Chocolate (and paint and oil colours) mill
Figures 1 & 2ofPlate 47, exhibit this Machine. It is, merely, an attempt to effect, by power and a rotatory motion, what is done by hand and a vibrating one. To understand this latter, my readers (who have not seen chocolate made) will suppose a metallic rolling-pin, but cylindrical held in both hands, and moved parallel to itself, over a slab of marble, to and from the person employed; who holds the instrumentfastwhen pushing it from him, and suffers it to turna littleevery time he draws it towards him. He thus presents, sometime or other, every particle of the chocolate to every part of the slab and the roller: and this is also done by the Machine shewn inPlate 47. Infigs. 1 and 2,Arepresents a cylinder of stone or metal, used instead of the aforesaid slab; andBa cylinder answering to the roller in question. The latter is placed, by it’s axis, on two forksa b, so as to lean, by it’s weight, obliquely against the cylinderA, which it does less or more heavily as the forks, or standsa b, are placed nearer or farther off from the general centre. Further, the motions of these two rollersAandB, are connected by two equal (or nearly equal) wheelsc d, by which, whenAis turned,Bturns also; but so as to give the surface of the lattermuch lessvelocity than that ofA, though in the same direction. By these means, all the matter adheringto both cylinders (for chocolate is made in an unctuous state) is at one time or another, brought into intimate union, and ground together; and thus is the usual problem resolved, on rotatory principles: nor need we mention the several scrapers, &c. that would be applied to gather up the paste to the middle of the rollers, when spread abroad by the grinding process.
It may not be useless, just to say here, that this is likewise a good mill for grinding paint or oil colours.
Mangle
I have insisted, often, on the propriety, mechanically speaking, of doing every thing by rotatory motion; and thus of avoiding oscillation wherever it is possible. The present Mangle is another attempt to employ that principle. InPlate 47,figs. 3 and 4, is an under cylinder, turned as usual by any convenientpower.Bis a small cylinder not connected with it, nor touching it, being intended merely to receive the weight of the mangle-cylinderD, with thegoodsrolled on it.Cis an upper cylinder as heavy as necessary, or loaden through it’sjournalsor centres, with sufficient weights to make it so. Again, the motions of the two cylindersAandC, take place in such a direction, that any round body placed and pressed between them, would receive from them the same motion; and thus, a roller of goods, there introduced, will bemangled. This process is so performed, because the cylinders have toothed wheelsa,b, on their axes, but which donotgeer together: These wheels being connected by an intermediate wheelc, which makes them concur in producing the rolling effect above mentioned. But, one thing remains to be observed: the wheelsa b, though drawn apparently equal, are not equal. The upper onea, has a tooth or twomorethan the under—so that the motion to the right hand of the under surface of thatcylinder, is not equal to the opposite motion of the cylinderA. And hence, the cloth rollerD, progresses fromDtowardsx, between the cylindersA C, and finally falls out atx, after as many turns of the whole, as the wheelsA Chave been calculated to give; and this, is according to the degree of mangling required.
It is too late to bring this Machine into what might almost be called an overstocked market of ingenuity—since many power Looms exist, work, and seem to want nothing to make them perfect. But an idea offorty yearsstanding, founded on a principle worthy of attention then, may perhaps not be altogether vain at present: Besides—I have engaged in my prospectus to present it to the public. I could, indeed, enter into other parts of the Power Loom—which I had then begun to execute; but such is the rapidity with which that Machine is nowstridingto perfection, that it would be superfluous. I merely then, fulfil my promise.
On the afore-mentioned occasion, I thought it of importance, that the force employed to throw the shuttle, should be capable of being regulated to any and every degree: and especially should be fullypreparedto act,beforeit’s action began: and should, then, act independently of every other impulse.
