 
 capabilities in the hands of a good workman. This is 
 practically the lathe which serves the purpose of the 
 watchmaker, who, with a bow of whalebone strung with 
 a horse-hair, and a graver or other tool held in one hand, 
 turns up the pivots and small wheels upon which he has 
 to exercise his skill. There is, indeed, one advantage 
 in a bow-lathe, viz., its comparative portability. On a 
 
OUR BOW-LATHE, 59 
 
 small scale it may be made, and is made, to clamp iu a 
 vice or to screw to a table ; and may be made either to 
 work with a bow held in the hand, or, by the addition of 
 an upright pedestal to hold a bow overhead, it may be 
 arranged to work through the medium of a treadle. We 
 made such a lathe in after years, taking a hint from 
 an old French work, and give a sketch of it here, as we 
 used it for many light jobs with very satisfactory results. 
 It is pretty much like the Swiss turn, or turn bench, 
 but we made certain additions and alterations which we 
 believed to be improvements. In the first place, the flat 
 bar of iron, B, on which the rest of the lathe is fitted, was 
 made thick, and flattened out at one end, M, so that it 
 could be arranged as a clamp; and the jaws of this were 
 outward, so that if clamped to a table on the right-hand 
 corner, the bar would stand clear, so as to allow the cord 
 also to pass down fiee of the table to a light treadle, a 
 mere strip of board three inches wide. The popi)it on the 
 left of the bar was fixed by a couple of screws, the other, 
 which was free to slide on the bar, was clamped by the 
 screw seen below it, as was also the rest-socket, C, into 
 which the upper part, L, fitted, the same screw clamp- 
 ing both. Q R S is the support of the bow N, and 
 this we made of hollow iron tubing, in pieces fitted 
 together where the lines are seen across it, so that it 
 could be taken to pieces for the sake of portability. As 
 
6o 
 
 BO V ENGINEERS. 
 
 t=>QOtl3czzriIZl==i 
 
 Fig. 4.— Our Bow-Lathe, 
 
OUR BOW-LATHE. 6i 
 
 we could not manage to fit these with screwed joints, we 
 fitted into every other piece a turned bit of wood, which was 
 tightly driven into the tube, but about two inches of which 
 was left standing outside. This, which was turned very 
 slightly smaller, fitted the other bits of tube, so that the 
 whole fitted together like the joints of a fishing-rod, and 
 were very stiff and firm. Over the horizontal rod 0, we 
 made a sliding piece of hard wood to clamp with a screw, 
 and the bow fitted a mortice in the lower part of it, and 
 was then wedged in so as not to slip. At M there was 
 a flattened bit of solid iron screwed to the bar, the top 
 being filed round for the first joint of the tube to slip 
 over it. The central turned spindles, AA, which fitted 
 into the poppits, were pointed at one end, and had conical 
 centre holes at the other, and either or both could be 
 turned end for end at pleasure. The mortice in C, 
 through which the bar B passes, was made higher than 
 those in the poppits, so that it fitted loosely on the 
 upper and lower edges of the bar, but closely on its 
 sides. Thus the screw below could draw it down nearly 
 half an inch, and when the foot of the rest, L, was put 
 through the other mortice, it was easily fixed by the 
 screw in any desired position. 
 
 The poppit, K, and its fittings composed our boring 
 collar, which was necessary to hold one end of any bar 
 which required to be hollowed out or bored. The poppit 
 
62 BOY ENGINEERS. 
 
 fitted on the bar exactly like the other two, one of which 
 it replaced at pleasure. K was of hard wood, made to fit 
 in a mortice and clamp with a screw, with conical holes 
 in it nicely bored. The exact centres of these we marked 
 by running this poppit close to the other, and giving 
 a slight tap to the centre-point so as to mark it. 
 
 T is one of the chucks already described in speaking 
 of the large lathe. Any round flat bit of work was held 
 either by being pressed on the points, and kept against 
 them by the back spindle, or pinched between two guch 
 chucks, in which case, the centre-point came against the 
 back of the second chuck instead of against the work 
 itself. W is one of another set of chucks — spindles for 
 holding washers, small wheels, rings, and other such 
 articles ; the pullies were made to drive on tightly, the 
 spindles or arbors being slightly conical. Some of the 
 pullies were like that shown for a hand-bow of whalebone, 
 and fine gut or hair; others like a cotton reel, which, in 
 fact, we actually used for the cord from the overhead. 
 These arbors were all of steel drilled at each end, so as 
 to run truly on the points of the spindles. We had them 
 from the size of a small knitting-needle to that of a 
 cedar pencil ; but for still larger work we used to make 
 them of boxwood, which answered very well. We had 
 various other contrivances for special work, which, how- 
 ever, need not be detailed here, as some of our many 
 
OUR BOW-LATHE. 63 
 
 " dodges " will probably be described on a future page, 
 when speaking of our amateur engineering, and the 
 better lathe which we afterwards obtained. This last, 
 nevertheless, did not displace the one here described, which 
 always kept its place in our workshop, and often proved 
 even the more serviceable of the two for certain kinds of 
 work. 
 
Chapter III. 
 
 WORKSHOP APPLIANCES. 
 
 HIS chapter will be devoted to a description 
 of other of our workshop appliances, of which 
 many were home-made, and answered so well, 
 that we never found it necessary to provide 
 more expensive appliances from the tool shops. First 
 there was our drilling apparatus. We had so often seen 
 the village blacksmith at work, with his old-fashioned 
 crank drill and press frame, that we thought we could 
 hardly do better than adopt it in a modified form — i.e.y 
 we did away with a certain heavy and clumsy contrivance 
 overhead — a long beam hinged at one end and fitted with 
 a weight at the other. We replaced this affair by a frame 
 of wood, as we had not then funds for much iron-work, 
 
OUR DRILLING MACHINE. 
 
 65 
 
 and after we had funds we used this drilling hench for 
 years. It consisted, first of all, of a strong stool, which, 
 with the rest, we have only shown in profile and section, 
 
 Fig. $.— Our Drilling Machine. 
 
 to make the construction more clear. The bench and 
 cross piece above were of ash, as we considered that upon 
 
66 BOY ENGINEERS. 
 
 these the strain would come ; but the uprights were of 
 deal, because the tendency would only be to stretch those 
 lengthwise. They were mortised into the bench and 
 cross piece, and pinned through the latter with oak pins 
 or trenails, but under the bench they were fastened by 
 wedges, which could be knocked out and the whole frame 
 removed, leaving the stool free for sawing or any other 
 purposes. The lower mortises were strapped with hoop 
 iron, to prevent any chance of their being split out by 
 the wedges. The stool was two feet long and ten inches 
 wide. The uprights three inches wide by two thick, the 
 widest sides in and out, and the top four inches by two, 
 the broad surfaces above and below — so that, as seen in 
 the drawing, the edges of these parts are shown. The 
 feeding screw was picked up at an old iron store, and 
 the blacksmith fitted to it a nut which we let in flush in 
 the upper bar, putting a plate on below to keep it in 
 place. As the strain was in the contrary direction, this 
 did not need to be specially strong, and four three-quarter 
 screws held it very well. We could thus oil the nut at 
 any time by taking oJEF the plate. The brace we of 
 course bought, as well as the drills, but we afterwards 
 learned to make the latter ourselves, to our great advan- 
 tage. To hold the work to be drilled, we used all sorts 
 of different contrivances — blocks of wood sometimes on 
 each side of it, wedged up ; iron bolts and clamps through 
 
OUR DRILLING AI A CHINE. 67 
 
 the bench, with nuts underneath, and various extern [)ore 
 arrangements. We also made mortises in our vice 
 bench, and could mount the same frame over this when 
 we pleased, so that work which we found it impossible 
 to secure upon the drilling-bench, could be held in the 
 tail vice itself. Altogether, we never had a more service- 
 able tool in our workshop than this rough-and-ready 
 affair, which was often put to somewhat unfair tests 
 when we had to drill larger holes than usual. 
 
 To set the drills upright for work, we used a plumb- 
 line in two directions, standing a little way off, and hold- 
 ing the line between the eye and the drill, and shifting 
 the work until the drill was truly vertical in both direc- 
 tions. All we then had to do was to work away at the 
 crank, and feed with the screw, and the drill would 
 descend perfectly true, and bore very rapidly. I think we 
 gave ten shillings for the brace with six drills, the screw 
 and its nut, and the raw material of which the bench and 
 side pieces were made. The screw I believe was an irou 
 bench screw, of which probably the nut had been lost, and 
 thus it had found its way first to the scrap heap, and 
 then to the rag, bone, and old iron merchant, who had dis- 
 posed of his donkey-load to the keeper of a marine store. 
 It would be curious to trace the history of such a screw 
 through the various phases of its existence, until at last it 
 returns to the melting-pot from which it originally came. 
 
68 BOY ENGINEERS. 
 
 I think if a tiling of this sort could write its experiences, 
 and describe the scenes it had witnessed, the homes it 
 had visited, and the characters it had met, the result 
 would be such a book for boys as I shall never write as 
 long as I live. Our old screw, however, was silent 
 (unless it wanted oil, and then it sang loudly, or wailed 
 sadly), and if " it could a tale unfold," it never did so. 
 
 For a long time we were very badly set up in screwing 
 apparatus. This was an expensive item, and the most we 
 could do was to possess ourselves of a screw-plate with 
 double handle, and three or four holes, and a smaller one 
 of clock-size with eight. The taps were few and bad, but 
 we found means to increase these from the plates them- 
 selves, and though not of first-class pattern — not being 
 grooved, but merely squared up — they did pretty good 
 work, good enough for most of our early engineering 
 requirements. One or two holes of the plate were indeed 
 useless, from having been used upon very hard steel, which 
 had worn down the threads, but we could cut screws from 
 about three-eighths down to one-sixteenth very well. 
 
 Our great ambition was, however, to become possessors 
 of a stock and dies, and we searched catalogues, and 
 advertisements, and sale bills over and over again, but 
 could meet with nothing suited to our finances ; and not 
 till we had made a good many steps in advance of our 
 early trials at engineering did we succeed in obtaining this 
 
CONSUL TA TIONS. 69 
 
 most desirable screwing apparatus. It came, nevertheless, 
 in due time, like many other tools and workshop appliances, 
 and, perhaps, on the whole, it was well that we did not 
 possess a stock earlier in our career, for our inexperience 
 would in all probability have caused its destruction. 
 
 With the few appliances alluded to, in addition to files 
 and such-like, we worked steadily at all kinds of 
 mechanical jobs for two or three years, and by this time 
 we had grown from little boys into big ones, and both 
 brain and hand began to yearn after somewhat better 
 tools, and work of a higher quality. "We began to find 
 our lathe especially unfit for real engineering operations 
 in metal, although sufficient for occasional work ; and we 
 determined, after due consideration, to replace it by one 
 with a fly-wheel and treadle, mandrel and chucks. 
 
 How we talked over this work ! and how many plans 
 we drew before we decided upon the best ways and 
 means. The bed was to be wood, of necessity; but 
 we determined upon having beech very carefully planed 
 with an iron plate on the upper surface, put on with 
 countersunk screws, and filed up as true as we could 
 succeed in making it. It was to be six feet long, 
 because, although we noticed that a great number of 
 lathes were made with four-feet beds, we considered that 
 it would be as easy to make one two feet longer, and 
 that it would be much better for wood- turning, in whifih 
 
70 BOY ENGINEERS. 
 
 the work is often of some leugth. The standards to 
 support this bed we also determined should be made of 
 beech, and the flj-wheel quite plain, not grooved for gut, 
 but suitable for a strap, because we found this could be 
 easily met with at an iron store, foundry, or machine 
 shop, secondhand, whereas a bevelled and grooved one 
 could only be bad at a lathe-maker's. 
 
 We knew, however, that this would not give us the 
 slow speed necessary for metal turning, but we thought 
 we could easily turn a small pulley or drum of wood 
 with a hole for the axle, and that we could attach it also 
 by a couple of screws to the spokes of the fly-wheel, to 
 secure it from slipping round upon the axle. Tliis we 
 subsequently made, and very well it answered. The 
 main difficulty, we felt, would be the mandrel and its 
 fittings, and the back poppit ; in short, the upper works 
 of the lathe. 
 
 In the midst of our deliberations, and when wooden 
 poppits and very inefficient substitutes for mandrel and 
 collar were determined on, a kind friend who heard of 
 our dilemma, and was charitable enough to appreciate our 
 vaiious attempts to make our own apparatus, brouglit us 
 an old I'usty mandrel fourteen inches long, with a worm- 
 eaten pulley and some half dozen short lengths of screw 
 threads cut upon it. Eagerly we accepted such a prize. 
 It was apparently from some rejected and disused brass- 
 
A VALUABLE PRESENT. 71 
 
 turner's shop, for there was a bit of brass rod broken short 
 off inside the female screw intended for the chucks. The 
 first operation was to clean it, which we commenced by 
 boiling water and soda, with a very hard scrubbing brnsh 
 and sand. This soon got rid of a thick mass of old liai- 
 dened oil and dirt, and enabled us to see something ol" 
 the brio^ht but tarnished metal below. Testino: the latter 
 with a file, we found that it had been hardened at each 
 end, and was a promising concern. In fact, the only 
 really bad part about it was, that one set of guide 
 threads for screw cutting was damaged, but not so as to 
 have become absolutely useless. There was one point, 
 however, which we regarded as a drawback, and this was 
 the length of the mandrel, which would have the effect of 
 shortening the bed ; we therefore added a foot to the 
 latter in our plans, determining to make it seven feet 
 instead of six. The pulley was wholly gone, but it was 
 now a very easy matter to replace it, as we were quite 
 used to the pole-lathe. We began by roughly sawing 
 out a round piece of beech. We then drove it tightly 
 upon the mandrel, mounted this in the lathe, and turned 
 up the wood. It therefore proved (as we foresaw) 
 absolutely true, and being intended for a strap, we 
 merely turned it slightly large in the middle, rounding it 
 off each way. I forget who put us up to this now well- 
 known secret of turning pulleys to receive straps ; for I 
 
7* BO Y ENGINEERS. 
 
 remember that it was at that time customary to turn 
 them with a rim on each side to keep the strap from slipping 
 off, the result being that the said strap generally found 
 . its way up on the rim, and insisted on riding partly there 
 instead of on the flat surface. It was, however, dis- 
 covered by some observant mechanic, that if a strap were 
 made to run upon a conical surface, its tendency was to 
 run up towards the largest part, instead of slipping down 
 in the other direction, as would be expected. If, there- 
 fore, two short cones were placed base to base, i.e.^ with 
 their large ends together, the strap would evidently keep 
 on and retain its place in the middle of such pulley. 
 This is the form now universally adopted, except that 
 the sharp edge at the meeting of the cones is always 
 rounded off considerably, the pulley being simply larger 
 in the middle than at the other parts. This will be 
 evident from the sketch given of our renovated lathe in 
 fig. 6. The screw guides cut on the mandrel are seen 
 at CCC ; being of a different pitch, one had eight threads 
 to an inch, the next twelve, and the third sixteen. 
 There had been one of twenty, but it was so damaged as 
 to be useless, and these three pitches sufficed for our need. 
 At A is seen a block of mahogany screwed to the bottom 
 of the poppit, and having three vertical mortises and three 
 horizontal ones opening into the others. In the vertical 
 ones were three squared plugs of wood, and in the 
 
OUR RENOVATED LATHE. 
 
 73 
 
 horizontal ones were wedges which, being driven in, 
 raised the plugs until their upper surfaces touched, and 
 pressed against the guide screws sufficiently to be deeply 
 indented by them. Thus, if the mandrel was free to 
 revolve, and also to move along horizontally in its 
 bearings, and one of these plugs was made to press 
 
 Fig. 6.— Our Renovated Lathe. 
 
 against its screw, the mandrel would of necessity 
 traverse end-wise at the same rate as the pitch of that 
 particular guide screw. Hence, this is called a traversing 
 mandrel, and a screw to match any one of the guides is 
 easily cut upon wood or metal by merely holding a point 
 tool or a chasing tool of the right pitch quite still upon 
 the rest. The traverse is from left to right, the man- 
 drel advancing in that direction in its collar, so as to 
 make the screw a right-handed one. The mandrel 
 is quite cylindrical at DD, where it passes through its 
 collars. 
 
74 BOY ENGINEERS. 
 
 Another wedge may be noticed at H, in the left-hand 
 standard of the mandrel head. This was fitted to raise a 
 slip of steel, so as to make it enter a shallow groove 
 turned in the mandrel at that point, which then prevented 
 its traverse. This was used when the lathe was not 
 required for screw-cutting ; a sh-oulder in front, just 
 behind the screw on the nose of the mandrel, prevented 
 it from running back in its bearings, and took the 
 pressure of the screw in the other or biick poppit. This 
 latter was merely cut out of a bit of sound beech, and 
 carefully bored to receive a pointed screw. It was not 
 very handsome, perhaps, but answered its intended 
 purpose, and we improved the general appearance of the 
 poppits by rendering them as smooth as possible, and 
 giving them a couple of coats of good black paint. We 
 took a great deal of trouble to rig up our French man- 
 drel, and spent on it a vast amount of patience, which 
 was on the whole well rewarded. The stand, with 
 crank treadle and fly-wheel, are omitted in the drawing, 
 as the main object of the latter is to show the general 
 arrangement of the traversing gear and its fittings. 
 These French mandrels are not often met with now, but 
 very similar ones may be found in the shops of some soft- 
 wood turner's, as they are far cheaper to fit up, and 
 quite as effective in use as the more neat and costly ones 
 generally found in modern amateur's lathes. The lung 
 
LATHE FITTINGS. 75 
 
 mandrel is, moreover, an element of steadiness, and is not 
 without some peculiar advantages. 
 
 I must now give an account of some of our lathe 
 fittings, without which we could not have made any 
 practical use of it. "We intended, if possible, to turn 
 articles of brass as well as of wood ; but for the small and 
 light articles likely to be undertaken by us, we rightly 
 imagined that wooden chucks would suffice, if made 
 with iron ferrules to prevent splitting. One chuck, how- 
 ever, we found it possible to obtain in metal, viz., a taper 
 screw fitted into the centre of a brass plate, which only 
 needed to be attached to a wooden base by four ordinary 
 wood screws. We procured two of these, one with a 
 large and the other with a small centre screw. In order 
 to mount these properly, it was necessary to cut an 
 internal screw in the blocks to which they were to be 
 attached, of the same thread as the mandrel, viz., 
 eight to the inch, the same pitch as the coarsest of the 
 guide screws. To accomplish this, it was, of course, 
 necessary to mount the block on the mandrel with the 
 hole to be screwed outward. We therefore, sawed off 
 a piece of dry beech about an inch longer than would be 
 required for the chuck, and bored it with a centre-bit 
 at one end, so that the mandrel screw would almost enter 
 it. We then forcibly screwed it on, allowing the mandrel 
 screw to cut its own thread. This it did sufficiently well 
 
76 BOY ENGINEERS. 
 
 to secure the work, and euable us to turn it, and 
 accurately square up the end. This end we now bored 
 as it ran in the lathe, making the hole the exact size of 
 the smallest part of the mandrel screw {i.e.^ its size 
 between the threads, which we had previously ascertained 
 by measuring it with callipers). We now had to cut the 
 inside screw, our first attempt with the new mandrel. 
 
 We had been advised to procure a small set of chasing 
 tools, which, in point of fact we had learnt to use fairly 
 well, even with the pole-lathe, and we had a pair of the 
 pitch required. But we had as yet no experience of a 
 traversing mandrel. Holding the tool across the rest, 
 which we turned round so as to stand across the end of 
 the work, we freed the mandrel to allow it to traverse, 
 and drove in the wedge, so that the small block above it 
 geared with the screw above it. We then found that by 
 giving the crank a half turn to and fro, the mandrel 
 advanced steadily as required, and traversed backwards 
 and forwards evenly. But at first we found that the 
 rest was placed too near, so that the work touched it 
 every time it advanced. This was easy to remedy, but 
 we also found that the moment the points of the inside 
 screw tool touched the work, the tool itself was carried 
 forward instead of cutting a thread. We had, however, 
 as yet no slide-rest to hold the tool, and had to contrive 
 a temporary apparatus to suit our present purpose. We 
 
TOOL HOLDER. 77 
 
 saw that it would be necessary to have some means of 
 shifting the tool somewhat towards the left hand as the 
 cuts deepened, but othepwise it must be motionless ; to 
 do this effectually would need some kind of slide, bur, 
 considering that the depth of the screw-thread was ar, 
 most but one-eighth of an inch, and that this was conse- 
 quently the full amount of traverse necessary for the 
 tool, a slide seemed hardly requisite, especially as screw- 
 cutting would not, in all probability, be a very frequent 
 occurrence. Moreover, we soon found it unnecessary 
 even to provide for a traverse of the tool of this amount, 
 because as soon as a thread was fairly traced, we dis- 
 covered that it was better to stop the traverse of the 
 mandrel and finish it by hand, the thread already cut 
 sufficing to draw the tool forward at the proper rate. 
 After divers sketches and suggestions of a more or 
 less complicated character, we cut out a block of ash with 
 a stem to fit into the socket of the ordinary rest, and cut 
 a groove lengthwise, forming a narrow channel in which 
 to lay the tool, but which was wide enough to allow ir. 
 a little movement sideways. In this we laid the chaser, 
 and found that we could very easily steady it by grasping 
 the rest and the tool together, and after a little practice 
 we managed to cut our screws very easily. 
 
 Til is first attempt was a little less satisfactory than 
 subsequent ones, but was sufficiently well done to serve 
 
BOY ENGINEERS. 
 
 the required purpose. We did not cut the threads to 
 quite their full depth, and then by screwing the block 
 forcibly on the mandrel, after rubbing a little soap upon 
 it, we finished it to an excellent fit, as this process com- 
 pressed the wood and made the screw threads smooth and 
 polished. When cutting screws in this way in boxwood, 
 we did not find it necessary, however, to resort to this 
 mode of finishing them, as that wood being very hard 
 and compact, will allow a screw to be chased at a slow 
 speed, but woods like beech or ash, that require to be cut 
 at great speed in order to produce a smooth surface with 
 the tools, cannot be thus screwed in an equally satisfactory 
 manner, but are left by the tool in a comparatively rough 
 state. Screws can only be well cut in these by what are 
 called Y tools, which cannot be always procured except at 
 the London tool shops. They are in form like a folded slip 
 of paper, and are made exceeding sharp on both edges. 
 
 We had made out of a piece of dry and sound box- 
 wood an exact copy of the nose of our mandrel, so that 
 we could at any time test the accuracy of our chucks by 
 screwing this into them without the necessity of removing 
 them from the mandrel ; and as I may be addressing 
 young mechanics, let me tell them by all means to follow 
 our example, as the convenience is very great. 
 
 Having finished the screw and found it correct, we 
 cut off the wood with a parting tool to insure its being 
 
CHUCKS. 79 
 
 perfectly true, and then, screwing it on the mandrel as 
 already described, still further finished it with a chisel. 
 We also recessed the end, so as to allow the brass plate to 
 fit in flush and to be held centrally without shifting, 
 while being secured by three-quarter inch screws. As 
 we had taken extreme care to level the bottom of the 
 recess, we found that when all the screws were in place 
 and the chuck finished, its pointed taper screw was per- 
 fectly true with the back centre. 
 
 Both the taper screws having been fitted in the same 
 way, they were now used as chucks to hold other pieces 
 requiring a similar process of boring and screwing to make 
 cup-chucks. Some of these we made of boxwood, because 
 the screws were more likely to remain for some time true, 
 but as we soon found that the very hardness of this wood 
 prevented it from gripping work as securely as other more 
 elastic woods, we made other chucks of beech, ash, and 
 hornbeam, the latter wood proving excellently suited for 
 such work. 
 
 The wooden chucks, intended to be hollowed out to 
 receive any object to be turned, were very simple 
 afi'airs, merely blocks of wood bored out and screwed to 
 fit the mandrel, turned on the outside, and fitted with an 
 iron or brass ring, so that they could not be easily split 
 by driving the work into them. Some of these rings 
 were forged by the blacksmith — others were bits of stout 
 
8o BO V ENGINEERS. 
 
 tube. In short, whenever we came across a bit of metal 
 likely to prove serviceable, we made a prize of it, and put 
 it by for future service. For ferrules for our tool handles 
 we got bits of gaspipe or old gun barrel, which we cut off 
 with a hack-saw, and turned up bright after they were in 
 place on their respective handles. 
 
 Our lathe was now in fair condition for use, and we 
 only needed to add to the stock of apparatus from time to 
 time as it might be needed. After the experience we had 
 necessarily gained in fitting up this lathe and the previous 
 one, we felt it very unlikely that we should meet with 
 difficulties of an insurmountable character in the amateur 
 engineering work which we proposed to carry on. We 
 had, in fact, learnt to make light of difficulties, and had 
 gained a habit of perseverance and ingenuity in devising 
 makeshifts to meet casual emergencies which ever after 
 served us in good stead. If we had not precisely the tool 
 or the apparatus required, we contrived to make something 
 else serve instead, and thus, while we saved money we 
 avoided any useless accumulation of tools. 
 
 The list of turning tools in our possession, all neatly 
 handled and ranged in a tool-rack by the lathe, was as 
 follows : — 
 
 Two gouges. 
 Two chisels. 
 
TOOLS. 8r 
 
 Three pairs of screw or chasing tools. 
 
 One point tool for brass. 
 
 One round-end ditto. 
 
 One heel tool for roughing down iron. 
 
 Two gravers. 
 
 One flat or planishing tool for brass. 
 
 Two side tools for brass. 
 
 Six variously-shaped tools for hard wood. 
 
 A pair of in-and-out callipers. 
 
 A pair of compasses. 
 
 The drills used in the carpenter's and smith's braces we 
 used also in the lathe, having made a boxwood chuck 
 with a square hole in the centre to receive them. The 
 back poppet, however, of our lathe was not a very good 
 form for advancing any work against the drills, but we 
 made it answer fairly well by turning a thimble or flange 
 to slip over the point, sufficiently loose not to revolve 
 with the screw, but fitting it closely enough not to shake 
 about when in use. This, being made flat and true, 
 presented a broad surface against which the work could 
 abut, and by which it could be gradually and steadily 
 advanced. 
 
 We subsequently managed to pick up secondhand 
 a far better poppet of iron with a cylinder and leading 
 
82 
 
 BO Y ENGINEERS. 
 
 screw, such as is used in all the better-class lathes of the 
 present day, but this was not obtained for three years 
 after we had fitted up the one described. 
 
 I must now describe some of the work which we 
 managed to produce with the above tools. 
 
Cjiapt'er IV. 
 
 OUR WOODEN CLOCK. 
 
 BOUT thia time we had come into possession of 
 some oli books on mechanical subjects, in one 
 of T^iich was a description of a curious German 
 clock, in which a wretched individual was 
 decapitated every two or three minutes, his head being 
 on each occasion deposited in a plate held by the execu- 
 tioner's assistant. No doubt it was meant to represent 
 the decapitation of John the Baptist, as there was a painting 
 above it of a eacred character, but very roughly executed, 
 and (as was stated in the description) partly obliterated in 
 the oiiginal. The beheading of the figure was done in a 
 mar.Dsr ohort, sharp, and decisive, at the end of the 
 allot^'^cd time, but the head gradually went back at each 
 
84 BOY ENGINEERS. 
 
 tick of tlie clock until it rested on tbe neck of the con- 
 demned victim, where it remained until the time came 
 for its next removal. The description of this old clock 
 excited our ambition to reproduce it, and after much 
 calculation and much sketchiu"; of the various details, 
 which culminated in what we were pleased to call " a 
 working drawing," we began our work with great zeal, 
 and after a good deal of labour and some partial failures, 
 we actually accomplished it, and even added other 
 mechanism to the original design. Our chief difficulty 
 arose from the fact that no description was given of 
 the details of the machinery, nor did we know much about 
 clocks at that time. We had consequently to read up our 
 subject from the commencement, makiug notes as we pro- 
 ceeded of the principles involved. These notes I append 
 here to show other boys our methodical way of learning 
 our new trade of clockmaking. 
 
 PRINCIPLES OF CLOCKS. 
 
 1. The main consideration is the pendulum, which is, 
 in fact, the actual timekeeper, the spring or weight and 
 the wheels being necessary only for the purpose of record- 
 ing the number of beats made by the pendulum, and for 
 keeping it in motion. 
 
 2. The number of beats made by a pendulum in a 
 given period depends entirely upon its length. If a 
 
OUR WOODEN CLOCK. 85 
 
 weight is hung on the end of a string, and is made to 
 oscillate from side to side, these oscillations will occur at 
 equal periods, whether the arc described by the swinging 
 weight be large or small, for any given length of string. 
 
 But this is only precisely true up to a certain point for 
 a pendulum or suspended weight, because the arc which 
 it describes is a part of a circle of which the point of 
 suspension is the centre, and the arc of which the above 
 rule of oscillation is always true is not part of a circle 
 but of a cycloid. The difference, however, between the 
 arcs, for the short distance of the swing of a pendulum, is 
 so small, that it may be considered that a pendulum of 
 a given length does actually perform its oscillation in 
 equal times. 
 
 To impress facts like the above on our minds, we always 
 resorted to practical experiments, especially in any case 
 where a mechanical law appeared incomprehensible. In 
 this case, for instance, we fancied that the pendulum must 
 of necessity take longer to traverse a large arc than a 
 small one ; but after hanging a weight to a rail by a piece 
 of string, and timing its oscillations, we saw at once that, 
 when first started on a large arc, the impetus carried it 
 forward rapidly past the lowest point and up the opposite 
 hill, and that this impetus became less and less as the arc 
 of oscillation grew smaller, so that tlie weight took as 
 long to traverse from side to side a couple of inches or 
 
86 BOY ENGINEERS. 
 
 less as it had taken at first to accomplish its longer 
 jourDG)''. 
 
 While watching the swinging of our string pendulum, 
 it so chanced that one of us began to whistle a tune, and 
 we noticed how beautifully our apparatus answered as a 
 timekeeper. We had but to shorten it to make it beat 
 quick time, or lengthen it for a slow march. AYe thus 
 unconsciously invented the tape and weight now often 
 used to teach music in schools ; the tape being marked at 
 varying intervals, at which it is to be held in the finger 
 and thumb, and the oscillation of the weight marking 
 time accordingly. We did not, however, attach any 
 great value to our discovery, because, being but boys, we 
 concluded that others besides ourselves, and of maturer 
 years, must necessarily be well acquainted with a fact so 
 apparently simple, and so easy of practical application. 
 In this way, no doubt, many inventions are lost from time 
 to time, and we have since learned never to take the 
 knowledge of mankind for granted, but to make notes of 
 every fact we may chance to discover for ourselves, and to 
 add suggestions of any possible application of it which 
 may from time to time occur to our minds. 
 
 We found, in short, that this habit of observing and 
 noting simple facts had resulted in some of the most 
 important discoveries and inventions ever made, including 
 the steam-engine and electric telegraph, and that not only 
 
OUR WOODEN CLOCK, 87 
 
 had our greatest engineers been invariably accurate 
 observers of natural facts, but also unwearied experi- 
 menters, who carefully wrote down the results of their 
 experiments, to assist them in subsequent investigations. 
 Our own further notes about pendulums were as 
 follows : — 
 
 Thirdly, The string being impracticable in a clock, 
 and the pendulum requiring a rigid bar to support the 
 *' bob " or weight, this bar needs to be theoretically 
 of invariable length, and freely suspended, so that its 
 oscillations shall not be retarded by- friction, nor caused 
 to vary in duration by the effects of temperature. These 
 requirements become in practice sources of much diffi- 
 culty, owing to the fact that metals expand by heat and 
 contract by the action of cold, and therefore a bob 
 suspended from a wire, as in common clocks, would not 
 give the same results as a timekeeper in. winter and 
 summer, not even under the variations of temperature 
 occurring almost every day. "Wooden pendulum rods are 
 less liable to vary in length, especially if varnished, and 
 this is a very good material to use, where more compli- 
 cated means cannot be employed, to compensate the 
 expansion and contraction of metal rods. 
 
 Fourthly, A long rod keeps time better than a short 
 one, because its swing is steadier, and it is less easily 
 checked or stopped by slight causes, and, on the whole. 
 
88 BO Y ENGINEERS. 
 
 a pendulum beating seconds is the best to use where 
 a long clock-case or plenty of room is available, and 
 appearance is not of importance. A secondc pendulum is 
 39*37 inches long from the point of suspension to the 
 centre of gravitj'^ of the bob for northern latitudes, which 
 is quite near enough for boy clockmakers, at all events ; 
 but it is as well to note that this pendulum, if used near 
 the equator, would cause a clock to lose time, because the 
 force of gravity which acts on falling bodies, and, in fact, 
 causes them to fall, and causes the pendulum bob 
 therefore to descend when lifted, is less at the equator 
 than elsewhere. 
 
 Ffithly, As our first clock was meant in a great 
 measure to give us an insight into the mechanism of 
 clocks, and would in all probability be far from perfect as 
 a timekeeper, we considered that wooden wheels might be 
 very well employed throughout, except in the scape-wheel, 
 which would be constantly acted upon and rapidly worn 
 by the pallets of the pendulum. This we saw at once 
 must be made of metal — brass, if we could get it — tin, if 
 we could not. The pinions we intended to make of wire 
 if possible ; if not, we proposed to cut them as well as we 
 could out of the substance of the axles, which were to be 
 of wood, with wire pivots driven into each end. 
 
 We next proceeded to calculate our wheel train, as it 
 is called, — /.(?., to find out how many teeth each wheel 
 
OUR WOODEN CLOCK. 89 
 
 would require, and how many we must have on the several 
 pinions to give the required speed to each. The scape 
 wheel, acted on by a seconds pendulum, we found must 
 have thirty teeth, as it must revolve once in a minute to 
 receive a minute hand on the end of its arbor, the several 
 teeth escaping on each double swing of the pendulum 
 which beat seconds. We had nearly fallen into the 
 mistake of making our scape wheel with sixty teeth; but 
 a study of an old Cyclopaedia showed us that, although a 
 tooth escaped at each beat at one side of the wheel, the 
 tooth diametrically opposite to it was instantly caught on 
 the sloping face of the opposite pallet, which was so 
 fermed as to give the pallet a slight impetus each time it 
 oscillates, so as to maintain the motion of the pendulum. 
 Thus, practically, only half a tooth escapes at each single 
 beat of the pendulum, and thirty teeth are required 
 instead of sixty. This wheel, revolving once in each 
 minute, we had to arrange an intermediate oce, gearing 
 into that which would carry the minute hand, and which 
 must, therefore, revolve once in each hour, or sixty times 
 as fast as the escape wheel. This escape wheel, with a 
 pinion of eight leaves, therefore, we found must turn a 
 wheel of sixty teeth, which, with its pinion of eight leaves, 
 must gear into one of sixty-four teeth to carry the minute 
 hand. Then comes the barrel, with its string and weight. 
 The spur wheel not being fixed to the axle, nor connected 
 
90 
 
 BOV ENGINEERS. 
 
 rigidly to the barrel or drum, as will be explained, the 
 jiinion of eight leaves of the minute-hand wheel turns on 
 a wheel of ninety-six teeth in connection with this drum, 
 
 Fig. 7. — Clock Train. 
 
 which turns but once in twelve hours. To enable our 
 young readers more fully to understand the nature of 
 
OUR WOODEN CLOCK. 91 
 
 this train of clockwork, a sketch is appended here, the 
 teeth being omitted. Teeth, moreover, would be unneces- 
 sary if the sizes of the several wheels and pinions were 
 correct, and there was no slipping likely to take place, and 
 this rolling contact, as it is called, is still used in various 
 machines, but not in clocks. The number is affixed to the 
 wheels to specify the number of teeth in each, while the 
 number 8 is that of the pinions. These, it must be under- 
 stood, are small wheels fixed on the axle of the large ones, 
 either close to the latter or at the further end. Beginning- 
 at 96, the main, or great wheel, as it is called, which 
 turns once in each hour, we see it driving the pinion of 
 eight leaves of what is called the centre wheel, because it 
 is commonly so placed that its axle, carrying the minute 
 hand of the clock, shall project through the centre of the 
 clock-face. Ninety-six being twelve times eight, it is 
 plain that while the great wheel revolves once, the pinion 
 will revolve twelve times ; and as the great wheel revolves 
 once in twelve hours, this will revolve twelve times in the 
 same time, or once in each hour, which is just what we 
 require for the long hand of a clock. Of the short or 
 hour hand, we shall speak presently, as it is not driven in 
 any part of this train, but by wheels just below the dial- 
 plate. 
 
 As the pinion revolves once in an hour, the spur 
 wheel 64 will do the same, because it is on the same 
 
92 BOY ENGINEERS. 
 
 axle ; and as there are eight times eight in sixty-four, 
 the pinion and wheel marked 6o will revolve eight times 
 while the centre wheel revolves once — i.e.^ eight times 
 in an hour. Now this works into a pinion of eight 
 leaves on the arbor of the minute or scape wheel, and 
 eight will not " go " into sixty, as boys say, without 
 leaving a remainder. However, it will " go " seven 
 times and four over, which is 7| or 7J times ; that is 
 to say, this wheel will revolve ']\ times while the second 
 wheel, 60, revolves once. Therefore, while the latter 
 revolves eight times {i,e.^ each hour), the scape wheel 
 will revolve 7| times multiplied by eight, which equals 
 sixty ; and this is again just what is required to carry 
 the seconds hand. We have worked upwards from 
 the great wheel to make the relative speeds of the 
 wheels clear to the reader, assuming that this great wheel 
 revolves once in an hour ; but although the number of 
 the teeth are arranged for this speed, the governing 
 power is the seconds pendulum working on the teeth of 
 the scape wheel. It vould, however, come to the same 
 thing to begin with this wheel as revolving once a minute, 
 and so to work from it down to the great wheel which 
 drives the whole. 
 
 The next consideration was the pendulum, or rather 
 the pallets, which were to act upon the scape wheel. 
 
 We were sorely puzzled for a time between anchor 
 
OUR WOODEN CLOCK. 93 
 
 pftllets, dead beat, recoil, pin escapement, and others, 
 of which we found accounts in some old books ; but for 
 our first clock we came to the conclusion that the old- 
 fashioned anchor would be easiest to make, because it 
 only needed sawlike teeth on the scape wheel, whereas 
 the dead-beat pallets required teeth of peculiar construc- 
 tion, which we doubted our ability to make. 
 
 Eventually, we picked up a wheel and its pallets 
 ready made at a clockmaker's, who kindly presented us 
 with this important treasure, and took some pains to 
 point out to us the principles upon which it was con- 
 structed. The pendulum, as already explained, is, as 
 he told us, the timekeeper, but it would soon cease to 
 swing if left to itself, and the train of wheels set in 
 motion by the weight is necessary to give it through the 
 scape wheel a slight impulse to and fro, to keep it in 
 motion. One side of the teeth of the scape wheel are 
 radial, the other sloping, and in this form of wheel the 
 latter are the foremost, and fall in succession on the ends 
 of the pallets. These, it will be seen from the accom- 
 panying figure, are so shaped that the teeth falling on 
 their rounded faces are first checked, and then tend to 
 push the pallets from them, and so give swing to the 
 crutch or wire to which they are fixed, first in one 
 direction, and then in the other, one of the curved 
 
94 -^OY ENGINEERS. 
 
 faces of the pallets being on the outside, and the opposite 
 one on the inside. 
 
 In the drawing of the clock train, the tooth, A, has 
 just dropped upon the inner rounded face of the pallet, 
 B, which cannot get free until the pendulum has swung 
 far enough to allow it to escape. The tooth on the 
 opposite side, however, has already escaped from the 
 left pallet, upon which its successor will fall as soon as 
 A gets free and advances, the scape wheel moving in 
 the direction of the arrow. 
 
 In the days of our boyhood there were many clocks 
 in use fitted only with an hour hand, and as there 
 appeared to us certain difficulties connected with the 
 minute hand, which would need what is called dial-work, 
 if the two hands were central, we decided to make use 
 of a plan, which we afterwards learned was not unusual 
 in astronomical clocks, but which we felt at the time 
 to be a serious departure from ordinary rules— z.^., we 
 fixed the hour hand to the axle of the great wheel of 
 the winding barrel, which necessitated its going round 
 backwards, the minute hand retaining its place on the 
 pinion of the centre wheel. The appearance of the 
 clock-face was consequently that of the accompanying 
 illustration, in which is also displayed the scene 
 of that dreadful, but constantly recurring, execution of 
 the criminal already referred to. We discarded, however, 
 
OUR WOODEN CLOCK. 
 
 Fig, S.— -Tbat Awful aock." 
 
96 JBO Y ENGINEERS. 
 
 the original characters, as scarcely in accordance witli 
 our ideas, and called the tragedy the execution of the 
 tyrant Bluebeard. I am afraid our carving of the wife- 
 destroyer in question would scarcely have found a place 
 at the Royal Academy, the figure rather resembling one 
 of those Indian or Chinese idols, or " Samis," to be 
 seen at the British Museum and elsewhere. "We en- 
 deavoured, however, to produce a physiognomy of the 
 ferocious type, which a blue beard of wool considerably 
 enhanced. 
 
 This subject enabled us, however, to add one or two 
 startling accessories, which were very effective. We made 
 at one side of the stage a cupboard containing a headless 
 skeleton, popularly supposed to be that of one of the 
 luckless wives. Anatomists might possibly have been 
 found to suggest that a mouse had originally owned the 
 bones, but anyhow it was a skeleton, and a real one, and 
 the door of the cupboard which contained it was forcibly 
 flung open each time that the executioner did his duty, 
 while at the same moment, two or three strokes upon a 
 deep-toned bell proclaimed the sentence of the law to 
 have been duly carried out. A black flag was also 
 hoisted, and remained a few moments as a silent corrobo- 
 ration of the fact. 
 
 There is so much amusement always attaching to 
 automata of the above kind, that all the details of 
 
OUR WOODEN CLOCK. 97 
 
 tlie ways and means will be added. Most of such move- 
 ments are very simple, aud tliey become all the more 
 amusing by being accomplished in that peculiar jerky 
 style with which, to this day, the figure of the cuckoo 
 performs his part in the Swiss clocks, which are as 
 much prized as ever, although so comparatively common. 
 
 Let it be noted that a woman holds the dish for the 
 reception of the criminal's head. The female in question, 
 so young and so lovely, is supposed to be that happy but 
 inquisitive survivor who held the position of last wife to 
 the tyrant ; and we subsequently regretted that we had 
 not placed " Sister Ann " upon the hou.<e-top waving 
 her hand to the expected brothers. The difficulty resulted 
 not from our lack of the requisite mechanical skill, but 
 from the fact that the decapitation of Bluebeard showed 
 the brothers in question to have already arrived upon the 
 scene. 
 
