Chapter II: Preface (2)

This Wheel (see Plate 8, fig. 1,) is technically called a Bucket-wheel. It is plunged almost entirely in water, oil, mercury (or other heavy fluid) contained in the vessel A B. It’s axis carries a _waved_ wheel a b, on which rolls a friction-pulley p, running on a pin in the mortice of the bar c d. This bar works the pump f; which by the descent of it’s _loaded_ Piston, drives _cold_ air (or gas) into the tube g, communicating with _several_ collateral ones placed _across_ the vessel, so as to convey the air to h, below and beyond the centre of the wheel. A fire being made at F under this vessel, the water (or other fluid) is brought to a proper heat; and if then the pump f, be made to give a stroke or two, air will be forced from the tubes at h, which having been heated in the passage, will bubble up into the buckets h, i, k, &c. and turn the wheel so as to perpetuate it’s own supplies from the Pump, and furnish a surplus of _power_ for other purposes. This results from the fact, that air (for example) in rising to the temperature of boiling water, expands, under the pressure of the atmosphere, to about three times the volume it occupied at the mean temperature: so that it resists the entrance into the vessel as _unity_, and acts (when heated) as 3: leaving a power of _two_, in the form of a rotatory motion.

It will occur to many readers, that azotic gas or nitrogen, might be used with advantage to turn this wheel: only adding to the Machine a _long_ returning tube, leading from the top of the vessel, through air or water, to the _suction valve_ of the pump f; and _that_ in order to bring down the temperature of the gas from the heat it had acquired in the vessel, to the mean temperature; at which this gas is said to occupy only 1/7 of the space it fills when at the heat of boiling water.

I have now to observe that this invention was _executed_ in 1794, of which abundant proof remains. Since then, it has been proposed by other persons, and is I think, patentized either in France or England: but a different method is employed of introducing the cold _air_, namely an inverted screw of Archimedes, whose manner of working I do not entirely recollect. What I here wish to observe is, that this concurrence of idea between others and myself, gives me no pain; since it would be more strange if it did not happen, while so many active minds are ransacking nature for the very purpose of unveiling her secrets. Only I think it incumbent upon me to use every method, consistent with truth and honour, to avoid being thought unjust enough to purloin other people’s ideas, and call them my own.

OF
AN EQUABLE PUMP,
_Or Machine for raising Water without interruption or concussion_.

This Machine is represented in Plate 8, fig. 2 and 3. It is composed of two barrels A B, both of them forming part of the column of water to be raised; connected together by a crooked tube C, of equal diameter, out of which the lower Piston-rod passes through a stuffing box into the air: as does the upper Piston-rod at D, where the column leaves the Pump to pass upward. The two Pistons fixed to the rods E and F, are of the bucket kind; made as thin and light as possible; their valves opening upwards and their motions being such, generally, that when one of them is drawn up, the water rises through the other, _then descending_: But here lies both the novelty and utility of this Machine; these upward and downward motions are _not_ reciprocal: Both Pistons fall faster than they rise, and thus leave an interval of time _when they both rise together_; during which their valves, respectively, close by their own weight _before_ the column of water falls upon them. In such manner, indeed, that the column never _falls_ at all. By this important arrangement, the work is constantly going on, and _no commotion_ occurs to absorb _Power_ uselessly, or to destroy, prematurely, the Machine; circumstances which _constantly_ attend every Pump Machine acting by merely reciprocal motion.

This non-reciprocity then, I produce by several methods; one of which (perhaps the most easily understood) is that shewn in fig. 2: There, A B are two friction-rollers, made as large as possible, rolling on the curves C X, the ascending and descending parts of which are essentially _unequal_. For example, the rising part of the curve occupies 2/3 of the whole circumference; and the falling part 1/3 only; so that both curves recede from the centre at the same time, during 1/6 of a revolution, at the two opposite positions, A C and X Y. Applying then, these curves and levers to the Pump-barrels represented in fig. 3, we obtain that _continuity of uniform motion_, which is necessary to doing the greatest quantity of work with the least power; and to securing the greatest durability of the Machine. Having hinted at a _minimum_ of power, I must add here that this Machine appears to promise that result, much more credibly than any reciprocating pump whatever; especially if to this continuity of motion we add a certain _largeness_ of dimension that shall produce the required quantity of water, with the slowest possible motion of each particle; and even here this _continuative_ principle helps us much; since pistons and valves of the largest dimensions may be used without introducing any convulsive, or (what is synonymous) any destructive effects.