Power loom shuttle driver
Infig. 1ofPlate 48,Ais a wheel or pulley of about six inches in diameter, from which two cords proceed in oppositedirections (B C) to thepickers, which drive the shuttlesD Ein the usual method. This pulley runs on an axis going through the bottom of the lathe, (or beater) and itmighthave a crank, behind, of a radius equal toa b: but to shew the whole in one figure, I suppose the following mechanism to be placed in the front of the lathe, and justbeforethe face of this wheel or pulleyA.c dis a bar turning on the centrec, and receiving at it’s other end the pressure of a springe d, which in it’s turn, is susceptible of different degrees of springiness, as regulated by the screwf. On a studiin the wheelA, is put the small bari d, which forms also a turning joint in the barc d: and thus communicates the effort of the spring to the studi, and thence to the wheelA. Finally, this wheel has either under it, on the front side of the lathe, or on it’s axis, at the back, a pulley, by which it can be turned, by means of one or other of the cords brought from thebreast beamof the loom, round the pulliesxandy, to this wheela b i, according to the dotted lines. Supposing then,oneof these cords to be tightened by the backward motion of the lathe, it will draw the wheelAabout half round: when the studiwill rise to the pointb, straining the spring to get over the centre: and as soon as itisover, the spring willact, and drive the picker and the shuttle with the desired speed, independently of any othermover. And it is evident, that now the opposite cordxory, will be tightened so that when the lathe shall be again pushed backward to form the opening for the shuttle the slide will be carried back over the centrea, and re-produce another impulse in a contrary direction.
The rapidity with which a vacuum is formed by an Air Pump, depends on theratiobetween the contents of the receiver and those of the pump barrels. If the latter be just equal to the contents of the former, (which is averylarge proportion) the exhaustion will follow this series:—there willremainin the receiver after each stroke, the first contents being 1,1⁄2,1⁄4,1⁄8,1⁄16,1⁄32,1⁄64,1⁄128,1⁄256, &c. But if the pump barrel containstwicethe volume of the receiver—then the remaining air, after the strokes, will be1⁄3,1⁄9,1⁄27,1⁄81,1⁄243,1⁄729,1⁄2187,1⁄6561, &c. being much nearer to a vacuum than on the former supposition.
To meet this case, then, I have thought a water pump might be used: that is, a barrel or vessel,muchlarger than the receiver; and which by the action of a smaller pump, placed on a lower level, might be alternately filled with water and emptied so as in a few operations to complete the exhaustion, very nearly.
Vacuum pump
Thus, infig. 2ofPlate 48,Ais a receiver,Bis a large vessel that can be filled with water from the tubCbelow; andDis the pump, worked by the handleE. It is a common water pump, (so much the readier adopted, as requiringlittlecare in the execution.) The question was to make this pump alternatelyfillandemptythe vesselB. Adverting first to thefilling,a care two cocks, having each a side-passage for the water; and these passages arenowso placed, as by working the pump we suck water out of the tubC, and throw it into the vesselB, through the valveb;—by which means all its air is driven out through the lateral valvee. When this is done, the cocksc d(which are so made as to be worked by the samemover) are turned into a new position, which opens the pipepto the pumpD, andthatqto the returning spoutr; by which means the water is drawnfromthe vesselB, and thrown into the tubC: so that the air is again drawn out of the receiverA, through the inverted valves, into the vesselB, and another degree of exhaustion occasioned. This being done, the cocks are again put into their present position; the air expelled by the water through the valveeas before, and a new stroke prepared. It is scarcely needful to add, that if the vesselBcontained ten times as much volume as the receiverA, the exhaustion of the latter at each emptying of the vesselBwould follow this ratio—1⁄11,1⁄121,1⁄1331, &c. thus approaching by rapid degrees to a perfect vacuum. The water, or liquid, used for this purpose would of course be as perfectly purged of air, as possible.
The principal mechanical merit I conceive this Machine to possess, lies in the facility it gives of taking a stream of water ashigh, and discharging it aslowas possible: and both nearly in the direction in which it naturally flows. Of the advantage it possesses in keeping the water a long time from falling, I shall not now speak, as it would require more discussion than this work comports; and, moreover, the Plate confines us to a somewhat contracted representation, which I hope my readers will excuse.