 We must now recur to the clock train, of which a side 
 view is given here in fig. 9, in its place in the frame- 
 work, which was made of beech, the holes being bushed 
 with little bits of brass wire, drilled to receive the pivots 
 of the several spindles. The numbers of teeth on the 
 wheels and pinions are here specified as before, but the 
 way in which the latter gear into each other will be more 
 clearly understood, as the axles or arbors of the wheels 
 
 are clearly disphiyed. P shows the position of one of the 
 
 O 
 
98 
 
 £0y ENGINEERS. 
 
 Fig. g.— Clock Train. 
 
OUR WOODEN CLOCK. 99 
 
 arms of the anchor pallet, attached to the metal rod V, 
 called the verge. This passes through the inner frame at 
 H without touching it, and also through the back frame, 
 and is pivoted on a piece of brass of the form shown, 
 whicli is screwed to the woodwork. This was done 
 partly to insure the easy working of the pendulum, and 
 partly for the greater ease of getting the verge into its 
 place. D is called the crutch, and is formed of a stout 
 wire screwed into a small boss upon the verge. It is bent 
 out at E, or has another wire inserted at that point, 
 which falls into a slot in the rod B, of the pendulum, as 
 shown again at G, or a fork is made at E, in which the 
 pendulum hangs. The pendulum, therefore, it will be 
 seen, is suspended independently of the verge and pallets, 
 being hung from a projecting stud at T by means of a 
 thin spring, S, or a bit of silk or other substance allowing 
 it to swing easily and freely. In our clock, the pendulum 
 of wood had a saw-cut made at the top extending half an 
 inch downwards, and into this we inserted a bit of watch- 
 spring ground very thin. This was slipped into a saw-cut 
 in the stud T, and secured by a pin passing through it. 
 The form of the rod was like W in the cross section, that 
 it might oscillate with little resistance from the air — a 
 refinement scarcely necessary, considering the general 
 nature of the workmanship and design. 
 
 It was necessary to wind the clock from the back, 
 
BOY ENGINEERS. 
 
 owing to our putting the hour hand upon the spindle 
 of the drum and great wheel. The squared part of the 
 spindle B was therefore made long enough co reach the 
 back frame, in which an opening was left for the key. 
 This we subsequently found so great a drawback, 
 necessitating our taking down the clock to wind it, that 
 we grooved the barrel like X, and made use of a chain 
 which merely hung across it in the groove, and had 
 sufficient hold in the latter to prevent slipping. To wind 
 it, we then only had to lay hold of the other end of the 
 chain, which had a light weight attached, and pull it, the 
 ratchet and click answering the same purpose as when we 
 used the drum with a long cord wound about it. To 
 insure the chain against any chance of slipping, we drove 
 in all round the bottom of the groove short wire pins, 
 which caught the several links as the wheel revolved. 
 
 The figures were made to perform their several parts 
 in the following manner : — In fig. 8, it will be noticed 
 that the executioner and vengeful wife both stand within 
 a small circle, which represents a little platform pivoted 
 vertically upon a wire axis. The arm of the woman, it 
 will be observed, is also pivoted at the shoulder, so as 
 to allow it to move up and down. The object of this 
 is to cause her to raise the plate level with the victim's 
 chin just before the fatal deed is done, immediately 
 after which the head is carried forward upon the plate 
 
OUR WOODEN CLOCK. loi 
 
 by the rotation of the fair lady ni)OU her axis. The 
 latter raovemeut alone upon the part of the executioner 
 enabled him to do his duty, which we compelled him to 
 do at each quarter of an hour. All the movements were 
 done by jerks, as usual in such automata, and which 
 made the whole scene ten times more grotesque than if 
 accomplished in a graceful manner. To begin with the 
 executioner. The -movement of this terrible person 
 needed to be especially sharp and sudden ; we therefore 
 accomplished it by the release of a spring, bent gradually 
 by a cam until the latter was released at the appointed 
 time, and then gradually bent again until the fatal hour 
 recurred. 
 
 In fig. 9, W is a stout wire pivoted at the lower 
 end into a horizontal arm of brass attached to the frame ; 
 at its upper end it carries P, the circular disc on which 
 the executioner stands. X is a flattened pin fixed to 
 the upright wire, which is acted on by four projecting 
 studs fixed at equal distances into the face of the wheel 
 60, so that one of these studs comes into action at each 
 quarter of an hour. A second projecting pin, Y, is 
 constantly pressed by the wire spring S, fixed below 
 into the brass plate which carries the wire W. Su[)pose 
 that in its present position the spring rests lightly 
 against Y, and that the executioner's sword has passed 
 under his victim's neck, the beard preventing the space 
 
1 02 ^OY ENGINEERS. 
 
 "between the reck and shoulders left to admit the sword 
 from being seen. The figure must now gradually rotate 
 on its axis, so as to draw the sword back again, and when 
 a certain position has been reached the figure has to 
 be released suddenly, and carried round by a rapid 
 movement so as to cause the sword to pass through the 
 neck, at which moment also the head must be jerked 
 forward into the dish. This is done by the pins in 60 
 pressing against the little pallet x as the wheel revolves, 
 by which action the other pallet presses back more and 
 more the spring S. This will go on, causing the figure 
 to rotate and draw back his sword until the pin escapes 
 from x^ when the spring S, being now fully strained, 
 will be able to act suddenly on the pin Y, and the 
 executioner will deftly repeat his fatal work. 
 
 We must now turn our attention to the head. This ia 
 fixed to the end of a steel wire passing ea&ihj through 
 a hole in the inner frame. All the parts must be made 
 to move as easily as possible, to prevent the clock from 
 being stopped by their action. For this reason the 
 spring S must be only just strong enough to give rapid 
 motion to the figure. H is a long light spring of 
 hammered brass or steel, fixed at one end to the frame, 
 and at the other to the horizontal wire carrying the 
 head. The latter, if blackened, will not show, tlie back 
 of the stage being also painted a dark colour. N is a 
 
OUR WOODEN CLOCK. ro^^ 
 
 wooden -wheel on the axis of the hour wheel, into which 
 is fixed four stout wires bent as shown, which alternately 
 act upon the spring H. They are bent so as to slope 
 gradually from the wheel a short distance, after which 
 they are parallel to the surface of the wheel; they then 
 turn sharply down and are fixed into the wood. This 
 sharp bend of each comes exactly opposite the pins on 
 the other side of the hour wheel, and act at the same 
 moment. The wire spring H is so bent and so placed 
 that, as the wheel N revolves, the bent wires catch it 
 first on their inclined part, which pressing back the 
 spring, gradually draw the head of the figure back until 
 it rests upon the neck, and remains during the time that 
 the flat part of these wires touch it. But just as the 
 sword of the executioner falls, the spring drops off the 
 wires suddenly, and the head is shot forward In an 
 instant upon the plate, looking as if wholly detached, 
 especially if seen from below as the clock hangs on the 
 wall. As the wheel continues to revolve, the spring is 
 gradually pressed back again, rising upon the inclined 
 surface of the next wire. What are at first sight 
 complicated motions are thus readily produced by a few 
 bits of bent wire. The arm of the woman is raised by an 
 equally simply contrivance. An eccentric pulley of box- 
 wood, L, is fixed on the axle of the hqur wheel 60, the 
 eccentric hoop or strap being a bit oi wire fitting it 
 
I04 BOY ENGINEERS. 
 
 easily, and twisted together at the ends. To this is 
 attached a bit of silk, K, the other end of which is 
 tied to an extension of the arm of the figure concealed 
 by the dress, as is also the silk cord. The arm and 
 its attachments only are here drawn. M is the pivot 
 on which the arm is hinged at the shoulder. The 
 eccentric is so placed that it will draw the string tight, 
 and cause the plate to rise level with the head, just 
 at the moment the latter is about to be cut off and 
 thrust forward, so that it is apparently caught very 
 cleverly. As the eccentric continues its revolution the 
 arm with the plate is allowed gradually to drop, the 
 plate being slightly weighted with lead to keep up a 
 proper tension of the silken cord. 
 
 The black flag is hoisted at the moment of execution 
 by the upper part of the long spring coming in contact 
 with the end of the bent lever, and pressing it suddenly 
 forward, thus raising its straight end, which forms the 
 flagstaff. All the various movements have to be exactly 
 timed, but present no great difficulty. The eccentric, for 
 instance, is lightly pinned until its action has been tested, 
 and then it is secured. The wheel is also tested before 
 being fixed on its axle, and the springs and wires will 
 need only a little careful adjustment by means of the 
 pliers. The long spring may be of watch-spring, straight- 
 ened by being pinched in a fold of stout leather, and 
 
OUR WOODEN CLOCK. 105 
 
 drawn a few times between the fing-er and tlinmh or the 
 jaws of a vice until the curl is taken out. Brass wire, 
 however, is equally good for the purpose, and if 
 hammered or drawn through a conical hole in a steel 
 plate, so as to compress and harden it, is largely used 
 for this purpose by organ and harmonium makers and 
 others ; and if a turn or two is taken by winding it round 
 a small iron rod, as shown here, make^ a pleasanter, and 
 to some extent a better, spring than the steel. If used, 
 it should be flattened where it has to act against the lever 
 of the flag, or any similar part of the mechanism. The 
 opening of the skeleton cupboard is not detailed on 
 purpose to exercise our reader's ingenuity. It was made 
 to fly open with a jerk a few seconds before the decapita- 
 tion of the criminal. The ingenious youngster who may 
 chance to read these pages should devise various acces- 
 sory movements — as, for instance, a bell to strike before 
 the execution takes place. A small lathe and a very few 
 simple tools and materials only are required to make the 
 above. The clock will possibly not keep very good time, 
 owing to the extra work laid upon it of moving the 
 automata, but if care is taken not to overload it, it will 
 answer fairly well as a timekeeper. 
 
 
Chapter V. 
 
 SOME MORE AUTOMATA. 
 
 E succeeded so well with what subsequently 
 obtained the name of " that awful clock," that 
 we thought we would try our hands at a few 
 more of these mechanical toys, and among 
 them, our next attempt was a piping bullfinch, such as 
 we had read about, but not at that time seen. At first 
 we did not hit upon the best mode of producing the bird's 
 Bong, but it answered fairly enough until we found out 
 the better and simpler plan. 
 
 This very pretty little mechanical songster was first 
 brought into notice at the Exhibition of 1851, where it 
 found crowds of enthusiastic admirers. At Paris it met 
 with equal honour, and, indeed, although called a piping 
 bullfinch, the real toy was a number of birds on a tree 
 
SOME MORE A UTOMA TA, 107 
 
 under g'lass, hopping to and fro, and chirping and 
 twittering most naturally, their wings fluttering and 
 beaks moving, and even their throats expanding and 
 quivering as if alive. They were formed as we made our 
 own, of the skins of real birds over a framework of wire 
 and wood, the skeleton being preserved where possible. 
 Our own was, of course, but a humble affair, as we con- 
 tented ourselves with a little movement of the wings and 
 quivering of the beak, our chief attention being directed 
 to the mechanical arrangements for producing the bird's 
 song. This part of the apparatus we made so as to serve 
 permanently, as we intended from time to time to change 
 the warbler, arranging the notes to suit the particular bird. 
 The lower part of the stand contained the mechanism, a 
 tree branch forming the perch, upon which any bird could 
 be mounted at pleasure in a few seconds. We had a 
 linnet, goldfinch, and bullfinch, and subsequently added 
 on a separate branch a thrush ; and I still think that, for 
 mere youngsters, we managed to give very good imitations 
 of their respective songs. We subsequently, however, 
 attempted a still higher flight, not by the addition of a 
 skylark, but by an attempt to imitate the song of a 
 nightingale, which, it is well known, has a greater 
 natural variety of notes than any other of our native 
 songsters. 
 
 We had first to consider the wind-chest or bellows, and 
 
io8 BOY ENGINEERS. 
 
 here we found a few experiments necessary. Oar first 
 idea was to make a miniature pair of double bellows, like 
 those of a blacksmith, to keep up a continuous blast, and 
 to attach to the upper part a sliort whistle pipe, with 
 keys like those of a flute, to ba acted on by a series of 
 little tappets on a barrel, pinned like that of a musical 
 box. A trial of this, however, did not satisfy us, as it 
 was found impossible to imitate successfully the trill or 
 quiver of a bird's song. We consequently discarded 
 the double bellows for a pair of single acting ones kept 
 open by a spring inside ; and on trying these with a 
 common whistle of one note only, tapping the movable 
 board of the bellows with the fingers, we found it more 
 hopeful. We found, however, that although a whistle of 
 one note would give, for that note, the kind of sound 
 required, it did not answer so well with two or three 
 notes and keys, but that it was necessary (as in a 
 cuckoo clock) to have one distinct pipe for each note with 
 its own separate single bellows, unless we inserted a wind- 
 chest like that of an organ between the bellows and the 
 pipes. We were decided on the latter course accidentally, 
 by hearing an organist shaking upon two keys of very 
 high pitch in an organ that was undergoing repair or 
 being tuned, and the notes, chancing to be very nearly 
 those required, sounded so birdlike, that we no longer 
 hesitated to adopt the above plan. 
 
SOME MORE AUTOMATA. 109 
 
 "We commenced by making a shallow box of quarter- 
 inch deal for the top and bottom, but with the end 
 pieces as well as the back and front of half-inch stuff, 
 which at once gave strength and neatness to the work. 
 In the top board were four holes for pipes, and under 
 these were four pull-down pallets, like those of an organ, 
 hinged with leather, the same strip serving also to face 
 and render them air-tight. These were pulled down by 
 brass wires hooked into eyes or rings in each, and they 
 were kept up by springs also made of brass wire. The 
 pull-down wires, hanging straight down from the pallets, 
 passed of necessity through holes in the lower board of 
 this case or wind-chest, through which it was necessary 
 that they should move easily, but without allowing wind 
 to escape round them. They were not indeed air-tight, 
 but by careful drilling were sufficiently so for our purpose. 
 Although, however, a little leakage was not likely to be 
 of great importance, we glued a strip of leather along the 
 bottom of the wind-chest, to form a kind of padding 
 where the wires passed through, which, fitting closely 
 round them, made the case tolerably wind-proof even 
 under full pressure. As we foresaw difficulty in attaching 
 the pull-downs to the pallets, we left the front of the 
 chest open until they were arranged and hooked to their 
 respective loops, and we also took care that the ends of 
 the pallets should come as close to the front as possible, so 
 
no BOY ENGINEERS. 
 
 that with a small pair of pliers we could easily manage 
 the work. 
 
 In all our subsequent automata, as well as in this, we 
 found that we always saved much time and temper by 
 careful consideration beforehand of all such minor details. 
 If every individual part is not planned with due care, it 
 is almost sure to be found when too late that some wheel, 
 or wire, or lever, cannot by any possibility be got into 
 its place. 
 
 A story is told of an architect who, after he had 
 planned a house, and had it partially built, suddenly 
 discovered that he had forgotten to provide for a stair- 
 case, and as by no possible contriving could he after- 
 wards insert it, he hit upon the Swiss method, and put it 
 outside, introducing thereby a novel feature in English 
 domestic architecture, and making a name and a fortune 
 out of a mistake. It is not, however, easy to act in a 
 similar way with a badlv-planned piece of machinery, and 
 an oversight in such a design entails a very good chance 
 of failure in its working. 
 
 Happily a little forethought, and, let it be confessed, 
 a little previously dearly-bought experience, enabled 
 us to escape this dilemma, and we had no difficulty of 
 the kind to contend with on the present occasion. 
 
 Having completed the little wind-chest, which was 
 three inches long, an inch and a half wide, and an inch 
 
SOME MORE AUTOMATA. 
 
 Ill 
 
 deep, we attached it to a framework which allowed 
 the bellows to be placed below, leaving room above 
 them for the working of the levers which were to act 
 on the pull-downs. A sketch will, however, make this 
 
 
 Fig. lo, 
 
 part of the arrangement clearer than any mere verbal 
 description. 
 
 A section of the wind-chest is given at AA of fig. lO, 
 and this was concealed in the stand of the automaton. 
 The pipes, BB, Avhich are here represented as standing 
 upright, were also laid flat on the top of the wind-chest, 
 
112 £0Y ENGINEERS. 
 
 a short bit of lead gaspipe connecting them with the 
 wind channels and valves below. These valves or pallets 
 are seen in cross section at CO, and again at Z as seen 
 from below, and at MN as seen from one side. In the 
 latter figure, M is a cross section of the wind-chest 
 with the lower end of a pipe inserted, P is the pull-down 
 wire, and N the spring which keeps the pallet shut. 
 A light spring sufficed, as the tendency of the pres- 
 sure of wind in the chest was also to keep the valves 
 close. 
 
 KK are feeders, or the movable parts of the bellows 
 hinged at HH. These drive the wind into the upper 
 part or reservoir, L, through two valves in aa, the fixed 
 board which separates the upper and lower parts of 
 the bellows. These valves, not shown in the drawing, 
 are merely flat bits of board faced with soft leather 
 covering two holes. They open upwards to admit wind, 
 but shut down air-tight when not thus raised. There are 
 similar ones in the bottom boards of the two feeders. 
 The latter are worked alternately by means of a rocking 
 lever, GGr, centred on a pivot, the ends being connected 
 by wires, FF, to the cranks at each end of the barrel, 
 as will be explained presently. 
 
 GGr are coiled springs to press down the top of the 
 reservoir, and drive the wind out into the chest, aa. 
 The wind passes up a short wind trunk, D, at the back, 
 
SOME MORE AUTOMATA. . 113 
 
 and is merely a square wooden pipe opening- into 
 the upper reservoir at a point in the central board, aa, 
 to which its lower end is attached. The chest is thus 
 kept full of wind at the necessary pressure to cause the 
 pipes to speak as soon as either is opened by pulling 
 down its pallet. 
 
 In the section it appears of necessity as if the bellows 
 was level with the front of the chest, and the pallets just 
 above it. In the other drawing, however, to the right 
 hand, T is one of the pull-downs, and V a second lever 
 or rocking shaft going to the bellows, which are placed 
 back beyond the plane of the pull-downs. These are 
 worked by the arrangements shown. B, is a lever of 
 iron or brass one-eighth thick or less, hinged at its centre. 
 One end is filed to the shape shown, the other is flattened 
 and drilled to receive the end of the pull-down which 
 passes through it, and is screwed to take a nut below. 
 By means of this nut the tension of the wire can be 
 regulated with great nicety. is the end of the barrel, 
 which is exactly similar to those of organs, J being a 
 part of the same seen in front, with one crank, I, fixed 
 to the end of the axle. At W is seen the same crank 
 with the wire which leads to the rocking shaft of the 
 bellows, as already explained. Q shows wire staples of 
 various lengths driven into the barrel at intervals. 
 They are shown also at J. By means of the end of the 
 
114 ^OY ENGINEERS. 
 
 levers R, of which one goes to each pull-down, motion 
 is communicated to the pallets, which are opened by 
 the action of the sta[)les as the barrel revulves. If a 
 staple is long, like that shown, acting on the lever, the 
 valve of that particular pipe is held open for a long 
 time, until in fact the staple has passed and escaped 
 from the lever. Short notes are the result of the short 
 staples, some of which are mere single pins, which hold 
 the pipe open for a second only. If, instead of a steady 
 note, one is desired with a quiver or " trill," the top of 
 the staple, instead of being made straight and level, is 
 indented or waved, so as partly to open and close the 
 valve with great rapidity. A shake between two notes 
 is made by inserting their staples, so that they may 
 act alternately. Four pipes, each with its own row 
 of staples running round a barrel, suffice in this way 
 to give great variety of song. By driving one end 
 of a staple deeper than the other, the valve it is connected 
 with is opened very gradually, giving a note of increasing 
 loudness; and by varying the form and size of staples, 
 every variety of note is capable of production with great 
 accuracy. 
 
 In the present case, the barrel, being of small size, is 
 just as well made of a solid piece of wood. Willow, being 
 soft, allows the pin to be driven in very easily, and is 
 what we ourselves used, Tlie staples were of brass wire 
 
SOME MORE A UTOMA TA. 115 
 
 flattened ; but though we flattened ours with a hammer, 
 ^e subsequeutly discovered that wire can be readily bought 
 drawn flat, triangular, or square, as well as round. 
 
 A few particulars may as well be entered into here about 
 making the barrel, which may be mysterious to such as 
 know nothing about it. It is, however, a simple affair; 
 and when we come to speak of our graud attempt at 
 making an organ, it will be seen that to prick and staple 
 a barrel does not need such an unusual amount of brains. 
 In short, a boy's brain canister may very easily contain 
 sufficient gumption. Suppose, for instance, there are 
 four pipes, which have to sound at stated intervals, and 
 for a stated period. Cover the barrel, if of mahogany, 
 with white paper, or if of white wood, leave it as it is, 
 and while still in the lathe, draw four lines upon it at the 
 distances of the four levers which are to work the pull- 
 downs and valves. Each of these circumferential lines 
 will mark the position of a circle of pins and staples, 
 each circle of pins acting only upon one pipe of the set. 
 Now, whether the apparatus be an organ, a musical box, 
 or our bird, the whole tune has to be completed in a 
 single revolution of the barrel, and the pins and staples 
 have to be so arranged as to produce it. The tune we 
 ourselves required was not very long, and it cerfainly 
 was not very complicated. We may write it as — twitter- 
 twitter-twit — twit-twit — twitter — twit— t - 1 — titter-itter 
 
1 16 BOY ENGINEERS. 
 
 — ter — twit-twit; but we can't express the wondrous 
 trill, and shake, and tremolo, like or unlike a bird's song, 
 which we contrived to elaborate. 
 
 We may consider the tune to contain exactly eight 
 bars. It was therefore necessary now to draw eight lines 
 along the barrel lengthwise, which we were forced to do 
 ■without that convenient addition to a lathe — a dividing 
 plate and index. This was not so difficult a feat after 
 all, for we simply cut a strip of paper long enough to go 
 round the barrel, and folded it into eight equal parts, 
 and having drawn a line with a straight edge (the top of 
 our lathe-rest) along the barrel as a starting-point, we 
 marked the divisions at each end, and drew lines 
 from one to the other. Each circle first drawn upon the 
 circumference of the barrel was thus exactly divided into 
 eight equal parts, either of which represented one bar of 
 music. These main lines we ruled with red ink, to dis- 
 tinguish them from those subsequently made, which 
 denoted lesser divisions or shorter notes. These larger 
 spaces were subdivided by black lines into four equal parts, 
 which sufficed as a guide to the arrangement of the pins 
 and staples. If we had, for example, been setting an 
 actual tune in common or four time, each space would 
 have contained one of the notes, and if, instead of 
 one crochet, we desired a semibreve, we had but to make 
 the staple long enough to span two notes or two divi- 
 
SOME MORE AUTOMATA. 117 
 
 sions. But in the present instance, we had not to 
 compose music beyond the simple twitter-twit suitable 
 for our bird, so that very accurate subdivision was not 
 necessary. XY in the drawing shows a part of the upper 
 board of the wind-chest, seen from below, except 
 that the openings under the pallets were round to receive 
 the pipes. The long slits are given to show at the same 
 time the form always used in organs. We adopted the 
 long pallet because it was on the whole easier to make 
 than a round one. The leather which faced it formed 
 also (as is usual) the hinge at Z. This leather appears 
 as a black line at the top of the pallet shown at MN. 
 
 In this our first attempt we did not make the works 
 self-acting, but led a cord from a large pulley on the 
 axle of the barrel to a smaller one with a winch handle 
 attached to it, by which we set the whole in motion. 
 In a better one made at a later date we used clockwork, 
 moved by a spring with a fan to regulate the rate, as in the 
 striking part of an ordinary clock. The whistles were 
 made exactly like miniature organ pipes as sketched, in 
 the construction of which no great difficulty presented 
 itself. 
 
 After what has been said about " the awful clock," it 
 will not appear very mysterious to the reader how we 
 contrived to give motion to the bird, which was set upon 
 a pedestal of rough wood with the bark on. The pedestaj 
 
liS BOY ENGINEERS. 
 
 being drilled first, then sawn apart lengthwise, and put 
 together with pins after the wires concealed in it were in 
 place. 
 
 By this means we could get at the wires readily to fix 
 tliem at first, and subsequently, if they should at 
 liny time need to be altered or readjusted. The 
 lower beak was carefully snipped off at the base, and a 
 bit of wood glued to it so as to lengthen it inwards, 
 and also form a lever, which moved upon a pin passed 
 horizontally through it. This will be understood on inspec- 
 tion of the drawing of the bird's head : h is the pivot on 
 which the lever turns, x the wire or silk going down to the 
 machinery below. After the attachments are made, the 
 skiu is again carefully glued round the base of the beak. 
 The wings were left luingiug to the skiu, which made the 
 joint, and were moved in a fluttering way by a T-shaped 
 bit of wire, the stem going down the pedestal by the side 
 of the other wire, and the cross head supporting the 
 wings, one on each side, and concealed by the feathers. 
 The movement was simply to raise the wings a little, and 
 let them fall again, which was accomplished by the end 
 of the wire resting on the edge of a wheel with undula- 
 tions round its edge, and so fitted as to turn somewhat 
 quickly but irregularly. This gave just the slight flutter 
 required. We found it indeed quite possible to dispense 
 with one wire in the pedestal, by attaching the end of 
 
SOME MORE AUTOMATA. 119 
 
 the thin lever, which was glued to the beak, to tlie Avire 
 which moved the wings. The same wheel moving both 
 at the same moment, gave an appearance of simultaneous 
 muscular action very true to nature. 
 
 In all these automatas, of which we made a good 
 many from time to time, we found that attention was 
 much needed in producing similar movements at 
 irregular fitful intervals. When this is skilfully accom- 
 plished there is less appearance of mechanical work, 
 because nature works just with what we may call 
 irregular regularity, and the failure even in such a 
 collection as that of Madame Tussaud's in giving a more 
 natural appearance, lies in the fact that the automatic 
 movements are too regularly performed. They suggest 
 clockwork the moment we look at them. 
 
 The fluttering of the wings of our bird being de- 
 pendent, as stated, upon a wheel with serrated or 
 irregularly-notched edge, we had only to make each part 
 as different in outline from any other as we could, to 
 secure the variable motions of the wings and beak. But 
 we even added to this irregularity of movement, in the 
 following manner : — 
 
 We drove the serrated wheel by a cord from a pulley 
 on the axis of the barrel, but we made this pulley 
 slightly eccentric, so that the cord was not always equally 
 tight. The result was, that when it was not strained 
 
120 BOY ENGINEERS. 
 
 sufficiently to drive the serrated wheel, the latter was still 
 for a few seconds, until the eccentric pulley revolved far 
 enough to enable it to draw the cord tight, when it of 
 course started again. It was just so arranged as regards 
 eccentricity that it made the cord tight enough to work 
 for the greater part of its revolution, and only slackened 
 it for about one-sixth part, during which the wings and 
 beak when worked together ceased to move ; and when 
 the latter was the case, we of course took care that the 
 warbling should also cease, by the absence of pins in the 
 barrel at that particular part. 
 
 In making this automaton without having any oppor- 
 tunity of knowing precisely the best way of doing it, 
 we had to work literally note by note, without any other 
 guide tliau the ear, aided by some recollection of the 
 successive notes of the bird we hoped to imitate. By 
 the help of a piano, however, on which to try the various 
 modulations, and aided still further by a good-natured 
 sister, who had the patience of Job, we succeeded, and 
 fully accomplished our self-imposed task, and mighty 
 proud we were too of our first warbler. 
 
Chapter VI. 
 
 OUR FIRST ORGAN. 
 
 HE success of our songster, described In the last 
 chapter, made us ambitious to try our hands 
 upon an organ. But we had to moderate this 
 ambition, and be content with a small afijiir, 
 on account of the cost of material necessary to be 
 incurred for a large instrument. We were therefore 
 limited to four octaves of notes, but with one additional 
 stop we could somewhat extend the scale, and we deter- 
 mined some day to try our skill in the fabrication of 
 a much better " kiat o' whistles," as amateurs' organs 
 have been ignominiously named. 
 
 In our youth, alas 1 there were none of the pleasant 
 and instructive mechanical works now in use. The 
 "English Mechanic" was not even born, and the " Encyclo- 
 
12 2 BOY ENGINEERS. 
 
 paedia Britannica " was our sole teacher of the mysteries 
 of an organ's inside. 
 
 We might have much simj)lified matters had we not 
 aspired to the one stop, which entailed, in addition to 
 a wind-chest, a sound-board — a part far more complicated 
 than its name would indicate, as it is not a board at all, 
 but a shallow box with slides to cutv off or open the 
 various rows of pipes as may be required. In large 
 instruments there are many of these sound-boards, and 
 the pipes are numbered by thousands. In the organ at 
 the Albert Hall, Kensington, there are rows and rows of 
 stops one over the other, but all within reach and com- 
 mand of the organist. 
 
 There is not, after all, any very great difficulty in organ- 
 building. It is merely joiner's work well and soundly 
 done. But the pipes offer difficulties peculiar to them- 
 selves. They may simply sound a noise, or a note of 
 music distinct and decided. Nothing but practice will 
 enable any one to make a thoroughly good set of pipes, 
 even in wood, and metal ones are hardly within the 
 province of boys, or indeed of the majority of their 
 elders ; but a boy may make pipes sufficiently well to 
 give a very fair tone, and may construct a small organ 
 which will give him and others both amusement and 
 pleasure. 
 
 The prime mover, as it may be called, is of course 
 
OUR FIRST ORGAN. 123 
 
 wind Biipplied to the pipes from the bellows, which 
 are of the double kind, like those of a blacksmith, but 
 alwa3's made of an oblong shape, aud generally occu[)yiug 
 the lower part of the instrument next the floor. Some- 
 times, however, the bellows are conveniently placed else- 
 where, and are set on end instead of lying horizontally. 
 From them the wind in a high pressure state passes up 
 the wind trunk, a wooden pipe of square or oblong 
 section, which is often provided with a valve at one side 
 opening outwards, and kept close by a spring. This is 
 to provide against any sudden forcible impulse of the air 
 by the ftiult of the bellows blower, as a sudden gust 
 opens the valve and allows of the escape into the air of 
 the' wind in its compressed state, so that only a steady 
 and uniform blast is conveyed into the wind-chest, and 
 thence through the channels in the sounding-board to 
 the pipes, by means of the slides and keys. Plenty 
 of wind steadily supplied is of the first necessit}^, and if 
 the bellows are too small, the instrument can never 
 prove of much practical value, but excess of wind is 
 easily got rid of by a simple plan of escape-valve, 
 which acts as soon as the reservoir rises to an undue 
 height. 
 
 Turning our attention, therefore, first to the bellows, 
 they are found to consist of three boards connected 
 together on all sides by an envelope or casing of leather. 
 
124 ^OY ENGINEERS. 
 
 In the lower and middle boards are flap valves — pieces of 
 wood covered with leather and hinged to open upwards, if 
 the bellows are to take a horizontal position. The hinge 
 is made by nailing down the leather which forms the 
 face of the valve, and which is cut long enough to 
 permit of its being thus used. In double bellows the 
 middle board is fixed to the framing, and the lower 
 one is M'orked up and down by the lever or rocking staff. 
 As it fajls, air rushes through the valve, but cannot again 
 escape, and is driven by the raising of the lower board 
 through the middle valve into the upper part of the 
 bellows, or reservoir, as it is called in an organ. The 
 upper board forming the top of this reservoir is pressed 
 down by springs or weights, and drives the wind oat 
 into the wind-chest through a pipe or trunk, generally of 
 wood, which opens into the reservoir just above the central 
 board to which it is fixed. 
 
 Bellows, however, made in this way would be apt to 
 rise and fall very irregularly, and would not be compact 
 when closed and empty. Between the several boards, 
 therefore, alluded to, there are oblong frames of wood, to 
 the edges of which the leather is nailed ; these frames 
 being the same size as the boards. These keep the 
 leather extended equally on all four sides, and rise and 
 fall as the bellows are alternately expanded and closed. 
 In addition to these, there are also crossed guides hinged 
 
OUR FIRST ORGAN. 125 
 
 by a pivot to the corners of the boards, and also pinned 
 together where they cross, which compel the boards to rise 
 horizontally and equally. 
 
 The boards and frames are generally of ash or elm, 
 which are tough durable woods, not liable to split by 
 driving the nails to attach the leather. They should be 
 dry and well seasoned to prevent the risk of warping, 
 which, however, would not be so fatal in the bellows as 
 to the wind-chest and other parts. Any soft and 
 pliable skin will do for the bellows of a small organ. 
 That called basil is very general, and is prepared in a 
 particular way for the special work. 
 
 It may, however, be mentioned here, that in a large 
 church organ of modern construction, the bellows are not 
 made like house or smith's bellows ; there are the three 
 main boards, but the intermediate part is not wholly 
 of leather, but of boards with leather joints, enabling 
 them to fold closely together and to rise evenly on 
 all sides. They are made, in fact, like the bellows of an 
 ordinary Accordion, except that in that instrument the 
 thin boards or ribs are of card instead of wood. They 
 require a good deal of careful cutting and fitting, but are 
 vastly superior to bellows wholly made of leather, and 
 are therefore no.v universally adopted. Made simply 
 of three boards with intermediate stretching-frames, there 
 is the advantage of not requiring corner gussets and such- 
 
126 BOY ENGINEERS. 
 
 like details, whicli are so difficult to cut and fit properly ; 
 but, on the otlier hand, more leather is needed, making 
 an increase of cost, and the finished work is not so 
 neat. Both methods are given, however, here, for we 
 used both, and I think with about equal success. In the 
 ensuing description, however, the orthodox plan will be 
 described. 
 
 For the wind-chest we used deal, straight-grained, 
 clean pine, as dry as we could obtain; and never did we 
 find greater need of sharp, finely-set planes to square up 
 and render it true in all directions. By this time, 
 however, we were tolerably versed in the practice of 
 joinery, and had satisfactorily passed that Pons Asinorum 
 of amateurs, the art of planing. The pipes were also 
 of deal, with the exception of the caps and blocks, 
 hereafter to be described, which were made of mahogany. 
 The lower conical tubes, which fitted into the holes of the 
 sound-board, however, we made of beech, as being easy 
 to turn, and already part of our stock-in-trade. The 
 keys were not altogether home-made, for we managed 
 to purchase an old worn-out piano of ancient date, whose 
 keys we modified to suit our purpose. They were rather 
 narrow, and the ivory finger-plates no longer of the 
 delicate colour which gives such beauty to the keyboard 
 of modern instruments. They nevertheless served us 
 very well, and saved us a great deal of difficult work. 
 
OUR FIRST ORGAN. 127 
 
 The four octaves of keys occupied a length of two feet, 
 and consisted of forty-nine notes, beginning and end- 
 ing with C natural. From this we took our various 
 dimensions. Forty-nine notes with two stops required 
 ninety-eight pipes, so that we certainly had our hands full 
 of work, as our heads were full of ambition and of hope. 
 The organ was, in fact, of very fair and serviceable size, 
 and, well handled, was capable of discoursing much music, 
 despite many sligbt defects peculiar to the work of 
 youthful amateurs. 
 
 As the keyboard required a width or length of two 
 feet, and au organ pipe of wood, being wider than a single 
 key, would need more room, we saw that we should 
 hardly be safe with a sound-board on which these pipes 
 would be placed, of less than three feet, even if we put 
 a few of the large pipes in front, and carried the wind to 
 them by leaden feeders. We therefore made it four 
 feet, so as to err, if at all, on the safe side. The bellows 
 might, we considered, be less, and we made them three 
 feet by eighteen inches, which proved sufficient. 
 
 The annexed illustrations will' show the relations of 
 wind-chest and sound-board with the mechanism of the 
 stops, by which one or more rows of pipes may be used 
 at the discretion of the player. 
 
 In fig. II, the sound-board is seen partly in section. 
 It con.sists of a strong shallow box, divided into channels 
 
12? 
 
 BOY ENGINEERS. 
 
 by bars planed very true, tlie euds of these being let into 
 the sules of the chest. Great care is taken to render 
 the chauiiels thus formed perfectly air-tight, even against 
 
 H 
 
 y/>'^Y^//^^.y^/-a^x^^-v^-^^' j^^^ 
 
 ^^\\\^\\\\^^\^\\\- i^\\\ ^^^\\^\\^x^^^^^ 
 
 Fig. II. 
 
 C, Channels. T, Top of lower part. S, Slide. T, Top board. D, Divisions or bars. 
 
 M, Holes iu lowest board. 
 
 the full pressure of wind that can be brought into them 
 by the bellows. There must be as many of these 
 
OUR FIRST ORGAN. 129 
 
 channels as keys, each answering to a single note. It 
 may be explained at once in this place, that the reason 
 the channels are needed is, that every single note of 
 an organ may have several pipes of wood or metal, of 
 which, when a hey is pressed, one or more may sonud as 
 may be desired. Taking the first channel, therefore, of 
 our organ, all the pipes standing over it were tuned to C. 
 "VVe liad but two pipes to each note, but if the sound- 
 board were wide enough, it is plain that several might be 
 ranged over the same channel. This sound-board bein<r 
 so far completed, the upper board is glued and screwed 
 Qn, but generally the whole of the bottom board is not 
 attached, a part of the bars appearing underneath until 
 the pallets are put on, and the wind-chest, which covers 
 and conceals them. In our small organ, however, we 
 covered the whole of the bottom of the bars as well as 
 the top, so that none of the inside arrangements were 
 visible. 
 
 Before screwing on the top and bottom, we took care 
 to glue the edges of all the bars, as well as those which 
 formed the outside or frame, and while the glue was hot 
 we put on the boards, and drove the screws home quickly, 
 making all perfectly wind-proof. 
 
 We now had to arrange the stop, and our method of 
 doing so will explain that adopted in large organs. 
 
 The object of a stop is to shut off any row of pipes, 
 
130 BOY ENGINEERS. 
 
 and therefore it has to act upon all the channels at the 
 same time. Suppose a hole to be bored, H, over each 
 channel, through which the wind would pacs if a key 
 were pressed down ; and suppose a row of pipes, properly 
 tuned, placed over such hole, any of these might be 
 sounded at pleasure. Let the pipes be now removed, and 
 a long strip of board, S, laid along over the holes, vv^itli 
 holes bored in it to match those below. It is evident 
 that a little movement of this board lengthwise would 
 close all the holes simultaneously, so that if the pi[)es 
 stood over the slide, not one of them would sound unless 
 the slide were again shifted, so as to make the holes 
 coincide as before. One such slide is arranged for each 
 row of pipes, and is called a stop, and named by the title 
 given to the pipes in that row, whether of wood or 
 metal. 
 
 Tiie slides are arranged thus: — Strips of clean deal or 
 mahogany, HH, are glued down at distances equal to 
 the width of the slides, and of exactly their thickness, 
 reaching from end to end lengthwise. These are the guide 
 bars between which the slides move. The slides them- 
 selves are preferably made of well-seasoned mahogany, 
 as not being liable to warp and twist, because it is 
 absolutely necessary that they should move smoothly and 
 easily, and without shake. Upon the edges of these 
 bars, which are from half an inch to an inch thick, or 
 
OUR FIRST ORGAN. 131 
 
 iu large organs even more, are glued strips of brown 
 pnper, on which rests the top board, which is bored at the 
 same time as the top of the sound-board and slide, to 
 receive the ends of the pipes. The paper raises this board 
 very slightly, just so much as to let the slides free. The 
 first guide strips are glued on flush with the top edge 
 of the sound-board, so that when the top board is on, and 
 screwed down, it forms with the top of the sound-board 
 another very shallow box divided by the guide strips 
 into long channels, but wider channels than those before 
 described. In fact, as regards the shallowness of this 
 part, it is of course dependent on the thickness of the 
 slides and the guide strips between them, and we found 
 three-eighth stuff amply sufficient for the purpose, making 
 the depth and thickness of the strips equal. 
 
 Dividing the total length of the sound-board into 
 eighths of an inch, in order the better to find out 
 the width we could aff'ord to each channel, and taking 
 three-eighths as the thickness of the strips by which to 
 divide it into the several compartments, we found that we 
 had 288 eighths, which would give us forty-nine divi- 
 sions of more than five-eighths, but less than six-eighths 
 each. Those would include the strips and the channels, 
 80 that if these were equal, we should have, roughly 
 speaking, three-eighth strips and three-eighth channels. 
 But as some of the large pipes needed more wind than 
 
132 BOY ENGINEERS. 
 
 such small channels seemed likely to carry to them, we 
 made some fully six-eighths, and others only quarter, antl 
 also used quarter stuff instead of three- eig-hths for a great 
 part of the distance. The outside of the framework 
 was, however, all of inch stuff, as this had to receive 
 the screws by which the top and bottom were fastened 
 on. 
 
 Oblong holes, or two holes a little distance apart, were 
 now necessary, as at M, in the front part of the lower 
 board of the sound-board communicating with the several 
 channels, over each of which holes the pallet had to be 
 fitted. In large organs the bottom board would have 
 ended, as shown, towards the right hand, so as to expo.se 
 the bottom of the bars, which would of course have 
 answered as well, the pallets being fitted to cover 
 the spaces between the bars, and prevent wind from 
 entering the channels. We thought it would be- easier 
 to work in the other way. 
 
 At P is a section across the centi-e of the sound-board 
 and wind- chest, which, with the previous description 
 and illustrations, will make the Avliule arrangements 
 quite clear. Here a will represent the upper board of the 
 sound-board, above which is the rack for pipes — a board 
 supported on short pillars, and boi'ed to fit the turned 
 feet of the pipes and keep them upright. Tlie white 
 space, bf is that of the slides or stop-boards ; <?, the upper 
 
OUR FIRST ORGAN. 133 
 
 board of the sound-board before the addition of the guides 
 and slides ; a?, one of the wind channels ; and e the 
 bottom board. Below this, which carries the row of 
 pallets, y, is fixed an oblong bos running the whole length 
 of the sound-board, and occupying width enough to allow 
 the action of the pallets to take place within it. It is 
 marked f^ and is called the wind-chest. It receives 
 its wind from the wind-trunk rising from the bellows, 
 which may open into it at either end or at the back, 
 as most convenient. Ours was at the left or bass end 
 of the instrument. The wire pull-down is seen at h, 
 which is acted on by the key direct in a small instru- 
 ment. 
 
 It will be noticed^ in this description of our organ, 
 that I frequently generalise, in order, while describing 
 the humble instrument which we contrived to make, to 
 give the reader some insight into the construction of 
 such organs as are made for our churches by modern 
 builders, the object being to make our little volume as 
 useful as possible, even to some few who may con- 
 descend to peruse its contents, though the jacket has 
 given place to coat-tails and other abominations of an 
 adult's dress. 
 
 We must now return to the bellows, a small portion of 
 which is illustrated here at BLB, and also at B2. The 
 first is a side view, showing the wood and leather as seen 
 
134 BOY ENGINEERS, 
 
 when the bellows are partially distended ; the latter, a 
 section showing the way in which the joints are con- 
 structed. In the first the leather is left white, and 
 in Loth drawings it is marked L. The sectional view 
 shows that the leather is placed inside as well as outside 
 tlie boards, the latter being bevelled off each way as at 
 E, to allow the boards to fold together as they ought 
 to do. 
 