One particular remains to be noticed in fig. 2. It relates to the means by which the _perpendicularity_ of the motion in the Piston-rods is secured. The arcs M are portions of cylinders having the bolts Z, for their centres, and which, _rolling_ up and down against the perpendicular plane O N, secure a similar motion to the bolts. The _tenons_ P, are cycloidal, on their upper and lower surfaces; and work in square or oblong holes in the plane N O, being kept _in_ their holes by the action of the two springs on a pin let through these tenons: and thus is the motion of the point Z of the levers M B, a perpendicular one; and that of the friction rollers A B, very nearly so.

My object in this work, is to make known the principles, and _some_ of the forms of these Inventions, but my limits will not permit their being dilated on; else I could give several more useful forms of this Machine: but, to make room for other subjects, I must hasten forward--reserving to some future period, many hints respecting the adaptation of those ideas to particular cases. Those of my readers who love to speculate on the doctrine of _permutations_, will anticipate how much may be done by the _combination of a hundred Machines_ with each other: and they will give me credit for detached items of knowledge--useful in themselves, though too minute to be severally brought forward. Should, however, the degree of patronage I have already experienced, be proportionably extended as the work advances, _I can and will_ follow it up with many useful hints, tending to shew the extent of some of my present subjects, and the amplitude of the sphere in which they roll.

It should be observed, in concluding this article, that the present Machine was executed in France, in 1793, and also proposed to the Government, as a substitute for the celebrated Machine of Marly. In the report then published, it was preferred to the whole multitude of former projects; but left _in equilibrio_ with _one_ modern Machine,--a competition which prevented it’s adoption for the moment--and indeed till I was _glad to escape the notice_, instead of courting the favour of the then rapidly succeeding governments.

OF
A SIMPLE MACHINE,
_For Protracting the Motions of Weight-Machinery_.

Let A, Fig. 4 Plate 8, be the barrel-wheel of a Clock, or other Machine, already in use, and driven by a weight; and let the _similar_ barrel B be added to the former; the motion of both being connected by the _unequal_ wheels C D. The rope or chain E F, is then led from the barrel A under the pulley P to the barrel B: By which arrangement, when the weight has occasioned _one_ revolution of the barrel and wheel A C, _those_ B D, will have made a lesser portion of a revolution in the ratio of the wheel C and D; (namely as 22 to 24,) and that motion will have _taken up_ 11/12 of the line which the barrel A has _given off_. By these means, the motion of the whole may be prolonged almost indefinitely. This System may appear to some persons open to the objection that the friction of the wheels C D, will absorb so much of the power, as to leave the rotatory tendency too feeble for it’s intended purpose. But I again take refuge in the well proved property of my patent geering,--of not impeding (sensibly) the motion of any Machine in which it is used.

Should it further be suggested, that this is only an awkward parody on the _differential wheel and axle_, ascribed by Dr. Gregory (in the introduction to his work, page 4,) to the celebrated George Eckhardt: I would answer, that I made _that invention also_; though doubtless _after_ Mr. Eckhardt; and especially after the date of the figure given by the Doctor, as coming from China, “among some drawings of nearly a century old;” Of course then, I do not pretend to priority of invention: but _truth herself_ authorises me to say, that I did invent this Machine also, _in the night between the 17th. and 18th. of January, 1788, and drew it in bed by moonlight, that it might not escape me!_ It was the result of a previous _fit_ of close thinking: and of the conclusion I _then_ drew, that in whatever way, _slowness_ of motion is obtained by the connection of two movements, _power_ is invariably gained for the same reason, and in the same proportion. The fact is, that all my ideas respecting differential motions, have flowed from this source; as will be evident to the attentive reader of these pages.