Inclined water wheel
Plate 48fig. 3,A Bis the section of the wheel, andC Da small portion of it’s circumference—which shews the form and position of the floatsa b c, &c.Eis a floor on which the upper water flows, and from which it falls thinly on to the wheel—whose motion is purposely made as slow as possible. The water then, occupies one half of the wheel’s circumference, falls by a gentle slope and finally leaves the wheel atd, whether it there touches the lower water, or not. This wheel is allowed to be incapable ofusingto advantage a large stream of water—but is doubtless fit to employ a small stream,in the best manner.
I have hesitated a moment to describe this method of helping the weak, in body or mind, to conquer their aversion to medicine—several persons having threatened me with a larger dose of ridicule than I am prepared to swallow. But surely, if we can only conquer a child’s timidity, so as to induce him to take, speedily, what his health requires, we shall not do a thing altogether laughable. We shall, perhaps, preserve a beloved child to the solicitude of a mother! and perhaps—a citizen to his country! If then, some laugh,morewill approve; and I therefore continue the promised article.
Medication vessel
Fig. 4ofPlate 48, shews this cup, composed of an inner and an outer vessel: the first to hold the medicine, and the latter a little tea, or other proper liquid to wash it down. The cups have a spout common to both; but the outer cup retains it’s contents as long as the small funnela, is stopped with the thumb or finger. Thus then, the medicine is first taken, while the liquid is retained in the outer vessel—but the thumb being removed, the liquid also flows into the mouth, and in a good measure removes the taste it was wished to disguise.
The art of constructing Mills, or Machines to be driven by the wind, is so well known, that the results are considered as being, very nearly, what a perfect theory would require. It is, therefore, no part of my purpose to discuss either the theory or practice of that art. But I thinkthat a still wider grasp may be taken of this powerful agent, so as to secure a further degree of utility, even while following less closely the abstract principles of mechanical philosophy. I enter then, directly, on the description of another of mywind Machines, in order to give an idea of the means I contemplate forlosingthe importance of those details in the magnitude of the general effect.
New wind machine
This Machine (seePlate 49,fig. 1,) is capable of great resultsmerely because it employs, at a small expence, a great mass of air in motion; whetherillorwell, is not the question: for as this source ofpoweris almost indefinite, methinks we may draw from it without reserve. The present method of so doing, consists in usinga very large sail, (A B) both to receive the impulse of the wind, and to raise the water. This figure isa sectionof the Machinein it’s length:—and it’swidth(not represented) is as great as the occasion may require. The sail is here shewn as placed over a lake or other sheet of water which it might be wished to drain, (or which may serve as a mill pond to drive any required Machines, by the water thus raised.)C Dis the water in it’s lower bed: andE, is a canal on a higher level, into which a large quantity is thrown at eachmanœuvreof the Machine,ais the bank of the upper canal, to which is affixed theedgeof the canvass, of whicha B A d, is a section; and whichmight belarge to immensity. At 1 2 3, &c. is a row of stakes as long as the Machine; and they are capped transversely with round poles, on which the sail rests when in it’s lowest position. In this state, also, the partbof the sail, plunges into the water, which rises above it in the prismatic form,b r s; a row of valves or clacks, (b) permitting it to rise through them, but preventing it from again falling that way. Thus, at every change, this prism of water, is sure to be replenished; and if we suppose the triangleb r sto have an area of ten square feet, and the prism to be one hundred feet long, the water there contained will be a thousand cubic feet—capable, however, of being augmented or diminished at pleasure, by slackening or tighteningthe sailtowardsA. Atd, is the weather-end of this sail, which is supported when at rest, on the surface of the water, by the posts and caps before mentioned. This endd, of the sail is connected with a row of postsC F, placed more or less closely, as the prevailing strength of the wind and thesizeof the sail may require. The sail is held to these posts byrolling pulley frames, of whichoneis seen atg, and is drawn up and down by the ropeg h, acting at one end directly on the rolling pulley-frameg, and the other on the saild, after having passed over a pulley (F) in the post itself: where note, that this effect can be communicated by proper machinery, from anyoneof these posts (C F) to all collateral ones; so as to make the manœuvres general,across the sail, whatever be it’s magnitude.