 It is now necessary to enter into the mystery of pipes^ 
 both wood and metal. Of the latter we should certainly 
 have made a great mess, for they can hardly be made by 
 amateurs a great deal more practised than we were in 
 organ construction. We made our second row, however, 
 in a way of our own, and gave it the name of Hautboy, 
 as being a kind of reed-stop, though I doubt if ever 
 before or since a similar one has been made. An organ 
 pipe is (omitting reed pipes) merely a well-made whistle 
 on a large scale, although, perhaps, the latter phrase is 
 scarcely correct, since the smaller ones are really very 
 small, not much bigger than a metal penholder ; but, on 
 the other hand, some of the wooden ones are as much 
 as thirty-two feet in length, and most organs contain 
 sixteen-feet pipes, which are certainly Goliaths among 
 whistles. 
 
 Before setting to work upon the pipes, we found it 
 necessary to make a sort of scale or guage, which I fear 
 
OUR FIRST ORGAN. 135 
 
 was at best a very imperfect and incorrect one j but, 
 as stated before, we had to hammer ideas out of our 
 own brains, and to work with very scanty information. 
 After all, however, it strikes me that nothing is ulti- 
 mately lost by a lad having to gain information by dec]) 
 thought and experiment. Gained in this way, it is 
 generally of a durable character, which is not tlie case 
 with the superficial information which is the result of the 
 modern system of cram. 
 
 We began quite at haphazard, by making a wooden 
 pipe to represent the middle C of a pianoforte, or what 
 I believe organ-builders call tenor C. I cannot recollect 
 what guided us in making this pipe four feet six inches long 
 by two inches each way, but possibly we asked some one 
 who was supposed to know all about it. However, when 
 we tried it with C on the piano, we found it about two full 
 notes lower than it ought to have been, and we cut off 
 first one inch, and then another, and found it getting 
 nearer to the required tone. We then reduced it by 
 little and little to four feet, and after some additional 
 manipulation about the mouth, raising and lowering the 
 block, which was fitted but not glued on tightly, we 
 managed to get the note correct, if not exactly of good 
 quality; but then we only tried it with the breath, and 
 also the kitchen bellows. This was our sample of 
 stopped diapason ; that is to say, it was not left open, but 
 
136 BO Y ENGINEERS. 
 
 was closed with a wooden plug, without which it would, 
 as we found by experiment, give a note an octave lower. 
 The latter would be called in organ phraseology an open 
 diapason, and in a large instrument the lower part of 
 this stop would probably be of wood, and the upper 
 octaves of metal. The principle of the pipes would be 
 exactly the same, as the sound is caused by the wind 
 striking against the thin edge of the lip, and setting 
 a column of air in more or less rapid vibration in the 
 body of the pipe, ovjlue, as it is technically called. 
 
 We found that for each note about the middle of the 
 scale, the length of the pipes must diminish very nearly 
 three inches ; but when the large pipes were reached, a 
 difference required to be made of four or five inches. 
 We heard afterwards, and subsequently proved, as usual, 
 by actual experiment, that great variety of tone could be 
 produced by varying the form of the flue. Thus a conical 
 pipe did not sound like one with parallel sides, nor did 
 a pipe with the largest part of such cone at the top 
 sound like one with the largest part close to the lip. 
 Again, we found it made a difference wliether the thin 
 edge of the lip was formed by bevelling off the pipe from 
 the outside or the inside, and that the formation of the 
 cap which covered or provided a channel for the wind 
 also tended to modify the tone. 
 
 The toning or voicing of pipes is indeed a very delicate 
 
OUR FIRST ORGAN. 137 
 
 matter. Wood can be voiced to speak like metnl, and 
 metal to imitate wood so closely as to defy detection by 
 any but the most critical and experienced ear. It is 
 highly necessary that this skill in voicing, however, 
 should be attained by those who hope to excel in organ- 
 building, because it is requisite that precisely the same 
 quality of tone should run through all the octaves of any 
 particular stops. It is not sufficient that each note 
 should be accurate in tune or pitch, but it must match 
 the rest iu what is called " timbre." A reedy note, for 
 instance, would be intolerable to a musical ear if it 
 occurred in the same stop which gave generally a flute- 
 like tone ; and yet a skilful organ-builder can, if he 
 clioose, make the same shaped pipe give the two qualities 
 of tone merely by the act of voicing it — i.e., regulating 
 the force and direction in which the wind shall strike 
 upon the thin edge or lip of the pipe. 
 
 I shall presently have to say a few words upon the 
 secrets of voicing, but it was a performance we had never 
 even heard of. "We made our pipes in the plain and 
 simple manner which will be described here, and if they 
 were not of first-class quality of tone, they spoke evenly, 
 and were in good tune ; and this to boys like ourselves 
 was a sufficient triumph for a first attempt. 
 
 It would occupy a larger volume than the present, to 
 detail the particular forms of pipes used in the present 
 
138 BOY ENGINEERS. 
 
 day in organs of large size and variety of tone. It will 
 be necessary to confine our remarks to the two kinds 
 denominated "flute" and "reed" pipes, and of these 
 sections and drawings are here annexed. Flute pipes, 
 whether stopped — e'.^., fitted at the top or open end with 
 a plug, which always raises the note of any given length 
 of pipe an octave — or open, consist of a flue, a block 
 with its air space, and a cap, to which must be added 
 a foot, which is the turned pipe on which the larger one 
 stands, and which carries to it the wind from the sound- 
 board. 
 
 I often smile now at the labour it cost us to make 
 pipes, the mystery a pipe was to our minds, and the 
 many failures for want of a little advice by which we 
 were compelled to purchase our experience. Of course 
 I am now writing as if we found no such difficulties, and 
 merely stating rather how we subsequently and rightly 
 made the pipes, after obtaining a pattern one and a little 
 kindly-imparted instruction from a builder. 
 
 The block, which is the first part to be considered, is 
 merely, as the name indicates, a solid squared-up piece 
 of wood, generally mahogany. To give the sizes of a 
 standard pipe of this kind, the block A, fig. 12, is two 
 inches long, one and a half wide, and one inch thick; and 
 it has a piece cut out of it as shown, which it is easy 
 to do with a fine saw and narrow chisel. This block 
 
' ORGAN DETAILS. 
 
 139 
 
 1^ 
 
 i 
 
 rig. xa 
 
140 BOY ENGINEERS. 
 
 must be planed trne upon all sides, or the pipe made 
 upon it will evidently be out of shape and useless. 
 
 B is a section of the pipe, D a front view, C the front 
 of the upper part alone above the block, E the foot, or 
 conical pipe on which the whole stands, and whicli is 
 seen in section in the first figure, in which the block is 
 also plain Ij'' seen at H. G is the cap that fits on in 
 front, and is so cut away on the inside as to cause the 
 wind to strike on the sharp edge or lip above it, which 
 lip is made by cutting back the lower end of the front 
 board, C. This cap is shown in perspective at K, where 
 its form may be very easily understood. In the section 
 of the pipe complete, B, the course of the wind can be 
 traced without difficulty. It may readily be imagined 
 that by leaving the mouth of the pipe more or less open, 
 enlaro-ing or diminishing the wind channel, adding to 
 or diminishing the width of the pipe in proportion to its 
 length, and otherwise modifying its dimensions, great 
 variety of tone can be obtained ; and after pipes are 
 finished, the operation of voicing is carried out, which 
 consists in openino^ out or diminishing the mouth, nicking 
 the edge of the front board, and in various ways regulat- 
 ing the size and form of the lip, so as to cause it to 
 give more purity of tone. So readily are variations of 
 tone attained by voicing and modifying these pipes, that 
 an organ may have several stops or registers of wood — 
 
OUR FIRST ORGAN. 141 
 
 i.e.^ several sets of wooden pipes — of which no two shall 
 sound the least alike. A great deal dei)ends on the 
 shape of the flue or body of the pipe, which, of course, 
 may be made, as here, with parallel sides, or with the 
 boards formed to produce a more or less conical shape, 
 and then again, the widest part may be at the top or 
 below. 
 
 As we did not attempt to make any metal pipes, I 
 shall not describe them further than to say, that the flute 
 or diapasons are made on precisely the same principle 
 as those which 1 have detailed here, only no block is 
 used, but the foot is continued to the mouth, and so 
 made as practically to serve instead of a block, it being 
 so arranged as to throw the stream of air against the 
 lip. This lip is formed by bending the metal inwards, as 
 may be seen any day in a penny tin whistle. These 
 metal pipes are of all imaginable shapes as regards the 
 flue, but the chief distinction recognised is, that some 
 are reed pipes and others diapasons. This reed is a 
 vibrating tongue of metal, which is tuned by a wire so 
 arranged as to lengthen or shorten at pleasure the free 
 end of the reed. "We made a sort of reed pipe ourselves 
 of wood, but it was a very troublesome job, and not very 
 satisfactory when done. 
 
 For this purpose we made our square flue pipe as 
 before, but on the top of the block we fixed the reeds of 
 
142 BOY ENGINEERS, 
 
 an old accordion, one in eacli pipe, so far as they would 
 go ; and having soon exhausted our stock, we made the rest 
 of brass, hammered to give it hardness and spring. In 
 fixing these, we had to hollow out the block, and so shape it 
 as to enable the reed to project downwards, because the wind 
 must strike on this projecting side. We could not there- 
 fore mannge without first riveting the tongues to a bit 
 of thin iron, which we then fixed with small screws to 
 the block. We tried various modifications of the plan, 
 fixing similar free reeds inside the front board of the 
 flue itself, and also in some other positions. We hoped 
 to get a tone like a reed instrument, hautboy, or clarionet, 
 for instance, but were only partially successful. 
 
 In after years, when time and funds permitted us 
 to launch out somewhat more freely in our mechanical 
 work, we found the experience of our younger days, and 
 especially the many blunders and failures of those days, 
 of great value ; and our early attempts at organ-building 
 developed, by practice, into a facility in work of this 
 nature which enabled us to build several very fair organs, 
 which we sold at a good profit. Bat I think none of 
 these grander and more complete instruments gave us 
 half the pleasure which we derived from that which we 
 have been describing. 
 
 The connection of the keys with the valves is, as may 
 be supposed, almost precisely like that described in our 
 
OUR FIRST ORGAN. 143 
 
 meclianical bird in the last chapter. It is illustrated in 
 fig. 13. A is the key, pivoted at E, where there is a 
 bit of brass between each key rising from a fixed board 
 underneath them. This brass is merely a bit of sheet 
 metal bent sharply at right angles like the letter L, so as 
 to fasten to the board at the bottom, and receive a wire 
 through the upright part ; or it may be — for we subse- 
 quently so arranged it — dispensed with, and replaced by a 
 single brass rod lying above all the keys in a deep notch 
 in their upper part, as seen at K in section, and at 
 RXX, as seen from above. The rod is not absolutely 
 continuous the whole length of the keyboard, as it was 
 difficult to get it straight of such length, but we made it 
 in three pieces, placing blocks, P, to take the ends of each 
 as shown at XX ; the keys on each side being cut away 
 where they occurred. The ends of each length were 
 made smaller, as at H, this reduced part entering holes in 
 the blocks. We found it necessary to put a second row 
 of the steady pins, F, about the middle of each key, which, 
 thus arranged, worked very freely and pleasantly. It will 
 be noticed that the pull-down wires which open the pal- 
 lets, V, of the sound-board pass at C through a piece of 
 bent brass, and that they are fixed by a nut; this enables 
 them to be strained to exactly the proper degree of tension, 
 which is of importance, as they should be just so tight as 
 to open the valve when the key is lightly touched. The 
 
t44 BO Y ENGINEERS. 
 
 black line under the wind-chest represents a plate of brass 
 attached to allow the wires to pass through nicelj'-drilled 
 holes in it. This is a sufficiently air-tight arrangement, 
 while at the same time the wires work more freely than 
 they would in a piece of wood. 
 
 There is not much more in the way of detail that needs 
 illustration, as there is no difficulty connected with the 
 bellows handle or leverage, by which the one stop was 
 pulled out aud pushed in. There was just a bell-cranked 
 shaped piece of wood, Z, turning on a centre, and attached 
 on one arm by a link to the slider, and by the other arm 
 to the stop-drawer, H, a squared bit of mahogany with a 
 turned handle. The method of attachment by screwed 
 wires and nuts allows sufficient play to the parts to 
 permit the slide and stop to move in a right line, instead 
 of partaking of the circular motion of the ends of the 
 crank. By an oversight the part A of the key has been 
 drawn as if standing considerably above the rest of the 
 key. This is only the case with the black keys. The 
 rest are level, but broader at the end A. The set were, in 
 fact, as stated, originally made for a pianoforte. The 
 wire z of the stops must not be supposed to be merely a 
 bit of bell-wire, but is stiff enough to push back the stop 
 as well as to pull it out. This will only answer for a 
 very light slide, for other mahogany rods must be used. 
 Rollers and trackers are also necessary in organs, in 
 
OUR FIRST ORGAN. 145 
 
 which the keys are not opposite their respective pipes, 
 but we managed our small organ without them. 
 
 Although in some of the details — as, for instance, the 
 rollers just alluded to— organs are constructed differently 
 to that here described, it has seemed better to stick as 
 far as possible to the original plan of our little book — to 
 show how a pair of lads, using their own talents in their 
 own way, triumphed over the difficulties met with, and 
 succeeded in building an organ of small size but of fair 
 tone, and capable of being played on with satisfaction to 
 others as well as to themselves. In trying our hands, 
 subsequently, at a larger concern, we altered many details 
 which experience showed us needed improvement, and 
 followed, so far as we were able, the plan of professional 
 builders. 
 
 In res[)ect of the last sentence there is a lesson to 
 be learned by experience. Boys and amateurs generally 
 are somewhat inclined to follow their own devices, under 
 the impression that their way of doing things is at 
 least as good, if not better, than that of professionals. 
 Let them be assured that nine times out of ten they are 
 wrong ; but there is nothing like experience to teach them 
 this. We boys (like other boys) were tolerably full of 
 self-conceit, but we very often failed utterly, and still 
 more often partially, in our attempts at the various 
 handicrafts, for want of knowledge and information 
 
146 BOY ENGINEERS. 
 
 which we would not condescend to ask, and after many 
 tiresome experiments, due to our conceit, we always 
 discovered that we had set about our task in an unworlv- 
 manlike manner, and we found ourselves at last working 
 in the very way in which we should have worked had we 
 at the first gone to some one who had been trained 
 to that work, and condescended to ask him to show ub 
 how to do it. A civil request of the kind is, moreover, 
 seldom, if ever, r<^fused to a lad by a professional. 
 
Chapter VII. 
 
 OUR HOUSE 
 
 E now began, like lads whose brains were some- 
 what like the troubled sea, to hanker after a 
 job of a heavier class, and the circumstances 
 which led to our choice were as follows : — 
 We had both left school, and having by no means 
 washed our time, we were now to have a year or two 
 at home under a private tutor, who was thouglitfully 
 selected for us, not for his scholarly attainments alone, 
 but for his predilection for mechanical and scientific 
 pursuits. A Cambridge graduate in mathematical 
 honours, his special task was to instruct us in the 
 theory of engineering, which his own knowledge of the 
 practical details enabled him to do with more than 
 ordinary facility, because if we failed to lay hold of any 
 
148 BOY ENGINEERS. 
 
 mechanical law, lie was often able by a simple experiment 
 to explain it to us in a way that at once fixed it indelibly 
 upon our minds. 
 
 We had, of course, left our old workshop behind us, 
 and not without a parting sigh of regret. I remember 
 well how we went to pay a last visit to the scene of our 
 many happy labours, and removing the old notice boards 
 of ''No admittance" and "Beware of the bull-dog,'* 
 we substituted another, which stated that " the car- 
 penter's shop and engineering establishment was per- 
 manently removed to larger premises." 
 
 These larger premises consisted of an orchard within 
 the parental estate, in which we now proposed to erect 
 a new workshop. This, however, was to be a combina- 
 tion of shop and study, as we fancied it would assist our 
 mental toil if it was carried on in close proximity to the 
 scene of our various handiworks. For this purpose we 
 determined to build a workshop with a study opening out 
 of it, and by our father's kind liberality we were enabled 
 to procure the raw material suited to our requirements. 
 The only stipulation made was, that we should construct 
 the building in a workmanlike manner, and not so as to 
 be an unsightly object upon the premises. As I was 
 now nearly nineteen, and my brother seventeen years of 
 age, both at that time, moreover, in robust health, the 
 actual labour in prospect did not terrify us. We were 
 
OUR HOUSE. 149 
 
 early risers and kept regular hours, which of all things 
 specially adds time to one's days. Desultory work is, 
 as we had seen with some of our companions, the 
 greatest bane to success ; and the surest way to accom- 
 plish life's various tasks in a thoroughly satisfactory 
 manner is to set apart certain hours for each of them. 
 We began our day, as hoys ought to begin, by a quiet 
 half-hour with our Heavenly Father, then we studied till 
 the breakfast-bell sounded punctually at eight. We then 
 had an hour at our work, generally putting things 
 straight, grinding and sharpening tools, and from ten till 
 one we had a grind ourselves with our tutor. After 
 early dinner we set to work upon our house, and gener- 
 ally kept at it till six, when we had tea. In the winter 
 months we had to arrange our time diiferently, but 
 always learned the value of order and discipline, acquired 
 partly at school, and partly under the kind but strict 
 rule of a most worthy father. As a Navy man, he had 
 himself learned to obey before he learned to command 
 others, and our home life was to no small extent 
 modelled on that of a man-of-war, nor, perhaps, can a 
 better model be found anywhere. 
 
 The foundations of our house were brick, and these 
 "were carried up all round two feet above the surface of 
 the ground. This work we might have had done for us, 
 1? At as we were intended for engineers, and had not yet 
 
ISO 
 
 BO Y ENGINEERS. 
 
 determined to what department of that profession we 
 should eventually turn, we thought a little practical 
 masonry would at any rate do no harm, but rather give 
 us an insight into details of work that we might some 
 day have to superintend. 
 
 I I 
 
 A A A A 
 
 Pig. 13. 
 
 Fig. 13 is the ground-plan. It will be seen that, 
 
 although we by no means despised learning, we gave the 
 workshop the place of honour as to dimensions, making 
 it twelve feet by ten, whereas the study was only ten \yj 
 
OUR HOUSE. 
 
 151 
 
 eight. But out of the latter we cut off a space of tliree 
 feet for a lavatory, otherwise it would have been larger. 
 This lavatory was an essential, as hand-washing cannot 
 be very well omitted after workshop operations, unless 
 grimy boohs are desirable. We had, however, no door 
 between our workshop and lavatory, which in fact formed 
 a lobby, the study opening out of it. The workshop 
 was well lighted by two windows in adjoining walls, one 
 being six feet long, the other three. The first of these 
 was two feet six high, the latter two feet. The details 
 of both will be found farther on. The study windows 
 were both two feet high by three feet wide. We used 
 nine-inch brickwork — i.e.., our wall was one brick 
 thick. 
 
 The bricks always need to be so laid as to bond 
 together in a proper manner ; the joints of one row must 
 never coincide with those of the one next above or below. 
 In one part of the front wall is illustrated the common 
 manner of laying one row of bricks of a nine-inch wall, 
 and in that just above it the headers A and stretchers B 
 would lie in the opposite direction; thus bringing the centre 
 of a brick over a joint AA ; this, it will be seen, will tie 
 together the inner and outer faces of such a wall, which 
 might otherwise easily split asunder in the central line or 
 joint of the stretchers laid longitudinally. This is called 
 Flemish bond, and gives to the front of the wall the 
 
152 ^OY ENGINEERS. 
 
 appearance so generally seen — the long and short sides 
 of the bricks alternating. A small portion of the face ot 
 pnch a wall is shown at CO, and will be recognised as the 
 more common form. 
 
 English bond is made differently. A row of headers is 
 laid, and on them a row of stretchers, and so on alter- 
 nately the whole height of the wall. In this case, the 
 front face shows apparently alternate rows of short and 
 long bricks, which certainly does not look so well. It 
 may happen that the total length of a wall is such that 
 nine -inch bricks, inclusive of joints, will not exactly 
 reach from end to end. There must, consequently, be 
 somewhere inserted half or quarter bricks. The joints 
 are, however, always made to break, as it is called, or 
 the whole would fail to be of that substantial character so 
 necessary. It is specially an object with a bricklayer to 
 make the joints overlap at the corners, so as to bond the 
 four walls of a building thoroughly together, each serving 
 as a support or buttress to the other. Thus if the first 
 tier ends at the corner with two stretchers, he will lay a 
 pingle stretcher only on the face of the wall, but behind it, 
 instead of the second, he will lay the ends of two stretchers 
 of the wall at right angles to it, thus turning the corner, 
 and this will also have the effect of getting the bricks of 
 that wall in proper order. The length of a brick is nine 
 inches, the width four and a half, so that two headers 
 
I 
 
 OUR HOUSE. 153 
 
 exactly cover the two stretchers beneath it. But it will 
 be found upon trial that a second row will not break 
 joint if a pair of headers are laid on a pair of stretchers, 
 simply as described, although this is the way to build 
 such a wall, but somewhere a brick must be split in each 
 row lengthwise, which will bring all the joints right for 
 that row or layer. In the same way in walls of a brick 
 and a half thick — i.e.^ one laid flat as a header, and one 
 laid flat as a stretcher alongside of it — it becomes 
 necessary very often to cut a brick either across or 
 lengthwise to bring the joints right; and the necessity 
 for window and doorways, which would interfere with the 
 regular bonding, may compel two headers to take the 
 place of a header and stretcher, or vice versd. A brick- 
 layer used to his work never hesitates, but sees exactly 
 where he can best place his half bricks, so as not to inter- 
 fere with the general appearance of his work, but we had 
 many a consultation on that score, as amateur masons do 
 in such cases. 
 
 We found the best way of learning the art, which, 
 after all, is very simple, was to draw plans to scale, 
 making the bricks the exact relative size, so as to find 
 out whether they would bond ; and we also made some of 
 wood also to scale, like those of a box of child's bricks, 
 and with these we built up walls of various kinds of bond, 
 so that we soon had the secrets of bricklaying at our 
 
154 BOY ENGINEERS. 
 
 fingers-ends. AVe also learned a good deal of plan- 
 drawing by thus putting things dow:i on paper, and 
 drawing everything properly to scale, a method we re- 
 commend to all young mechanics. 
 
 We carried the foundation, as I have said, two feet 
 above ground, and below we dug out our trenches 
 one foot deep, which brought four courses underground. 
 We had good, dry, and firm loam to deal with, and below 
 was gravel, so we found this to be quite deep enough to 
 secure the stability of a small light building. There 
 were eight courses above ground, each brick being three 
 inches thick. When I say two feet above ground, I mean, 
 therefore, eight courses, but with the mortar it was a 
 little higher. 
 
 The worst part of bricklaying was, we found, the 
 effect which lime has upon the skin of the hands, which 
 became dry, and would have chapped if we had had more 
 of the work to do. This results from what chemists call 
 the affinity of lime for water, which it absorbs. Thus all 
 the natural perspiration, which keeps the hands moist 
 and soft, is seized upon by the lime, leaving the skin 
 in a perfectly dry and inelastic condition. 
 
 Nothing shows this absorbent property of quicklime 
 more than the process called slaking it to make mortar. 
 
 Quicklime is carbonate of lime burnt. This substance 
 occurs in various forms in large quantities in nature. 
 
OUR HOUSE. 155 
 
 Chalk, marble, limestone, oyster shells, and indeed most 
 shells, with those beautiful stahictites found in caves in 
 Derbyshire and elsewhere, are all carbonate of lime in 
 varied forms. Ordinary limestone, forming hills and 
 rocks, is the substance most commonly used for making 
 quicklime, as it can be procured in almost all parts of the 
 country. This is broken into large lumps and burnt in 
 kilns, which are often holes dug in the side of a hill and 
 lined with firebrick ; and sometimes are built wholly 
 above ground, but the first is most convenient, as the 
 stone must be wheeled to the top or mouth and thrown 
 in. When thoroughly burnt, the lime is drawn out 
 at a hole made for the purpose at the bottom of the 
 kiln. 
 
 The lieat drives off the carbonic acid, or carbonic anhy- 
 dride, as it is now often called, in the form of gas, which 
 is fatal to animal life. It sometimes happens that the 
 lime-burners fall asleep too near the mouth of their 
 kilns, and are quickly sent to sleep by the gas, and 
 perhaps burned to death without awaking. It is a very 
 heavy gas, and escapes, therefore, but slowly into the air 
 above it. After this gas is driven off, the limestone is 
 found to have acquired new properties, which, however, 
 will not last long if it is left exposed to the air, as it 
 will again pick up carbonic acid and become what it was 
 before — viz., carbonate of lime. 
 
1 S6 BOY ENGINEERS. 
 
 In its new state it is called caustic lime, because it 
 will burn and destroy animal and vegetable matter, and 
 in this state it has the peculiar property of so entirely 
 absorbing water as to dry it, so to speak ; for if a 
 bucket of water is thrown on a heap of quicklime, the 
 latter heats very much, steaming and smoking, and then 
 all at once falls to pieces as a perfectly dry powder. 
 It is in this state that it is. used by the mason, being 
 called slaked or slacked lime, and mixed with sand or 
 road grit to make mortar. We had seen this oi)eratiou 
 very often, but until we ourselves performed it we had 
 thought little about the why and wherefore. Now, 
 however, our curiosity was roused, and our tutor kindly 
 gave us the information here recorded, with much more 
 about this and other gases which we cannot set down in 
 these pages, as we must go ou with the details of our 
 house-building. 
 
 The shallow flat-bottomed trench dug out to receive 
 the foundations of course marked out the outline of the 
 building. We had taken all possible care, therefore, to 
 make the sides truly square to the eiids. The partition 
 between the workshop and study we intended to make 
 entirely of wood, and here we only gave the wall half 
 the thickness, building it with single stretchers, the 
 joints overlapping as before. At the doorway the wall 
 was carried but one course of bricks above the level of 
 
OUR HOUSE. 157 
 
 the ground, to receive the cill, a piece of oak, into which 
 the doorposts were mortised ; but where windows occurred 
 we built up to the normal height, as the bottom of none 
 of these was to be less than three feet from the ground. 
 Having thus raised the foundations to the required height, 
 we laid upon them the main timbers or wall-plates, into 
 which all the chief uprights were to be mortised. These 
 were seven inches wide and six thick, and all the mor- 
 tise holes were marked and cut before putting them in 
 place upon the walls. Where they met at the corners, 
 they were half lapped into each other as seen at L, 
 fig. 14. 
 
 This drawing also shows the details of the timber 
 framing and boarding of the back of the house, in which 
 was the outer door. BB are the wall-plates last de- 
 scribed. They are bevelled off at the upper face all round 
 to throw off the rain. The uprights at the angles are 
 six inches square, the rest, including doorposts, four 
 inches by three. The wall-plates are laid flush with the 
 wall on the outside, so that a ledge of brickwork remains 
 of two inches on the inside. The uprights are placed 
 so as to be flush with the top edge of the bevelled part, 
 which is cut back one inch. The corners of the wall 
 plates are pinned together by the tenons of the corner 
 uprights, which go through the upper half lap into 
 but not through the under one. The posts are not 
 
^58 
 
 BOY ENGINEERS. 
 
 pinned sideways, but are held by the pinning of the 
 uprights, CO, so as not to weaken the half lap joint 
 
 GROUND LINE 
 
 Fig. T4. — House Construction. 
 
 unnecessarily. All the uprights are mortised into the 
 upper wall-plate, IIH, which extends six inches on each 
 side to take the outer rafter, and form eaves overhaue-in? 
 the end walls. 
 
 DD is a very essential tie-beam or diagonal strut, 
 wholly preventing any side play, and stiffening and bond- 
 
OUR HOUSE. 159 
 
 iug the whole firmly together. It is notched where it 
 crosses the uprights, and nailed to them. The doorway is 
 three feet wide, that between the study and workshop 
 being two feet six inches. The outer one was made 
 wider to allow of the easy admission of our work-bench, as 
 well as the exit of various articles. It is rather awkward, 
 after finishing some piece of work of more than ordinary 
 dimensions, to find that you can neither get it out at the 
 door nor at the window ; but we have known such things 
 occur among other accidents of the workshop. A, shows 
 one part finished by being covered by boards. There are 
 several modes of doing this which must be considered in 
 planning the timbers. The framing shown was designed 
 for horizontal boarding, as here illustrated ; but if the 
 boards were to be vertical, it would be necessary to intro- 
 duce horizontal timbers — one below the top wall-plate, 
 one just above the lower plate, and one running across 
 halfway between them. We illustrate here the best method 
 of boarding such outbuilding at A. The boards are put on 
 so as to lie quite level and horizontal. In this they are 
 generally tongued and grooved, i.e., a groove is planed in 
 the middle of the edge, into which is fitted a strip of thin 
 iron or wood, and the other being similarly grooved, is 
 forced up against it so that the tongue enters this also, 
 and although the boards may shrink and slightly separate, 
 no open space occurs between them. K shows a neat and 
 
i6o BO Y ENGINEERS. . 
 
 simple mode of placing upright boards, which are simply 
 nailed on side by side, and then a narrow strip or fillet, 
 bevelled off or moulded, is nailed on where they join. But 
 in this work the precaution should always be taken of not 
 nailing these fillets to both boards, because if this is done 
 and they shrink, the fillets will of necessity split. The 
 best way is to place the boards one-eighth of an inch apart, 
 and to fasten the fillets by driving long thin nails into 
 them down the middle, which, falling between the boards, 
 and passing into the cross timbers behind, leaves each 
 board perfectly free to shrink. At M is shown the 
 method of weather-boarding. The boards here are feather- 
 edged, that is, they are thick on one edge and thin on 
 the other, and they are made to overlap as shown, and 
 nailed one after the other, beginning at the lowest, to the 
 timbers behind, which are, of course, upright, as in the 
 drawing of the house. 
 
 Well-seasoned weather-boarding makes a sufficiently 
 neat outside for barns, stables, and other outhouses, and 
 in places where fir is grown it is very much used ; it is 
 also made of oak, which is more durable, but more ex- 
 pensive. Its chief fault is that it has a tendency to curl, 
 so that the upper surface of the boards becomes hollow 
 and the lower convex. This is not, however, a serious 
 defect, although it somewhat interferes with the regularity 
 of the boarding. We nailed our boards on to meet at the 
 
OUR HOUSE. i6i 
 
 edges, but attached them to the posts CC, which stood back 
 the thickness of a board behind the level of the corner 
 posts and doorposts. To these we nailed two-inch 
 fillets for the ends of the boards to rest against, and we 
 nailed them to these as well as to the other uprights, but 
 with much slighter nails. The framing of the other sides 
 was similar to that here delineated, except that tlie ends 
 were gables, and that the framing bad to be carried up 
 above the wall-plate. We originally intended to thatch 
 the roof, as affording on the whole the prettiest finish, but 
 as at that time a stable had been re-roofed and slates 
 substituted for baked tiles, we laid hands on these, and 
 found no great diflficulty in laying them in an efficient 
 manner. We thus were enabled to dispense with the ser- 
 vices of a professional thatcher, and to comi)lete the house 
 entirely without extraneous assistance. We bought a few 
 new and bright tiles, which we laid round the eaves and 
 on all the edges, and also laid them in a double row along 
 the centre of each side. They gave a nice finish to the 
 whole, and made the old grey tiles appear as if they had 
 been specially chosen to complete the design. 
 
 Had we lived a few years later, in these days of tarred 
 felt, we might certainly have built our house for less 
 money, and we could have nailed a few broad rough 
 boards as rafters, and covered them with this useful and 
 cheap material. Even the walls might have been so 
 
1 6 2 BOY ENGINEERS. 
 
 made with a similar lining within, and they would have 
 made a warm and snug building. The smell at first mi^ht 
 have been somewhat disagreeable, but we should not have 
 cared much about such a trifle. 
 
 There is some skill required, nevertheless, in order to 
 dse felt to advantage and to make a neat job with it. In 
 winter it is very stiif, and will crack if forcibly bent. In 
 summer it is perfectly pliable and easy to use, but the tar 
 is apt to come off and mess one's hands a good deal. The 
 surface, however, is usually dusted with fine sand to pre- 
 vent the surfaces clinging together when it is rolled up 
 for sale, and this renders it less sticky also to the fiii<ieis. 
 The neatest way to use it is to cut it into lengths of not 
 more than six feet, and to nail it to a level surface of 
 boards in panels, running a fillet afterwards where the 
 edges meet, and thus dividing it into panels. If the fillets 
 are painted of any light and bright colotir, the general 
 effect will be exceedingly pretty ; but every part must be 
 made as true as line and square can make it. The boards 
 upon which it is laid must be level, but otherwise it 
 matters not what their shape may be. Outside slabs of 
 fir, or any odds and ends having one flat side, will answer 
 the purpose ; but unless, as a wliole, they present a level 
 surface, every edge which stands up will slu)W a ridge, 
 and mar the general effect. The boards, however, need 
 not be put close together. They can be nine inches or a 
 
OUR HOUSE. 163 
 
 foot apart, but should not be much more, or the felt will 
 be apt to bag and appear loose between them. If a build- 
 ing thus constructed is to be used simply as a worksho[), 
 the timbers showing in the inside need not be covered, 
 and, indeed, they are exceedingly handy. If, however, it 
 is intended to use it as a study, or for any similar purpose, 
 it should be lined inside with flush boarding, and painted, 
 or, if preferred, it can be papered ; but in order to make a 
 good job of it, it will be necessary first to tack cheap 
 calico over the boards, straining it tightly. If this is not 
 done, and the boards shrink, the paper will crack in many 
 places. Having treated a boarded partition in this way 
 with pei-fect success, we speak from experience. We did 
 not, indeed, even line our study with boards, but we 
 strained canvas over the beams, and thus got a surfoce suffi- 
 ciently even to receive paper, and when finished it looked 
 exceedingly neat. We carried the canvas up into the roof 
 also — not to the angle, but to collar-beams about eighteen 
 inches below. We thus contrived an efficient ceiling, 
 which we covered with white paper ; all round the angles 
 and up the corners we nailed strips of beading or mould- 
 ing, so that, when all was finished, no one would have 
 known that the room was merely of wood and canvas. The 
 floor was boarded, but that of the workshop was made of 
 clay, laid and rammed down as hard and level as possible. 
 We must, however, now recur to some of the timber 
 
x64 
 
 BO V ENGINEERS. 
 
 work. Fig. 15 represents the end of the v^oirlrAhop 
 with the smaller window, showing the timber alao of 
 
 1 — r 
 
 Fig. 15.— Timber Framing. 
 
 the gable end of the roof, and the cross-timber ends or 
 purlines, aaa, running across from one gable to the 
 other. EE is called a collar-beam, its use being to tie 
 
OUR HOUSE. 165 
 
 the sloping sides of the roof, FF, together, and prevent 
 them from spreading sideways. GG is a tie-beam for the 
 same purpose ; but the last is only put at the two outside 
 trusses, as the triangular framework is called, whereas 
 the collar-beams are added to several of the intermediate 
 rafters in order to tie them together, and also to receive 
 the ceiling laths when the ceiling is laid at this height. 
 It is, however, generally at the level of the lower or main 
 tie-beam, GG. 
 
 In large roofs, perpendicular rafters are laid over the 
 purlines to carry the laths upon which the slates or tiles 
 have to be laid, and there are several of the main trusses 
 intermediate between those of the gables. In light roofs, 
 however, these are not needed, and the usual way is to 
 nail the rafters direct to the wall-plate and ridge-piece, 
 and to notch in or merely nail on the "Collar-beams, EE, 
 from rafter to rafter, to carry the ceiling laths, or to assist 
 in stiffening the roof timbers. We notched the purlines 
 just so far into the rafters that they should act as stifF- 
 eners, and also as laths. They were perhaps scarcely 
 matters of necessity at all, and it would have saved us 
 some trouble if we had put them inside the rafters instead 
 of outside, where it was necessary to notch them on to 
 bring them level with the slating laths. 
 
 Owing to the way in which we had built the house, 
 furnishing the walls with a horizontal wall-plate all round, 
 
1 66 BOY ENGINEERS. 
 
 but projecting at the gables to form level eaves, tbe rafters 
 did not rest on the actual wall-plates, but on another beam 
 notched down upon the projecting plates, as seen in this 
 drawing, where the shaded part shows its ends. 
 
 The construction of roofs of large span is calculated to 
 call forth the highest professional skill of the architect and 
 builder, and is a subject of peculiar interest. The main 
 object aimed at is, to convert the outward thrust upon 
 the walls into direct downward pressure, and to neutralise 
 all tendency of any particular part to bend or sag, by 
 straining pieces, ties, and struts. In fig. i6 we give a 
 few sketches to illustrate this in simple outline. 
 
 ABC may stand for a pair of rafters, resting at B and 
 C upon the wall-plates of the two walls, BH and CG. 
 Any pressure on A, or on the lines AB and AC, will 
 tend to make BC spread open, a becoming practically a 
 joint, and ab, ac, the legs of a pair of compasses ; and if 
 the points B and C are rigidly fastened to the top of the 
 walls, these latter will at once be thrust apart, and the 
 structure will fall. To prevent the legs thus spreading, 
 we may tie them by a cross piece at the line BC, which 
 is thence called a tie-beam. This, moreover, may be 
 replaced by an iron rod, as it is a true tie, and a rod of 
 this metal will bear an enormous strain without stretching 
 or breaking, if thus applied in the direction of its 
 length. 
 
OUR HOUSE. 
 
 167 
 
 This tie-rod or tie-beam will thus effectually hold to- 
 gether the lower ends of the rafters, and any weight now 
 applied will merely press downwards upon the walls. If 
 the rafters are very long in proportion to their size,they will 
 be inclined to bend inwards at the middle of their length, 
 F. To guard against this we require a strut, FD, at right 
 
 Fig. x6. — Boof Construction. 
 
 angles to AC, and here a tie-rod is of no use. We there- 
 fore need an abutment for such strut somewhere at 
 its lower end about the point D. Now if BC is a rod of 
 iron, and we rest the end of sucb strut upon it, it will 
 tend, of course," to make it bend or sag downwards, and a 
 
1 68 BOY ENGINEERS. 
 
 rod, AD, becomes requisite, whicli will prevent tins bending 
 from taking place. 
 
 I have snpposed iron rods to be used as yet, but with 
 timber a similar arrangement becomes necessary. BC in 
 this case will be a beam called, as before stated, a tie- 
 beam, and AD an upright, called a king-post ; FD will 
 be a timber strut. The lower the pitch of the roof the 
 greater will be its outward thrust. If the ridge were at 
 E, for instance, instead of A, the strain would be much 
 greater. Thatched roofs are of very high pitch. Slate 
 roofs much flatter, and a roof intended for tiles will 
 be intermediate between them. When a tie-beam is 
 inconvenient or unsightly, as in an open timber roof 
 where no ceiling is required, it is replaced by a beam 
 higher up, KF, called a collar-beam. This is dovetailed 
 at tlie ends into the rafters to give it a stronger hold. 
 It is not so effective, however, as a tie-beam, and, when 
 used, the timbers are differently arranged ; but each 
 timber and iron rod of the complicated roofs now to be 
 seen in railway stations and elsewhere is essential to the 
 stability of the structure. Even timbers which form 
 arches, or which, by their curved outlines, lend beauty to 
 the design, will, on examination, be found to act as tie- 
 beams, struts or braces. 
 
 At MNO of this figure is given the usual method of 
 notching a sloping beam or rafter into a tie-beam to 
 
HOOFS. i6g 
 
 enable it to receive the strain brought upon it, which is 
 an outward thrust tending to make it slip along the beam. 
 The abutment at effectually prevents such slip ; and in 
 heavy work the joint would be either strapped over with 
 an iron hoop or bolted through — generally tlie former, 
 which does not weaken the timber, as a bolt-hole does. 
 
 In our study as youthful engineers, under our tutor's 
 guidance, we made many experiments upon beams and 
 trusses, which also gave us some exercise in practical 
 mechanical work, as we made models of maliogany, care- 
 fully finished, with miniature straps and bolts, and rods 
 of iron and steel. In the lower part of this figure is a 
 sketch of a very simple but efficient mode of stiffening a 
 beam or plank which is frequently used in roofs. Let BB 
 represent the beam which is to support a pressure from 
 above on its centre, where the weight W is placed. The 
 tendency of this will be to bend the beam downwards and 
 to draw its extremities from off the upright posts or walls, 
 AA. This may be wholly prevented by placing under its 
 centre a strut or block, S, and adding a straining bar of 
 iron screwed at both ends, so that it can be tightened by 
 nuts, NN, a bearing for these nuts being cut in the beam, 
 60 that they shall lie truly at right angles to the bar and 
 bed well and fairly upon the wood. All downward pres- 
 sure at W tending to bend the beam is converted into 
 strain upon the iron rod tending to stretch it lengthwise 
 
I70 BOV ENGINEERS. 
 
 — a strain which, a very small rod will bear without 
 yielding. An engineer's business is to calculate tliese 
 questions of strain and pressure, and to determine what 
 sized rods and struts and beams are needed, so as to 
 render the structure as secure as possible without adding 
 unnecessarily to the weight. This is specially necessary 
 in designing roofs of large span. 
 
 A ramble over any old house will serve to show the 
 advance that has been made of late years in the art of 
 building. Those huge oak beams which were then 
 considered necessary, and which in turn needed walls of 
 undue thickness to support them, are no longer used. 
 We set our joists on edge, and saw up the large beams 
 into half a dozen such joists, bracing them where 
 necessary by intermediate struts to prevent side flexure, 
 and we calculate the probable thrusts and other strains 
 to a nicety, in order to economise the material, and 
 consequently the expense of the building. No doubt 
 this economy is sometimes carried too far. The reproach 
 of many a modern town-house is, that its walls are so 
 thin as to be absolutely unsafe to the inhabitants, and 
 not seldom do we read of newly-built houses collapsing 
 before being finished. This, however, is simply the 
 result of false economy, and not of the want of skill in 
 architects and engineers. Many of the houses alluded 
 to are merely raised by speculative builders, who work 
 
ROOFS, 171 
 
 b}"" plans of their own, and whose sole object is to build 
 houses cheaply for their own profit. In a well-con- 
 structed building, every part bonds and supports the 
 other, and the roof exercises no outward pressure tending 
 to thrust asunder the walls which support it, but is 
 simply a solid structure, bonded together at all points, 
 which acts only as a superincumbent weight, exerting a 
 force directly downwards, which the walls, if themselves 
 perpendicular, are exactly calculated to bear. The bur- 
 den is, in fact, carried by mother earth herself, patiently 
 enough, unless she chooses to set her back up once in a 
 way by an earthquake. 
 
 Fig. 17 is a drawing of the timbers of the roof as 
 they would appear when seen from above, but before the 
 battens which are to hold the tiles are put on. These 
 would, of course, run parallel with BBB, which is the 
 ridge-plate at the highest part of the roof; AC is the 
 ridge of the short bit of the roof which comes over the 
 projecting part of the study, but ends at the ridge of the 
 main roof; DD represent the wall-plates, or rather in this 
 case the beam which overhangs the building, and receives 
 the lower end of the rafters. 
 
 AE and AF are diagonal timbers where the roofs 
 meet, and to which the rafters both of the short roof 
 and of the long are nailed, forming, when the tiles are 
 on, a gutter at AE and AF, requiring to be leaded under 
 
172 
 
 BOY ENGINEERS. 
 
 the tiles to carry off the water. As C is the peak of 
 a gable, the end of the projecting part of the building is 
 what is called a pine end — i.e.^ triangular above the 
 
 
 
 
 ^ 
 
 
 _D 
 
 
 
 
 
 
 
 
 D^ 
 
 J^ 
 
 
 A 
 
 
 
 
 
 
 
 
 
 ~n 
 
 
 
 
 
 n 
 
 
 r 
 
 V 
 
 p 
 
 
 n"^ 
 
 // 
 
 ^ 
 
 J/ 
 
 t 
 
 
 
 
 
 
 ^■^ 
 
 
 
 -J/ 
 
 \ 
 
 
 
 1 
 
 
 D 
 
 ID 
 
 
 
 1 
 
 
 1 
 
 1 
 c 
 
 Fig. 17.— Roof Details. 
 
 wall-plate. A hip roof, on the other hand, slopes back 
 from the wall-plate to the ridge, leaving the wall, there- 
 fore, quadrangular. The rafters in the drawing appear 
 thin because they are set on edge, as is also the ridge- 
 plate against which they abut, and to which they are 
 nailed. 
 
 This roof cost us a good deal of trouble, being a severe 
 test of our capabilities as carpenters, but on the whole we 
 
OUR HOUSE. 173 
 
 succeeded better than we might have expected. We 
 made use of a dodge in fitting which we had seen used 
 by carpenters — ^viz., a strip of thin board the length of a 
 rafter, and another the length of the inclined timbers EF, 
 which we could cut to the exact angle required at each 
 end, and when we had once fitted this accurately to the 
 wall-plates and ridge-piece, we could mark every rafter by 
 it and saw them off, instead of having to try each one in 
 its place again and again until it should prove to be 
 correct. It is, of course, much easier to fit a thin strip 
 of board than a rafter two inches thick, which, if long, is 
 a heavy affair to manage on the try-try-again principle. , 
 
 The windows of our workshop were very simple affairs. 
 "We merely nailed on the beam, at the top and bottom of 
 the space left for that purpose, a few upright bars of wood 
 rebated to receive the panes of glass. We did not rebate 
 the side pieces, which were also of course two studs of the 
 framing, but merely nailed on some quarter-inch stuff a 
 little narrower than these studs, which had the effect of a 
 rebate. We then cut and puttied in our strips of glass. 
 In this, howe^'er, we showed a certain degree of wisdom 
 which may be worth recording for the benefit of other 
 boy-builders. We rightly conjectured that the windows 
 of a workshop would be peculiarly liable to breakage, we, 
 therefore, instead of long strips taking up the whole of 
 each space, placed only small panes, making the upper 
 
174 BOY ENGINEERS. 
 
 overlap the lower ones, so that in case of an accident, we 
 conld repair damages by inserting a new small pane only. 
 The light was not in this way interfered with, and at the 
 same time the wet was effectually kept out. An advan- 
 tage in our wooden workshop which we discovered at a 
 later date was the ease with which we could at any time 
 extend our windows in either direction by removing a 
 board or two and replacing it by another strip of glass. 
 We ultimately extended our three-foot light to six feet, 
 and our six-foot one to eitiht feet, besides addins: 
 another in the side wall at the place where we found it 
 necessary to place another vice-bench. We also subse- 
 quently converted part of the boarding into a shutter 
 hinged on the top to lift up for the admission of air, and 
 very advantageous we found it in the summer months 
 when we were often glad to throw it open as wide as pos- 
 sible; for though our work was i)lay to us, owing to our 
 fondness for mechanics, we by no means played at work 
 when we were so engaged. 
 
 Nothing now remained for us to do of any special diffi- 
 culty. The laths or battens were nailed on at such a 
 distance apart as to give the tiles a good lap, and the 
 latter, after being fitted with wooden pegs (oak), were duly 
 hung, which did not take us very long. The ridge tiles 
 were then added, and these we bedded in plaster to make 
 all weather-tight and snug. 
 
OUR HOUSE. 175 
 
 The framing of the light partition between the study 
 and workshop was a very simple matter, which we carried 
 out after having roofed in the building. The doors were 
 plain ledgers, i.e., upright boards bonded by three across 
 them to carry the liinges and lock. We tongued and 
 groved these boards together and ran a beading down the 
 edges of each. 
 
 The wooden floor of the study was laid on joists which 
 rested upon brickwork at each end and in the middle. For 
 this purpose we built up a wall inside the main one on 
 two sides and one parallel to them along the centre, nine 
 inches high above ground. Upon these we laid the joists, 
 taking care that they rested fairly upon the walls, and as 
 soon as we had laid the rows complete, we laid upon them 
 one board and temporarily tacked it down to keep the 
 joists in place, ready to receive the rest. We took as much 
 care as possible to get the boards close together, but did 
 not think it necessary to tongue and groove them. The 
 way in which we got them close together, as we had no 
 flooring cramp, was as follows : — We laid one board close 
 to the wall true and level, and nailed it down securely to 
 all the joists. We then did the same at the opposite 
 wall, thus firmly securing all the joists together, and 
 getting a solid foundation to work upon. Then we laid 
 the next board, but before nailing it we drove into about 
 four of the joists a stout short nail, three inches from the 
 
175 -BOV ENGINEERS, 
 
 edge of the toard lying loosely in its place, and between 
 these nails and the board we drove hari-wood wedo:es, 
 which, bearing on one side against the fixed nails and in 
 the other against the loose board, forced the latter up 
 close against its predecessor. After nailing this down we 
 drew the nails which we left standing an inch out of the 
 joist, and repeated the operation with the next board. 
 
 It is not necessary to describe the few remaining details 
 of our house-building operations, and we shall conclude the 
 chapter by a few words about the arrangement of our 
 workshop after the building was wholly completed. 
 
 The large window was honoured with the lathe for which 
 it was specially designed. The small one had. the carpen- 
 ter's bench in front of it, next to which came a stout 
 small bench of three-inch plank with a blacksmith's tail- 
 vice. This was subsequently removed to a new window 
 which we made, as already mentioned, as we found that we 
 required more light when our filing operations were re- 
 quired to be carried out with greater accuracy than in days 
 of early attempts at this apparently easy, but in reality 
 most difficult, work. Above the vice was fixed a drilling 
 apparatus, which could be swung round out of the way 
 when not required, and could be brought exactly over the 
 vice, or over any desired part of the drilling bench. We 
 shall describe this in a subsequent chapter. 
 
 The lathe tools had a special rack on both sides of the 
 
AN ORDERLY WORKSHOP. 177 
 
 large window, in which they were ranged neatly according 
 to size; and by this time, in addition to the chisels and 
 gouges, we had a fair stock of variously-shaped tools for 
 hard wood and metal turning. Another rack over the 
 carpenter's bench held the tools peculiar to that work, and 
 planes occupied a couple of shelves above. Files and drills, 
 and hard chisels, pliers, and screw wrenches, had a rack to 
 themselves above the vice-bench. 
 
 The next chapter will be devoted to a description of our 
 workshop fittings, as they existed after we had completed 
 them ; and although we were not fitted up with any 
 pretensions to stylishness, our workshop was far more 
 complete in its arrangements than many others which we 
 subsequently inspected, and which were more for show 
 than for real work. 
 
Chapter VIII. 
 
 OUR WORKSHOP FITTINGS AND APPLIANCES. 
 
 N a previous chapter I have spoken of the 
 renovation of the French lathe-head and the 
 subsequent addition of a cylinder poppit, 
 instead of the simple and inefficient screw in a 
 block of wood which we had heen compelled to use pre- 
 viously. The lathe-head with its guide screws was really 
 an exceedingly good one. We found that it was very 
 true, and had simply been laid aside and neglected, more 
 than deteriorated by wear and tear. We therefore saw 
 no necessity for throwing away money on the purchase of 
 a better. The strap pulley, however, was inconvenient 
 when we came to turn metal, because we could nut re- 
 duce the speed ; so we expended a little hoarded cash in 
 
LATHE DETAILS. 179 
 
 the purchase of a grooved fly-wlieel and crank shaft, and 
 we then turned a neat mahogany pulley, and grooved it 
 for a gut band. The wooden bed of our lathe we plated 
 with iron, fastened with countersunk s'-'ews and draw 
 filed, to make it as level as possible, and to give it a better 
 finish. We procured bars of two inches wide by a quarter 
 thick for this purpose from the blacksmith, which, being 
 rolled by machinery, were quite true from end to end. 
 This made a very good bed, fit for a slide-rest, which we 
 now made up our minds to purchase, although it was a 
 somewhat heavy outlay, costing us, in those days, seven 
 sovereigns. It was, however, a very good one, and twenty 
 years afterwards it was still in almost daily use, and as 
 good as ever. 
 
 This was not meant for turning ornamental work, which 
 we rather despised, but only to assist us in making models 
 and other works in metal; and indeed we made a quantity 
 of things, besides models of engines, including a capital 
 set of chucks and various lathe fittings ; and long after- 
 wards, when we discovered that ornamental turning needed 
 the highest skill, and was therefore by no means infra dig. 
 to a rising engineer, we made a very good slide-rest for 
 that kind of work, and learnt to use it, too, with great 
 efficiency. Knowing the need of steadiness in a lathe, we 
 braced ours at once to the window-sill with a couple of 
 iron rods, so that it was immovable and free from vibra- 
 
;8o BOY ENGINEERS. 
 
 tion, a very essential point when turning anything at a 
 high speed or using an eccentric chuck. 
 
 Our carpenter's bench was made to hold pieces of all 
 shapes and sizes, and we took a great deal of pains to make 
 it. The framing was of the ordinary kind, but planed 
 to give it a better appearance than it frequently wears 
 when made wholly of rough material; but the top of it was 
 of two-inch stuff, and was carefully faced all over, so as to 
 present a perfectly level surface, which we took care to pre- 
 serve. This is frequently not attended to in home-made 
 benches, in which any stuff, planed or unplaned, is deemed 
 good enough. The consequence is, that it is found im- 
 possible to do good work with a plane, because the board, 
 resting on an uneven surface, oscillates under the tool, and 
 a wedge is needed here and there to keep it steady ; or a 
 nail or two is ruthlessly driven into the bench to hold it 
 steadily, which nail is sure to be forgotten, and either 
 remains to tear a bit of skin off the workman's hand, or 
 to notch the chisel, plane, or other tool. The way in 
 which planing benches are often knocked about is what 
 boys call *' a caution " to behold. It should be as carefully 
 preserved as a dining-room table. There is no necessity 
 to spoil its level surface, for instance, by chucking down 
 upon it any heavy pieces of iron that need a temporary 
 resting-place. No need to bore holes with a centre-bit in 
 woric laid upon it without some spare piece underneath to 
 
WORKBENCH. i8i 
 
 receive the point of the bit when it has passed completely 
 through ; or to chop wood upon it so as to cut its surface 
 gradually into mincemeat. These and similar errors we 
 ourselves had to plead guilty to in our early days of ap- 
 prenticeship ; but having learnt that it was just as easy to' 
 preserve bench and tools in good working condition, we 
 duly reformed our manners and customs in this respect. 
 
 The top of the bench being level and of thick material, 
 we cut in it special holes and mortises to receive the 
 tenons of certain fittings, to be described presently. The 
 front board, of one-inch stuff, was also carefully planed, and 
 fixed exactly at right angles to the top, and the usual 
 carpenter's vice was fixed at the left-hand corner. This 
 was made with two screws, instead of with one and a 
 guide bar, as is often done. The outer movable board of 
 the vice was of ash, one inch and a half thick, and its 
 upper edge was made to come exactly level with the top 
 of the bench, so that when it was necessary to plane up a 
 narrow strip, it would hold it securely. 
 
 At the right-hand end of our bench we fixed another 
 kind of vice, which I think can be rendered clearly with- 
 out a drawing. It consisted of a block of beech six inches 
 long by three inches each way, with two short tenons below 
 two inches long — one at each end. The block and tenons 
 were all of one piece. 
 
 "We took, in short, a block five inches deep and three 
 
i82 BOY ENGINEERS. 
 
 thick, and marking it round on all sides at two inches 
 from the face, which was to be the downward one, and 
 also marking across at two inches from each end, we cut 
 out the piece between the two last markings, so as to 
 leave the tenons at each end. These tenons fitted accu- 
 rately into two mortises cut in the top of the bench, so 
 that when placed in them the appearance was that of a 
 simp,le block six inches long by three square standing on 
 the bench, its long sides parallel to the front and back 
 of the bench. It was, however, fixed securely by the 
 tenons. Lengthwise through the block was passed a 
 screw three-quarter inch in diameter. It was our old back 
 poppit screw, but the end was filed off square and flat, 
 instead of being left with a point. In a line with this 
 block and screw were a row of similar mortises at equal 
 distances, into any two of which therefore the block 
 already described would fit at pleasure. To complete the 
 apparatus, there were other blocks, with precisely similar 
 tenons, but only one to each, and these blocks were but 
 three inches, and some two inches, in length, instead of six. 
 To form a vice, therefore, all that was necessary was to 
 put the screw-block into place, and one of the others in a 
 mortise, at about such a distance from it as the article 
 required, and then to fix the latter when placed between 
 them by a few turns of the screw, interposing a bit of 
 hard wood to protect the surface of the work from the end 
 
BENCH FITTINGS. 183 
 
 of the screw. Of all our bencli fittings, we never found 
 one more serviceable than this, which we used to hold 
 work for mortising, and as a clamp for work glued, and 
 for a multitude of other purposes which need not be 
 enumerated; among others, for holding up pieces which 
 required to be planed on the edge, and which were not 
 60 thin as to yield to the end pressure thus applied. We 
 rightly named it " our universal vice." 
 
 Another vice or bench appliance of great use in plan- 
 ing pieces too thin to hold in any other way, consisted of 
 a block of wood similar to the last, but sawn about three- 
 fourths of its length through, so as to form a kind of 
 spring-clip ; through this a screw was placed crosswise, so 
 that when turned by a short bar, it brought together the 
 two sides of the wood which the saw cut separated. This 
 acted, therefore, as a vice for very thin laths, which were, 
 of necessity, held at the end from which the plane started 
 on its way, i.e.^ the right hand, so that the force of the 
 plane only tended to stretch the strip, and not to bend it. 
 All thin laths need to be planed in this way. We also 
 had blocks with a deep saw-cut, or rather deep shallow 
 groove made by two saw-cuts, one-quarter inch apart on 
 the upper surface, in which thin slips could be fastened 
 by a wedge, and various similar contrivances for holding 
 boards on edge, cylindrical and other shaped pieces, which 
 
1 84 BOY ENGINEERS. 
 
 often saved us mncli time. In short, the mortise holes 
 and blocks were as useful as they were cheap. 
 
 We also had a couple of round holes to take the stem 
 of our bench hooks or bench holdfasts, of which one was 
 of the old pattern, the other made with a screw to hold 
 down work. "We had also a carver's screw, a most useful 
 contrivance. It is an iron bolt with a screw and bow-nut 
 at one end, like those used to secure lathe poppits, and a 
 short conical screw at the other. The latter is screwed 
 into the block of wood to be carved, and the bolt being 
 passed through a hole in the work-bench, is secured by the 
 bow-nut and a large washer underneath. Then we had 
 also for use with the tenon saw a short strip of ash, with 
 a piece at each end projecting an inch, but in opposite 
 directions. One of these rests against the edge of the bench 
 upon which it is laid, while the other prevents the strip 
 of wood from escaping under the action of the saw. Its 
 form was like the letter Z, but the central line much 
 longer in proportion, and at right angles to the two other 
 lines which make up that letter. We had, of course, the 
 usual planing stop in addition to these other contrivances, 
 a very much better form of which is now made wholly of 
 metal, and getting into very general use. 
 
 The next workshop fitting which it is necessary to 
 describe is our filing or fitting bench. This was of three- 
 inch plank, fitted to the wall by a pair of bolts going right 
 
CASTING. 1 85 
 
 througli two of the joists, and screwed up with a nut and 
 washer on the outside. It was also supported by two 
 legs driven into the ground, and then notched into the 
 bench and fixed with screws. The tail-vice, with chops 
 three inches wide, was fixed to tha front of this, the leg 
 being let into a short pile of oak driven into the ground. 
 It was therefore very firm, and stood just so high as to 
 bring the vice chops on a level with the elbow, which is 
 the best height for accurate work with the file. Under 
 the bench was fitted a strong drawer, to contain various 
 odds and ends, such as screw taps, and dies, drills, small 
 bolts and nuts, and the thousand and one etceteras of a 
 smith's shop. "We had not, however, at the time, any 
 forge, and although we afterwards had a portable one, we 
 only used it for soldering, brazing, and doing light jobs. 
 We found it cheaper as well as better to get our forgings 
 as well as our castings done for us by those regularly 
 trained to that work. We did, indeed, now and then 
 cast small articles of brass, using blacklead crucibles, with 
 coke as the fuel ; but we so often found these articles turn 
 out badly, that, as a rule, we did nothing in the way of 
 founding. Still we could bend and weld light ironwork 
 with the forge, as well as heat rivets, alter the shape of 
 Blide-rest tools, make an occasional carrier for the lathe, 
 and so forth. Our forge proved, therefore, very con- 
 
1 86 BOY ENGINEERS. 
 
 venient, but was never admitted into our workshop, but 
 used out of doors or in an old shed. 
 
 Our drilling apparatus was at first merely the ordinary 
 blacksmith's brace pressed down by a lever overhead, with 
 a weight hung on at the end of it — a clumsy affair, still 
 to be met with at smith's forges in some country places, 
 and certainly effectual, as is proved daily by the work 
 done by its aid. It was, however, very much of an eye- 
 sore, and took up a good deal of room. "We therefore 
 replaced it by an upright rod of iron, and a sliding arm 
 with a screw passing through it, to give the necessary 
 pressure to the brace. This upright rod was fixed by 
 being made to pass through the vice-bench and rest upon 
 a collar, which prevented it from falling quite through, 
 but allowed it to swing round. Underneath the bench it 
 had a washer and nut, and a similar washer was let into 
 the top of the bench where the rod passed through it. Near 
 the top it passed through an eye-bolt, which, in its turn, 
 was screwed into one of the upright studs of the workshop ; 
 then the rod, which was of round iron one inch in dia- 
 meter, was very securely fixed in an upright position close 
 to the wall. The arm which projected from it was of 
 flat bar iron half an inch thick, with a boss or enlarged 
 part at each end. This, when fixed, was so placed that 
 the edges were above and below, and the broad or flat 
 parts sideways. The iron in this direction was an inch 
 
DRILLING. 187 
 
 wide. It was made thus stiff, becnuse it was necessary 
 that it should stand a good deal of strain without bending. 
 Both bosses were bored through — the one to slide up and 
 down the upright bar, the other to receive a screw six 
 inches long, with a hole in the lower end, into which 
 the upper pointed end of the brace fitted when in use. 
 This end was case-hardened, as was also the point of the 
 brace. We have not drawn the latter, as it is a tool 
 well known to boys of a mechanical turn, being found in 
 every blacksmith's shop in the kingdom. 
 
 Those were not days of twist drills, nor of the Anted 
 drills, which are equal to them, if not superior, but we had a 
 set of common diamond-pointed ones made to fit the brace, 
 which was not our own handiwork, and we soon learned 
 how to make and temper them ourselves — an accomplish- 
 ment always of value to the mechanic, old or young. It 
 is here, indeed, that the generality of amateurs Ing behind. 
 They require sets of drills, reamers, countersinks, and 
 such-like ; and if they need to make a hole for which they 
 have not a drill of precisely the required size, or if 
 they chance to break a tool of this description, they are 
 at a stand-still till they can buy a new one. Not so the 
 workman. He simply puts his broken drill into the fire, 
 and with a few strokes of the hammer remodels it, mak- 
 ing it smaller or larger to suit the job in hand. Then he 
 tempers it, and grinds it. and in a few minutes is dili- 
 
i88 BOV ENGINEERS, 
 
 gently at work. A cliance breakage is, in fnct, to a 
 good workman, of no sort of importance, but with him it 
 is not so frequent as with less skilful hands. 
 
 When first we tried to make a drill or two, as we had 
 seen the village blacksmith do, we burnt the steel, wliicli 
 fortliwith crumbled under the hammer, instead of taking 
 its proper shsipe, as we expected. We then found that a 
 white heat would not do at all, but that we must not raise 
 the heat beyond what produced a bright red, and that we 
 could shape our work at this temperature without breaking 
 it. Then we heated it to a bright red and quenched it, 
 ground it to a nice bevel, and broke it short off at first 
 trial. It was a great deal too hard and as brittle as glass. 
 Then somehow we learned that it was, as a general rule, 
 necessary to let down the temper of drills, taps, reamers, 
 and indeed of most other tools subject to strains or to 
 sudden blows, by first heating and quenching, and then 
 heating them again to a stated temperature known by the 
 colour which the metal takes under the influence of 
 oxidation. As the temperature rises the steel becomes 
 softer, and when at the desired degree it is suddenly 
 quenched again in water or oil. In this way we found 
 that we could make steel so hard that no file would scratch 
 it, and from this let it down as we pleased. Drills for 
 metal, unless for drilling steel, answer when the deep 
 straw colour is attained, or when this is beginning to 
 
TEMPERING STEEL. 1S9 
 
 change towards a blue. The shank of the drill should be 
 then tempered, even if the point is left hard. This may 
 be done by laying the shank on a bar of red-hot iron and 
 watching the colour as it spreads from that point up and 
 down the surface of the drill. Screw taps, again, being 
 subject to torsion, or a strain tending to twist them, need 
 very careful tempering, especially if not very well made, 
 as they then cut with difficulty, and require more power 
 to work them. 
 
 We found out such matters as these chiefly from numer- 
 ous failures, which often teach more than success ; but we 
 also learned the use of our eyes and ears, and picked up 
 many a wrinkle while innocently watching the work of 
 various tradesmen, but especially that of the blacksmith, 
 who, in country villages, combines the trades of farrier 
 and- shoeing-smith, tinman, brazier, and machinist. In 
 short, to a skilful village smith nothing seems to come 
 amiss in the way of metal work, and some are very skil- 
 ful in making axes, billhooks, and edge tools, which stand 
 work a great deal better than those ordinarily purchased 
 at tool-shops. Of course, if it comes to a question of 
 appearance, the tool-shops carry the day, for at these you 
 may buy axes beautifully polished for a part of their blades, 
 and the rest got up with a wonderful blue, which renders 
 the whole tool marvellous to behold j and it is a far greater 
 
I90 BOY ENGINEERS. 
 
 marvel if a tool thus finished proves of any value at all to 
 the buyer. 
 
 Of trestles, sawlng-horses, and low stools of thick stuff 
 with stout legs, for cutting mortises upon, it seems hardly 
 necessary to speak, yet we have known these conspicuous 
 by their absence in many a workshop of no mean preten- 
 sions, in which, if a board required to be sawn off, there 
 was a hunt for something upon which to rest it. The 
 best framed trestle we had was made after the fashion of 
 the Roman capital letter A. I fancy we had seen it 
 somewhere, for I doubt if we invented it ourselves. 
 The board to be sawn (lengthwise) was slipped through 
 above the cross piece in the centre, and the legs of the A 
 were pushed slightly outward, so that the end of the plank 
 rested on the floor behind the workman, while the other 
 end to be sawn projected, and was held up by the legs of 
 the trestle. As the sawing proceeded, the board was 
 slipped further through. This device holds the board in 
 the most convenient position possible, and is as easily 
 made as an ordinary sawing-stool. When the board to 
 be sawn was thin and of any great length, we found it 
 necessary to place an ordinary stool in front of our alpha 
 horse to support the end, which otherwise would be found 
 careering and prancing up and down at every stroke of 
 the saw, as if in mortal agony, while its sides were being 
 split, but not with laughter. Of all work which boys are 
 
SAIVS. 191 
 
 inclined to be shy of, sawing stands pre-eminent. In the 
 first place, they find it very difficult to drive a straight 
 course; and in the next place, it is uncommonly hard work; 
 and we often see boys splitting a board instead of sawing 
 it, by which, as the crack seldom runs straight, they are 
 sure to waste material. This laziness we never allowed 
 ourselves to be guilty of. We kept a half-rip and a hand- 
 saw in good order, and soon found arms and back grow 
 used to the work, and we made nothing of the labour of 
 sawing a three-inch plank twenty feet long from end to 
 end. In these days, however, one has not very much to 
 do with such heavy work, as it is easy to get at the saw- 
 mills any description of scantling, and the circular saw 
 will rip up such a plank as alluded to in about a 
 minute. 
 
 Talking of circular saws reminds me that I have not 
 spoken as yet of this handy and not very costly addition, 
 which we found means to make to the fittings of our 
 workshop. In those days such articles were not so easily 
 obtainable as they have since become, and we bought a 
 saw of six inches diameter and made a stand for it our- 
 selves, turning the spindle also upon which it was fixed, 
 A circular saw is only a round disc of steel with a central 
 hole in it, the teeth being cut round the edge. A spindle 
 with a shoulder is passed through the hole, and a washer 
 placed on the other side, which is forced up against the 
 
193 BOY ENGINEERS. 
 
 plate by a nut. Upon the spiudle a pulley is fitted for a 
 strap, and the whole is fitted up iu other respects like a lathe, 
 the saw being driven by a fly-wheel, crank, and treadle. 
 A flat table, however, takes the place of the lathe-bed, in 
 which is a narrow slit to allow the saw to project through 
 it nearly to its axle ; and upon this is laid the work to be 
 sawn. A six-inch saw will cut, therefore, only about two 
 inches, owing to the thickness of the spindle and its 
 collar and nut ; but a piece of wood two inches thick we 
 found quite hard enough work for our legs ; and, indeed, 
 we seldom used the saw upon more than one-inch stuff, as 
 neither of us, in spite of our ingenuity, had been able to 
 make for ourselves a steam leg to drive the machine. 
 Upon the saw-table there was a stop or guide, a strip of 
 wood an inch thick standing up parallel with the saw, 
 which could be adjusted to any distance from it. This 
 enabled us to cut strips of any width all true and all 
 exactly alike. We had also angular guides for mitres, 
 bevels, and such-like. 
 
 The handiness of a circular saw can hardly be over- 
 estimated. For any heavy work it is indeed useless when 
 worked by the foot, though capable of any amount of 
 work when steam power is used to drive it. But for light 
 work it is invaluable, and no workshop can be considered 
 complete without one. We had the spindle mounted 
 between two pointed and case-hardened screws under the 
 
GRINDERS AND BOBS. 193 
 
 table, and we could remove this saw and replace it by- 
 one for cuttiug metal, to saw off ferrules from brass tubes 
 and such-like. We also had other spindles fitted like a 
 knife-grinder's machine, with small grindstone and emery- 
 wheels, commonly called emery-bobs, and also with polishers 
 or glazers covered with leather. The machine, therefore, 
 was of somewhat extensive use; and one day, when we had 
 left our door unlocked, the knife-boy made free to enter 
 our sanctum, and try our precious buff-wheel as a cleaner 
 of knives — an operation which was so successful that we 
 took care the experiment should not be repeated. We 
 did, however, make a special knife-cleaner, which remained 
 some years in constant use. 
 
 There is a mode of using a circular saw which we 
 imagined to be an invention of our own, but whether or 
 no it was so I cannot now determine. We raised the 
 table by adjustable wedges, so that the saw might project 
 only a very little above it, and we then used it for cutting 
 rebates, such as are made in picture-frames and sashes to 
 hold the glass. We first cut the strips with the table 
 lowered down to its normal level, and then using the 
 parallel guide, we raised the table and made a saw-cut 
 from end to end of the piece, which we met by another' 
 at right angles to it. The two cuts of course removed 
 a square slip of the wood, and so formed the required 
 
194 ^OY ENGINEERS. 
 
 rebate. We used it thus for picture-frames, of which we 
 made several, as for many other purposes. 
 
 Long since that time this mode of rebating frames 
 has, I believe, become general, and the circular saw is 
 put to every kind of work which it is capable of execut- 
 ing, as well as to work which no one would have sui)posed 
 could be done by its means. Revolving cutters, by which 
 clock wheels are cut, taps grooved, and drills fluted, are 
 but circular saws of various sections and of small size, 
 which are, many of them, driven at a terrific rate, and 
 make splendid work in skilled hands. Of these we made, 
 however, no use in connection with the machine alluded 
 to, although we learned to use them with our lathe after 
 we became possessed of a slide-rest. 
 
 : We may here mention, for the information of mecha- 
 nical boys, who like to know how all sorts of things are 
 made, even though they themselves may not be trying 
 their skill at mechanical work, that the revolving cutters 
 are used extensively for making the various parts of sew- 
 ing-machines, some of which are of so peculiar a form 
 that, I daresay, many have wondered how they could be so 
 beautifully made by means of files and ordinary methods 
 of work. In the Government factories, also, where small 
 arms are made, the same tool is in extensive use. In 
 cutting V-grooves in the edges of brass slides for eccen^ 
 trie chucks, cutters of that section are adopted, and the 
 
TOOL CUPBOARD. 195 
 
 work is not only done very rapidly, but with a correctness 
 scarcely to be attained in any other way, although, before 
 such appliances were known, the skill and perseverance 
 of the filer and fitter proved equal to the task. It is, how- 
 ever, very difiiciilt to file a groove accurately along tlic 
 edge of a plate, and it will prove a rather hard trial of the 
 mechanic's skill to do it. Cutters can now, however, be 
 had at all good tool-shops, beautifully made, and of al- 
 most any section; and any young engineer who possesses 
 a lathe and a slide-rest ought to add a cutter spindle, 
 and learn to use it. 
 
 When our stock of better-class chucks was extended, 
 partly by purchase and partly by home manufacture, we 
 had a glass cupboard, or rather a cupboard with shelves 
 and a glass door, in which to keep (and show) them. 
 We found that unless they were put into some such 
 receptacle, the dust of the workshop made them exceed- 
 ingly dirty, and mixing with the oil, got into the movable 
 parts, and did, in course of time, real damage by grind- 
 ing such parts, and rendering them loose. Some of our 
 best tools we also, for a similar reason, kept in drawers 
 and boxes, as we had learned that good tools were worth 
 careful preservation, and would not do best work unless 
 they were thus jirescrved. Our big grindstone for 
 ordinary shopwork had a place in the workshop away 
 from the lathe. It was about two feet in diameter, 
 
196 BOY ENGINEERS. 
 
 moimted accurately on its spindle, and fitted with a crank 
 and treadle, besides having a handle that could be put 
 on at pleasure for grinding axes or heavy work. There 
 was a water trough below, which was lowered when not 
 in use, so as not to keep the stone wet in one part, and 
 also a cap or hood, to prevent water from being thrown 
 about the workshop, or aunoying the workman by splash- 
 ing his face and clothes. It is now the fashion to use, 
 in place of grindstones, revolving emery wheels, going 
 at perhaps 1 500 turns a minute, and having a stream of 
 water constantly running over tliem to keep the tool 
 from losing its temper. Even with this precaution it is 
 difficult to prevent heating the steel, which, if the stone 
 is run dry, may be made red-hot in a few seconds. These 
 emery wheels are also used to take oiff the hard scale or 
 crust from castings, which is so detrimental to tools, 
 and which has to be removed by the tedious processes 
 of pickling and chopi)ing, unless these emery wheels are 
 brought into use for the purpose. They were, however, 
 quite unknown when we built our shop, and were, there- 
 fore, not among its fittings, and only quite recently have 
 they become common. ,, 
 
 Such was our workshop as designed and made by us 
 with no professional assistance whatever. To this day 
 I look back upon it with pride, if not with affection. 
 It is one of those possessions that make an impression 
 
SCHOOL DISCIPLINE. 197 
 
 on the mind of a lad not easily effaced, as it was 
 essentially an integral part of the home of our boyhood 
 and early manhood. Even its association with the study 
 did not take in the least from the charm which it 
 possessed ; in fact, that study was entirely our own device 
 and our own suggestion. I have, indeed, heard some 
 boys speak disparagingly of their school-days and school - 
 work, with its strict discipline and restraint, but it is 
 a feeling of which we personally never partook, even in 
 our youngest days. As to discipline, we had always been 
 trained to yield implicit obedience to those who had charge 
 of us, whether at home or at school, and it was cheerfully 
 rendered. Moreover, as we advanced beyond those 
 earlier studies of childhood, which are, of course, always 
 more or less tedious and disagreeable, we liked learning 
 for its own sake. We were both naturally of inquiiing 
 disposition, and longed to escape from the trammels of 
 boyish ignorance, which we rightly believed kept us back 
 from a good deal of intellectual enjoyment. We won 
 prizes, but we did not in reality work for them ; they 
 fell to our lot as a matter of course, and were appreciated 
 not as something to show, but as mines of valuable 
 information ; for they were always well chosen, and of an 
 interesting character. When, however, we rose higher 
 in the school, we did work for the prizes, because the 
 elder boys were, by a wise arrangement^ allowed to select 
 
198 BOY ENGINEERS. 
 
 prizes of a certain fixed value according to their 
 respective tastes, and even to add from their own pockets 
 if tlie prize selected was beyond the money assigned to 
 them. I need hardly say that our choice was invariably 
 a book connected with mechanical arts. 
 
 In speaking of what we did, and how we worked at 
 what was first a mere boyish hubby, but ultimately 
 became the life's business of one of us, and for a time 
 of both, I cannot help feeling that I am to some extent 
 egotistical. Everything recorded of necessity bears this 
 stamp. It is nothing but ego and ille alter ego. I shall 
 conclude this chapter, therefore, with a record of a very 
 dear fiither, who, if he had a fault, was only too indulgent. 
 He too was naturally mechanical, but in another direc- 
 tion. With him the sea and the Navy, to which he 
 belonged, and which he certainly adorned, was every- 
 thing. As boy and man he was for ever making models 
 of ships; and well do I remember how patiently he 
 worked, and with what simple appliances he executed all 
 with a precision and neatness hardly to be excelled. I 
 have several of those models now, and though I have 
 seen many of similar character, I never saw any better 
 made. The hulls were not merely carved out of a 
 solid block, but built up from the keel rib by rib and 
 plank by plank, all riveted with brass wire nails or 
 fastened with copper studs and bolts. It is still a 
 
MODELS. 199 
 
 matter of wonder to me how he curved those small planks 
 80 gracefully round the bows and under the quarters, and 
 how he prevented the board from splitting. I believe, 
 however, that the holes were all drilled with one ot 
 the bow-drills used by watchmakers. Then, again, 
 masts and spars were rounded entirely by hand, and were 
 finished to perfection ; and there was the miniature 
 wheel with its facings of brass, the binnacle with its 
 compass, the hatchways and gratings and hammock 
 nettings, each and all as complete as skill could make 
 them, and a sailor's critical eye could plan them. Even 
 the sails, I believe, were my father's own handiwork, 
 beautifully stitched and finished as they were ; and the 
 little blocks with running sheaves in each, double or 
 single, as in a real man-of-war, were cut and carved with 
 the same untiring patience. Alas 1 those ships are 
 things of the past. Wooden walls are fading away 
 before the iron-built ugly monitors, and perhaps the old 
 Bailor, of which my father was a fine type, is also passing 
 away. 
 
Chapter IX. 
 
 ONE OR TWO ENGINES. 
 
 UR house completed and shop fairly furnished 
 with the necessary tools, our ambition centred 
 on a steam-engine, as, I believe, is almost 
 always the case, sooner or later, with lads of a 
 mechanical turn. This is not unnatural, for whatever 
 other machine or model of machine may occupy the at- 
 tention from time to time, the steam-engine is at present 
 the grand prime mover, without which they would be prac- 
 tically useless. If we could have managed to bore a larger 
 cylinder, and to make or procure a suitable boiler, we 
 should have tried our hands upon one of a size to do use- 
 ful work — to turn our lathe, for instance, when we were 
 engaged in any heavier work than usual. As it was, how- 
 ever, we were restricted in various ways. Our pockets 
 
STEAM-ENGINE. 20i 
 
 were not over-heavj'', our mechanical appliances limited, 
 and we could not manage to bore out a cylinder of the 
 size that would be needed for the above purpose. 
 
 We eventually decided on a cylinder three inches long, 
 with a bore of 1^ inches, which was as much as our lathe 
 and slide-rest were likely to do in a satisfactory manner. 
 
 We were saved, at all events, one great trouble, namely, 
 the construction of patterns for casting. We happened 
 to have amongst our acquaintances a member of a noted 
 firm of ironworkers, whose foundry was about ten miles 
 off, and from him we obtained for a nominal sum all the 
 castings of this engine complete. These consisted of 
 cylinder and its covers, valve box and cover, piston and 
 eccentric, guide bars and pillars, all of iron, eccentric 
 straps of gun-metal, bearings for the crank shaft of the 
 same metal, iron fly-wheel and bed-plate. The forgings 
 we found it easy to obtain in our own village ; but these 
 were very few — merely the forked connecting-rod, and 
 one or two odds and ends. The boiler we left as a matter 
 for consideration after the engine should be completed. 
 
 Before setting to work upon the engine, however, we 
 endeavoured to gain such a complete insight into the 
 theory of steam as a motive power as should give 
 us greater interest in our undertaking, and serve to 
 lay a sound foundation for future studies. It is here, I 
 think, that boys usually fail. They exercise their ingenuity 
 
202 BOY ENGINEERS. 
 
 upon the fabrication of machines without any real know- 
 ledge of the why and wherefore, and consequently, if ever 
 finished, the models serve merely as toys, which teach 
 them nothing, and are soon cast aside, as the interest in 
 them ceases. 
 
 I don't mean to say that we then moralised more than 
 other lads, but as our profession was to be that of 
 engineers, we took all pains to learn theory and practice 
 at the same time, and thus gained a good deal of know- 
 ledge in an exceedingly pleasant manner. 
 
 To begin with the water in the boiler, out of which, by 
 the aid of heat, we have to procure the steam required 
 for our purpose. Water is not a simple element, as was 
 formerly supposed — that is, it may be disintegrated into 
 two separate substances, which, strangely enough (for we 
 should not have conjectured this), are gases, which are 
 themselves invisible to the sight, and have nothing about 
 them suggestive of moisture. The one gas is oxygen, the 
 other hydrogen, which obtained its name from the fact of 
 its being an important constituent of water, as our young 
 Greek scholars will at once understand ; while oxygen was 
 named from being the supposed originator of acidity — 
 like some boys, it is a " pickle." These two gases, when 
 mixed together in certain proportions, are very ticklish 
 customers to deal with. Looking exceedingly innocent 
 and harmless — when in a glass vessel, the latter appears 
 
CHEMICAL EXPERIMENTS, 203 
 
 to be empty — they are highly explosive, and only await a 
 chance spark to make them go off with a hsing. Hych'ogen 
 gas alone will not do this, but will burn with a faint blue 
 flame, which, however, is intensely hot, and will, if a 
 stream of oxygen is driven through it, melt the most re- 
 fractory substances in nature. 
 
 A mixture of hydrogen and oxygen when exploded 
 produces water ; the two gases, if in suitable proportions — 
 viz., 8 of oxygen to 1 of hydrogen — combining wholly, and 
 leaving no residue. If these proportions are exceeded in 
 either, the excess will simply remain unaltered. In a 
 mere experiment on a small scale, with the gases in tubes 
 or other small vessels, the result in water will only appear 
 like dew upon their surfaces, so that boys who perform 
 the experiment need not expect, as we did, to see a tube 
 half-full of water as the result, because the gases thus 
 combined take up infinitely less space than they did 
 before. 
 
 In the vast laboratory of nature, chemical actions go 
 on upon a scale of which the student has no conception, 
 but I do not know that the explosion and combination of 
 these gases occurs naturally ; the Creator having furnished 
 our Globe at once with this compound substance, which is 
 essential to our life and happiness. 
 
 Now this compound is itself, under certain conditions, 
 explosive — a fact upon which experiments have yet to be 
 
204 BOY ENGINEERS. 
 
 made, and which deserves more atteution than it has vet 
 met with. You may not nnfrequently have noticed tliat a 
 tea-kettle boilinf^over on a hot kitchen stove will keep on 
 jumping- as the drops run down its sides, get under it, aiul 
 come in contact with the heated metal below. If the iron 
 is sufficiently hot, the water will, on reaching it, separate 
 immediately into globules, which do not at once become 
 vapoiised, but hop and roll about, till, with a slight ex- 
 plosion, they become instantaneously dissipated. The fol- 
 lowing quotation from Lardner's "Natural Pliilosoi)hy '* 
 will suffice to give all the information necessary upon 
 this point. The paragraph is entitled " Spheroidal state 
 of liquids " : — 
 
 If a drop of water or certain other liquids be let fall 
 from a funnel terminating in a small and fine tube 
 upon a surface of metal rendered red hot, the following 
 remarkable phenomena will be manifested: — 
 
 1. The liquid will not wet the sm'face, but will appear 
 to avoid touching it, and will assume a globular form like 
 that which water affects when it is diffused on a greasy 
 surface, or like globules of mercury upon glass. 
 
 2. Instead of entering into violent ebullition, as might 
 be expected, the temperature of the liquid will be very 
 little affected, and the drop of water will either remain at 
 rest, or be affected with gyratory motion. 
 
 3. When the surface on which it rests is cooled down 
 
PROPERTIES OF WATER. 205 
 
 to the temperature of 400° or 500", the liquid will begin 
 to diffuse itself on the surface, and will be suddenly 
 scattered with violence in all directions. These experi- 
 ments can be most conveniently made with a shallow 
 capsule of metal shaped like a watch-glass, which can be 
 kept at a white heat by a powerful lamp. The liquid can 
 be let drop upon it by a fine pointed syringe or funnel. 
 
 I have recorded this peculiarity of water, because it is 
 one upon which boys as well as men can make valuable 
 experiments, and because it has been thought that some 
 of those terrible steam-boiler explosions, of wliicli we too 
 frequently hear, are caused by the explosion of water 
 within, which in contact with a highly-heated surface 
 becomes spheroidal as above stated. Some have also 
 broached the idea that the water in these cases not only 
 assumes the conditions alluded to, but is even decomposed 
 into its constituent elements of oxygen and hydrogen, 
 which, if it is the case, would amply account for the wide- 
 spread destruction which occurs. 
 