The following then, is the operation. The wind blows (by supposition) in the direction of the arrows in the figure: and the rolling pulley-framegis quickly drawn up tog, where the hookiholds it fast. By a necessary consequence the wind fills the saild c r, and stretches it into the figured A B a: in doing which it lifts the waterr s, andpoursit, in all the width of the sail, into the canalE; thus raising a thousand cubic feet of water at each stroke. As soon as the water is turned into the canalE, the hookiis pulled outward, and the rolling pulleygis forced down, by the wind itself, to the position k, when the wind blowingoverthe sail, will give it a bent form, (k c a) and soon bring the sail into it’s present position on the posts 1 2, &c.—when water will be again admitted by the valves atb, and another stroke of the Machine be prepared.
The above contains the basis of this idea. I do not expect it will obtain at once universal assent: But if I knew the several grounds of objection, I am persuaded the greatest numberof them could be removed. The first I anticipate, is the difficulty of turning this Machine to the several winds that may blow over it. To this objection I would reply, that in such a case, the canalE, should surround an area made large enough for the sail, of some polygonal form, say an octagon, to different sides of which the stretching cords of the sail should be carried, so as to catch the prevailing winds—but the direction of which need not be followed to a nicety; since an obliquity of a few degrees would not prevent the effect.
It might be added, that it is not indispensable that the canalEshould be stationary. Made of wood, or metal, itmightturn round a fixed centre, and be braced into the necessary positions with ropes—when the posts only (C F) would have to be removed, or quitted for others duly placed. These ideas are connected with immense effects; and cannot, therefore, be lightly disposed of: they both deserve and require serious attention.
This is the last of those conceptions I shall now bring forward, for makingmorethan a common use of theWINDas a first-mover of Machinery. Horizontal windmills are well known; and this is a horizontal windmill—yet not like those already in use: for, here, the sails, very large and numerous, are placed on a boat in the form ofa ring, which thus moves through the water without any other resistance than that arising from the asperities of it’s surface.
Another boat-based windmill
InPlate 49,fig. 3,B Bis a section of the Vessel, placed in a circular canalD, into which the lower water flows through proper arches (C C) in the banks. The vessel is rigged with several narrow horizontal sails, stretched on ropes between the oblique mastsa b,c d; and so placed, that the sails (being a little wider than the interval between the ropes) canopenin one direction, but not in the other; and they are shewn open atc d, and shut ata b, in thefigure. This, therefore, is a mill, that takes all winds; and although it’s uses might be various, we shall finish it’s description as adapted to raise waterby the centrifugal force. As before hinted, the canalD Dis circular; and has a bank, sloping outward, with acanal (E) on it’s top. When, therefore, the wind blows, the ring boatB(held to the centre by the ropesf g) revolves around it; and by one or more water drags (h) which it carries, collects the water on and up the bank, and finally drives it into the canalE, from which it flows inanydestined direction. If for draining watery lands, it will be done rapidly; if for irrigating, it will be done abundantly: if, in fine, for driving any mill with the water thus raised, the machinery will be very efficient, as working with ten or twenty times as muchsail, as any other windmill can carry. I add, merely on this occasion, that the sails here mentioned, might be placedobliquely, instead of straight across the ring vessel; (see the plan infig. 2of thisPlateatE F) from which disposition, nearly all the advantages of theverticalmill might be transferred to the horizontal; and with this remark I leave the present interesting subject to the studious and candid reader.
My fiftieth and lastPlatecontains this idea: It isnotintended to vie with the usual mirror, in correctness of form, or intensity of local effect—but to offer, by the largeness of it’s dimensions, some properties whichbettermirrors cannot present. It isintendedto pave the way for the use of the Sun’s rays inEngines of Power. For this purpose, however, it must probably be transported to some tropical climate, where “a cloudless sun” diffuses it’s rays more constantly, and less obliquely, than in our northern climes.
Parabolical mirror
This is the more necessary here, because this Mirror can only be used in a horizontal position, and is in fact a fluid Mirror.Fig. 1, shews it mounted on a steady frameA B, and having a strong axis on which it can be turned, faster or slower, according to it’s dimensions; and it may or may not be floated on water, to lessen the stress on the axis. The Mirror, properly speaking, is composed of mercury—contained in the revolving vesselC D, whose motion should be given by proper machinery in the most uniform manner possible. The mercury, thus turned, acquires a concave surface,a,b,c; and receiving the parallel raysd c,e b, and,f a, collects theminto the focusF; in, or near which, is placed the vessel where the effect is to become useful, and which of course ismoveableso as to follow the sun’s motion. Those of my readers who have seen the machines used for fixing the sun’s image in the solar microscope, will be at no loss to conceive how our present focal station must bemovedto adapt it to afixedmirror. I shall only add further, that it is not necessarily anexactmovement that is here wanted; since the vessel to be heated would have dimensions somewhat large, and the focus itself be only brought to a moderate degree of precision. In a word, the utmost heat wanted would be, what could be usefully employed in heating water. It remains then to be observed, that the source of power, in this Machine, ismagnitude of parts, more than precision of form: yet it may be mentioned, that the form we thus procure in the revolving mercury, is a solid of revolution, having thelogarithmic curve(a,b c) for it’s section—a curve, which in fact, comes indefinitely near to the parabolic figure whichwould berequired, if greater precision were attempted. We finish then, by observing, that the bottom itself of the revolving vessel might be made concave, (like the dotted line underthat a b c) in order to avoid the necessity of using a large quantity of mercury, to form the reflecting surface.
This Mirror seems superior to the former, as depending onfixedmaterials. It likewise, produces the desired effect, by offering avery large surfaceto the sun, and directing the rays to a focus, nearly enough to give the heat required for water, as before mentioned.
Another solar mirror
To do this, a frameA(Plate 50,fig. 2) holds the Mirror; and this frame has a horizontal motion round thepostB, something like a common windmill. In this frame and on two horizontal trunnions, turns the MirrorC D: and one or both these trunnions are hollow, to admit of a process we shall shortly mention. This Mirror itself is composed of an air-tight ringC D, of a width proportionate to the diameter adopted; and on which are fixed twoheads, much like those of atambourine, (or theunderhead might be made of some metallic substance). The heada b c, is made of a fine texture, duly prepared and varnished till it becomes air tight, and then there are stuck to it, a number of smallhexagonallooking-glasses or mirrors of any kind, (seefig. 7) which thus fill up the whole space, and prepare the Mirror for the intended change of form.The method of giving this form, consists in exhausting, more or less, thistambourineof air, when, by the pressure of the atmosphere, the heads will take the forma b c, that is aspherically concave form—fit to reflect the sun’s raysas correctlyas this our object requires; and thus may some thousand small images of the sun be brought to fall on the same spot, and an immense heat be occasioned. The accounts we have of the destruction of the Roman fleet by theunitedmirrors of Archimedes, make this process appear the more feasible—as whatever were the methods of uniting thefociof his mirrors, a similar effectmay be expectedfrom this simple process.
My readers will perceive that this Machine has the advantages of the universal joint, by which it can be directed to the sun in every position; and even made to fix his ardours on any immoveable spot for a good length of time. The persons to whom I particularly address these ideas, will require no further details to conceive the less obvious circumstances of this Invention. In general, we want no effect that requiresoptical precision: but if we did, it could be obtained to a good degree, by methods similar to these.