 There is no doubt at all of this, that no safety-value 
 yet devised will counteract the effects of a sudden and 
 instantaneous increase of pressure within a steam-boiler. 
 It literally has not- time to act until the mischief is done, 
 the explosive force acting first upon the parts immediately 
 adjacent to the scene of action. 
 
 This is often proved by the barsting of an ordinary shot- 
 
2o6 BOY ENGINEERS. 
 
 gun, whicli will occur from a cause apparently quite in- 
 sufficient to produce such a disaster. A small piece of 
 dirt, for instance, stopping the muzzle never so loosely, 
 will not be driven out, as would be supposed, when the gun 
 is fired, but will instead cause it to burst. A piece of thin 
 paper pasted over the muzzle will do the same, slight as 
 the obstruction may appear to be, although it would 
 naturally be supposed that such a substance would in- 
 stantly tear and allow the charge to pass through it. 
 
 Take a glass tube and blow a pea through it, which all 
 boys know is a remarkably easy thing to do. Put a cork 
 in the end or close it with a finger, and try to hit your 
 finger with the pea ; you will see it stick fast to the 
 side of the tube, you can't blow it forward at all, and all 
 you do in the attempt is to condense the air in the tube, 
 and cause it to press the pea firmly against the side. 
 Again, take a glass tube, and cutting out a disc of card- 
 board with a central hole to fit the tube, attach it to the 
 end. Upon this lay another disc of the same size, say 
 two inches diameter, now blow ofi" the top one, holding the 
 tube upright. Of course it is easy to do so I Is it ? You 
 will get black in the face before you can do it, although 
 there is apparently nothing to prevent it. 
 
 This last experiment has hardly, perhaps, as yet received 
 a satisfactory explanation, but all tends to show that 
 causes may exist for explosion of steam-boilers against 
 
STEAM. «o7 
 
 which it is difficult wholly to provide. Safety-valves, 
 however well designed, have often failed in their action, 
 and before the suddenly-increased pressure has had time 
 to lift the valve, the boiler has given way. It is different 
 with a pressure gradually and steadily increased. In this 
 case the force spreads evenly, and the valve provided for 
 tlie purpose feels the effect, and has time to yield to it, 
 thus saving the catastrophe that must otherwise occur. 
 If you stand at a railway station, you will not see the 
 steam escape in a series of puffs from the safety-valve or 
 the top of the boiler, but pouring forth in a steady stream 
 as soon as it has attained power to lift the valve from its 
 seat. I may remark, too, that if you could look into the 
 boiler you would see no steam at all, but a perfectly clear 
 space above the water, because steam is not visible until, 
 on escaping into the atmosphere, it becomes cooled and 
 condensed into minute drops of water. If you look at 
 the glass guage which shows the exact height of the 
 water in the boiler, and of which the upper part is full 
 of steam, you will not see the latter, which is never- 
 theless there, and ready to do you faithful service at any 
 moment. 
 
 Water is commonly said to boil at 212" of Fahrenheit's 
 thermometer, and this may be said to signify that, at 
 ordinary atmospheric pressure, it will at that temperature 
 be converted into steam; and the more you stir up the fire, 
 
«o8 BOY ENGINEERS. 
 
 the more rapidly will the process take place, until the water 
 becomes, as we say, wholly boiled away. Like many other 
 common sayings, it is not exactly true that water boils 
 at this temperature, because it depends on various con- 
 comitant circumstances. The water, for instance, must be 
 pure and the barometer at a certain height, i.e.^ the weight 
 of the air must be at a specified number of pounds to the 
 inch of surface, which the barometer will show as equal to 
 29*92 1 inches of mercury. If the pressure of air is less, 
 as on the top of a mountain, the boiling-point will be at 
 a lower temperature. At Bareges, in the Pyrenees, 4164 
 feet above the level of the sea, the boiling-point is 204 '8, 
 the barometer standing normally at 2 5 "5 1. 
 
 Now in a steam-boiler the pressure is of course very 
 great indeed, and rises with every degree of heat applied, 
 and the water in this case is not converted into steaiu 
 at 212°. In proportion to the increase of pressure, the 
 increase of the temperature at which the water boils takes 
 place. The pressure of steam on the inch at what is called 
 one atmosphere is 15 lbs. If this is raised to 30 lbs., the 
 temperature of the water at boiling-point will be 250* 
 instead of 212. Before we can state, therefore, the tem- 
 perature of the water when it begins to pass into a state 
 of vapour, we must know what the pressure is u])on each 
 sqnare inch of its surface. 
 
 Before we can understand the steam-engine thoroughly, 
 
STEAM. 209 
 
 we must also kuow how much steam a certain quantity of 
 water will produce, and this is remembered easily enough, 
 for a cubic inch of water will expand into a cubic foot of 
 steam, or so nearly that this will answer as the starting- 
 point for any calculations that it may be necessary to 
 make upon the matter. Let us go a step further. Suppose 
 we place a cubic foot of water into a close vessel and 
 evaporate it into steam, it is evident that it will exert 
 . an enormous pressure on all sides, tending to burst the 
 vessel, or boiler as it is called in reference to the steam- 
 engine. 
 
 It is this pressure which is made use of in the steam- 
 engine, and the limit to which it can be raised is probably 
 that of the strength of the boiler. In the present 
 day these boilers are made with great care and skill. 
 They are of iron plates riveted together, generally in the 
 form of a cylinder, as it is the simplest and also the best 
 to witlistaud internal (or external) pressure ; and in order 
 to add to the heating surface, and thus raise the 
 necessary steam as quickly as possible, tubes pass through 
 it, either a number of small diameter, as in railway and 
 marine-engine boilers, or fewer, as in the Cornish 
 engines, in which there is either one large tube going 
 through from one end to the other, or this is turned and 
 brought back again, forming a pair of tubes, in which the 
 flame from the fire-grate and the heated gases constantly 
 
2 lo BOY ENGINEERS. 
 
 circulate. These tubes do not weaken the boiler, as 
 might very naturally be supposed, but act as stays or 
 bonds. Those of a locomotive, which may be as many 
 as 200, of about two inches diameter, and which run 
 from the fire-box at one end into the smoke-box at thu 
 other, are fixed into the two extc^al plates by couical 
 rings of steel, driven into them at the ends when in 
 place, thus forcing them outwards against the holes 
 through which they pass. These end plates are of much 
 thicker iron than the rest of the boiler, because the 
 number of holes made in them weakens them, in addition 
 to which it would hardly be possible to fix the tubes in 
 thinner plates, as there would uot be sufficient substance 
 to resist the pressure of the couical ferrules. Fixed by 
 these, any of the tubes can at any time be easily removed 
 and new ones supplied in case of wear or accidental 
 breakage; and in engine- works you may often see whole 
 piles of these tubes which have been removed, in order to 
 get at the inside of the main boiler, and which will be 
 replaced and secured as before in a very short space of 
 time. 
 
 Large boilers are, in addition to careful riveting of the 
 plates, strengthened by stays and struts inside of cast or 
 wrought iron, to assist in resisting the enormous strain 
 to which they are subject when in use. This strain, at 
 40 lbs. to the iuchj will amount to no less than 2\ 
 
BOILERS. 211 
 
 tons to the foot, tending to tear the plates asunder. This 
 pressure is, however, as a rule, considerably exceeded, 
 and with perfect safety if the boiler is well made ; yet 
 the plates of which it is composed are less than half an 
 inch in thickness. 
 
 Perhaps some of my readers may wonder how it is that 
 they do not see any of the rivets when looking at a 
 railway engine, except those at the two ends. The 
 reason of this is, that the body of a boiler is always 
 covered with a lagging, as it is called, of wood, witli a 
 layer of woollen felt underneath, to prevent the heat from 
 escaping by radiation, as it would otherwise do. This is 
 laid on in thin strips, and hooped over like the staves of a 
 cask, and it is then painted a bright green or other colour, 
 and varnished. The actual boiler plates are thus wholly 
 concealed, and the engine wears a bright and handsome 
 appearance, which is enhanced by the bright gun-metal 
 fittings and polished rods of iron and steel. 
 
 The main point to be aimed at in the construction of 
 boilers is, to give as large a heating surface as possible, 
 so as to produce steam with rapidity, and with a small 
 consumption of fuel. Hence, the value of tubes, through 
 or round which the fire and hot gases are made to 
 circulate, each of which represents therefore so many 
 square inches or square feet of heating surface. In 
 spite of all care in lagging both boiler and cylinders, 
 
212 BOY ENGINEERS. 
 
 it is found impossible to utilise satisfactorily all the heat 
 given off by the burning fuel. There is always some 
 degree of waste, and although, as a rule, the cylinders 
 are brought as near the boiler as possible, the pressure 
 existing in the boiler is never wholly imparted to them. 
 Some engines, too, consume more fuel in proportion to 
 the water converted into steam than others made from the 
 same patterns, and in all respects exactly like them. 
 There is, in point of fact, even in the best-made engines, 
 a great loss of power from excessive friction and other 
 causes, in spite of constant so-called improvements and 
 additions. But of all engines to waste power, models are 
 the worst. They are, as a rule, the most useless and 
 unsatisfactory machines in existence. There is, first, 
 the difficulty of heating the boiler efficiently, especially 
 where gas cannot be had for the purpose. The fire- 
 grates, if such there be, are too small for coal, coke, or 
 charcoal, and the draught insufficient. If spirits are used, 
 they boil over, joints are unsoldered, paint burnt off, a 
 great mess made, and very probably substantial injury to 
 the table is the result. With regard to solder, indeed, I 
 readily admit it should never be used, but in sjnall 
 models it almost becomes a matter of necessity, and in 
 bought ones cheaply made, it is quite certain to have a 
 place. I have seen a pretty locomotive take its first 
 trip half the length of a table, and quietly fall to pieces 
 
MODELS. 213 
 
 then and there, while the spirit, having boiled over and 
 ignited, meandered in luminous streams all over the 
 table. It is always, therefore, the best plan to work upon 
 as large a scale as the state of the funds will allow; and 
 our engine with its three-inch cylinder never gave us 
 much trouble in the above particulars, because all tbe 
 parts were large enough to be put together with screws 
 and bolts and rivets, and the boiler had a sufficient fire- 
 grate to allow a good layer of charcoal to burn within it. 
 The draught, too, so necessary to keep the fuel in a state 
 of incandescence, was amply maintained when the engine 
 was at work by sending the waste steam up the chimney 
 in the orthodox way. As to the additional labour 
 entailed by a model of large size, it was not to be com- 
 pared with the advantages otherwise gained. Moreover, 
 we gained far better practice in filing and fitting than we 
 should have done with a very small engine. 
 
 The first thing we did was to make a very careful full- 
 sized drawing of every part — a true working drawing, from 
 which we could take off distances and sizes, with the cer- 
 tainty that we should be right if we followed them exactly 
 in the construction of the engine. Without such drawing 
 our work would have been of that haphazard kind which 
 never did answer and never will. We had, moreover, 
 here an advantage over makers of large engines, in that 
 we could draw every detail of the full size, thus escaping 
 
214 BOV ENGINEERS. 
 
 chance mistakes, which often occur in reading from a 
 scale. In machine-works, drawings are made of a certain 
 number of inches to the foot — three inches, for instance, in 
 a drawing signifying three feet, or any other quantity 
 determined. It is easy to understand how, in making 
 drawings, or in reading them oif for the actual construc- 
 tion, mistakes are liable to occur, which may, perhaps, not 
 be discovered until the various parts are ready to be put 
 together. With our own drawing, three inches stood for 
 three inches, and we were not obliged to refer to any scale 
 of parts in the prosecution of our work. 
 
 Centre lines were not forgotten as starting-points from 
 which to measure right and left, so that if a slight error 
 was made, it would not be multiplied by constant repeti- 
 tion. No one accustomed to work as boys usually do, in 
 a happy-go-lucky style, can have any idea of the con- 
 fidence imparted to a workman who feels that the draw- 
 ings laid before him are thoroughly trustworthy ; and to 
 work with confidence is to work in a masterly manner. In 
 making, for instance, the connecting rod, or in filing up 
 a bearing, or turning the axle of the fly-wheel, we had 
 not to set each up in its place to try whether it was 
 exactly the size required. All we had to do was to refer 
 it to the drawing, and if, on careful measurement with 
 the compasses or callipers, it was exactly in accordance 
 with the drawing, we laid it down with perfect cunfidence, 
 
BORING CYLINDERS. 215 
 
 and proceeded to make some other part. The result was, 
 that when all were finished, tliey dropped into their re- 
 spective places on the bed-plate, and every part proved 
 satisfactory. 
 
 The first consideration is invariably the accurate boring- 
 of the cylinder. This cannot be satisfactorily done without 
 a slide-rest, although, no doubt, it is j^ossihle to do \i. 
 There are, moreover, two methods of accomplishing this 
 ■work. The first is to chuck the cylinder, and fix a boring 
 tool or inside tool in the slide-rest; the second is to attach 
 the cylinder itself to the rest, and to use a boring bar, i.e.^ 
 a bar of iron mounted between the lathe-centres with a 
 boring tool fixed in a slot which passes through it. This 
 tool revolves, while the cylinder is made to travel slowly 
 onwards. This is the way in which large cylinders are 
 bored, and a great deal of similar hollow work ; but to ac- 
 complish it the rest must be wholly self-acting, traversing 
 along the bed by means of a screw or rack, to which 
 motion is given by a set of wheels and pinions in connec- 
 tion with the mandrel. For smaller work this plan is not 
 so often used, and as our lathe was of the sim})ler kind, 
 we had to chuck the cylinder and use a fixed tool. The 
 proper chuck for such work is a face-plate of iron turned 
 perfectly true upon the surface, and furnished with what 
 are called dogs — e'.e., clamps to hold any work securely 
 down upon the face of the chuck. The latter may be of 
 
2 1 6 BOY ENGINEERS, 
 
 tlie universal kind. There may be, first of all, the face- 
 plate, and then a pair of sliding jaws like those of a vice, 
 but of curved outline, which can be made to approach each 
 other, either by a single screw with a right thread on one 
 lialf and a left-hand thread on the other, or by a pair of 
 independent screws. The first method forms a self-centring 
 chuck; the second does not, and is, for some purposes, 
 advantageous. With this chuck, all that has to be done is 
 to place the cylinder on one end upon its face, and screw 
 up the jaws until they grip it securely. To assist in 
 centring accurately when independent jaws are used, there 
 are a number of concentric circles made upon the face- 
 plate as a guide. We had neither a self-centring chuck 
 nor a chuck with independent jaws, but merely a face- 
 plate or circular disc of iron screwed to the mandrel, in 
 which there were four slots, and in these there were 
 clamps — mere hooks which could be drawn down upon the 
 work by nuts underneath. These held the cylinder down 
 upon the chuck by means of the flange, to which the 
 cylinder cover had subsequently to be attached. 
 
 To begin with, we had a good look at the casting, test- 
 ing it with a small T-square, to see whether either of the 
 flanges was more accurately at right angles to the bora 
 than the other. Finding it to be so, we first clamped 
 down this one on the face-plate, getting the bore to run 
 as true as we possibly could, and then we faced up the 
 
TURNING CYLINDERS. 217 
 
 outer flange as true as possible. We then reversed the 
 cylinder, putting the corrected flange against the chuck, 
 and secured it firmly, having first interposed a small bit 
 of wood, previously turned true on botli sides, and hollowed 
 out to about what would be the finished size of the 
 cylinder, which thus stood about half an inch off the metal. 
 This bit of wood was turned perfectly level on both sides, 
 and its object was to raise the cylinder so far off the metal 
 that the tool could go entirely through it without coming 
 in contact with the face-plate. Tlie cylinder once fixed, 
 was not removed until finished, except that the edges of 
 the two flanges were afterwards turned up again. But we 
 bored and turned off the face of the outer flange while 
 the cylinder was on this chuck to ensure the flanges being 
 exactly at right angles to the bore. This is of the greatest 
 importance, because if it is not true the engine will never 
 work well, as the stuffing-box will not be central, and the 
 piston and its rod will not fail to rub more on one side 
 than the other. In all work needing accuracy, it is 
 necessary to consider beforehand exactly how you intend 
 to carry out the work to the finish after doing part of 
 it well; and removing it from the lathe, you will find 
 that you have got into a dilemma, and cannot get on 
 without remounting the work ; and, try as much as you 
 like, you never will remount it to run exactly as it did 
 before. 
 
2 1 8 BOY ENGINEERS. 
 
 Now here again we had learned by ex[)erience and by 
 a previous failure. The first engine we tried to make was 
 a brass one, because we considered it would be easier to 
 turn. The cylinder was two inches by one and a half, and 
 we drove the casting into a wooden chuck and bored it 
 out, succeeding very fairly. We were proud of our work 
 and took it out of the chuck to show a friend how well 
 we had done it. We then set to work upon the valve-face, 
 and made the ports, and, I believe, the piston. Next we 
 had to face up the flanges and fit on the cylinder covers 
 This seemed a very easy job. We turned a bit of wood 
 to fit inside the cylinder, but no I it was no longer true, 
 nor could we get it so. We then turned a cylindrical rod 
 and drove it inside the cylinder, so that it should be 
 turned on the same centres as the rod ; but, alas I in 
 driving it on we damaged one end of the wood slightly, 
 and the back centre-point of the lathe did not fall into 
 exactly the same position. We tried the face-plate, and 
 at last we had to compromise matters and make the best 
 of a bad job. The engine would work pretty well, but 
 we never liked it, owing to the fact that we ourselves knew 
 what no one else did, that it was at best a muddled job, 
 and that the piston would not move freely, except in the 
 exact position in which we had placed it, and other parts 
 had to be left slack to allow a little play, or the friction 
 brouo[ht it to a stand-still. There U a chuck, but we did 
 
TURNING. 219 
 
 not know it then, on which a cylinder can be truly re- 
 mounted, but the best way by far is first to true up one 
 flange, then to lay this on the face-plate and clamp it 
 down securely, and never to take the cylinder off again 
 till the bore is finished and the other flange turned. The 
 edge of the flanges are of no real importance ; the first 
 can be turned when that flange is faced, and the other 
 before removing it from the chuck, after having otherwise 
 completed it. Every part will thus be true, and you wiU 
 have, as we found, but little trouble in completing the 
 several fittings. This was the way in which we turned and 
 bored the three-inch cylinder of the engine which I am 
 now describing. 
 
 As illustrations are a great assistance to the reader, and 
 we are recording our own engineering accomplishments 
 in order to encourage others, a drawing is given here of 
 the various operations carried on, and of the various 
 details of the enorine itself. Fiof. i8 is a section of the 
 cylinder mounted ready for turning, and as if seen look- 
 ing down upon it from above. A is the part of tlie cliuck 
 which screws on the mandrel. BB is the flat round part, 
 the actual face-plate which has the slots in it. CC are 
 the hooks or clamps by which the work is held down, and 
 of which there are of course four. The face of the chuck 
 is drawn at the side at H, but on a smaller scale. D \k 
 the flat bit of wood under the end of the cylinder, here 
 
220 
 
 BOY ENGINEERS. 
 
 represented as a board only, but in reality bored out to 
 the size of the inside of the cylinder, which latter is 
 represented at KK. A sectional drawing, it must be 
 remembered, gives an object as it would appear sawn 
 tlirMiigli down the centre as here, or sawn across, or 
 
 Fig. i8 
 
 sawn diagonally, and is an excellent mode of drawing to 
 explain machinery. F is the tool, which is supposed to 
 have almost reached the bottom. It is merely a flat stee} 
 
INSIDE TOOLS. 231 
 
 bar to clamp in the slide-rest, drawn out into a long 
 rounded shank which is turned to the left, and sharpened. 
 The upper face is flat, the metal below it being bevelled 
 off as shown at L, but the flat surface is not horizontal, 
 but slightly tending upwards, which gives a sharper edge. 
 This will be better understood from the sketch of a 
 straight tool at M of a similar kind. For cutting brass 
 this face would be left horizontal, as that metal will not 
 be cut so well by a sharp-edged tool. 
 
 The tool shown here is represented with a round end, 
 but for the first cut on iron a point tool is better. It 
 takes off less at a cut, but it produces a satisfactory sur- 
 face, consisting of a series of shallow groves of a V shape, 
 which can, if desired, be afterwards obliterated by a tool 
 like that in the drawing, or with a flat end. A great 
 deal of turned work is, however, left direct from the point 
 tool. If the feed is slow, the grooves run into each other 
 so nearly that a level surface is to all intents and pur- 
 poses produced, and as the cutting edge is so small, less 
 power is needed to drive the tool than would be required 
 to drive a tool with either a round or flat end. We began 
 our boring operations with an inside diamond-pointed tool, 
 and at last took a very light cut with another with round 
 end, which produced a surface over which the piston 
 worked very smoothly indeed, and which soon became very 
 highly polished. Accuracy of bore is, in fact, of fur more 
 
222 BOY ENGINEERS. 
 
 real importance than smoothness of surface. The latter 
 is sure to be produced before long by the friction of the 
 parts, even if the bore is left as it comes from the pointed 
 tool ; but if the cylinder is larger at one end than at the 
 other, additional wear can but increase the error. Indeed, 
 the engine never will in such case work satisfactorily, 
 because the piston will be tight in one position and slack 
 in another, and in the latter the steam that ought to drive 
 it forward will of course escape round it and produce no 
 useful effect. It might perhaps be supposed that, as the 
 piston of an engine is packed, generally with elastic metal 
 rings, these would expand, and so fill up the space when 
 the larger part of the cylinder is reached. This is the 
 case to a certain extent, but the friction is vastly increased 
 by the powerful pressure exerted in the rings as they 
 enter the smaller part of the cylinder at each stroke, and 
 too much care cannot possibly be taken to make the 
 cylinder exactly the same size from end to end. 
 
 We now had a well-turned cylinder, with both flanges 
 truly at right angles to the bore of it, and the next thing 
 to do was to turn up the cover or covers. There are 
 generally two of these, but one is sometimes formed by 
 the bed-plate when the cylinder is to be placed vertically. 
 Ours was to take this position, and therefore we only 
 reeded one. This was a round disc cast with a short 
 tenon to fit inside the cylinder when turned, and with a 
 
STEAM ENGINE. 
 
 223 
 
 boss on the upper side to be bored out for the reception 
 of the gland or stuflS.ug-box through which the piston-rod 
 
 Fig. 19. 
 
 has to work. Fig. 19, DE and F represents this — Y 
 being the top view or plan, and DE the section of the 
 
224 BOY ENGINEERS. 
 
 same througli the stuffing-box, which is shown as just 
 ready to be lowered into the gland, where it will be held 
 by the two studs and nuts. GF is the perspective view of 
 this part. The space below the gland is filled with pack- 
 ing — either tow, or india-rubber, or patent metallic pack- 
 ing — but always tow in a small engine, which is forced 
 into close contact with the piston-rod by screwing down 
 the gland. It must be well greased to render it quite 
 steam-tight, and it should not grasp the piston-rod so 
 closely as to add greatly to the friction, yet closely enough 
 to allow no steam to escape. 
 
 Now, in turning up the cylinder cover, the same rule 
 holds good that was mentioned in respect of the cylinder 
 itself. It must be turned as far as possible at once ; it 
 must, however, be chucked twice, as both sides have to 
 be turned. We first turned quite truly the under side by 
 driving the casting into a boxwood chuck, taking care 
 that it fitted it tightly, and bedded closely down on the 
 bottom of the hollow — i.e.^ the bottom of the inside of the 
 chuck. There was a second deeper hollow permitting the 
 boss to go into it out of the way, but this was not made an 
 exact fit, as all that was necessary was that the flat part of 
 the cover should bed well down, and that the edge should 
 be held securely. We now turned the first side very care- 
 fully, making the tenon fit very truly inside the cylinder, 
 which, being finished, we could apply as a test of accuracy 
 
CYLINDER COVER. 225 
 
 at any moment. Of course, we could not get at the outside 
 edge of the cover, as it was driven into the chuck just so 
 far as to allow the tenon part to remain outside it. We 
 had no special difficulty in making a good fit of them, as 
 we had now had plenty of practice. 
 
 Having faced up and completed this under side of the 
 cylinder cover, we turned a few concentric circles upon 
 the face of it, not deep, but about one-tenth of an inch 
 apart; so that we could, if we chose, smear them over 
 with red-lead and oil before screwing down the cover. 
 This plan is commonly used in steam-engines to secure 
 a perfectly steam-tight joint, but if the parts are faced 
 up with perfect accuracy, no packing of any kind should 
 be needed. We had to face ours by hand with a flat- 
 ended tool, because there was not space enough for a 
 slide-rest tool to traverse, and it was a very simple job, 
 not worth rigging up the slide-rest to accomplish. The 
 next job was to face up and finish accurately the top of 
 the cover. This was cast with a moulding upon it, which, 
 like many other things in this world, was for mere show, 
 and not for use, but there were two plain flat parts upon 
 it requiring to be turned true and level. There are but 
 three kinds of tools necessary for brass-work — the round 
 end, the point, and the flat tool, sometimes called a 
 jilanisher. These are none of them made very keen, 
 because a keen tool catches into brass ; they therefore are 
 
226 BOY ENGINEERS, 
 
 ground to 90* or not less than 70**, and even when the 
 I cutting edge is 90° or a right angle, it is just eased off 
 
 a little upon the hone. We had also learnt one peculiarity 
 of brass which is often most annoying, viz., that it is 
 given to chatter terribly, so that instead of a smooth and 
 even surface, it is all over minute waves. To prevent 
 this, some put a bit of leather on the rest under the tool, 
 but the best plan is not to lay the tool quite flat upon 
 the rest, but to raise it a little at one corner — something 
 like the way in which a chisel is raised for wood-turning. 
 The edge thus attacks the metal diagonally, and if a little 
 play or spring is allowed it by the hand, it will cut very 
 cleanly and the annoyance will cease. There is another 
 thing or two worth mentioning here in respect of this 
 material, which applies to gun-metal as well. 
 
 In commencing to turn brass-work, the rough outside 
 will always be found sadly detrimental to the tool. This 
 is because it contains numberless fused grains of sand 
 imbedded in the metal, which are intensely hard. To get 
 rid of these, the castings are often thrown for a short 
 time into a pickle of sulphuric acid and water, which by 
 its solvent property destroys this surface and renders the 
 I metal fit for the lathe. With a pickle of nitric acid or 
 
 I' nitric and sulphuric mixed, a beautiful colour is given to 
 
 rouo^h castinfj^s, which are then dried in hot sawdust after 
 being washed well in water, and left in the rough state, 
 
GLAND. 227 
 
 edges only here and there being turned, and burnished, 
 and lacquered. By burnishing the cutting edge of a 
 scraping tool for brass, a beautiful lustre will be given to 
 the woik which no emery polishing can beat. We were 
 not, however, up to these various dodges, and patiently 
 worked on the castings as best we might, until, by dint 
 of labour, we put upon them a sufficiently satisfactory 
 face. 
 
 There was no great difficulty to be overcome in facing 
 this cylinder cover, but we had to take special care to 
 drill it centrally to the size of the piston-rod, and then 
 with a very narrow round tool we hollowed out to a cup- 
 like shnpe the place for the gland — i.e.^ we first turned a 
 cylindrical hollow, and then rounded it at the bottom, so 
 that the gland would slide accurately into it, and the 
 packing would be pressed sideways against the piston-rod 
 as well as downwards. For the same reason the gland 
 itself is generally cup-shaped below in the opposite, 
 direction. 
 
 Before removing the cover from the chuck, we held a 
 point tool so as to mark a circle a quarter of an inch from 
 the edge as a guide in drilling the holes to receive the 
 bolts by which it was to be attached to the cylinder. If 
 the drawing is inspected, it will be seen that the cover 
 lias a flat part just outside the stuffing-box at ah^ then a 
 moulding, and then a flat part again. That marked ah 
 
228 BOY ENGINEERS. 
 
 was to take the ends of a pair of guide-bars, of which 
 mention will be made again by and hy. 
 
 The piston H and its packing KK is shown in its place 
 in the cylinder. The packing here was of tow, wound into 
 a groove left for the purpose in the edge of the piston. 
 L is the piston-rod riveted into the middle of the piston, 
 in which a hollow is made below to receive the head; 
 abc are called the ports or steam-ways. One side of the 
 cylinder is cast with a thick projection extending from 
 one end of it to the other, and in this are ca^^t, or cored 
 out, as it is called, two channels by which steam is admitted 
 alternately above and below the piston. These do not 
 run into each other, but have an exit as shown. There 
 is also a central passage, which is clear of the others and 
 lies between them, being connected with a pipe screwed 
 into the side of this part, whence it turns either into the 
 air, into the chimney, or into a condenser, in which, in 
 low-pressure engines, the steam is again converted into 
 water by exposure to cold. In our engine this pipe was 
 carried into the chimney of the boiler to increase the 
 draught, as it always is in locomotive engines, and it is 
 from it that the incessant puifs of steam issue with such 
 a loud noise, the result of the high pressure at which it 
 escapes. 
 
 M of this same drawing is the eccentric of cast iron 
 with its ring or strap of brass. N is the hole through 
 
ECCENTRIC. 229 
 
 which (eccentric to the real centre) the axle of the fly- 
 wheel passes. We shall speak of this again and point 
 out its action, its object being to move the slide-valve 
 which has yet to be described. The strap or hoop is 
 generally made in two parts, with lugs or projections to 
 receive bolts, by which they are again united when in 
 their place upon the sheave M, To prevent the hoop 
 from slipping off the disc sideways, the latter is turned 
 with a deep rectangular groove, which allows the hoop to 
 enter it a little way all round, or there is a pin which is 
 screwed into and quite through the hoop, so as to fall into 
 this groove, or the hoop is channelled on the inside and 
 the disc itself enters this channel. 
 
 The pin was the easiest plan, and was therefore the one 
 which we ourselves followed. It is, however, just as well 
 in a small engine to bore out the eccentric and leave it as 
 one piece, and, having slipped it over the sheave or disc 
 of the eccentric, to attach to this another thin disc on 
 each side ; or, lastly, to turn the disc so as to leave one 
 rim standing up, and then screw on one disc only on the 
 opposite side. 
 
 In all such matters as this there is a vast difference 
 between a model and a larye ensfiue. The latter has to 
 be constructed so as to give to all parts the greatest 
 possible strength combined with the necessary freedom of 
 motion in the moving parts. In a niQ^Q\^ friction is the 
 
230 BOY ENGINEERS. 
 
 great drawback to success. A very little will often suffice 
 to prevent the machine altogether from working, and in 
 every case it consumes by far the greater portion of the 
 power, so as practically to preclude small engines from 
 doing useful work. Nothing will counteract this except 
 careful fitting and ample lubrication, especially in respect 
 of the piston and slide-valve. In very small engines the 
 stuffing-boxes are left wholly without packing, and a very 
 little tow or cotton is all that can be allowed round the 
 piston. 
 
 With the cylinder, however, as large as the one made 
 by us, useful work was really possible, although such a 
 small engine cannot be worked with economy. The same 
 cost for fuel which will produce a given amount of power 
 in an engine with a three-inch cylinder will suffice for 
 a cylinder twice as large, and with twice the effect. 
 Engines of small cylinder surface are generally driven at 
 a very high speed, and are worked at high-boiler pressure ; 
 but those of large cylinders, such as are used in Cornwall 
 as pumping engines for mining purposes, and which are 
 usually on the condensing principle, are worked at low 
 pressure, and very slowly indeed. Massive engines, again, 
 are fitted with cylinders of large diameter in proportion 
 to their height, and the stroke being very short, they are, 
 in screw-steamers especially, worked at great speed ; but 
 
ECCENTRIC. 231 
 
 they tire almost alwaj'^s condensing engines, not higli pres- 
 sure, like land and locomotive engines. 
 
 As we have drawn an eccentric and its strap, we may as 
 well say a word or two more about it, for it is an essential 
 part of every engine. It is, in point of fact, only a crank, 
 but usually of very short throw or traverse. Whether it 
 is a fancy or no, the eccentric appears a much more 
 smoothly working contrivance than an ordinary crank, and 
 yet, if the pin of the latter were to be greatly enlarged, it 
 would become one. The eccentric stroke is twice the 
 distance between the centre of the disc and that of the 
 crank shaft, or between its real centre and tliat which is 
 used as such ; for if the drawing is inspected, it will be 
 seen that the hole for the axle is a little on one side. 
 The object of this part of an engine is to work the slide- 
 valve, which only has a comparatively short traverse, and 
 whose office is to close and open alternately the ports of 
 the engine so as to admit and cut off the steam. This 
 valve is like an oblong box with a broad rim round its 
 edge. When placed in the middle position, it covers all 
 three ports, the central one being covered by its inside or 
 hollow part, and the top and bottom ports by its broad 
 rim or flange. Outside it is entirely cased in by a large 
 box called the steam-chest or valve-casing, and into this 
 the steam is admitted by a pipe from the boiler. When 
 all the ports are closed, this steam cannot get into the 
 
232 BOY ENGINEERS. 
 
 cylinder at all, but when by the rotation of the crank- 
 shaft the eccentric comes into action and causes the valve 
 to slide down or up a little distance, either the upper or 
 lower port leading to the cylinder is opened, so that steam 
 can pass through it into the cylinder, and at the same 
 time the other two ports are connected by both being in- 
 side the valve or box, so that the steam can escape by 
 that port into the valve, and out again by the middle port 
 into the air or into the condenser. 
 
 I have explained this because I remember well how, as 
 a boy, the action of this valve puzzled me, and how, in 
 every model I attempted at first to make, I tried to follow 
 some other easier plan ; yet after all it is a simple method, 
 and an inspection of the drawing will render it clear. 
 
 TT is the valve-casing or outer box into which steam 
 from the boiler passes by the steam-pipe. Now if V, 
 which is the slide-valve, is inspected, it will be seen that 
 inside it the ports a and b are connected, but not <?, 
 which is, however, open so that steam can enter it. Tliis 
 steam too, getting under the piston, will force it up in 
 the cylinder, and any steam or air which is above it will 
 go down through the upper port and into the slide-valve, 
 and thence into the middle port, and so escape. Just 
 before the piston gets to the top, the rod of the eccentric 
 moves the valve down so far that the lower port and 
 centre one come into connection inside the valve, "while 
 
SLIDE VALVE. 233 
 
 the top one is now open for steam to enter the top of the 
 cylinder. It will push down the piston, therefore, while 
 the steam underneath it from the last stroke will escape 
 into the middle port as before. So by the slight move- 
 ment of this cleverly-arranged slide-valve, the alternate 
 up-and-down movement of the piston is secured, and the 
 engine kept at work. The outer box or valve-casing has 
 its stuffing-box just the same as the cylinder through 
 which the valve rod passes steam-tight. This rod is the 
 same as that marked E. on the eccentric, but drawn to a 
 much smaller scale. 
 
 It is necessary, of course, to make the valve move 
 steam-tight, but very smoothly upon the surface on which 
 it slides, or else steam would get under it and interfere 
 with the working of the engine. This is one of the diffi- 
 culties to be mastered in making, and this is how we 
 succeeded. The valve was brass, and we first of all filed 
 its face as level as we could, trying it by a straight-edge 
 or thin steel rule (the blade of a square). When it 
 seemed to be quite level, we finished by rubbing it on an 
 old school-slate, which brought it very soon to a beautiful 
 face. We wetted the slate during the process. Then it 
 was necessary to get a similar face upon the part on 
 which the valve was to work. It was more difficult, 
 simply because the surface was larger, but we did it in 
 the same kind of way, first filing and then rubbing down, 
 
234 BO Y ENGINEERS. 
 
 and we took great care to keep the face of the part parallel 
 to the inside or bore of the cylinder. 
 
 In every case, nevertheless, a little play mnst be allowed 
 to the slide-valve, which must be so attached to its rod 
 that the latter does not in the least tend to lift it. The 
 steam pressure will keep it close if it is allowed to 
 do so. 
 
 There are several methods of doing this, but we followed 
 that commonly used in locomotive engines, and shown 
 in the same drawing at Nos. i, 2, and 3. This is a 
 frame of iron, left white in each of the sketches, which it 
 will be seen spans the whole of the valve, and into a boss 
 on which the rod is screwed : i is a view from the back; 
 2, from the side; 3, a perspective view, which will assist 
 also in rendering more clear to the reader the form of the 
 valve itself, with its broad flange acting as a cover to 
 the ports. This frame fits round the valve, but quite 
 loosely, so as only to move it up and down, but not so as 
 to hold it. Thus the steam can act freely in pressing it 
 against the valve-facing. At fig. 4 is seen a hinge 
 which allows free play to the eccentric rod, and by which, 
 when expansion gear is not used, but the valve worked 
 direct from the eccentric, the valve can be moved without 
 the intervention of any guides. This, however, brings a 
 little undue strain upon the stuffing-box, and consequently 
 the frame has often a second rod and stuffing-box od the 
 
EXPANSION GEAR, 235 
 
 opposite side, which of course keeps the rod in a direct 
 line. But we were not content with either plan. We 
 made ours to reverse, and to cut off steam at any part of 
 the stroke, by which we entailed upon ourselves the 
 trouble of fitting two eccentrics instead of one, and also 
 some levers which this action renders necessary. 
 
 Let me explain, first of all, about this cut-off system, 
 commonly named expansion gearing. In a high-pressiu-e 
 engine, the steam may be entering the cylinder with a 
 force of forty, fifty, or a hundred pounds pressure on 
 the square inch, giving to the piston, according to the 
 number of inches of its surface, a great degree of impetus. 
 Economists have argued that there is not the slightest 
 occasion to continue this impetus throughout the whole 
 stroke, but that the steam may be cut off before it is 
 nearly finished, and allowed to continue its action on the 
 piston by its expansive force, which, though it will of 
 course gradually get less and less, will sufifice to drive the 
 piston forward. The steam is therefore admitted at full 
 power for a second, and then the valve moves and cuts it 
 off altogether, and the piston continues its journey under 
 a diminished pressure, until by the opening of the other 
 port its action is reversed. 
 
 Locomotive and marine engines are always fitted with 
 expansion gearing, but not generally speaking farm 
 engines, and it is not commonly applied to fixed engines. 
 
236 BOY ENGINEERS. 
 
 unless of a very large size. A good deal depends on the 
 price of fuel. In coal districts, where it is cheap, economy 
 is not much studied, but where the supply is more limited, 
 it becomes very important to reduce in every possible way 
 the quantity required to work a steam-engine. 
 
 It is evidently, therefore, a great object to do this in 
 ocean steamers, which have to carry their supply of coal 
 on board, and which have, perhaps, long voyages to make, 
 with no opportunity of renewing their stock of fuel. 
 
 Our own object, however, in using expansion gearing 
 was a very different one. It was solely because we wished 
 to make our engine as perfect as we could. 
 
 I have spoken also of reversing action, which, as all 
 young travellers know, is absolutely necessary in a loco- 
 motive, which they will, no doubt, have frequently noticed 
 as capable of going backwards or forwards at pleasure ; and 
 they will have also probably noticed that the engineer in 
 charge, when desiring to change the direction, pulled 
 towards him or pushed from him a handle. This handle 
 is connected by levers with a pair of eccentrics on the 
 crank axle, one being the forward, the other the back- 
 ward eccentric, either of which can be brought at pleasure 
 into gear with the rod of the slide-valve. 
 
 This link motion is shown in fig. 20. BC are the two 
 eccentrics, keyed on the same axle, D, side by side, but at 
 right angles to each other as regards their throw ; EF 
 
LINK MOTION, 
 
 537 
 
 are the eccentric rods, which are pivoted at G to a pair of 
 lugs, one at each end of the link L, which is suspended 
 at R from a cranked lever OAR. A is the fixed point 
 on which this lever turns, so that if the handle is palled 
 back, it will pull up the link with it, raising the end G 
 
 Tig. 9o> 
 
 of the eccentric rod E, and also that of F. K is the rod 
 of the slide-valve, working between guides, HH ; but 
 if there are two stuffing-boxes to the valve-casing, these 
 
238 BOY ENGINEERS. 
 
 are not required, as their object is to cause the rod to 
 move in a right line. M is an arched piece of iron with 
 notches in it, into which falls a spring catch N, connected 
 with a secondary handle near that of the main lever, being 
 pivoted to it. 
 
 Now it will be noticed that EGK are in a line, and 
 that the motion of the eccentric C will be imparted 
 directly to the valve-rod, just as if the whole were a simple 
 eccentric and valve-rod, but the lower eccentric rod in its 
 present position will only cause the link to vibrate without 
 moving the valve- rod at all. There are other forms of 
 link used, but this is the most common. To reverse the 
 engine, the lever D is pulled back until the other eccen- 
 tric comes into a line with the valve-rod, and by drawing 
 back D, or pushing it forward to a short distance only, 
 securing it by the spring catch N, the traverse of the 
 valve becomes limited, and the steam is cut off at any 
 desired point of its stroke. If this drawing, which repre- 
 sents the levers as they would appear in a locomotive 
 engine, is turned so as to place the letter B and eccentrics 
 at the bottom, it will exactly represent the link as applied 
 to our engine, in which, as will be described by and by, 
 the cylinder was placed with its stuffing-box downwards, 
 and the crank axle was down below it, which is a capital 
 plan, as the more the weight is placed at the bottom, the 
 steadier an engine will work. It makes no sort of 
 
REVERSING. 239 
 
 difference whetlier or not tlie cylinder is horizontal, or in 
 any other handy position. 
 
 The reason that a link motion serves to reverse an 
 engine is this : When the piston is equally in the middle 
 of its stroke, where we may suppose it to have arrived 
 at the time the steam was turned off and the ensfine 
 stopped, it is evident t^at it will be ready to move 
 indifferently in either direction according to whichever 
 side steam is first admitted. By the way in which the 
 eccentrics are fixed, one will be ready to move the slide- 
 valve in one direction and the other in the contrary 
 direction, and this link enables the engine-driver to 
 throw either into action at pleasure. He has conse- 
 quently power to admit the steam to either side of the 
 piston as he pleases, or to stop the engine by drawing up 
 the link till the slide and stud P of the slide-valve rod 
 falls half way between E and Gr, when the motion of the 
 eccentrics will only cause the link to oscillate upon P 
 without moving the valve-rod at all. 
 
 It must be clearly understood that the only union 
 between E and K is by the link — the piece P being 
 attached to the valve-rod, and the link sliding up and 
 down upon it. The link is attached to E and F perma- 
 nently at GG. When, therefore, the link is raised by 
 the levers, the eccentric rods go with it, but PK do not 
 The arch M is fixed to the bed-plate in a locomotive, and 
 
240 BOY ENGINEERS. 
 
 occupies a place close to the engine-driver's right hand, so 
 that it is not situated, as here, over the eccentrics, hut a 
 long way hehind them ; and the connection is made with 
 the hell crank A, by a long flat rod, which would be 
 attached at about the point ON, and this would not be 
 the handle, as represented here, but only a cranked lever. 
 This is one of the cleverest inventions connected with a 
 locomotive, and is now also applied to engines for many 
 other purposes. It works easily, is not liable to get out 
 of order, and enables the expansion principle to be carried 
 out to great nicety. The arch is here represented as 
 single, but in practice two are placed side by side about 
 two inches apart, and the lever works between them. All 
 these levers are flat bars with forked ends, and we made 
 ours in the same way, filing up all of them, or grinding 
 them on emery wheels where perfect surfaces were not 
 needed. 
 
 In making a working drawing of this part, to get the 
 proper curve of the link, which is, however, sometimes 
 made straight, we struck the arc from the centre of D the 
 crank-shaft, which brought it as nearly as possible correct, 
 60 that it worked smoothly. The slide P, it is evident, 
 must fit and yet not jam in the link. It was made thus : 
 The end of the valve-rod was forked so as to span the 
 link, and the plate P, of which the hindmost only is 
 shown, but on the near side is a similar one. The circle 
 
LINK MOTJON. 241 
 
 at P is a pin, which is turned to fit nicely "between the 
 sides of the link, and which extends through it. It has 
 a shoulder turned down, and the tenons thus formed are 
 screwed, and the flat plates are then screwed to thein. 
 The small fig. 2 will make this clear. AA is one side of 
 the link, B the round piece of iron or brass turned with 
 tenons, on which plates CC are screwed or riveted. At 
 P is seen one plate, which, as the dotted continuation of 
 the lines shows, goes across both sides of tbe link j and 
 the similar plate represented as removed would be on this 
 side. The rounded part, therefore, alone is between the 
 sides of the link, and will move up and down freely in 
 spite of the curve, which is as easily traversed as if it 
 were straight. The forked end of the slide-valve rod is 
 dotted, and merely to show that it spans the plates, and 
 is attached to the same tenons as they are. It would of 
 course be in reality standing straight out towards the 
 spectator, and not hanging down as drawn ; in fact, it 
 could not occupy the latter position, because it is held up 
 by the guides. » 
 
 It is now necessary to say a few words about the action 
 of the eccentric. Its entire traverse or stroke is, as stated, 
 twice the distance between the real centre of the disc 
 keyed on the shaft and the centre of the latter, and this 
 is exactly the traverse it will give to the slide-valve. In 
 getting it out, therefore, the two centres, i.e.^ its own and 
 
 Q • 
 
842 ^0 Y ENGINEERS. 
 
 the centre of the hole to be made in it for the crank- 
 shaft, are to be the same distance apart as the stroke of 
 the valve in either direction — i.e., the width of the port 
 and a little over — a very little, so as to make sure that 
 tlie valve will cover it, and travel just beyond it before 
 the motion begins in the opposite direction. AU crank 
 action is alike in one particular, whether produced by 
 eccentric or otherwise. The action upon a slide actuated 
 thereby is not of equal speed throug-hout, being greatest 
 when in the middle of the stroke, and least when at the 
 ends. This is not a great drawback to its use, as it is 
 counterbalanced by its extreme handiness in other respects. 
 The eccentric, considered as a crauk, must be at right 
 angles, or nearly so, to the other crank driving the fly- 
 wheel. Its greatest throw must be at a time when the 
 other crank is at its least, or on the dead centre ; but the 
 eccentric having to begin its work of opening the valve 
 a little before the piston is at the end of its stroke and 
 the crank in the position named, it is set forward a little 
 upon the shaft, instead of being quite at right angles to 
 the other. 
 
 Having entered almost necessarily into explanations of 
 the action of eccentrics and of link motions, we must now 
 go on to state how we actually made these portions of our 
 engine. We left off at the boring of the cylinder and 
 fitting of its covers, with the facing up of the valve and 
 
PIN DRILLS. 243 
 
 its seat. The valve-casing and its cover was merely a 
 matter of filing and neat fitting — the gland being small, 
 was cut with a thread outside, and screwed into its place, 
 the boss being drilled and tapped for that purpose. We 
 just ran through the boss a drill the size of the valve- 
 rod, and followed it with a larger, which was carried 
 down nearly to the bottom, but not quite, so that it made 
 a recess, of which the bottom was tapering. The ])roper 
 tool for this sort of work is a re-centring or pin-drill, i.e.^ 
 a drill with a projecting end, which goes into the hole 
 first diilled, while its edges cut the cavity larger. This 
 ensures the cavity being concentric with the hole originally 
 made. These pin-drills are used very extensively in the 
 mechanical trades to form countersunk holes for cheese- 
 lie.ided screws, and should form part of every amateur 
 mechanic's stock in trade. If our readers go to the 
 ffunmaker, he will show them several kinds of this useful 
 tool, which he uses to a very great extent. They will be 
 found also at any machine-shop, but not always at tool- 
 shops, as most workmen make their own, because they 
 are required of all sorts of odd sizes, and there is no 
 standard size recognised, as there is of other drills. 
 Not having any, and, in fact, never having seen one, we 
 did our work as stated, and made a satisfactory job 
 of it. 
 
 In making this engine and many other things, we had 
 
244 £0Y ENGINEERS. 
 
 occasion for a number of six-sided nuts, not that square 
 cues were not a deal easier to make, but tbe hexagonal 
 form was vastly to be preferred, as more correct in 
 design theoretically as well as practically. In the days 
 whicli I am speaking, bolts and nuts could not, I 
 fancy, be purchased ready-made of all sizes, as they 
 can now, and we had to make our own, with a screw- 
 plate to cut the threads. Now a six-sided nut is a 
 difficult customer to deal with, and needs very careful 
 filing to get it true and even. We accomplished it 
 thus : — AVe cut a notch in a bit of tin with an angle of 
 135°, which we got at first by dividing a circle into six 
 equal parts, and connecting the points of division by 
 straight lines, so as to represent a six-sided nut ; cutting 
 out this, we used one of its angles as a gauge, by which 
 to cut the notch in our slip of tin. We then took a bar 
 of iron long enough to make six nuts, and we filed it up 
 to six sides by help of our gauge. We then sawed it oif 
 with a hack-saw into six equal pieces, each of which we 
 afterwards drilled, drove on a taper mandrel, and turned 
 at each end, rounding ofi" neatly the one whicli was to 
 stand uppermost. When cut off, and while still upon 
 the mandrel, we touched up each nut with a smooth file 
 to give it more perfect finish, and we thus made all our 
 nuts precisely alike. We then placed them in a vice with 
 lead clamps to prevent bruising them, and drilled them 
 
BOLTS AND NUTS. 245 
 
 half from one side and half from the other, running 
 a broach through afterwards to equalise the holes ready 
 for the taps. The shanks of the bolts were turned by 
 hand with a graver, and finished with a file, and they 
 were cut from rods sufficiently large to allow of being 
 filed up to six-sided heads ; but we gave up this as en- 
 tailing unnecessary labour, and generally turned the 
 heads also in the lathe and left them round. Thus 
 made, however, they were liable to turn round and 
 round in their places while the nuts were being screwed 
 up ; we therefore cut a nick across the heads for a screw- 
 driver, by which we could hold them until they got a 
 bite upon the surface of the parts where they were 
 placed, after this they could be tightened without 
 turning. 
 
 The handles ON were just the parts that, if well-made, 
 add much to the appearance of an engine. We made 
 them therefore of round iron, centred and turned up at 
 the handle end to a nice shape, and then filed down 
 neatly, the flat sides being rounded in a hollow sweep 
 into the turned part at A, where the pin goes upon which 
 it turns ; we also finished the top in the lathe, but the 
 end R being forked to receive the end of the bar which 
 is attached to the link, we made it of a separate piece. 
 This was turned on a taper mandrel first, to face up its 
 two round sides, and then, having bored and tapped the 
 
246 BOY ENGINEERS. 
 
 other part by v.hich it was to "be attached to its arm, 
 we mounted it on a chuck with a projectiug centre-screw 
 to fit it, and thus were enabled to turn up the neck 
 as well. 
 
 Wherever a fork of this kind occurs, if it is large 
 enough to turn, it is better made as a separate piece, 
 unless the arm upon which it occurs is a very short one. 
 This arm, when the boss is mounted in the lathe, flies 
 round and round with great rapidity, and endangers the 
 knuckles, or even the face, especially if the turner is 
 short-sighted, and obliged to look closely as his work 
 proceeds. It is in making small models that these parts 
 give most trouble, especially if the lathe is not one that 
 runs lightly and easily. It may be taken as a general 
 rule that the lathe should be suited for the work, and 
 that not only cannot heavy work be accomplished on 
 a light lathe, but that light work cannot be done on 
 a heavy one, as may be easily proved by turning a set of 
 studs in a six-inch lathe, such as is usually fitted with 
 back-gear for metal work. It will be found altogether 
 too sluggish and heavy, with too much impetus when 
 once speed is got up, and too little at starting afresh 
 after stopping to inspect what has been already done. 
 Having experimented upon shirt-studs with just such 
 a lathe, I speak from expei'ience ; at the same time it is 
 absolute bullying to turn heavy work and to use heavy 
 
ECCENTRIC DISC. 247 
 
 cliucks upon a really light latlie fit for ornamental tuiniug. 
 I do not say that it cannot be done, for I have seen the 
 naves of farm cart-wheels turned upon a three-inch centre- 
 lathe, propped up to six inches with a block of wood 
 permanently fixed under the poppit. It took in the work 
 in this way, but it is easy to understand the strain upon a 
 mandrel and collar designed only to carry work of the 
 very lightest description. No doubt it has long ago been 
 worn out and descended to the scrap heap. 
 
 The discs of the eccentrics do not in the drawing show 
 the mode in which tliey were turned. They were, in fact, 
 bored first through the real centres, and turned and 
 faced up on a mandrel. This hole was of no iniportauce, 
 as it did not interfere with that for the axle, and it 
 was consequently left, and not plugged up or concealed. 
 A groove was turned in the edge of each disc to receive 
 the pin or pins ; for there were two spoken of before, 
 and shown at opposite sides. They had no heads, and 
 were sunk to the level of the brass hoops, so as not to pro- 
 ject. They did not, of course, show at all, but are drawn 
 as if the disc was a section, the dotted line being su[)posed 
 to be the bottom of the groove. The eccentric hoops in 
 this case had no lugs, and were cast and made in one 
 piece, which was mounted in a boxwood chuck, that had 
 a place cut out to receive the projecting part C, and 
 carefully bored and faced on each side ; and while the 
 
248 BO Y ENGINEERS. 
 
 latter work was being done, a line was traced with a 
 point tool as a guide for subsequently filing to a true 
 circle concentric with the inside the outer edge of the 
 hoop, which could not be turned on account of the pro- 
 jection C, unless, indeed, the lathe were fitted with a 
 segment stop by which the rotation of the mandrel could 
 be arrested at any point. This, however, was a complica- 
 tion which our lathe did not possess, and we filed the 
 brass up to the lines traced on each side, and then 
 rounded off the angles to give it a nice finish. 
 
 The link LL was made of a plate of iron a quarter of 
 an inch thick, filed down to three-sixteenths. We first 
 cut out this link on paper, and gumming it to the 
 iron, marked it all round with a finely-pointed centre- 
 punch. We marked it on a piece not much broader than 
 needed, and before shaping it on the outside we drilled 
 holes all along the slot, which we threw into one by a 
 rat-tail file, and then finished by carefully, filing all 
 over. It was a somewhat tedious job, and required care 
 to get the faces true and square to each other, but we 
 accomplished it at last by not hurrying over it, and we 
 got the angles all sharp, and the surfaces flat ; and when 
 finished and in place upon the engine, it looked exceed- 
 ingly workmanlike. We also managed to fit the joints 
 of this link motion and its levers, so that they worked 
 nicely without being too slack and shaking about, as they 
 
LINK MOTION. 249 
 
 often do in model engines. All this required care and 
 patience, but in onr various attempts at meclianical 
 manipulation, we had acquired a fair degree of both, and 
 were seldom guilty of hurrying our work, and thereby 
 spoiling it. 
 
 The semicircular notched plates were cut in a similar 
 manner out of a bit of lock-plate, but for these, of which 
 a pair were made, we took advantage of the lathe. We 
 clamped upon the face-plate, on a bit of board placed to 
 allow the tool to cut quite through without coming in con- 
 tact with the face-plate, the bit of iron plate, and with a 
 tool fixed in the slide-rest cut out its centre so as to leave 
 a ring, of which, however, the outside was of course 
 square. We then cut out this again, at a width sufficing 
 for the pieces we required, so that we produced now a 
 circular ring of flat metal, which fell off as soon as it was 
 completed. We then marked the diameter and sawed it 
 into halves, which we fixed together in a vice, and drilled 
 for a pair of studs at each end, which were turned with 
 shoulders, and riveted into the plates at each end, to 
 keep them a given distance apart. Before the rivets, how- 
 ever, were put, and while still clamped together in the 
 vice, we filed the notches so that they should exactly 
 tally with each other. I had almost forgotten, however, 
 one important part of the proceeding, viz., heating the 
 ends and screwing them in a vice, in order to bend up a 
 
25 o BOY ENGINEERS. 
 
 little bit to receive a hole for a screw, Ly wliicli the pair 
 when finished were attached to the bed-plate in wliich 
 they rested. This bed-plate was fixed to the boiler, which 
 was a vertical one, in the manner we shall by and by 
 describe. This boiler, however, we decided not to attempt 
 ourselves, because we wanted to put a good amount of pres- 
 sure upon it, and did not feel certain of our capabilities 
 in regard to riveting and fitting it. It was, however, 
 made to our own plan, and got up steam and kept up the 
 supply very well indeed. 
 
 The boiler, as will be seen from fig. 21, was cylindrienl, 
 but stood upon a square base in which was the fire-grate. 
 This consisted of a grating which sloped slightly upM^ards 
 from the furnace door. The latter was on the side oppo- 
 site to the cylinder and flj-'-wheel, so as to keep the dust 
 a.nd dirt from the working parts as much as possible. A 
 circular flue from the back or nearly the back of the 
 grate went entirely through the boiler vertically, forming 
 a chimney at the top, and into this the exhaust steam 
 was carried by the pipe P, which turned upwards in the 
 funnel. The other pipe just below it brought the steam 
 from the boiler into the steam-chest of the slide-valve, 
 which being at the back, is concealed from view by the 
 cylinder. 
 
 M is a tap for drawing off the water of the boiler, and 
 was of large size to enable it also to carry off any sedi- 
 
Fig. 21. 
 
252 BOY ENGINEERS. 
 
 ment which, settling at the bottom, would prevent the heat 
 of the furnace from exercising its full power upon the 
 water. ABC are gauge taps for the purpose of testing the 
 height of the water, and D is the glass water-gauge for 
 the same purpose. We made the gauge, but not the taps, 
 which were easily procurable from the gasfitters. S is 
 the safety-valve with its lever and weight. The latter, 
 hung on the outer notch, registered a pressure of fifty 
 pounds to the square inch, we seldom worked at a higher 
 pressure than twenty-five pounds, but the boiler was 
 tested and considered safe at eightj^ pounds. The cylin- 
 drical part was of copper, the lower part of iron plate, the 
 two fastened together with a circular row of rivets, a layer of 
 red-lead being interposed. To stiffen the whole there were 
 two wrouglit-iron rings turned up bright, and partly on 
 these, and partly on a pair of short pillars, rested the bed- 
 plate HH,to which the cylinder andother parts of the engine 
 were bolted. The bearings of the crauk-shaft,however, were 
 on the top plate of the iron base, the fly-wheel being outside. 
 The row of ornamental holes on the lower part were 
 merely to admit more air to the fuel, which was charcoal 
 with small bits of coke mixed with it. The reversing 
 {^'ear is partly visible, and needs no further explanation 
 than what has been already given. G is the outside of 
 one of a pair of guides of cast iron, the inner sides and 
 edges of which were filed up very truly to receive the 
 
OUR ENGINE. 253 
 
 gun-metal block attached to the end of the piston-rod, 
 to cause it to move in a perfectly straight line. These 
 were supported by pillars, KK, screwed into them and 
 fixed to the bed-plate. The fly-wheel was of cast iron. 
 This we could not ourselves turn, as it would not go into 
 our lathe, but a friend faced up the rim on all sides, and 
 also the boss or nave in the centre, which gave it a nice 
 finish. The rest was painted over with dark green and 
 varnished, as were also all parts in which the castings 
 remained in the rough state. This engine gave us fully 
 one quarter-horse power, and I think would have given 
 more if the grate and its fuel had been better arranged. 
 
 In a previous page, speaking of the method we adopted 
 to face up our slide-valve, I remarked that it was not the 
 right method of doing it. Before concluding the present 
 chapter, therefore, I will say a few words upon this 
 subject, which in practical mechanics is of such extreme 
 imfiortance. 
 
 There is hardly a machine in use which has not one or 
 more flat surfaces, upon the absolute truth of which its 
 action more or less depends. The face of a slide-valve 
 and of its seat is but a case in point. 
 
 Before my young readers or their parents were born, 
 the only plan which was available was to use a chipping- 
 chisel, and to follow it up with the file, first with very 
 large and coarse ones, and then with lighter and finer, 
 
254 >0 V ENGINEERS. 
 
 until something approacliing a level surface was obtained. 
 Tlien, if greater accuracy were needed, and especially if 
 two level surfaces were intended to work together, they 
 were coated with emery and oil, and rubbed to and fro, 
 until both surfaces had attained such perfection as this 
 method was calculated to produce. 
 
 This in time made by no means a very bad surface, and 
 for years was considered amply sufficient to meet all 
 circumstances. It had, nevertheless, certain drawbacks. 
 In the first place, the emery got imbedded in the face of 
 the work, and the surfaces continued to grind and abrade 
 each other long after they were supposed to have become 
 quite clean. Then, again, as metal is seldom equally 
 hard at all points, the emery ground the soft spots more 
 than the hard ones, and consequently the surfaces were 
 very rarely as perfect as they were supposed to be, 
 although for want of better means they were of necessity 
 used in that imperfect state. At last came to the fore 
 one of our greatest living mechanics, now known in all 
 lands as Sir Joseph Whitworth. I wish I could tell you, 
 boys, about his life, but I have not much doubt that, like 
 all our greatest and best men, he had to fight his own 
 way, and gained his present proud position by dint of 
 downright (and upright) hard work. For men are only 
 born mechanics in one sense, and that a limited one — 
 they are born with mechanical tastes and predilections. 
 
STUDY, 255 
 
 We can't tell how it is, but Providence has given to 
 nearly every one a liking for some one study or pursuit 
 beyond all others, and if those likings are duly cultivated 
 by study and diligent practice, they will profit not only 
 the possessor, but the world at large. 
 
 Now, the mistake which many of our mechanical boys 
 make is this : They think mechanics so natural to them 
 that hard work, especially hard reading, is unnecessary. 
 The consequence is, they remain always at the same level, 
 they just muddle along, playing at mechanical work, but 
 they never do any good with it. 
 
 To make the necessity of study more clear, let ua 
 suppose one of our young friends desires to make an 
 engine or a machine to do certain work. It is not 
 enough that he has devised in his own brain a certain 
 vague plan, but he must reduce this first to a very 
 accurate working drawing, i.e.^ a drawing in which every 
 detail is clearly set out to a certain definite scale, so that 
 if the parts of the machine are made by that drawing, 
 they will fit into their proper places, and work as they 
 are intended to do. Now, the first question is as to dze 
 and then proportion. The .different levers must be large 
 enough in order that they may have the requisite 
 strength, but they must not be too large, so as to waste 
 material and add unnecessarily to the weight and to the 
 cost. To determine this point alone, much theoretical 
 
2S6 BOY ENGINEERS. 
 
 knowledge is necessary. The strength of bars of iron of 
 a given size and shape must be known, both iu regard to 
 their ability to stand a strain tending to bend them, and 
 also iu many cases tending to twist them or to crush 
 them. The question may arise whether a bar should be 
 of a square, or oblong, or circular, or elliptical section ; 
 whether steel, or iron, or brass is preferable ; whether it 
 should be of cast or wrought metal ; and without technical 
 knowledge of the nature of these materials, the question 
 must be decided by rule of thumb. What is the result? 
 Perhaps you complete a four-horse engine, and the con- 
 necting-rod is only stroug enough for one-horse power ; 
 or the expansion and contraction of the metal under 
 different temperatures having been lost sight of, rivets 
 loosen and plates crack ; or the moviug parts are so 
 unduly heavy that half the power which ought to have 
 been useful is expended in giving them motion. 
 
 An engineer must have a whole lot of this sort of 
 information at his finger-ends, besides the more ordinary 
 elementary knowledge of the laws which govern nature. 
 He must not only be able to do certain work in a certain 
 way, but to know why that way is preferable to any 
 other ; and he must have an immense deal of general 
 knowledge which I cannot now stay to detail. 
 
 Then comes manual practice, the handiwork part of 
 the question ; and I know of no detail of mechanical work 
 
FILING. 2 SI 
 
 which will more entirely prove the necessity of such 
 practice than tliat now under consideration — the produc- 
 tion of a level surface. Looking at a skilled mechanic 
 using a file, any one would imagine that a very short 
 apprenticeship would teach him to do the same. I can 
 only say, Let him try it; and in five minutes his self- 
 assertion will have taken flight, and he will have been 
 taught an important lesson about his own ignorance that 
 will do him a great deal of good. 
 
 To file a level surface is, in fact, a test of skill of so 
 high a class that not many will do more than barely pass 
 muster in respect of it. The first necessity is, to have 
 tools of accuracy to test the work as it proceeds ; the next, 
 to have properly selected files; the third, to have a good 
 scraper, sharp and well hardened, to follow the smooth 
 file. 
 
 Of tools of accuracy required, the first is a steel straight- 
 edge, perfectly true and reliable ; the second, a surface- 
 plate, large enough to allow the work to be tested to lie 
 wholly upon it ; the third, a set-square ; the fourth, a scrib- 
 iug-block. With these you are fitted up for real work. 
 
 The straight-edge is merely a steel rule, the sides of 
 which are truly parallel vO each other. Sometimes, as 
 in those now imported from America, they are graduated' 
 in inches, with subdivisions, ranging, if required, to sixty- 
 four in the inch ; sometimes they are without these. The 
 
258 BOY ENGINEERS. 
 
 graduated straight- edges are about one-eighth of aa inch 
 wide, and may be had from one inch to two or three feet 
 in length. Workmen, however, usually make their own 
 of steel less than half this thickness. There are also 
 straight-edges much broader — say one inch wide, with a 
 rib on the back to stiffen them. These are of cast iron, 
 and beautifully got up on the face, but are not nearly so 
 common as the first named, except in the large sizes; 
 The surface-plate is an extended or very broad straight- 
 edge. They are of all sizes, from six inches square up- 
 wards. They are of cast iron, ribbed on the back to keep 
 them perfectly stiff, and with two handles, and feet, to 
 rest them on (at the back), because, being tools of perfect 
 accuracy, all possible care must be taken to make them 
 so stiff and strong as not to yiekl in the least in whatever 
 position placed ; and this is practically a great deal more 
 difficult than the tyro would suppose. 
 
 The set-square is of steel, and is simply a very accurate 
 one cut out of sheet steel, or it is made with a broad back, 
 so as to stand upon the surface-plate without being held, 
 which is often very convenient. Sometimes, however, 
 this tool, instead of being of the usual form, is extended 
 in width on both faces until it becomes like a sheet of 
 note-paper opened to a right angle, or a long strip of card 
 folded lengthwise to a right angle, and filled up in the 
 angle by cast ribs, both surfaces thus forming accurate 
 
TO OLS OF A CCURA C Y. 
 
 259 
 
 I M I 1 1 I 1 1 > I I I I I I I IM M' 1 1 ' I M <P > I ' ' I ' I Ml I 
 
 Ficr. 23. 
 
26o BOY ENGINEERS. 
 
 surface-plates. These are, of course, more costly than the 
 ordinary steel square, and the tyro need not buy one ; but 
 the}'' are very useful in machine manipulation. These we 
 will illustrate presently, as the next will perhaps hardly 
 be understood without a sketch. 
 
 This is the scribiug-block or surface-gauge always 
 used in connection with the surface-plate, and represented 
 at F of this plate. To return, however, to the straight- 
 edges : A represents the simple form, B the ribbed and 
 broader kind, of which the face used for testing is here 
 shown upwards. There is, in the longer ones, a flat piece 
 or foot at the angle where the inclined ribs meet on pur- 
 pose to stand the tool upon when not in use. C is a 
 square made so as to stand by itself, and D a plate-squuie 
 for testing broader surfaces. This may be of any size, 
 and is often made much longer in proportion to its width 
 than represented here. E is a surface-plate turned upside 
 down upon its face to show the ribs by which it is stiffened 
 at the back, and the handles by which it is lifted. Its 
 three feet are also shown. 
 
 The face of this is worked so true and so absolutely 
 level, that if one is stood feet-down upon the bench, and 
 another lowered upon it, the top one seems to float upon 
 a thin film of air shut in between them, and can be spun 
 about in all directions with a touch ; but if the upper one is 
 slid on from one edge, instead of being lowered down direct 
 
SURFACE PLATE. 261 
 
 from above, it will pick up the bottom one if it is lifted, 
 as thej are pressed together by the weight of the atmos- 
 phere, there being no air between them to counterbalance 
 that pressure. They are made exactly in the way presently 
 to be described, by which all surfaces are now got up at the 
 best engineering workshops. 
 
 The scribing-block F, also used with the surfece-plate 
 upon which it stands, is perfectly level underneath, and 
 the slotted plate is at right angles to the base. This plate 
 carries a short slide, which works up and down smoothly 
 in the slot, and through which is a screw, with a slit or 
 hole in it to receive the bent needle or scriber bc^ of hard 
 steel. This can be raised, therefore, and turned about at 
 pleasure, and a turn of the milled-headed nut fixes it at 
 once in any position. The scriber can be changed for 
 another, curved differently, and this is also so held that 
 it can be lengthened or shortened at pleasure in either 
 direction. There is no more useful tool to the metal- 
 worker, who, indeed, cannot possibly do accurate work 
 without it. 
 
 Let us consider the uses of these several appliances. 
 
 The first thing to do in working up a level surface is to 
 see that it is not winding. For this we require two straight- 
 edges like A, wide enough to stand on edge by themselves. 
 Laying them in this position, one at each end of the sur- 
 face to be tested, we look at them from such a position 
 
262 BOY ENGINEERS. 
 
 that the eye just catches the upper edges of both, and if 
 these agree, we know that at any rate in that direction 
 there is no wind. We then try another position, and if 
 in any one we detect the error, we must file away the sur- 
 ftice where too high, and get the whole as true as we can 
 in respect of that error. We next proceed to face up one 
 side, the one which we have corrected thus far. If there 
 are any projections much above the level, or if it is a 
 casting, we commence by using a chisel, called a chipping- 
 chi.sel, with which we remove all the hard skin of the iron, 
 and all the larger prominences. Then with a coarse file 
 we remove the rough edges left by the chisel, and work 
 all down to a tolerable level, and in this operation we test 
 the surface in all directions with tlie straiglit-edge, look- 
 ing under it at the line of light, and noting where the 
 metal needs lowering. Having done this so far as a coarse 
 file will enable us, we take a bastard or second-cut file 
 and go over it again ; and now, if we have one of the 
 broader straight-edges like B, we rub its face with a little 
 red ochre and oil to colour it, making a very thin layer 
 of it ; and when we try the surface now, we shall redden 
 all the high parts, and so more easily enable ourselves to 
 distinguish the prominences which need the file. When the 
 straight-edge will guide us no further, and the surface is 
 approaching a true level, we substitute the surface-plate, 
 which enables us to test at once a much greater area, using 
 
SCRAPER. 263 
 
 the red ochre and oil smeared over its face as hefore. If 
 the object is small, the surface-plate will be stood on the 
 bench, and the work placed upon it ; if large, the surface- 
 plate will itself be lifted and turned over upon the work ; 
 and in either case, by a slight rubbing we mark all the high 
 places. Now, however, we have to discard the coarser and 
 middle-cut files in fav(mr of the fine ones, whicli are to 
 be used until it is found that they no longer can be made 
 to localise their action sufficiently — i.e.^ that in using 
 them we are in danger of filing too large a surface. The 
 file is then laid aside, and the scraper used instead, or 
 alternately with the file. G is a scraper, made commonly 
 of an old three-sqnare file, ground to a point, so as to 
 give three somewhat curved and very keen edges, which 
 must be constantly renewed by rubbing on the oil-stone 
 during the progress of the work. With this tool any 
 given spot that is too high can be scraped off from any 
 part of the surface, and minute points attacked in the 
 centre of a large surface which no file will reach. In 
 use, the handle must be firmly grasped in the right hand, 
 and the blade in the left, and the whole tool may need to 
 be steadied by keeping the elbows close to the sides, and, 
 as it were, hugging the tool. The work must be held in 
 the vice, or, if this is not possible owing to the size 
 or shape of it, it is to be laid on the bench, and held 
 securely by nails tacked in around it. The high parts 
 
264 BOY ENGINEERS, 
 
 should be scraped by square touches, a few in one direc- 
 tion and a few crossing them, as shown in the sketch. 
 The surface-plate must be applied again and again, and 
 it will redden more and more of the surface, and this, 
 when broad, can again be filed, and then probably a few 
 points only will be reddened, and the scraping will have 
 to be renewed, and so on, patiently and steadily attacking 
 the higher parts until the whole surface is found on trial to 
 be reddened uniformly, showing it to have been reduced 
 to a true level. 
 
 I know of no work that tests the patience like this, 
 or which, when done, will give a feeling of greater satis- 
 faction. 
 
 If there are faces to be got up at right angles to this 
 first, one of these must be taken in hand next ; and here 
 not only has a level surface to be produced, but the right 
 angle must be accurately kept. The work has to be laid, 
 therefore, on the surface-plate with its finished face down- 
 wards, and the square G or D brought up from time to 
 time against the face which is being worked ; and if D is 
 used, it may be reddened on the vertical side, and will 
 mark the part that is not truly square ; and here again 
 the file and scraper must be patiently used until the 
 second surface proves to be correct. Of coarse the time 
 required will wholly depend upon the extent of surface 
 and skill or the contrary of the workman ; but all this i.s 
 
REAL WORK. 265 
 
 real work, of which not one step can te shirked or even 
 hurried over, and in which all has to be done in regular 
 order — first, one face as a starting-point; next, one of 
 the sides at right angles to it; then the side next to 
 this ; and lastly, if necessary, the fourth side, and also 
 the ends. It is, therefore, all straight sailing after all, 
 but by no means easy work ; and unless the scraper is 
 well managed there will be scratches made, and the 
 surface, instead of having the beautiful mottled appear- 
 ance it ought to exhibit, will not be beautiful at all, but, 
 though true, it will be unsightly. When it comes to facing 
 np the last side, and in other cases to be described 
 presently, the scribiug-block is necessary. The block 
 in the drawing is placed upon the surface-plate, and the 
 scriber, which is merely curved so as to point downwards, 
 is supposed to be feeling the thickness of the block at all 
 parts as it is moved about on the surface-plate under its 
 point. There are many cases in which this use of the 
 instrument is valuable. Either the scribing-block or 
 the work may be so moved. At present we are supposed, 
 however, to be about to face up the fourth side of a rec- 
 tangular metal block. It is evidently necessary, in order 
 to make this side truly parallel with the opposite one, to 
 file and scrape off the upper surface to a certain depth all 
 round measured from the face already finished. For this 
 purpose a scriber is put in with a point bent more nearly 
 
266 BOY ENGINEERS. 
 
 at right angles, like that on the right-hand side, and while 
 the work is held fast the block is slid along it to mark a 
 line a short distance from the edge all round the work 
 which is the guide-line for filing. The sides to be 
 marked should be rubbed with chalk to make the line 
 more visible, but the scriber is of hard steel, and will 
 scratch any metal softer than itself sufficiently to make 
 the line show ; and when the surface is levelled down to 
 it, it must of course be accurately parallel to that on the 
 opposite side. The scriber is thus a gauge for thickness 
 and for parallelism of opposite surfaces, but it is also a 
 universal gauge for which engineers find a score of uses. 
 
 Marking work ready for the file is called lining out, and 
 in all work of accuracy has to be done with care before 
 any but the preparatory processes of chipping and rough 
 filing have been done. All the above are called tools of 
 accuracy, and are never found, therefore, in the shops of 
 the blacksmith, nor of many country workmen professing 
 to keep repairing shops for engines and machinery. No 
 lathe-maker, engine-builder, instrnment-raaker, or others 
 who have to work to accurate measure, could do anything 
 without them, and their use should always be learut by 
 the amateur. 
 
Chapter X* 
 
 OUR CARVING-MACHINE. 
 
 SUPPOSE a boy's first carving-machine is the 
 mucb-coveted and ill-used pocket-knife, which, 
 if it ever did cut (which is very doubtful, for 
 the steel of which it is made is of the worst 
 possible quality), certainly became hopelassly blunt after 
 a week's possession. As a carving tool, its capabilities 
 are usually great upon bread and cheese and cake, some- 
 what less upon lawful whittling of sticks, and terribly 
 successful upon the edges and surfaces of school-desks, on 
 which it is invariably used to carve initials and dates. 
 Who does not remember the excitement caused by the 
 acquisition of a new specimen of this highly-prized tool, 
 especially if fitted with a dozen implements or so, all as a 
 rule useless for the various purposes which they are nomi- 
 nally intended to serve ? The eager eyes of the admiring 
 
>6S BOY ENGINEERS. 
 
 throng of small Loys allowed to inspect but not to toucTi 
 -—the chorus of approval as each detail is successively 
 opened to the view — the delicate passing of the rhumb 
 along the edge of the blades, accompanied by an assur- 
 ance of such keenness as few rival knives can possibly 
 possess ? Ah ! boys, we oldsters don't forget these sen- 
 gations of our early years, and if we now smile at yours, 
 it is not from lack of sympathy, for we should think you 
 very apathetic lads if you did not evince these innocent 
 excitements. But I fear experience is already dawning 
 €ven upon some of you. A few at least of the elder among 
 you have already begun to find out that one-half of the 
 world gains a living by cheating the other half, and that 
 pocket-knives are but insidious wares after all — the most 
 pretentious being generally the worst. If there are two 
 pocket-knives at five shillings each, one with a pair of 
 bla»des only, the other with tweezers and gun-pick, cork- 
 screw and reamer, and possibly with other adjuncts, you 
 may be sure that the first is the best, and that the last is 
 a humbug, worth nothing at all. As a rule, you will find 
 that, in apparently getting the least for your money, you 
 get the most; and that if anything is to be had very 
 cheap, it will prove a very dear bargain in the end. 
 Generally speaking, it may be taken as a rule that good 
 finish is not put upon a very common article, and this is 
 perhaps specially true in the matter of knives. But you 
 
POCKET KNIVES. 269 
 
 must understand what Is meant by good finish : it is not 
 polish, but ffood fitting. Looking down the back, you 
 will see no daylight between the spring and the sides-— 
 no rough places ; the blades will open smoothly, without 
 difficulty, and when open will not shake from side to side 
 upon the rivets. There will be no sharp corners to tear 
 your pockets or wound your hands, and the whole 
 knife will have a finished and neat appearance, and it 
 will probably be considered dear at the price demanded 
 for it. 
 
 In our pocket-knife-days we had endeavoured in a 
 small way to do a little carving, but with very poor suc- 
 cess. Afterwards an inspection of some carvings of oak 
 that fell into our hands aroused in us an ambition to copy 
 them with gouge, chisel, and mallet, and we found it on 
 the whole more tedious than difficult, and, unless with 
 figure subjects and elaborate floral designs, we succeeded 
 in some other attempts of the kind. But we often talked 
 together about the possibility of doing by machinery a 
 great deal of the work then always done by hand, espe- 
 cially when some simple design required to be reproduced 
 in quantity, as was so frequently the case. We heard 
 about that time of a copying machine that had been made 
 and used in London, but we knew nothing of its details, 
 and could not set off in our minds a satisfactory kind of 
 apparatus. "We also wanted, if possible, to contrive a 
 
2 7 o BOY ENGINEERS. 
 
 macliine which should rather enable us to follow any 
 design of our own, and which would work quite inde- 
 pendently of any pattern, which we understood was 
 not the case with Jordan's machine. Our difficulty was 
 that a gouge or chisel, working either directly up and 
 down or horizontally, or at any given angle, would not 
 under any circumstances serve the required purpose, and 
 yet gouge and chisel seemed to be the tools chiefly used 
 by professional carvers, although known by other names, 
 according to the forms of their cutting edges, and the 
 bent or straight form of their shanks. After numerous 
 experirfients in this direction, we found it necessary en- 
 tirely to abandon this line of proceeding, and to devise a 
 machine on a completely different principle ; and we 
 eventually hit upon revolving tools of such varying shapes 
 as were needed. Since that time an enormous amount of 
 work, not only in wood, but in metal, has been done by 
 revolving cutters and drills, and this method is extending 
 daily ; but in the days of which I am speaking the sys- 
 tem was but just coming into notice, and was, moreover, 
 not received in England with a great deal of favour. 
 America in this, as in other mechanical innovations, fore- 
 stalled us, there being apparently in that country less 
 tenacious adherence than with us to old-established 
 methods of work. The chief agent we perceived would 
 be the drill, because this could be easily made of any re- 
 
CAR VING MA CHINE. 27 1 
 
 quired shape, and easily renewed if it should be broken ; 
 and what we chiefly had to do was to devise means either 
 for moving the work about in all directions under a fixed 
 drill, or to mount the drill itself in some sort of swinging 
 frame, which we could so move as to cause the drill to 
 traverse freely over the work, and to rise and fall as de- 
 sired. This may appear a very simple thing to contrive, 
 but practically we found that it required a great deal of 
 thought, and not a few experiments, to enable us to carry 
 the plan to a successful issue. 
 
 I believe the first thing which gave us a hint in the 
 right direction was the constantly-recurring use of the 
 centre-bit, which not only serves to cut a hole through 
 a board, but, when desired, to scoop out a deep or shallow 
 cavity only, and this, if the tool is keen, it does with 
 very great neatness, leaving in tolerably close-grained 
 woods a very good surface both at the bottom and side 
 of such cavity. Carrying out this a step further, we 
 saw that it would be easy to bore out such cavities so 
 as to intersect, or partially intersect, each other, which 
 would give cavities of various external forms, of which 
 the Gothic trefoil and quatrefoil were simple examples. 
 These are represented in the following figures, A and B, 
 while the others are all forms producible by a centre-bit 
 alone without any aid from machinery, it being only 
 necessary to know just the various positions for the 
 
272 
 
 BO V ENGINEERS. 
 
 point of the centre-bit, and the proper diametrical sizes 
 of the latter respectively. 
 
 lu fig. 23 is shown the kind of work a centre-bit will 
 do, and this plate contains but a few simple designs of 
 many that can be marked out by our mathematical 
 
 L Fig. 23. 
 
 yoniigsters. A is a pentagon in a circle, which is the 
 foundation of the five-looped figure called by arcliitects a 
 cinq^uefoil or five-leaved design. The lines radiating 
 
DESIGNS. 273 
 
 from the ceutre of the maiu circle to the angles are those 
 on which lie the centres of the five circles which cut 
 each other to form the figure, aud their centres are on 
 points ou the circumference of the inner circle in which 
 it is cut by the radiating- lines. All this can he cut out 
 by the same centre-hit, the inner darker circle being- 
 again cut out to a lower level. The outer small circles, 
 the centres of which are also on the radiating lines, 
 need of course a smaller ceutre-bit. 
 
 When this has been thus cut out, a five-looped recess 
 will have been obtained, and, if desired, it might easily 
 be inlaid with ivory if a dark wood is used, or with 
 ebuny if a light wood, as satin-wood or maple, has been 
 chosen, and no one would guess it to have been carved 
 by so simple and rapid a process. As a stand, for 
 instance, for any small vase, or merely as a tray for 
 rings, it might be made very elegant aud useful, but in 
 this case, the outer circle, or outside of the block, would 
 be turned in the latlie, then the pentagon marked, and 
 also the circles to be cut out. Next, the part between 
 the hexagon and outer circle should be cut away a little, 
 bO that the hexagon may stand up above the level of the 
 outer part, and lastly the recesses cut, which may need, 
 perhaps, to be bevelled off at their upper edges with a 
 very sharp chisel (used bevel downwards.) A simpler 
 finish thau ivory would be to line the whole recess 
 
2 74 £0Y ENGINEERS. 
 
 neatly with red velvet. To make it into a first-class 
 afi'uir, a thin plate of ivory covering the hexagon, and 
 cut to match the pattern, might be glued all over the 
 top, in which case the wood should be black ebony or 
 some very dark wood. 
 
 The next design to be treated in a similar manner 
 represents a hexagon on a circle, with a trefoil inside for 
 the recessed design, which, as the circles here left show, 
 can also be cut out with one size of centre-bit. The 
 generating lines of the centre points are left to show from 
 what points the circles are struck. The other trefoil de- 
 sign, marked D, is in some respects better, but has not 
 the hexagon outside it. This is the true Gothic trefoil, 
 which is struck from the three j'oints of an equilateral 
 triangle, the radius of each circle being equal to half of 
 the side of snch triangle. The double lines, coupled with 
 the shading, show the effect produced by bevelling off the 
 recess, the width between the concentric circles (left 
 white) showing the width of the bevel thus made. The 
 triangle, left to show the mode of sketching the design, 
 Avould, of course, be cut wholly away by the centre-bit. 
 The outside double circle might here re})r<.'sent a neatly 
 rounded beading cut in the lathe round the edge, or 
 merely a bevelled edge (bevelled outwards). 
 
 Lastly, we have in C a quatrefoil, of which the centres 
 are the angles of the included square, the radius equalling 
 
DESIGNS. 2-]$ 
 
 half any one side of such square. This worked with a 
 large centre-bit would serve, perhaps, as a stand for four 
 little glasses to contain violets, or on a still larger scale, 
 as a stand for four egg-cups. Now, all these are usually 
 done in the lathe, cut out and worked by special apparatus, 
 of which the eccentric cutter stands pre-eminent ; but, 
 writing for boys, my desire is to show by what simple 
 means even designs of a complicated nature can be 
 made if skill and iogenuity are exercised in their pro- 
 duction. The lathe apparatus will, beyond a doubt, make 
 cleaner and more finished work, but it is not only expen- 
 sive, but also delicate, and it needs more careful usage 
 than boys are wont to give, whereas this is cheaply and 
 easily to be done by any lad who knows how to sharpen 
 his tools and use them. 
 
 The centre-bit will do almost any recessed work of which 
 the outline is formed by the intersection of circles, and in 
 which the sides of such recesses are vertical. The draw- 
 back to its use is the point which, on the other hand, is so 
 necessary to assist the workman in placing his circles cor- 
 rectly that it cannot easily be omitted. The point, how- 
 ever, of an ordinary centre-bit, when required for such 
 work, maybe shortened so as only just to hold the cutters 
 in position. After the whole has been, however, roughed 
 out, a cutter of similar form, without any point, will serve 
 to finish the bottom of the recess, and will obliterate tho 
 
276 BOY ENGINEERS. 
 
 lioles made in the centre of eacli circle, and level the whole 
 of the recess uniformly. 
 