I shall only add here, that thisfig. 2is givenas a section—because intended to represent a parallelogram, as well as a solid of revolution: and thus (with proper mirrors) to make what now appears a spherical focus,a linear one—fit to heat acylindrical vessel with it’s contents; and thereby drawpowerfrom the sun’s heat,withoutrunning expense. I am serious when I say, that we can thus, practically, collect the solar rays which fall on many hundred square feet of surface; and produce by them, at any desired distance, effects to which those obtained frommodernburning mirrors, are but as sparks to a blaze.
Engraving machine
This Machine supposes at once anew kindof engraving, and admits of patterns ofvery largedimensions. This kind of engraving will be best understood by persons acquainted with figure-weaving; and especially with the manner ofmountingthe looms for that purpose. In that System, (seePlate 50,fig. 8) the patterns are drawn on ruled paper divided into squares; and each of these squares represents a point in the texture, composed of one or more threads each way; insomuch that whenever thatsquarehas any desired colour in it on the pattern, it’s threads aretakenby the person who prepares the loom; and they aremissedin every case where nothing appears in that square, or a colour not then wanted. Now, whatever be the dimensions of these elementary points on the loom, they may be represented by squares of any convenient size on the pattern: only remembering that the smaller they are, in reality, the better will be the delineation. Thus in carpeting, for example, an element of this kind may be a square of one tenth of an inch and more; while one on a ribbon or a piece of silk, is often not the hundredth part. And therefore, the perfection of this engraving depends on the fineness of the points of which the figures are composed. For, in a word, this System proceeds on thesame principle. When any part of a line requires a dot or mark to be made, the Machine strikes a blowthere; and when no impression is to be made, the Machine (by means that will be shewn) suffers the cylinder to pass that place without striking. The means of regulating this is committed to workmen who merely know how toreadoff the patternin it’s length, as it is now read offin it’s widthby the weaver. To describe the construction of the Machine, (as exhibited infigs. 3 and 4ofPlate 50)Ais the cylinder to be engraved; andBis a worm-wheelfixedto it’s mandril, and destined to turn it. This it does, slowly, by the endless screwa, as turned by proper straps on the fast and loose pulliesb c, (figs. 3 and 4).Cshews a second wheel, concentric with thatB, but running loose on it’s axis, which is a pin fitted into the end of the mandril. This wheel, when the threads of the screwaarefine, requires a motion more rapid than the wheelB—to give which motion by means of the latter, we use a pair of multiplying wheelsd, which geer, one in the larger bevil wheel cut near the edge of the wheelB; and the other in a smaller bevil wheel cut or fixed on the inner face of the wheelC—and whence this latter wheel receives a velocity of about ten times the speed ofB. The use of this wheelC, is to carry, across the Machine, certain bars, of wood or metal, shewn infigs. 5 and 6, whose function is to carry short pins or studs 1, 2, 3, 4, &c. for the purpose of determining the placeswherethe punch is to act, and where it is not. To this end,g his a frame, which is raised by acamor tappeti, fixed in theendless screwa, once every turn; andthatthrough the medium of the little tumbleri e f, by which is finally determined whether the stroke shall take place or not—formbeing a section of the stud bar offigs. 5 and 6, it’s pins,when they occur, raise the endfof the bent leverf e i; and when there is no pin or stud inm, this lever is not raised, and the pointi, doesnotcome near enough to the cam to be laid hold of, in which case no stroke is given. This then, is so whenever the studs fail in the barm; and these fail whenever thepattern-readerhas said to the stud-setter,miss: and they occur whenever he has saidtake—both which cases happen more or less often according to the state of the squares in the pattern.