 I am now writiug to a great extent in advance of our 
 actual work, and shall continue to do so, as it seems a 
 |)ity to stop short of the developments of our primitive 
 means for carviug and ornamenting work by means of 
 revolving cutters and drills. Our first machine was similar 
 to the drilling apparatus that has been elsewhere described 
 (fig. 22 M.), and was fixed upofi the lathe-bed and driven 
 by a cord from the fly-wheel in the usual way. The 
 spindle passed through two collars, and pressure was 
 obtained by hand, or by hanging a weight on the lever, 
 60 as to leave both hands at liberty to mauage the work. 
 It was made entirely of wood, the holes in the projecting 
 arm being bushed with brass. A good deal of lubrication 
 was required to prevent wear, owing to the rate at which 
 the drill revolved ; for we soon found that the faster we 
 could drive it, the better was the work produced. When 
 at full speed, with a flat ended and a keen drill, we could 
 hollow out a box in pretty hard wood in a few minutes, 
 moving the work about in all directions as rapidly as 
 possible, so as to cut all parts at once to about the same 
 level, and even square and oblong boxes could thus be 
 cut out of the solid, only needing a little work with a 
 sharp chisel to clean out the corners, which a revolving 
 cutter could not, of course, reach. The practical fault 
 
DRILLING MACHINE. 277 
 
 of our drilling machine was that the platform was too 
 confined. There was only space between the drill and the 
 pedestal, or bracket which supported it, for a very small 
 object. We had, however, proved satisfactorily to our- 
 selves that a drill could be used for work of this kind ; 
 all that remained was to modify the apparatus, and vary 
 the shapes of the drills, to render the whole more gene- 
 rally efficacious. There was no occasion to provide for 
 a great extent of verfTcal movement, and with a deeply 
 grooved pulley on the drill-spindle, we could depress it 
 six inches without the cord slipping off, especially when 
 the horizontal part of it, between the driving-pulley aud 
 the guide, which turned the cord downwards, was of 
 ample length. 
 
 The next point of consideration was the limit to the 
 position of the drill-spindle, which had of necessity thus 
 far only a vertical movement in its bearings, so that no 
 undercutting of the work was possible. 
 
 To show the steps by which we advanced, I have given 
 a second drawing at N, by which it will be seen that we 
 pivoted the part which carried the bearings and the drill, 
 BO as to be able to place it at an angle in respect of the 
 work, and keeping the latter still upon a horizontal table, 
 we were thus enabled to undercut it at pleasure, aud to 
 get under the parts which we desired should stand up 
 clear of the general surface. 
 
278 BOV ENGINEERS. 
 
 The next step was a very important one, and gave us 
 several advantages. It is represented at OP. Here, it 
 will be observed, the bracket which carries the drill is 
 pivoted on a horizontal arm which is slotted, and a bolt 
 goes through the slot into the top of the pillar, which 
 is the main standard of the machine. This gives a 
 radial motion round the pillar, and the drill will 
 describe the arc of a circle, the centre of which is the 
 bolt, and the arm can by means of the slot be 
 shortened when desired, so as to bring the drill-spindle 
 in close proximity to the pillar P, or extended when the 
 work is of larger area. The latter now has, it will be 
 seen, plenty of room, instead of being confined to a small 
 space as in the first drawing. This radial movement 
 was itself also an accurate guide for drilling round a 
 circle, and was frequently convenient merely for drill- 
 ing a circle of holes in a plate, as well as for the special 
 purposes of ornamental carving, for which it was devised. 
 
 It will, upon consideration, be evident that a mere 
 slotted bar will not necessarily move steadily round a 
 central bolt, but would be apt to slip along it length- 
 wise. In the slot, therefore, is shown, just abov^^, a slid- 
 ing piece of brass, which, strictly sp^'aking, ought to be 
 chamfered or cut on each side with a V-shaped groove, 
 and the groove or s-lot in the arm ought to have been so 
 shaped as to fit into this. Of course we had no means 
 
DRILLIAG MAClinyE, 
 
 279 
 
 to do this, nor do I tliiuk we kuew much about such a 
 plan, hut we managed something that answered almost 
 as well. We got a piece of solid brass, which we squared 
 
 pv 
 
 'I lA 
 
 f 
 
 I D 
 
 M 
 
 U 
 
 Fig., 94. 
 
 up, and drilled in the centre for the main bolt to hold it 
 on the top of the pillar, and which is represented here by 
 R, and we then prepared a top and bottom plate, S and 
 T, to be attached to the block when the latter was in 
 
28o BOY ENGINEERS. 
 
 place in the slotted arm. The lower plate was considered 
 a fixture when in place, but the other was fixed by two 
 screws instead of four. The block was a shade less 
 thick than the depth or thickness of the arm, so that 
 when this top plate was screwed tightly down, it fixed the 
 slide securely in any desired part of the slot, but when it 
 was necessary to slide the arm backwards or forwards, 
 the slight loosening of the two screws, which were at 
 opposite angles, sufficed to free it. We put two pins 
 in the other two corners of this plate to save having to 
 manipulate four screws, and the pins were quite sufficient 
 to assist in retaining the plate in its place. 
 
 By the time we had made these alterations and 
 additions, it became evident to us that we must not 
 depend on the lathe as the foundation of our carving 
 machine, which, thus modified, was of too large a size to 
 be easily mounted on the lathe-bed. We therefore set 
 to work at a stand, and made our carving apparatus an 
 independent machine altogether, with its own fly-wheel 
 and treadle. We pressed it into service, however, for 
 ordinary drilling purposes, and very handy indeed we 
 found it. 
 
 With a perfectly flat, or a plain, round ended drill at 
 a high speed, we could face over a block of boxwood, and 
 give it a perfectly level surface, simply moving it about 
 by hand all over the platform on which it rested; for 
 
DRILLING MACHINE. 281 
 
 this, however, it was necessary to lower the drill to 
 a certain determined distance, which was done by the 
 simple means now to be described, and was another 
 invention of which necessity was the parent. 
 
 The upper part of the drill-spindle above the top brass 
 was cut with a rather fine screw thread, and upon this 
 was a nut rounded off somewhat below and case- 
 hardened, and upon the bearing rested a steel collar or 
 washer, also hardened, which was added to protect the 
 brass from wear when the nut rested on it, because it 
 would still be rapidly revolving, and would soon have 
 ground its way into the brass. The spring E, coiled 
 loosely about the spindle, and abutting on the lower 
 brass, held up the drill when it was not pressed down by 
 the lever handle. The nut V was the st6p, which could, 
 of course, be easily placed in any position on the spindle, 
 which could no longer descend when it came into contact 
 with the opposing steel washer. This contrivance proved 
 very convenient in drilling ordinary holes to a certain 
 depth. 
 
 When the drill-spindle was thrown into an inclined 
 position for undercutting, the pressure of the lever was 
 of course partially removed from the top of it, so that it 
 ceased to act with the same force; but this was easily 
 remedied by hooking on to the end of it a band of India- 
 rubber, or an ordinary coiled spring, such as is used by 
 
282 BOY ENGINEERS. 
 
 bell-hangers, and of wliicli it was easy to regulate the 
 tension. 
 
 Nos. I to lo of this figure show the drills we made to 
 Use with this machine. Kos. I, 2, 3, are undercutting, and 
 with them this work could be done without turning the 
 spindle out of its vertical position. No. 4 is also an 
 undercutter, but leaves the bottom flat, and makes a 
 rectangular groove below the surface similar to that 
 formed by a grooving-plane ; but in combination with the 
 circular movement of the whole drilling-frame upon the 
 upright pillar, it will cut such groove all round the inside 
 of circular work. No. 5 is a simple round-ended drill, 
 useful for roughing down broad surfaces to be afterwards 
 levelled by a flat-ended drill, or for making semicircular 
 grooves and hollows. No. 6 is the ordinary centre-bit, of 
 which several sizes are needed; and No. 7 is a similar tool 
 without the centre-point, and is intended to finish work be- 
 gun by the ordinary bit. No. 8 is for simple holes or to drill 
 angular grooves ; and No. 10, of which there must be two 
 or three sizes, is a narrow tool, sharp on its extreme edge and 
 on the sides, and very slightly wider at the end thau it is a 
 little above. Its use is to drill out long narrow grooves, 
 for permitting strips of wood of any desired colour to be 
 inlaid, technically called " stringing." It is evident, that 
 even for such simple work as has been just described, a drill- 
 ing instrument like the above is a valuable addition to the 
 
DRILLING MACHINE. 
 
 2Z- 
 
 workshop. Inlaying, especially, is a ready means of 
 ornamenting-, at sliglit cost, the woods which have no 
 special beauty of their own, and modern taste has renewed 
 the old device of running narrow strings or lines of the 
 parti-coloured ornamental woods round the panels of 
 furniture made of plain white pine, giving the articles an 
 elegant and highly-finished appearance, without any con- 
 siderable addition to the cost of the plainer material. 
 The drill marked 9 allows of no longitudinal traverse, and 
 will not form a continuous beading, as by its rotation it 
 would constantly destroy its own work. It is used for 
 forming a succession of rounded prominences or beads, 
 the drill being lifted after each has been formed, and 
 lowered again upon the adjacent part of the material. 
 A continuous beading can only be cut by a revolving 
 cutter like No. 9 split into two halves lengthwise, and 
 this has to be carried up one side and down the other, 
 60 as to cause the two cuts to meet exactly on the centre 
 of the ridge thus formed. There is not much need to 
 use such a tool, however, because a straight beading is 
 more easily made by an ordinary beading-plane, such as 
 carpenters are in the habit of using, and circular-headings 
 can be cut readily in the lathe with a tool like No. 9 
 held quite still upon the rest. 
 
 As I have had to speak of string-courses of inlaying, 
 concerning which, I daresay, many of my readers have 
 
284 BOY ENGINEERS. 
 
 wondered how both strip and groove are cut so neatly, I 
 will here let them into the secret. The groove is made 
 by a tool exactly like the ordinary marking-gange of the 
 carpenter, but instead of a mere point capable of scratching 
 a line, it has a keen-edged cutter projecting from the 
 >-tock, which can be made to stand out farther and farther 
 as tlie groove gets deeper. By this simple tool a groove 
 is cut which is everywhere exactly parallel to the edge of 
 the frame or panel, or part to be inlaid. The narrow strip 
 of veneer is cut with a similar tool, but in this is a mere 
 knife-edge instead of a chisel. In soft wood a similar knife- 
 edged gauge is just run round the work, in order to make a 
 clear cut through the fibres which stand across the path of 
 the intended groove. Without such pre[)aratiou for the 
 chisel-ended cutter, the latter would not cut with sufScient 
 neatness, however skilfully used, but when it had to pass 
 across the grain of the wood, it w^ould tear up the fibres 
 and completely spoil the surface. Any one can make such 
 cutting-gauges, and they are useful for other purposes as 
 well as stringing and inlaying. 
 
 Now it was by no means our intention to limit our 
 machine to such work as that described. We wanted it to 
 assist in absolute carving of any form or object, in addition 
 to mere recessing and drilling. For this pur[)ose, the 
 chief requisite ap|ic;ired to be the })Ower to move the work 
 itself, or the drill, or both, to a much greater extent thaa 
 
FOLIAGE. 
 
 285 
 
 could be done as it then stood. Analysing a drawing of 
 foliage, for instance, it was evident that it consisted of 
 straiglit lines and curves, but the latter in far the larger 
 proportion. Taking as a sample a vine-leaf, it would, if 
 blocked out, be represented like fig. 25, where I 
 
 have supposed it required to cut such a leaf on the sur^ 
 face of a wooden block, so that it shall stand up in bold 
 relief. The lines ABCDE, drawn round it and en- 
 
286 BOY ENGINEERS. 
 
 closing it, show that all outside these may be freely cut 
 away witliout any fear of injury to the proposed carving. 
 A carver would, in fact, block out his work thus with 
 chisel and mallet, and so would an engraver. A round 
 or flat-ended drill might be therefore made to perform 
 this duty very easily, the block being moved about by 
 hand on a fixed platform, and in this way the outer por- 
 tion would very quickly be sunk to a sufficient depth below 
 the general level. Still moving the block by hand, the 
 next step would be to drill out the spaces inside the first 
 lines, and to map out the leaf more nearly to shape. 
 This would be done with a smaller drill, probably No. lO 
 of those shown, which, if keen and working with great 
 speed, would make a well-defined cut, and edge round the 
 leaf very neatly. Then would follow an under-catting 
 drill to take off the perpendicular surface now existing 
 round the leaf, and level it off below, so that it would 
 stand up more in relief from the block out of which it 
 was cut. For all these operations the work would be 
 kept upon the horizontal platform. If still greater relief 
 were needed, or any part required to be cut clean away 
 from the block, as, for instance, part of the stem or a 
 tendril, or even a portion of the leaf, so as to admit light 
 below it, the block might be turned upon edge and a 
 proper sized and shaped drill passed through under the 
 leaf or stem. But up to this time we have considered 
 
CARVING. 287 
 
 the drill as only cutting a level surface wherever it was 
 in action, because it would be pressed down upon the 
 work by the weighty lever or spring, until checked in its 
 descent by the nut, the position of which, as already 
 explained, decides its downward traverse. 
 
 In cutting, however, the upper surface of a leaf, it is 
 necessary to be able to deepen at pleasure the cut of the 
 drill so as to cause it to carve out correctly the various 
 depressions, while it must be also able to pass lightly 
 and almost without cutting the higher portions of the 
 object. In Jordan's carving machine, and still more 
 recently in the Medallion machine, the descent of the 
 cutting tool is regulated by a pattern, upon the surface of 
 which a dummy or blunt drill rests, and as this rests 
 or rises and falls it causes the tool at work upon the 
 adjacent block to follow its movements exactly, and the 
 pattern is thus copied with the utmost fidelity. 
 
 But ours was not to be a copying machine if we could 
 possibly help it, and consequently no pattern was to be 
 used to guide the path of the drills. We found it 
 necessary to discard the weight or spring altogether, and 
 to depress the lever by hand. This left us but one hand 
 at liberty to move the block about, but with a light one 
 (and we did not attempt heavy work) we did not find 
 this create much difficulty, and we could cut deei)ly at 
 pleasure; and by easing oft tlie pressure to suit the 
 
a88 BO Y ENGINEERS. 
 
 prominences, we soon found it possible, with merely a 
 round-ended drill, to pass over the surface and follow 
 all the sinuosities of a leaf with very great ease and 
 correctness, and we amused ourselves very extensively and 
 became very expert at this novel occupation. 
 
 Beginning with the simpler leaves, we advanced to 
 groups of complicated foliage. Very frequently we could 
 not wholly work these with drills, and had to call in the 
 aid of one or two carving tools to help us, hut as far as 
 possible we made the drills do the work. We found, 
 moreover, that, as a general rule, a round-ended drill 
 would accomplish nearly all the details, owing to the 
 fact of there being so few right lines or level surfaces in 
 nature, all objects exhibiting more or less curvature of 
 outline and of surface. 
 
 Since our day fretwork has become a fashion with the 
 amateur world, ladies included, but alone there is a same- 
 ness about it which soon makes it uninteresting. In fact, 
 it is already not nearly so general as it was a few years 
 ago, for people soon tire of mere tracery of perforated 
 patterns, unless they are obliged to do such work to pro- 
 vide food and clothing, when it no longer becomes an 
 amateur pursuit. To make such work worthy of the 
 labour spent upon it, it should be carved instead of being 
 left flat, and nothing will do this so nicely as revolving 
 drills, because fretwork is very delicate and easily broken, 
 
LEAVES. 289 
 
 and the pressure of a drill can be made as light as possible. 
 Moreover, with a fine-pointed drill the most delicate lines 
 can be followed, such as those which indicate the elegant 
 venation of leaves. These veins, by the by, it may be as 
 well to state, are not generally grooves on the surface, as 
 they are so often rendered by amateur carvers, but elevated 
 ribs, being, in point of fact, minute branches containing 
 sap, which by their means and by means of the thin 
 membrane connecting them, is exposed to the action of 
 the atmosphere. The leaf membrane is for the most part 
 double, embracing these capillaries of the branches 
 between the two surfaces. The circulation of the sap is 
 in this way very like that of the blood in the human 
 subject, which is brought by the given capillaries to the 
 skin and then returned to the heart to be renovated — the 
 renovating power being the oxygen which it meets with 
 in its passage through the lungs. But I must not stay to 
 dwell here upon this detail of a most interesting subject. 
 The wood-carver secures first of all the main features of 
 the subject in hand. If he has to carve a group of leaves, 
 he will block out, in the first place, the outline of the whole 
 mass, so that he may be able at once with mallet and 
 chisel to cut away all the wood outside it, which he will 
 reduce to a uniform surface or nearly so. He will then 
 see what are the main portions to be similarly mapped 
 out, avoiding for the time all minor details, but always 
 
290 BOY ENGINEERS. 
 
 being on his guard to leave plenty of substance, because 
 if the wood is once cut away too much, it is next to 
 impossible to restore it. Of course, het'ore he takes even 
 the first step he will have carefully outlined his work so 
 far as it is possible to do so, but there are lesser details 
 upon the faithful representation of which the beauty of 
 the finished work will depend which have to be cut with 
 no other guide than the eye. 
 
 A fast-revolving drill gives a charm to this kind of 
 work, by allowing the details to be traced out as by a 
 pencil, for each line can be followed with great rapidity 
 as well as accuracy ; although, if the drill is a fixture, the 
 work itself has to be moved about under it, instead of 
 the tool itself being movablej which would be the more 
 natural and more convenient method. It has often struck 
 the writer (and our inventive readers cau work out tlie 
 idea and make a fortune, as, of course, inventors always 
 do), that a movable drill is not by any means impossible. 
 We all get our hair brushed in these days by revolving 
 brushes, feeling as if hair and scnlp were being carried 
 clean away, and the brush, while still at high speed, is 
 moved about in all directions j the driving band being an 
 elastic strap of india-rubber. Our undeveloped notion is 
 a similar apparatus, but driving a drill instead of a brush, 
 which drill is to be cartied about the work as required 
 while continuing its rapid rotation. The drill, however, 
 
i 
 
 REVOLVING CUTTERS. 291 
 
 would hardly answer if to be held by the hand alone. It 
 ought to be at the end of a horizontal arm, which arm 
 should have at the end a universal joint to enable it to 
 move with equal facility in all directions. Just wcrk it 
 out, boys, and we don't object to going shares in the 
 profits of the invention. 
 
 Revolving cutters are now (1877) quite the order of 
 the day. The wood-planing machine, for instance, is but 
 a roller armed with sharp knives, something like those 
 of a lawn-mower, which are made to revolve at tremendous 
 speed, while the plank is caused to travel underneath it ; 
 and wheel-cutting for clockmakers and others is per- 
 formed by little circular cutters of the form of tlie spaces 
 between the teeth, which are thus, as it were, sawn out 
 with great truth and rapidity. Twist-drills are channelled 
 in a siinihir way, and also taps, and reamers, and fluted 
 drills; and the slots in long shafts are drilled out while 
 the tool or the work is made to traverse lengthwise. 
 E-evolution and rotation is now the rule, and even human 
 events are often said, not without reason, to revolve in 
 a circle, and thus to repeat themselves periodically. 
 
 I dare say our boys may have noticed that on the soft 
 wood-carvings done chiefly in Switzerhmd, but also in 
 many other districts where fir and simihir material is 
 avaiUible, a good deal of the ground-work is done with 
 a kind of matted pattern, which has the eifct of giving 
 
292 BOY ENGINEERS. 
 
 greater relief to the smooth leaves aud other sharply cut 
 work. This is not carved, but is merely indented by a 
 punch, on the end of which is generally a star-like 
 pattern, or other simple device, which suffices to give a 
 dead surface easily and quickly produced, aud sufficiently 
 effective for the purpose. 
 
 There are many devices of this kind used both on wood 
 and metal, and with respect to the latter more especially, 
 the punch, or the roller with a pattern on the outside, 
 which is a perpetual punch, is largely used to produce 
 mouldings, scrolls, and headings, which give such finish 
 and*handsome appearance to the work. The more elevated 
 parts are then generally burnished and lacquered to a 
 condition of great brilliancy, and the recessed parts are 
 dulled by the action of an acid which partially corrodes 
 the surface, thus giving the contrast so necessary in all 
 such works of art. The home of first-class work in metal 
 is, beyond a doubt, Birmingham, but a good deal is also 
 done in London, especially by those who make the various 
 articles used in the decoration of churches. 
 
 Before dismissing the subject of our carving-raachincj 
 I may add a few words. upon carving in the ordinary way, 
 because the work is one of great interest, and boys who 
 are naturally fond of lathes and mechanical apparatus, 
 and accustomed to carpentry, ought by no means to 
 neglect it. 
 
ARTISTIC CARVINGS. 293 
 
 As a lesson, there is one special advantage in this art, 
 which may be regarded as a development of drawing. 
 None will make good workmen but those who are in the 
 habit of observing natural objects with close attention. 
 Again and again the carver must go to nature as his 
 model and copy. Tliere is some special peculiarity in 
 every leaf and tree-stem, and almost in every separate 
 blade of grass — constant variety, and unvariable beauty 
 of outline as well as of surface. An autumn leaf has 
 not the form of the same leaf growing in all the vigour 
 of its summer health and vitality. The beauties of early 
 morning are modified by the action of the mid-day sun, 
 and change their aspect without losing a particle of their 
 loveliness under the softer hues of eventide. There is the 
 distinct beauty of youth and of age, and the well-trained 
 eye of the artist recognises all these, and with brush or 
 chisel, as the case may be, gives permanent expression to 
 the truths which have become impressed on his mind. 
 The boy who tries his hand at carving learns to estimate 
 all the natural beauties of our lovely world at a far 
 higher value than he who cares not to represent them in 
 this way. The one observes where the other only sees^ 
 and to the first nature oiTers daily fresh delights which 
 the other has not the soul to feel, much less to enjoy. 
 Therefore, if only to open up for themselves new sources 
 of pleasure of the highest kind, I would recommend every 
 
294 BOY ENGINEERS. 
 
 boy who can handle gouge and chisel with ordinary skill 
 to turn his attention also to the art of carving. For 
 this, however, he must, in the first place, learn to draw, 
 whicli, as a mechanical engineer, he will find a matter of 
 necessity ; hut, then, for the latter purpose, the chief of 
 his work will be done by the aid of mathematical instru- 
 ments, whereas the delineation of foliage and natural 
 objects will require almost exclusively skill in what is 
 called freehand drawing. 
 
 The amount of skill, however, in the latter, which is 
 required in order to commence the work of carving, is not 
 very great, inasmuch as the power of delineating nature 
 by pencil and carving tool will increase with practice, and 
 in learning to carve, the pupil will daily increase his 
 knowledge of drawing. 
 
 But what used at one time to be considered drawing 
 is very diiferent to the art as it is now taught. 
 
 There is no longer prevalent the show jnece, done in a 
 great measure by the master, whicli used to be taken 
 home to show to admiring friends in the school holidays. 
 Some impossible landscape out of perspective, and so un- 
 like any terrestrial features of ordinary landscape, tliat it 
 would have stood with equal truth for a sketch of some- 
 body's estate in the planet Jupiter. All this style of art 
 has given place to accurate outlines of simple objects, or 
 shaded drawings thouglitfully and truthfully carried out. 
 
DRA WING. 295 
 
 Many a lad who in old days used to bring liome draw- 
 ing prizes, and who imagined that he could paint as well 
 as draw, could not have accurately delineated a sprig of 
 oak leaves or a simple weed ; but now that photogra])hy 
 has taught us how to represent our object with fulelity, 
 and now that Ruskin and others have stood up so man- 
 fully for truth instead of conventionalism in art, we 
 have arrived at the proper kind of drawing to serve the 
 purpose of the carver. We have learnt to draw simple 
 outlines with the nearest attainable approach to perfect 
 accuracy. 
 
 Supposing our young reader to have acquired the power 
 to trace on a block of wood a leaf or a group of leaves, 
 he is in a position to go a step further and carve a like- 
 ness of it with the proper tools. These tools have divers 
 names and are sufficiently numerous, but practically they 
 are nearly all of them gouges and chisels. The shanks of 
 them, however, are longer than those ordinarily used by 
 the carpenter or joiner, and they are variously bent to 
 enable them to reach into corners, and to undercut where 
 necessary, and, in short, to do what a straight tool could 
 not. 
 
 They are sold in sets, and are not very expensive ; and 
 if the student will really set to work with dogged deter- 
 mination to persevere, the result of his labours will 
 amply repay the outlay, which is more than can be said 
 
296 BOY ENGINEERS. 
 
 for many of the pursuits in which amateur workmen 
 indulge. 
 
 Having, as already described, "blocked out the work by 
 cutting to the extreme outline of the whole design, the 
 next step will be to gauge the thickness of it, so as to 
 find out to what deptli from the surface any given parts 
 may be lowered, and this depth is to be marked upon 
 the side or edge of the block. Then this part must be 
 blocked out like the first, and lowered as far as neces- 
 sary, the main tools as yet being a mallet and chisel or a 
 mallet and gouge. But after a while, these will have 
 to be laid aside, and one of the regular carver's tools 
 taken up, and you will learn that these are exceedingly 
 sharp, and must be kept so, and that to have the left 
 hand in such a position as to receive a cut if the right 
 hand should slip, is not exactly the most sensible thing 
 to do. I ought, by the by, to have told you that the 
 work is commonly held by the carver's screw. This is 
 a short bar of iron with a conical pointed screw at one 
 end, which is inserted in the under side of the block of 
 wood to be carved, and it has about three inches of the 
 other end screwed, and a hand-nut fitted to it. This end 
 is put through a hole in the bench, and a washer being 
 slipped on it, the hand-nut is screwed tight. In this way 
 the wood will be very securely held, and both hands wiD 
 be left at liberty to guide the tool. 
 
CARVING. 297 
 
 The whole further operation will consist of scooping 
 out and cutting the hollowed parts and rounding the con- 
 vex ones with such of the tools as seem the best suited to 
 the purpose. You will find the gouges all of different 
 curvature, some almost as flat as chisels, others curved to 
 nearly the half circle. Then you will find tools like a 
 folded slip of paper, or the V-tools for cutting screws in 
 Boft wood, and others like ordinary chisels, but of vary- 
 ing width. There is no rule as to which is to be used 
 They should all lie before you in a row, so that you see 
 at once the shapes of the cutting edges, and after finish- 
 ing what you can with any one tool, you should always 
 lay it again in its own jilace in the row, so as to know 
 in a moment where to put your hand upon it. 
 
 The best way is to range them in order of width, 
 which will also be, generally speaking, in the order of 
 curvature ; the broader gouges being the least curved, and 
 the narrower ones more so. Order in mechanical work 
 of all kinds is most valuable in saving of time and 
 trouble. 
 
 It will have to be remembered always, that, whether in 
 carpentry, turning, or carving, sharp edges must be left, 
 except where the nature of the design absolutely necessi- 
 tates rounding them off; and wherever this is a necessity, 
 the rounding must be evidently done for a set purpose. 
 
 Hence the inexpediency of using sand or glass paper 
 
298 BOY ENGINEERS. 
 
 to finish work to a smooth surface. All should be clean 
 cut with very keen tools, which will leave such a f^ice as 
 can be produced in no other way. 
 
 If a bit of Caen stone is to be had, the young carver 
 can exercise his powers also upon this. It is cut and 
 carved much in the same way as wood, but finished 
 witli scrapers of various shapes ; it is very soft, easy to 
 cut into any desired shape, and looks exceedingly well 
 when finished. This substance can be turned, and marble 
 also; but even in the case of round pillars it is seldom 
 done in that way, as practical hands will round it per- 
 fectly by hand-tools alone. 
 
 A visit to any stone-mason's where best work is done, 
 especinlly a visit to ecclesiastical decorators, such as Cox 
 of London, will prove highly interesting to our young 
 friends if they can obtain admission. There they will see 
 Jordan's carving-machine actually at work, and will see 
 also plenty of skilled workmen carving the most elaborately 
 undercut work by hand alone, both in wood and stone, 
 including the hardest marbles and granite. Such a visit 
 will show him how expeditiously, as well as skilfully, 
 work of this kind is done by those who are well practised 
 in the art, and what exquisite work results from the 
 skilled manipulation of a few simple tools. They will 
 probably go back to their own work with a just sense of 
 its inferiority ; and if they are boys of the best metal, they 
 
PLUCK AND PERSEVERANCE. 299 
 
 will be roused to greater diligence, and more than ever 
 determine to excel. 
 
 I would not give a farthing for a boy who would go 
 back from an inspection of such work to give up his own 
 feeble attempts, and thus confess himself unable to do 
 what hundreds are doing every day. Unless a lad has 
 Bpirit enough to contend against difficulties, until he com- 
 pels them to yield to his energies, he can never become a 
 great man, and the most he will do is to crawl through life 
 without doing good' to his fellow-creatures, or executing 
 any but the most unimportant work that falls to the lot 
 of mortals. A cat without energy would never catch a 
 mouse, but she onght to have no dinner till she can per- 
 form that simple feline duty. 
 
 Although in this chapter I have passed from the 
 capabilities of a home-made machine to the capabilities 
 and actual doings of skilled workmen, I may return so far 
 to the actual subject of this volume as to say, that we 
 executed carved work, of probably no great excellence, 
 ourselves, besides what we accomplished with the drilling 
 apparatus. Moreover, we set to work wisely, so far as 
 regards copying from nature. I remember an attempt, 
 not wholly unsuccessful, at a bunch of grapes with a few 
 vine leaves and tendrils, which formed the base of a 
 bracket-shaped stand for a clock, and was duly presented 
 to our father on his birthday. Being carved in oak, we 
 
300 BOY ENGINEERS. 
 
 had difficulties to contend witli besides those resulting 
 from a very insufficient stock of tools. I am afraid that 
 we also found a difficulty in respect of IVeeping the grapes 
 long enough to serve as our model until the work was 
 done. Like lads, thougli, we managed it after a fashion 
 of our own. We began the bnnch at one end, and as fast 
 as we roughed out a few of the berries so as to guide our 
 efforts, we forthwith ate them, so that by the time the 
 last grape was cut in wood the bunch had wholly vanished. 
 I have known an artist of maturer years carry out this 
 principle by eating one half of a ripe peacli while be 
 painted the other, a representation of the former not being 
 required in the picture upon which he was engaged; so 
 that I may conclude that old boys and young ones have 
 very similar tastes, and are equally disinclined to let good 
 fruit be wasted, so long as it can be made to serve the two- 
 fold purpose of a model of still life and food for life that 
 never is still. 
 
 The vine tendril and smaller branches gave us a good 
 deal of trouble, as they were carved in full relief. We 
 first drilled underneath, until we were able to insert the 
 point of a small saw, and thus removed the superfluous 
 material, leaving the stem or tendril standing, for a part 
 of its length, clear of the wood beneath it. We Jien, 
 partly with a penknife and partly with a rat-tailed file, 
 rounded off the part, and finished it to represent the 
 
STV/SS CARVINGS. 
 
 301 
 
 natural stem. Wherever the latter was so thin as this, 
 we took care to leave it supported here and there, instead 
 of cutting it quite free. This is always done in work of 
 this nature. 
 
 Accurate delineation and clean cutting are the char- 
 acteristics of good work. Glass-paper must be very 
 sparingly, used, as it rounds off angles and edges, which 
 ought to be left sharply defined. If the cheap Swiss 
 carvings, now so common, are examined, they will be found 
 very inferior, not so much owing to any neglect of clean 
 cutting, but in having hardly any reUef, and in being 
 carelessly worked. Cheaply, because rapidly executed, the 
 material is thin and poor; it is cut out with a small saw 
 into something like leafage, and the upper surface is 
 hollowed variously with a sharp gouge, and a few offhand 
 angular cuts are made to stand for a representation of the 
 leaf veins. So far as they go, they are clever, and far 
 cheaper than they could be made in England ; but after all 
 they are deceptions, and not accurate representations of 
 nature, and, except for our younger readers, should not be 
 taken .as models worthy of being copied. They come into 
 the same category as fretwork, which is a mere pattern of 
 nothing^ useful in its way, but not such as the eye of an 
 artist can dwell upon with pleasure. If our readers can 
 visit some old church, or some church of our own times 
 designed by a first-class architect, and carried out by 
 
302 BOY ENGINEERS. 
 
 workmen capable of artistic carving, they will at once 
 recognise the beauties of high-class work. They will note 
 how massive it is as a whole, and yet how delicate in 
 detail. They will see also that there is no mere shallow 
 surface-work, but that all is in high relief, and well under- 
 cut, and yet that sufficient support is left everywhere to 
 render the work durable, and prevent the lighter portions 
 from being easily broken oflF. All this is characteristic of 
 work done previous to the Reformation in the time of 
 Henry YIII. and Elizabeth. After that date art degene- 
 rated sadly. Instead of being deeply cut, carved decora- 
 tions were merely superficial, and correct representations 
 of natural objects no longer occupied the attention of the 
 carver. Happily, such work is again dying out, and there 
 is a widely spreading taste for what is well called " high 
 art." 
 
 It is not, however, easy to state in so many words in 
 what high art actually consists as bearing specially upon 
 the subject of carving. It is not every one who recognises 
 the difference between what is commonplace and what 
 is really artistic. A simple leaf may bear the first char- 
 acter, and it may equally bear the second ; and it is the 
 same with a group of leaves or flowers as of other objects. 
 The Alps are grand, the hills of our own land are beauti- 
 ful, the hedgebank worthy of the artist's highest skill. 
 The hand of Nature delineates and colours each alike 
 
CARVING AND FRETWORK. 303 
 
 aristically ; all alike are lovely, but each has distinctive 
 beauties. A representation of the last may be as high art 
 as a representation of the first, as it is not the subject but 
 the manner in which it is treated which characterises the 
 result. 
 
 The best way is to seek out as studies what are known 
 and acknowledged to be works of real excellence, especi- 
 ally the carved work to be found in churches of Early 
 English, Decorated, and Enrly Perpendicular style. Get a 
 taste for work of this kind, and you will not long be con- 
 tent to carve bread-platters and butter-dishes and book- 
 racks. 
 
 At the same time there is no harm in working at these 
 lesser objects to get into the way of using carving or turn- 
 ing tools. They are useful if not artistic, and admiring 
 friends will be glad to possess these specimens of your 
 handiwork. But don't stop at such as these, and don't 
 be content to copy other people's work. Work out, if you 
 like, a sheet of fretwork, designed at the small sum of one 
 shilling, and then put the sheet in the fire, and set to 
 work to design from real leafage, which Nature will pre- 
 sent you with at all times free gratis, and without even a 
 stamped envelope for reply. 
 
 Now, I dare say some of you young fellows are inclined 
 to cut all this prosaic stuff of mine. You want to get 
 ahead, and to hear what other mighty works the }'oung 
 
304 BOY ENGINEERS. 
 
 engineers accomplished. Well, T don't care much 
 about that. You can turn over, but I hope sometimes 
 you will " hark back," as fox-hunters say, and have 
 another look at the despised pages ; for I should not 
 have written them if I were not certain they are full of 
 sound advice. 
 
 You know the old saying, Set a thief to catch a thief, 
 or make the biggest poacher in the parish head-keeper, 
 because old evil experiences will help him in his new 
 sphere. Well, we have had our own evil experiences, too, 
 in the carving line. We thought ourselves mighty clever 
 with our fretwork and platters, and such-like artistic 
 sport ; but it was like poaching — it would not bear the 
 truthful and pure light of day. We got entranced by 
 seeing some real honest work, and at last we chucked all 
 else aside, and said to ourselves, " We will henceforth aim 
 at the highest, and get as near it as we can." That is all 
 I want you lads to do. Get a noble ambition to excel, 
 and you will not long be found among the slugs and 
 koddidods (as youngsters call the snails), those slimy 
 creeping things that leave their mark, indeed, wherever 
 tliey go; but it is just that kind of mark which ought to 
 be obliterated as soon as possible. Boys, and men too, 
 leave marks oftentimes of a very similar character, which 
 we need not stay to particularise ; but your old friend 
 would fain stir you up to leave behind you such marks of 
 
TRUE NOBILITY. 305 
 
 genuine nobleness, reflected in every act of life, in every 
 work of brain or hand, as shall make the world acknow- 
 ledge that mechanical boys are very high-class human 
 machines indeed, worthy of all kindly help and encourage- 
 ment. 
 
Chapter XI. 
 
 OUR ELECTRICAL AND PNEUMATIC APPARATUS, 
 
 N the year of grace 1877, there are used both 
 electrical bells and pneumatic parcels' delivery 
 apparatus, and also, we believe, pneumatic 
 bells, though not very generally. Now I do 
 not suppose our claim will be allowed if we state that we 
 were the sole originators and inventors of both these bells, 
 although we do not claim the parcels' delivery. But the 
 fact is, we were just like so many of our peculiar race. 
 "We talked of the possibility of doing this or that; made 
 a few more or less successful experiments, concluded that 
 tlie idea would not work out as a practicable marketable 
 invention, and so let it sli[), while other more knowing 
 hands made fortunes out of the very same designs. This 
 is just as it should be. An inventor, if he is to reap 
 pecuniary rewards, must prove himself worthy to receive 
 
INVENTORS. 307 
 
 them. He must not get into his head some vague idea 
 that possibly such and such things would be serviceable, 
 and then fancy himself worthy of reward. He must work 
 out each step of his invention until he has actually 
 RENDERED it Serviceable. Crude ideas are all very well as 
 the seed of great results; but if the sower of them cannot 
 cultivate the tender blade as it springs up, and cannot, 
 from want of necessary skill or knowledge, watch and 
 cherish it till ready for harvest, he has no right to expect 
 a reward. That same seed, we must remember, can be 
 sown by many ; and it is a fact that many persons do hit 
 upon precisely the same ideas j but whereas one who is 01 
 a practical turn of mind will patiently follow it up, and 
 work it out step by step until he reduces it to a market- 
 able commodity, another, with less patience or less energy, 
 will leave it just where he found it, and consequently he 
 is not to be called the inventor, although the idea occurred 
 to him first. Now it was just so with pneumatic and 
 electric bells. We made both by way of ex{)eriment, but 
 as to practical use, we stopped short of it by a very long 
 distance indeed. We argued, that inasmuch as batteries 
 soon cease to give out their pristine power, and as the 
 slightest hole or faulty connection would destroy the air- 
 tight continuity of a tube, neither electric nor pneumatic 
 bells would have a permanent advantage over the usual 
 system, and we therefore never troubled ourselves any 
 
3o8 BOY ENGINEERS. 
 
 more about either. We could ring a bell b}^ either 
 mode, but as to the advantage of any system, we gave 
 the palm to the wire and crank, aud coasidered the other 
 two methods merely as byplay for the lecture - room or 
 study. 
 
 But if the history of any great invention is traced from 
 the commencement, it will be found, generally speaking, 
 that what at first was a mere lecture-room experiment, 
 of no apparent practical value, was but the germ of that 
 which, in the hands of the manufacturer, ultimately be- 
 came of vast benefit to mankind, and of great commercial 
 importance. Photography had just such a beginning. 
 It had been noticed that a solution of nitrate of silver 
 darkened on exposure to the light, aud probably the fingers 
 and clothes of our young experimentalists have often 
 borne testimony to this property of the salt in question. 
 Thence it became an amusement to copy leaves aud other 
 objects by laying them on a piece of paper saturated with 
 the nitrate, and pressing the two together between two 
 slips of glass, or by clamping them in a frame with a 
 sheet of glass above. Exposed to the sun's rays, those 
 parts of the paper unprotected by the leaf darken, and 
 that immediately under the leaf remaius white or nearly 
 so — the leaf allowing the light to pass but slightly through 
 it, and not at all where the midrib and thicker parts 
 exist. A copy was thus obtained which was light 
 
PHOTOGRAPHY. 
 
 309 
 
 upon a dark background, but very soon the whole paper 
 became uniformly black. To prevent this, it was disco- 
 vered that a solution of hyposulphate of soda would so act 
 on the parts which had not been affected by the light as 
 to prevent any change taking place when light was sub- 
 sequently admitted, and thus it became possible to fix 
 the photograph and render it far more permanent. Ulti- 
 mately (for I cannot stay to trace the invention through 
 its various stages) photography became what • it is now — 
 one of the most useful and interesting arts of the period. 
 
 Look, again, at the toy sold to this day, which was 
 called an {Bolipile — a small globe with bent, hollow arms, 
 from which the steam of a few drops of water rushing out 
 and striking the opposing air, sent the whole spinning 
 round any number of times in a minute. Or, again, a 
 jet of steam impinging on the vanes of a wheel gave 
 rapid motion to the latter. In each case a mere child's 
 toy was produced, yet herein lay the germ of our gigantic 
 engines of perhaps a thousand horse power. 
 
 While I am writing, another invention is in ovo, and 
 we can as yet hardlv see the ultimate result. Experi- 
 ments have proved that it is absolutely possible to talk 
 and sing by telegraph. We have in its infancy an instru- 
 ment called a telephone, by which sounds such as those 
 of speech can be carried to a distance of many miles, 
 and heard so distinctly that the tones of any friend's 
 
3 lo BOY ENGINEERS. 
 
 voice can be recognised. Then, again — though here the 
 infant has reached a stage of larger growth — we have the 
 spectroscope. It is known that a ray of sunlight passing 
 through a prism of glass is divided into a band of vari- 
 ously coloured rays, which are always alike and always in 
 the same order. Some one found that if the spectrum 
 (as the baud is called) of burning metals or gases is 
 taken instead of that of the sun, the colours are different 
 and are crossed by dark bands, but that a spectrum of 
 any one burning substance is always the same. From 
 this we now read the various facts of sun and star light, 
 and actually can declare what gases and metals are burn- 
 ing in those furnaces of the far-off luminaries ; and other 
 grand facts of nature will no doubt yield up their well- 
 kept secrets to the persevering inquiries of the scientific 
 world. All these and similar discoveries, which will soon 
 become so familiar to us all that we shall not regard them 
 as anything specially marvellous, have sprung from very 
 small beginnings; and although scientific men are ofien 
 set down by the ignorant as mere experimentalists, wast- 
 ing time over useless if not absolutely childish pursuits, 
 the world is indebted to them for tlie advance made year 
 by year in our civilisation and commercial prosperity. 
 The usual course is this : The man of science discovers a 
 fact not hitherto known — some peculiar law of nature or 
 of some substance in the natural world. He makes ex- 
 
DISCOVERY. 311 
 
 periments, testing his discovery under various conditions, 
 and gradually is able with confidence and decision to 
 declare the laws which govern it, and probably also to 
 suggest some one or more possible applications of it. 
 Then comes the practical manufacturer with his own pecu- 
 liar knowledge, and adapts the facts already ascertained 
 to the trade processes with which he is familiar; while in 
 all probability other manufacturers recognise the possi- 
 bility of the same invention becoming serviceable to them 
 also; and what at first appeared likely to profit one class 
 only, frequently turns out to be of universal value. 
 
 But our boys will be asking who gets the profit ? That 
 depends very much upon circumstances. The scientist is 
 unfortunately not always nor generally a business man, 
 and he is obliged, as above stated, to content himself with 
 the bare facts of his discovery. Very often its applications, 
 or possible adaptations, do not strike him at all. He is 
 taken up with the gradual development of new facts con- 
 nected with it which arise as he carries out his experi- 
 ments. He has not the time nor the peculiar frame of 
 mind necessary to recognise the commercial value of wliat 
 he has discovered, and though he may gain honour as the 
 inventor or discoverer, that honour does not generally 
 carry with it much in the way of profit. It is an honour 
 as empty probably as his own purse. The manufacturer 
 reaps the pecuniary reward — sometimes a very substantial 
 
312 BOY ENGINEERS. 
 
 one indeed ; but in so doing lie in turn opens up in all 
 probabilit}'' new sources of profit for otliers owing to the 
 close connection existing between commercial industries. 
 
 You see, therefore, boys, that it is as well to cultivate 
 business habits as to c?rry on experiments in the depart- 
 ment you may have selected as your own line of life ; and 
 at any rate, if you should make a discovery or hit upon a 
 new invention, get some real friend of extensive knowledge 
 in commercial matters to give you the benefit of his 
 advice ; but take care he is a real trustworthy friend 
 before you take him into confidence. In no case will you 
 get all the profits, and by judicious management you may 
 perhaps secure your proper share. 
 
 As regards our electric and pneumatic apparatus, we 
 got 72(7 profits, simply, as I have explained already, because 
 we did not carry our experiments far enough to become 
 of practical use to any one. But how far we actually went 
 I will now explain. 
 
 We will begin with the electrical department ; and as I 
 don't know how far my readers are acquainted with the 
 mysteries of batteries, and with the nature, so far as 
 known, of what we call electricity, it will be necessary to 
 say a few words about it by way of introdaction. 
 
 What electricity is we do not know. It has a great 
 deal in common with light and heat, and it has been 
 supposed to be so far identical with these that they 
 
ELECTRICITY. 313 
 
 are in reality all the same under different condilions. 
 Tliev are, in fact, in a certain degree intercliangeable, each 
 producing the other. But after all the theories which have 
 in turn been advanced and rejected about the precise 
 nature of these mysterious powers, we have practically to 
 deal with their effects^ and, consequently, it is to these 
 that our attention as practical people is chiefly directed. 
 
 There are several modes in which we can produce 
 electrical effects. If we heat a sheet of coarse brown 
 paper by the fire, and rub it sharply with a piece of dry 
 flannel or the coat-sleeve, we shall apparently bring to a 
 state of tension its inherent electricity ; and if we hold it 
 in one hand, and apply to the surface the knuckles of the 
 other, a sharp snap will be heard, and a spark will 
 pass from the paper to the hand, after which the former 
 will renew its normal condition, or, at any rate, will have 
 but slight electrical properties, which will soon cease 
 altogether to exhibit themselves. 
 
 The same sheet may be excited again an indefinite 
 number of times with the same result ; and when thus 
 excited, it will attract to itself dust or feathers, or other 
 light substances near it, which it will retain, and after a 
 while let drop and pick up again ; or, if held above the 
 head, the hair will be similarly attracted, and stand 
 literally on end, as it is supposed to do in cases of fright ; 
 but whether it does so or not I cannot say, because I 
 
314 BOY ENGINEERS. 
 
 never was sufficiently terrified to put the matter to the 
 proof. 
 
 A glass rod dried thoroughly, and rubbed with a silk 
 handkerchief, will also pick up light substances, and 
 behave itself similarly to the sheet of paper; but any such 
 substance picked up by the one will be repelled by the other 
 if held near, showing that though electricity is excited 
 in each, it is of a different nature. This is generally 
 called positive and negative electricity, but it might be 
 called, I think, electricity of two poles, like magnetism, 
 of which there is, at the ends of any magnetised bar, 
 exactly a similar condition of the force, one end of the 
 bar repelling, the other attracting, similar poles held near 
 it. The north end of such a bar attracts the south, and 
 repels the north end of a similar bar, and positively 
 electrified substances repel positively, and attract nega- 
 tively, electrified ones. There is no knowing why the 
 electrical condition of a substance should be thus brought 
 into a state of tension by friction, so as to render its exist- 
 ence visible ; but there arises again here a strong sus- 
 picion of its identity with heat, which we all know to be 
 similarly excited ; and when we rub our hands together 
 or strike them to produce warmth in winter, it is quite 
 possible that, in the production of this warmth, we also 
 produce a difference in their electrical condition. It may 
 be said, perhaps, that unless we can arrive at some cer- 
 
THEORY. 315 
 
 taintv, it is of little nse to tlieoi'i-=e 011 tlii? matter at all, 
 as it is quite as likely that our theory, whatever it ma)^ 
 be, will ultimately prove false; hut it is impossible to go 
 on with the study of any scieuce without theory, which 
 arises almost of necessity as the result of experiment. 
 
 Suppose you had come into possession of a pair of 
 balanced magnetic needles, such as are used in ships' 
 compasses, and your experiments had shown you that 
 both of them exercised an attractive, and yet both a 
 repulsive force, as you would very soon discover. You 
 would, of necessity, begin to build up the theory of mag- 
 netism under two conditions. You would reason thus : 
 *' Here is a peculiar force or power existing alike in both 
 these needles, which seem to divide in the middle of 
 them, for below a central line each attracts the same 
 end of a similar needle, and above that line it rejDels 
 that end and attracts the other." And you would be 
 on the road to discover the poles of magnetic bars 
 or needles ; you would see that the north pole of one 
 attracts the south pole of another, and repels the north, 
 and so in a similar way with the opposite ends ; and the 
 further you carried on your experiments, the more per- 
 fectly would you find the theoiy establishing itself in your 
 minds, of a positive and negative pole; for you would find 
 that it is impossible to produce the one without at the same 
 time producing the other. 
 
3 1 6 BOY ENGINEERS. 
 
 And as soon as you had tluis laid the gronnd-work of 
 a theory of magnetism, yon would find yourself in a far 
 better position to continue your investigations and to 
 cairy on your subsequent experiments. For us, of course, 
 it was only necessary to follow the beaten track already 
 laid down by men of science, original research not being 
 much in the way of youngsters like ourselves. We 
 therefore read sufficient only of our subject to make U8 
 familiar with the more generally recognised laws of 
 electricity and magnetism, and then proceeded at once 
 to put our knowledge to the test of experiment. We 
 found that of the two means employed to generate 
 electricity, chemical action was most used, as being 
 easier in many respects to manage than friction. The 
 first bells, however, ever made were constructed in con- 
 eection with the ordinary frictional electrical machine, 
 with its. glass plate or cylindei and amalgamated silk 
 rubber. 
 
 The chief reason for abandoning frictional electricity as 
 a source of power is the uncertainty of its action. The 
 old cylinder or plate machine had generally to be coaxed 
 and coddled before it would act at all. It was necessary 
 to rub it dry before the fire, and leave it to become warm ; 
 and even a little adherent dust would often suffice to 
 weaken or wholly prevent its action. On a fine shui-p 
 frosty day the machine exhibited its full vigour. On a 
 
FRICTIONAL ELECTRICITY. 317 
 
 damp foggy day, when, of course, some friend specially 
 called to see a few experiments, these would utterly 
 fail. 
 
 This sort of waywardness would never do for trans- 
 mitting telegrai)hic signals, or ringing-bells, or driving 
 clocks ; and if no more satisfactory source of electricity 
 had been discovered, we should never have arrived at our 
 present perfection in such matters. Moreover, although 
 frictional electricity would send forth a continuous stream 
 of sparks, these were not exactly what was required. They 
 might be compared to the fire of a file of musketry, being 
 a succession of little explosions, which, however, could be, 
 IS it were, bottled up, and let off with a big bang all at 
 once. 
 
 Passing by the old story of Galvani and his wretched 
 frog, there is no doubt that that vivisectionist experi- 
 menter was the first to observe the electrical effects 
 excited by chemical action, or, as it was then supposed, by 
 the contact of metals of different degrees of oxidability. 
 It was eventually shown that mere contact did not suffice, 
 but that it was necessary for the metals to be acted on 
 by some fluid which could affect their composition and 
 change their chemical condition, generally by the process 
 of dissolution. It was also found to be important that the 
 solvent used should be such as would act on one 7netal 
 more vigorously than on the other; and a common com- 
 
3 1 8 BOY ENGINEERS. 
 
 bin at ion was a rod of zinc and one of copper (or plates 
 of these raetals), acted on by a dilute solution of sulphuric 
 acid and water. 
 
 If a strip of each of these metals are placed in a tum- 
 bler opposite to each other, but not in contact, and the 
 tumbler be half filled with the above solution, or with 
 strong' salt and water, verj^ little action will be apparent 
 at the surface of either metal, and none at all if the zinc 
 is pure, or if it is amalgamated with mercury, by rubbing 
 some over it while wet with the acid with a piece of 
 cork or a bit of cotton-wool. (Don't use the fingers, or 
 you may find you have become a patient for the family 
 doctor by reason of mercurial poisoning.) But if now the 
 upper ends of the metals are connected by a copper-wire, 
 or caused to touch each other directly, a quantity of 
 bubbles will rise on the surface of the zinc, and a current 
 of electricity will pass, which will cease as soon as contact 
 between the metals is broken. 
 
 But I am sure my boys will ask, " How are we to know 
 ^vhether or not a current is passing at any given time ? " 
 In a very simple way. You all know what a mariner's 
 compass is, viz., a steel needle magnetised and suspended 
 to turn freely upon a point, and this needle, if left to 
 itself, will stand north and south. The ends are called 
 poles, so that we have a north pole and a south pole. 
 All magnetised bars have ilto^e two poles, and if you 
 
COMPASS. 
 
 319 
 
 bend them like a horse-slioe, thus hringing both ends- 
 almost together, the poles will remain unaltered. You can 
 make such a needle very easily by rubbing with a 
 magnet a common sewing-needle, and passing it through 
 a bit of cork to form a centre. From this you can either 
 suspend it by a thread, so as to leave it free to turn, or 
 you can float it in water ; and in each case you will find 
 it arrange itself so as to stand north and south. So 
 much for our compass needle. 
 
 Now if you set up your simple battery of zinc and, 
 copper, and connect the two metals with a wire reaching 
 across from one to the othei) and place this so that the 
 wire lies north and south, you are ready to test the pas* 
 sage of the current. 
 
 The moment you bring your suspended needle over or 
 under the wire, round it goes, and stands east and west, 
 or at right angles to its former position. If the current, 
 however, is very weak, it may not quite reach this posi- 
 tion, but it will turn some distance towards it. If you 
 hold the needle above the wire, it will turn in one direc- 
 tion to take up its new position ; and if you hold it under- 
 neath, it will turn the other way, so that you can also 
 prove in which direction the current is passing, as well 
 as gauge its strength. 
 
 A little consideration will show you how to intensify 
 the effect of the current. If you coil the wire so as to 
 
520 BOY ENGINEERS, 
 
 form a loop (but yoa mast not let the wire touch itself), 
 and place the needle in the loop thus formed, the upper 
 wire will act as stated, and the lower also, so that the 
 needle is deflected with twofold power. 
 
 This power can also be still increased to a very mucii 
 greater extent by using what is called insulated wire, i.e.^ 
 wire covered with silk, cotton, gutta-percha, or other non- 
 conducting substance, and coiling it round and round a 
 great many times, so that instead of the current passing 
 louud the needle once only, it may do so several times. 
 
 If the wire is not thus covered, and the coils touch 
 each other, they will act only as a single coil, because the 
 current will pass freely from one coil to another ; but with 
 insulated wire it cannot escape thus laterally, but is com- 
 pelled to traverse the whole length, whether it be an inch 
 or a thousand miles. 
 
 It will be easily conceived that the necessity of always 
 arranging the battery -wire north and south would be 
 practically a drawback to its use, and this can be avoided 
 by using an astatic needle — i.e.^ one which, having a north 
 and south pole, will nevertheless stand in any position in 
 which it is placed indifferently. 
 
 This needle is simply a compound arrangement — a com- 
 bination of a pair of equally magnetised needles attached 
 to a common centre, to make which the simplest way is 
 to magnetise two sewing-needles, so that one may have 
 
GAL VANOMETER. 321 
 
 the north pole at the eye, the other at the point, and 
 then to stick both in the same bit of cork, one above the 
 other, the north pole of one just above the south pole of 
 the other. If they are pretty equal in magnetic power, it 
 is plain that the tendency of one to stand with the eye to 
 the north is just counteracted by the other, which would 
 fain take the opposite position, and thus the effect of the 
 earth's magnetism is annihilated or balanced, which is 
 practically the same thing in this case. Thus, if we 
 make an astatic needle, and place it so that the lower one 
 is inside the coil and the other above it, we get a power- 
 ful combination, which, as it were, multiplies the effects 
 of the current as many times as there are coils, and an 
 instrument is made by which a very minute quantity of 
 electricity passing along the wire is instantaneously de- 
 tected. The instrument is called a galvanometer or gal- 
 vanic multiplier. 
 
 For ringing a bell, which requires a considerable amount 
 of the mechanical power, the deflection of a needle by the 
 electric current will not suffice, but this is the ordinary 
 needle-telegraph that is seen at railway stations, post- 
 ofSces, and other places. We shall, therefore, pass on to 
 another effect of the current, but we thought it as well to 
 explain first of all how we could detect such a current in 
 its passage along a wire where no spark or sign is visible 
 to tell of its existence. 
 
 X 
 
322 BOY ENGINEERS. 
 
 If a current of electricity is sent from a batter3' through a 
 wire insulated in tlie manner already described, and coiled 
 several times round a bar of soft iron, the iron will become 
 a temporary magnet, and will continue to exliibit all the 
 peculiarities of such — a north and south pole, for instance, 
 and the power to attract ii'on and steel — as long as the 
 current continues to flow; but the moment it is interrupted 
 the magnetism of the bar will cease. 
 
 It may be mentioned also here, that a coil of wii-e 
 througli which such current is passing becomes itself 
 magnetic, and if free to do so, it will place itself north 
 and south — or in the magnetic meridian, as it is called — 
 just the same as a magnetised needle. 
 
 This property of .the current was rapidly turned to 
 several practical uses, and bell-ringing at a distance was 
 one of the first. It was also thought to be a favourable 
 power for use in driving machinery or actuating a clock, 
 which would continue to go as long as the strength of the 
 battery remained unimpaired. The bell would ring, how- 
 ever, in a different manner — viz., by an interrupted cur- 
 rent, as will be presently ex[)lained, the hammer striking 
 as often as such interi'U})tion took place. 
 
 It must not be supposed that a slip of zinc and one of 
 copper in a tumbler would suffice for any practical pur- 
 pose, although the existence of a tolerably strong current 
 is readily seen. Indeed, if, instead, of a narrow strip, of 
 
ELECTRO-MAGNETS. * 323 
 
 metnl, sheets of some size are used, and the wire connecting 
 them is small, the latter will be actually heated white hot 
 or fused as the current passes through it. The quantity 
 of electricity thus generated is indeed enormous, hut ac- 
 tion soon grows weaker, as the dissolved zinc interferes 
 with the passage of the current ; and not only so, hut 
 gradually becomes deposited on the copper, thus dimi- 
 nit<hiug the exposed surfaces of the metals. The result is 
 that the action of this kind of battery soon ceases alto- 
 gether. Before passing, nevertheless, from this class to 
 the next, we must state that the power of such a combina- 
 tion was vastly increased by multiplying the elements of 
 which it is made — i.e.^ the zinc and copper plates. Sup- 
 pose a row or a circle of tumblers, in each of which is a 
 plate of zinc and one of copper, but the zinc of one 
 coupled to the copper of the next, and not to its own, by 
 a copper wire soldered to the metals. The last of the 
 series would be a solitary zinc on the one side, and an 
 equally solitary copper at the other. To each of these a 
 wire is soldered, and any object or arrangement intended 
 to be affected by the current is placed between these two 
 wires so as to complete the connection, or the wires may 
 be thems(dves brought into contact, when a current will 
 pass. This current is not great in quantity unless large 
 plates are used, but it is of great intensity, producing 
 effects which a single pair of large plates, equal in size 
 
324 BOY ENGINEERS. 
 
 to the whole set thus arranged, will not supply. It is 
 not easy to explain quantity and intensity, but the best 
 example of it in another substance is steam. In the 
 boiler, it is in a state of high tensiuu or intensity, but 
 the quantity is no more than if we release it, when it will 
 form a large cloud, but though the same amount of steam 
 is there, it floats idly above us. It is quantity which in 
 the boiler becomes intensity. The heating power of a cur- 
 rent is always seen best when a large pair of plates are 
 used, or where the electric current is large in quantity and 
 the wire so small that it cannot conduct it fast enough, 
 the heat arising, it is supposed, from resistance, as the 
 smaller wire will fuse, while a large bar as the conduct- 
 ing medium will be scarcely warmed. 
 
 Electricity in quantity, however, without intensity, will 
 not manifest other serviceable peculiarities. It will not, 
 for instance, produce chemical decomposition, such as 
 dissolving water into its constituent gases, oxygen and 
 hydrogen, or effect chemical changes in other sub- 
 stances, unless the different elements in those substances 
 are but freely held together in their natural state. We 
 shall, however, probably recur again to this action of the 
 current, when we speak, as we propose to do, of electro- 
 typing and electroplating. We must now return from 
 our wanderings to the bell, the construction of which was 
 and is very simple. The battery, however, being of 
 
BATTERY, 325 
 
 necessity one needing great permanency of action, we 
 must speak of it first, as the simple pair of plates would 
 probably cease to act in an hour or less. 
 
 Professor Dauiell was the first to inquire into the 
 causes of decreasing action in a galvanic battery, and to 
 devise a remedy. He first of all directed his attention to 
 the escape of hydrogen gas, which rose in thousands of 
 bubbles as the acid acted upon the zinc and dissolved it, 
 carrying off with it in its ascent a good deal of electricity, 
 but a great quantity of this gas adhered also in bubbles 
 to the surface of the copper, and the zinc being also 
 dissolved and forming an oxide, the solution became 
 saturated and weakened, and by and by the same oxide of 
 zinc depositing upon the surface of the cop[)er, action 
 wholly ceased. The solution of the difficulty lay in pre- 
 venting, if possible, the evolution of hydrogen and forma- 
 tion of the zinc oxide, or, at any rate, in preventing its 
 deposition upon the copper plate. This was accomplished 
 by enclosing the zinc in a porous vessel with its acid 
 solution, and thus keeping it apart from the copper. 
 The porous diaphragm may be of brown paper, sail- 
 cloth, pipeclay, or plaster of Paris, which last is generally 
 used, or of ordinary china, in the state called biscuit, i.e.^ 
 before it has been' glazed and fully baked. This inner 
 vessel (for it is generally arranged so as to stand inside 
 the others) may be filled with the sulphuric acid solution, 
 
326 BOY ENGINEERS. 
 
 or with salt and water, muriate of ammonia, and possibly 
 some other solutions ; but these do not come into contact 
 with the copper, which is surrounded with a solution of 
 sulphate of that metal, constantl}^ replenished and kept up 
 to a state of saturation by crystals of the salt resting- on 
 a shelf just level with the surface of the liquid. How 
 then does this become weakened so as to need such fresh 
 supplies of the salt? By the action of the rising hydrogen, 
 which combines with the oxygen of the zinc oxide, and 
 now reduces the copper and deposits it in a metallic state 
 on the surface of the copper plate, which is thus con- 
 stantly renewed. If sulphuric acid is used as the exciting 
 solution, the surface of the zinc is amalg-amated as stated 
 above, and then no local action takes place until the two 
 metals are united by tlie connecting wire or band, and 
 then the zinc is only dissolved very slowly indeed, while 
 the electric action is steady and powerful. The copper 
 deposit is of a beautiful red colour and is jdzw-^ copper. 
 Thus it is evident that the action of this battery, unlike 
 that of the two elements with a single solution, may be 
 kept up for a very long- time without any important 
 diminution of power, the disturbing- causes which render 
 the simpler battery rapidly weaker being wholly removed. 
 It is therefore called Daniell's constant battery, and was 
 the one which we always used, because it was easily and 
 cheaply made, and also very convenient. 
 
OUR BAT2ERY. 
 
 327 
 
 General!)' speaking, a Duniell cell consists of a solid 
 rod of zinCj standing in a porous plaster tube — the rod 
 being about half to tlueu-quarter inch diameter, and the 
 
 Fig. 26 — DanieU's Galvanic Bell. 
 
 porous tube an inch and a half: its size is of no great 
 importance. This stands in a cylindrical copper vessel tlie 
 game height as the porous tube and zinc rod, this outer 
 vessel forming the copper element of the batter}-, and 
 
328 BOY ENGINEERS. 
 
 being about the size of a common one pound gallipot. 
 Inside is generally a shelf of perforated copper, and this, 
 which is circular, forms also a support to the inner porous 
 tube containing the zinc rod. Keeping of course the 
 principle of this battery, we made ours as follows, which 
 is an equally efficient plan, and more easily constructed. 
 
 Fig. 26, A is a common earthenware jam-pot, calculated 
 to hold a pint of solution. Inside it is a plate of copper, 
 B, about as thick as a sheet of ordinary pasteboard, the 
 substance being of no importance, because all action takes 
 place upon the surface of the plate o\i\y. Too thin a plate 
 is, however, inconvenient, because it does not give a good 
 support to the conducting wire which is soldered to it , 
 but if it is very thin, it will be as well to let the wire 
 go quite down it to the bottom, and to solder the whole 
 length, which will stiffen it. This plate is of such a size 
 that, when bent round into a cylindrical form, it just fits 
 the pot, resting close like a lining inside it. It need not 
 be soldered, because the pot in which it is placed holds 
 the solution. The porous cell C we made thus : We 
 took a sheet of stiff but not very thick brown paper, and 
 coiled it to form a cylinder, which we joined with stiff 
 gum-water up the side. When dry, we cut out a round 
 piece of wood in the lathe to form the bottom, which we 
 put in place, and secured with two or three small pegs of 
 hard wood. This cell was about half the diameter of the 
 
OUR BATTERY. 329 
 
 outer one. To stiffen and make it of a more permanent 
 character, we now painted it all over on the outside with 
 plaster of Paris of the consistence of thick cream, which we 
 laid on with a hog's-hair flat brush, purposely leuviiio- tlii.s 
 coat in a very rough state. We also plastered the bottom 
 to render the cell water-tight. When dry, which it soon 
 became, we repeated the process with a stiffer coat, laid 
 on in the same way, and also poured a little of it inside 
 so as to make a more solid bottom. When this was dry, 
 we rubbed it down to reduce it to a smooth surface 
 for the sake of appearance, just as we do many things 
 equally useless, for it would have answered as well in the 
 rough state. We now had a very fair cell, very porous, 
 and sufficiently stiff if carefully used to last a long time, 
 but it was not much thicker even with a third finishing 
 coat than stout cardboard. We finished it by drying in 
 the oven. 
 
 Our zincs we first thought of casting, but we sub- 
 sequently determined to use sheet-metal instead, as easily 
 procurable with a nice smooth surface ; and we therefore 
 cut it out and amalgamated it on both sides, and then 
 coiled it into the form of a cylinder, as we had previously 
 done with the copper, so as to line, but not press, the 
 porous cell. The amalgamation of the inside of this zinc 
 cylinder was solely to protect it against undue local 
 action, for we had already learned that it was only the 
 
330 BO Y ENGINEERS. 
 
 outer face which was opposed to the inner face of the 
 copper which had any eifect in producing the electric 
 current. Hence, also, the cast rods are as effective as 
 the coiled zinc plate, and being harder in practice, owing 
 to greater steadiness caused by their weight, are generally 
 used by the makers of electrical apparatus. A copper 
 wire was soldered to the zinc, and to give elasticity and 
 freedom in arranging cells side by side, or connecting 
 them with other apparatus, this wire was coiled round 
 a rod a few times to convert it into a helix, the rod being 
 afterwards removed. By this means it was an easy 
 matter to lengthen or shorten these connecting wires as 
 might be necessary, and there was less danger of upsetting 
 pot and all in adjusting them, as not unfrequently 
 happens when there is no such elasticity provided. A 
 single cell thus constructed instantly raised to a white 
 heat a few inches of thin platinum wire connected to the 
 ends of the copper wires by being twisted round each, 
 and a bar of soft iron tliree or four inches long, surrounded 
 by a few coils of covered copper wire (the size of bell- 
 wire), became strongly magnetic when the ends of the 
 coil were connected to those of the battery. We made, 
 however, a set of four of these half-pint cells, and with 
 these we were able not only to sound a bell at any 
 required distance, but to carry on an extensive course of 
 experiments, including the working of a telegraph and 
 
OUR BATTERY. 331 
 
 simple clock, which had but one fault— it did not keep 
 correct time I 
 
 Since the days of those early experiments, a great 
 many forms of battery have been invented and put to the 
 proof, but Daniell's, in a modified form, still bears the 
 palm as an efficient and easily-constructed arrangement, 
 calculated to bear the wear and tear of rough usage, and 
 of which the copper element is saleable at any time at 
 a good price as old metal. It is, in fact, from the very 
 nature of the arrangement, absolutely improved and 
 thickened by use, and it is only the zinc element and the 
 porous cell which require renewal. 
 
 Of course, we spoilt our clothes, and made the usual 
 messes with our acid solutions, but all was carried on in 
 our workshop, where no carpets or curtains existed, so 
 that we did no great harm. Here, then, at a small cost, 
 we possessed a battery quite equal to our need, and 
 although we subsequently took a turn at electrical work 
 with other forms of battery by way of experiment, our 
 bell was connected with this simple arrangement of 
 Daniell's, and I shall now describe it in detail before 
 proceeding to speak of other apparatus of a similar 
 nature. 
 
 First, there is a mahogany board or base, and upon it 
 is fixed by a screw the horse-shoe electro-magnet D. 
 This is a bar of soft iron, round which is wound in two 
 
332 BO Y ENGINEERS. 
 
 coils a quantity of insulated copper wire covered with silk 
 or sealing-wax, varnished for neatness, and to preserve 
 it from injury. The wire, it must be understood, is 
 wound first on one leg or side of the horse-shoe, and then 
 carried across and wound in the same direction round 
 the other. The ends are left out and carried to SS, two 
 br<iss screws. FG is a piece of watch-spring, on which 
 at FGr two small lumps of steel are soldered, or one lump 
 extending over both poles of the magnet. This is called 
 the keeper. The spring is fixed on the top of an upright 
 rod of brass or wood, K, screwed firmly to the stand. T 
 is the bell, an old clock-bell, fixed as shown, and H is the 
 hammer, which does not touch it quite even when the 
 keeper is drawn down; but when this happens, the sudden 
 jerk causes the hammer to strike, owing to its being on 
 the end of a spring. If, however, the keeper is gently 
 lowered with the finger till it rests on the poles of the 
 magnet, the hammer is about one-sixteenth of an inch 
 off the bell. This is necessary, or the sound would not 
 be a clear sharp sound, but a dull jarring one ; and in all 
 cases hammers to strike bells are so poised as to spring 
 back a little after the stroke is made, and not to rest 
 upon the bell. The hammers of a pianoforte also leave 
 the wire the instant the note is struck. 
 
 We have explained that the electro-magnet has no 
 attractive power unless a current of electricity is passing 
 
ELECTRIC BELL. 333 
 
 round it. In this case, the current is produced by the 
 battery above it; but, as sketched, no current will pass, 
 because there is no connection between the zinc and 
 copper or positive and negative poles of the battery. No 
 action is therefore going on ; the soft iron is not magnetic, 
 and the bell does not ring. 
 
 Now look at the apparatus marked M. It is, like the 
 other, a stout board of mahogany standing on four knobs 
 or legs, which are of no special importance. Ris a roller 
 of wood turning on pivots at each end; P, whicli is fixed 
 to it, is a flat plate of tolerably stout brass, held up a 
 little above the horizontal position by a short coiled 
 spring, 0. Q is another but lighter spring just press- 
 ing on P, so as to be in perfect contact with it, whether 
 it is in the position here shown or pressed down, but it 
 is^ not strong enough to resist the action of the spring, 0. 
 N is a cnp-shnped hollow in the mahogany board, into 
 which projects the end of the wire W, inserted from 
 underneath, and this hollow is filled with mei'cuiy — with 
 whicli also the point of the wire is amalgamated, thus 
 ensuring perfect contact, A pointed brass wire is soldered 
 into the part P, so as to dip into the mercury when P 
 is pressed down by placing the finger on the flat -headed 
 screw seen above it, which is not absolutely necessary, 
 as the finger might be laid directly upon P, but it gives 
 a finish to the apparatus. A wire from S is in metallic 
 
334 BO V ENGINEERS, 
 
 contact with the spring Q. Let the pointed wire now be 
 depressed into the mercury. The connection is at once 
 established between the two poles of the battery, and is 
 also made to pass round the coils which surround the 
 magnet. Starting from Z, the zinc end of the battery, 
 it will pass by N to the mercury, thence by P and the 
 si)ring R to S, where it meets the end of the coil. 
 Passing round this it goes to S at the left hand of the 
 apparatus, and thence to the copper element of the battery, 
 completing the circuit. But the moment communication 
 is thus established, FG is attracted and goes down with 
 a jerk, causing H to strike the bell very sharply ; for so 
 instantaneous is the action, that no measurable time 
 exists between the depression of P and the stroke 
 of the bell, which can be repeated as often as desired 
 by depressing P and allowing it to rise again, and 
 thus a succession of strokes can be made on the bell at 
 pleasure. 
 
 In order to bring all the apparatus into one picture, 
 M is represented close to the other piece of apparatus, 
 but it is not so in reality. The battery A may be, for 
 instance, with the bell and its adjuncts, in the kitchen, 
 or the battery may be in the cellar, and the bell in the 
 kitchen, with a wire from one to the other. But M must 
 be in the room from which the bell is to be rung — i.e.^ 
 in the parlour or sitting-room, as the wire connecting S 
 
ELECTRIC BELL. 335 
 
 and Q may be of any desired length, and also that from 
 the battery to N. Miles and yards are all one iu making 
 electrical connections ; although, of course, with very long 
 wires more care is necessary to prevent the damp atmos- 
 phere and other causes from affecting the completeness of 
 the circuit. When the apparatus is required within the 
 house only, insulated wire alone should be used, as it is 
 not very expensive, and saves battery power; but for longer 
 circuits, where it would be too costly, more battery power 
 is needed to make up for waste of electricity by its escape 
 into the atmosphere, or from other causes which affect 
 it. In damp weather electrical apparatus never acts so 
 well as in dry weather. 
 
 It is evident that every time the handle of P is 
 depressed one stroke will be given, so that to ring a good 
 peal, P must be depressed rapidly a great many times. 
 But this need not be done by making an alteration in 
 the arrangement. Let the wire from the right-hand coil 
 be brought to the base of the pillar K, and soldered to it. 
 As the pillar is metal, and also the horizontal spring, 
 both these will become parts of the circuit along which 
 the current will pass. The wire twisted round the pillar 
 being insulated (covered vnth cotton, or sealing-wax, or 
 gutta-percha), will not take up any part of the current 
 which passes along K, and the end of it is attached to Q. 
 Of course, as explained, the length of this wire is of no 
 
33^ BO Y ENGINEERS. 
 
 importance. The end above K is bent over and rests on 
 the Kpripg G ; and to make more certain the metallic 
 contact, both shonld be amalgamated, bnt tlie}^ will do 
 witliont. The dotted wire at S leading to Q is of course 
 not in this case used, and there must be no connection 
 made here. 
 
 Let P now be depressed as before. The current will 
 leave the zinc as before, pass to the mercury cup, thence 
 along P and Q, where now there is attached the end of the 
 coiled wire K ; up this coil to the horizontal spring, thence 
 down the brass-pillar to the magnet, and back to the 
 battery. The moment this connection is made, down goes 
 the keeper, and the bell is struck; but no sooner does 
 this occur than connection is broken, because the curved 
 end of the wire K no longer touches the spring, and as 
 the magnetism of DD instantly ceases, up flies the 
 keeper. But then connection is immediately made again 
 by the horizontal spring touching the bent wire, and 
 another stroke is given on the bell, and this goes on inces- 
 santly as long as the pressure of the finger on P continues, 
 the spring with the hammer oscillating at a tremendous 
 pace, and making such a row on the bell as would awaken 
 the Seven Sleepers. The board E may be screwed to a wall, 
 and the whole arrangement may be considerably modified. 
 In the drawing, DD should be nearer K, so that there 
 may be a longer bit of the spring between J and H, to 
 
ELE CTRIC BELL. 33 7 
 
 give more elasticity to the hammer, or the hitter may miss 
 striking if the current should get weak. 
 
 If the plau here given is to be carried out exactly for 
 practical use in a house, the board M and its fittings may 
 be let into the wall, and the knob on P need be shown, 
 which may be of china or ivory. A still easier apparatus 
 to make would be arranged by forming P of a bit of toler- 
 ably stifl clock-spring, fixed into the board at one end, 
 and so bent as to stand up a little above it at the other 
 end. It would not then need the supplementary S2)ring3 
 Q and 0, nor the roller and its bearings. For actual 
 use it would be much better thus modified. 
 
 Possibly some of our young readers may wish to repeat 
 the above experiment, and fit up one or more electric 
 bells or other electric apparatus themselves; and so, before 
 speaking of our pneumatic bell, we will add a little to the 
 information already given. 
 
 There are in these electrical machines several connections 
 to be made, to comjilete the current as it is called. Now 
 it is absolutely essential in all cases that the metallic 
 contact should be perfect. A little dust getting in at the 
 places in question would be fatal, and rust and other 
 causes sadly interfere with the passage of the current 
 from one part to another. Whenever, then, you find 
 such apparatus fail to work, always suspect the connec- 
 tions, for here you will generally discover the cause of 
 
338 BO V ENGINEERS. 
 
 failure. Copper wire and brass are more generally used 
 than iron or steel, and these should always be wetted with 
 sulphuric acid, and have a little mercury rubbed on to 
 amalg-amate parts which are to come into contact. 
 
 Where a steel spring has to be used, it is a common 
 plan to solder a bit of platinum foil to any part which is 
 to form a point of contact of this nature, because this 
 metal is not liable to rust, and is a good conductor of 
 electricity. When copper wire covered with silk or cotton 
 is used to make a coil like DD, it should be carefully 
 examined to see that it is really well covered, because 
 otherwise the current will pass at the uncovered part to 
 the iron, and be of no avail for the intended purpose. 
 
 You can make a magnet with ]>lain copper wire if you 
 are on your guard in this respect, thus : Wind a bit of 
 silk or worsted or a strip of flannel or any non-conductor 
 round your iron bar so as to cover it ; or turn a bit of 
 wood like a cotton reel, with very broad flanges at the 
 ends, and bore it till it will slip over the iron, making 
 one for each limb, or wrap paper or card round it. 
 The big reels will be the best, because they will prevent 
 the coils from slipping. Now coil the copper wire round, 
 leaving the coiIs> sufficiently open to preclude all chance 
 of tlieir accidentally touching each other at any point. 
 Wrap this round, as before, with a bit of silk or flannel, 
 and then wind the coil back over the fii'st ; and so on till 
 
GAL VANIC APPARA TUS. 339 
 
 you have added as many coils one over another as you 
 wish to have. Wrap the last with a bit of green silk, or 
 varnish it with red sealing-wax — varnish made by dissolv- 
 ing the wax in spirit of wine — and you will have a per- 
 fectly efficient electro-magnet, but it will have cost a little 
 more trouble to make. In every case, even when covered 
 copper wire is used, it is better not to wrap it directly on 
 the iron, but to use what I have called the big cotton 
 reels, or a covering of card. The cotton reels, however, 
 having broad ends, allow you to coil the wire very neatly 
 on them, and when the last coil is on, and the whole 
 wrapped round, and the wood varnished, the apparatus 
 Avill present the neat and workmanlike appearance so 
 attractive in apparatus bought at the philosophical instru- 
 ment maker's. 
 
 Covered wire is not expensive by any means, and can 
 be bought at scores of places in London and often in large 
 towns ; and there is no better exercise for mind and hand 
 than to make all the apparatus needed, instead of buying 
 it. Merely twisting the ends of wires together, after 
 taking off the cotton or silk, will form a metallic connec- 
 tion between them, but it is better, in addition, to solder 
 them wherever possible. 
 
 I have said nothing yet of the cup-like hollow N filled 
 with mercury. Tliis is an old and excellent way of 
 forming a connection. If the wires dipping into the 
 
340 BOY ENGINEERS. 
 
 mercury are themselves coated with that metal, nothing 
 can be more perfect than the contact thus attainable. 
 The experimenter should, however, be cautioned that the 
 mercury will effectually spoil any gold with which it 
 comes into contact, because it forms with it a very brittle 
 amalgam. Eiugs and chains and gold watches should 
 never be worn, therefore, when mercury is to be used for 
 any puipose. In my younger days I had no such diffi- 
 culties to contend against, because I had no gold at any 
 time ; but boys are somewhat changed to what they were — 
 (the more the pity), and get hold of cheap jewellery and 
 cheaper cigars, and other like abominations, which take 
 away the old boyish energy and manliness, and substitute 
 a prig'gishness and unnatural precociousness which is 
 detestable. In old days, boys had no ambition to be 
 anything else, and were rather inclined to regret the fact 
 that marbles, tops, and other treasures must soon be laid 
 aside for the more serious pursuits of real life. But 
 nowadays boys wish to be thought men, and fancy that 
 by poking nasty cigars and pipes into their lips, dangling 
 a watch-chain, and wearing rings and shirt-studs and 
 pins, they look like their elders. Poor fellows ! how they 
 must inwardly lament the absence of whiskers and the 
 deep voice of manhood, which they vainly strive to imitate. 
 This book will be useless to young prigs like these; but 
 as long as we have a few real hearty English boys left, 
 
METALLIC CONTACT. 341 
 
 tliere will be some vrortliy of our best exertions in 
 writing for tlieir benefit, and it will give us pleasure to 
 help them in all possible ways to amuse themselves pro- 
 fitably during leisure Lours and during tbeir mucli-valued 
 holidays. A very extraordinary circumstance connected 
 with electro-magnets must be mentioned here, as we shall 
 have to refer to it again by and by. Suppose the ends 
 of the coil wrapped round the magnet to be connected 
 with the battery, by any means that will cause the 
 current to flow and to stop alternately at will (as, for 
 instance, the method adopted in the last case for pro- 
 ducing a rapid succession of strokes upon the bell). 
 Now suppose that a very fine covered wire is wrapped 
 round over the first coil — a great length is necessary 
 compared witli that of the first or primar}^ coil — and the 
 ends of the secondary coil are connected with a galvano- 
 meter or compass needle as already described, so as to 
 enable us to detect the passage of a current by electricity 
 if such should occur. If the ends of the first wire are 
 connected immediately with the battery by being attached 
 to its plates or to its terminal wires, and the ends of the 
 secondary fine coil are attached to the galvanometer, the 
 needle remains steady; but if contact is broken for an 
 instant between the first coil and the battery, the needle 
 is instantly deflected, but only for a moment ; and if the 
 contact is then made again, it is deflected momentarily in 
 
342 BO Y ENGINEERS. 
 
 the opposite direction, thus proving a current of electricity 
 to be passing in the second coil of fine wire. Yet observe, 
 this secondary fine coil has no connection whatever with 
 the battery, and is also entirely insulated from the wire of 
 the main coil over which it is wound; no current passes 
 except at the moment contact is broken or renewed 
 between the battery and the primary coil. A simj^le way 
 of causing a rapid succession of currents to pass is to 
 attach one end of the battery wire to a file by twisting it 
 round it at the tang, and then taking the end of the 
 primary coil and running it down the teeth of the file. A 
 stream of sparks will be produced, and the needle will oscil- 
 late with great rapidity, as contact is made and broken at 
 every tooth of the file over which the wh-e passes. Instead 
 of the galvanometer as a test of the passing current, the 
 latter may be detected in another way whicli will afford 
 very tangible proofs of its existence. The ends of 
 the fine wire having had about six inches of the silk or 
 cotton covering removed, are to be wrapped round two 
 pieces of sponge, which should be wetted with salt and 
 water, and grasped firmly one in each hand. Let some 
 one now make contact with the file as before. A succes- 
 sion of shocks more or less painful will pass through the 
 arms and hands, the sensation being much like a repeated 
 series of cramps or spasmodic contractions of the muscles, 
 far from pleasant, and the worst of it is, that if the 
 
SECONDARY CURRENTS. 343 
 
 current is a strong one there is no power to relax the 
 grasp and drop the sponges. I might tell you boys a 
 tale of m}^ own early freaks in electricity. Well, it was 
 no great misdeed, but only of a bit of rather cruel fun 
 which I had in company with a young doctor, almost as 
 much of a boy as I was myself at the time. 
 
 The aforesaid doctor had a groom, who was also a sort 
 of man-of-all-work, carrying out medicine, helping to 
 pound drugs, and to hold refractory patients who objected 
 to surgical operations. This man had but one eye of any 
 practical use, for though the other was there, it was 
 opaque and sightless, with a tendency to squint, which 
 gave to the face a most grotesque appearance. The doc- 
 tor had recently purchased a battery and coil for experi- 
 menting on cases of rheumatism, and the force of the 
 shock could be regulated to great nicety, from such as a 
 strong man would hardly care to try as an amusement, to 
 such as would not injure a delicate child. Such instru- 
 ments are common enough now, but were then not gener- 
 ally known, and somewhat expensive. After dining one 
 day with the doctor, I began inquiring about his instru- 
 ments and so forth, as I was fond of surgical matters, and 
 used to find great delight in overhauling cases of instru- 
 ments of torture. At last I got hold of his new galvanic 
 apparatus, which he essayed to explain ; but, except a 
 dog and an old Tom-cat, we could find no suitable sub- 
 
344 ^OY ENGINEERS. 
 
 ject for experiments which we graciously declined to try 
 upon our own august persons. All at once we espied 
 Thomas, who had just returned from carrying out a bas- 
 ket of drugs. Poor Thomas 1 Little experience had he of 
 galvanism, hut I think he had a lesson on that eventful 
 day. Suffice it that we got him to lay hold of the 
 sponges, and we turned on the full power of the battery. 
 He wriggled, he twisted, he fairly roared — and so did we, 
 but at last the wire gave way and he was free. And now, 
 boys, I must ask to be free too, for we have had a good 
 many hours together over various mechanical subjects, 
 and once more I must say " Adieu." Possibly I may 
 address you, however, once more, and detail a i^"^ more 
 of our early experiments as 
 
 BOY ENGINEERS. 
 
,^^^: 
 
 
LIBRARY OF CONGRESS 
 
 013 970 608