To be a little more particular: infig. 5we see a part of the wheelCoffig. 3, and also a part of the stud barsm m, whichgeerin the wheelC, and which being conducted by the guidesn, follow the motion of that wheel, presenting atf, (fig. 3) a stud to raise the leverf e, whenever the pattern requires it. It may be mentioned, that these studs actobliquelyon the wingfof this lever, and thusraiseit as they pass under it. And further, these stud bars are made and fitted to each other in the manner shewn atfig. 6. There is a geering tooth under every stud hole, and the last stud hole of a given bar has, fixed in it, a thin tubea, into which the stud enters the same way as in any other place: but this tube whether studded or not serves to lay hold of the succeeding barb, by it’s first hole—so, in fine,as to make the bars endless; the attendant having nothing else to do than to hook them to each other as the wheelCdraws them in.
Thus then, are the strokes of thehammer frame,g h, conformed to the pattern: for these bars have been studded before hand by one or more readers and setters; and it is a merely mechanical process to put them in while the Machine moves: from which, by the bye, theyfall outafter the passage into a proper box, and the studs out of them, to becomposedagain from the succeeding figures of the pattern. A dozen or two of these bars might be prepared atanytime and place, and toanypattern, which they will thus transfer to a cylinder atanydesired moment, without the further preparation of dies, punches, mills, &c.—as used in other Machines. N. B. The strength of the blows thus given by the hammer frameg h, is lessened or augmented by the position of the pointifixed to the bent leveri e f, and which makes that lift higher or lower as required—which is a mean ofshadingoffered by this Machine. But to mention it’s other properties, the endless screwa, (figs. 3 and 4) carries another endless screwo,more or less fine, which turns at the same time the wheelp, and, by that, the long screws s, whose office it is to shift, slowly, the punch carriersk l, along the Machine, fromkbyl, towardss. And here an observation occurs: this can only be so, when the pattern permits the action of the puncheskorl, to take placespirallyon the cylinder; that is, whenthesketchesare distinct enoughnotto shew the anomaly that would occur were astraightpattern thus transferred to a set of spiral lines. But should it be desirable to engrave patterns so correct as to require an exact parallel motion round the cylinder,thenthe motion of this screw mustnotbe continual—but must intermit and be resumed, at every beginning of a new line round the cylinder. I hope, I make myself understood: a pattern drawn onsquares, produces lines all parallel to the first; while the spiral motion of the punch causes a slight deviation—which, in a word, can either be suffered or avoided. At all events, this deviation is so much the smaller as the punch motion is slower in both directions; and, infinepatterns, must bevery small. One remark will close this part of the subject: although a fine pattern, requires a great number of blows, and thus a certain expence of time, each blow can be so much the lighter and more frequent; so as to compensate, in some degree, for this cause of delay. I add, that the levers shewn above and aroundfig. 6, are intended to lift the hammer frameg h, equally at both ends: while the screwZregulates thedepthto which it is permitted to fall.
I observe, finally, that, according to the size of the intended pattern, there are more or fewer of the punch bearersk l, connected, by their nuts, with the screws s; each of which thus engraves it’s sketch, similar to the collateral ones; and that were it wished to makeonepattern of the whole length and circumference of the cylinder, a single punch bearer would be required—since nothing else limits the extent of a pattern engraved by this Machine.
Thus have I gone through my proposed “Century of Inventions,” for every imperfection in which I beg the indulgence of my numerous readers. And here I can truly say I haveneglectednothing—although the precarious state of my health may have sometimes veiled the evidence of my descriptions. On the other hand, I did not even attempt many of the lesser details of execution; as I wrote for those to whom they would have been superfluous: but as to the objects themselves, I believe there is not one that is without the pale of practical utility. In a word, many of the subjects have been frequently executed, andare in daily use: and as to those which remain to be tried, I engage, if called on, to give them useful existence. And the better to convince candid minds of the serious attention I have paid to these subjects, I shall addthe scaleson which they have been executed, or to which they are drawn—those scales expressed by a fraction, shewing what proportion the figures bear to the reality. Thus the scale of one inch to a foot will be expressed by the fraction1⁄12; that of two inches to a foot, by1⁄6, &c. that is, the figures, in these cases, will be (nearly)1⁄12or1⁄6of the size of the Machines. This premised—and also that we shall observe the alphabetical order, the following is the