OF
AN INSTRUMENT
_For drawing Portions of Circles, and finding their Centres by
inspection_.

It is a known property of _an angle_ such as g d f (plate 9 fig. 1) when touching two fixed points g f, and gliding from one of these points to the other, to describe a portion of a circle g d f. My object in this instrument is to determine, by inspection, the radius of such circle in all cases.

To do this, I connect with the jointed rule m d n, another rule like itself but shorter g e f, so as that the figure g d e f shall be a perfect parallelogram: and I then say that knowing the distance of the points d and e, (the distance d f being given) I know the radius of the circle of which g d f is a portion. To prove this, a little calculation is necessary: In the circles A B and a b (fig. 6) draw the lines E D; _f d_, _d g_, _g f_, _g e_, and _g D_; and bearing in mind the known equation of the circle, let _d n_ = _x_, _g n_ = _y_; and g D = a, the absciss, ordinate, and radius respectively. The equation is 2ax - x² = y²: from which we get _a_ = (y² + x²)/(2x) the denominator of this fraction being the line _d e_. But further its numerator (_y_² + _x_²) is equal to the square of the chord g d of the angle E D g, which chord I call _c_. This gives _a_ = _c_²/(line _d e_); from which equation we derive this proportion _a_ : _c_ ∷ _c_ : line _d e_; Putting then the chord _c_ = 1 (one foot for instance) this proportion becomes _a_ : 1 ∷ 1 : 1/_a_; whence we draw this useful conclusion, that, whatever portion of a foot is contained in the line _d e_, (expressed by a fraction having _unity_ for its numerator) the radius of the circle will be expressed _in feet_ by the denominator of that fraction. Thus if the line _d e_, be 1 inch or 1/12 of a foot (and the line _g d_ or _d f_ be 1 foot) the radius of the circle will be 12 feet; and so for every other fraction. Now in the instrument itself the two points _d_ and _e_, _are connected by a micrometer-screw_ (not here drawn) of the kind described in a subsequent article, and by which an inch is divided in 40,000 parts, each of which therefore is the 1/3333.33, &c. part of a foot: so that if the distance _d e_, were only _one_ of these parts, we should produce a portion g d f of a circle of 3333.33, &c. feet radius--being more than half a mile.

I had omitted to observe, that the _points_ or studs, against which the rulers m n slide, to trace the curve (_by a style in the joint d_,) that these studs I say are fixed to a detached ruler o p, laid _under_ the parallelogram on the paper, and having two _stump points_ to hold it steady: _one_ of the studs being moveable in a slide, in order that it may adapt the distance f g, to _any_ required distance of the points _d e_: We note also that the dotted curve g d f is _not_ the very circle drawn, but one parallel to it and distant one half the width of the rulers. In fact the mortices of these rulers are properly the acting lines, and _not their edges_. I expect, for several reasons, to resume the subject of this instrument before the work closes.

OF
AN INCLINED HORSE WHEEL,
_Intended to save room and gain speed_.

My principal inducements for giving this Wheel the form represented, by a section, in fig. 3, (see Plate 9) were to save _horizontal room_; and to gain speed by _a Wheel_ smaller than a common horse-walk,--and _yet_ requiring less obliquity of effort on the part of the horse. With this intention, the horse is placed _in a conical_ Wheel A B, more or less inclined, and not much higher than himself: where, nevertheless, his head is _seen_ to be at perfect liberty out of the cone as at C. The horse then walks _in_ the cone, and is harnessed to a fixed bar introduced from the open side where, by a proper adjustment of the traces, he is made to act partly by his weight, so as to exert his strength in a favourable manner. This Machine applies with advantage where a horse’s power is wanted, _in a boat or other confined place_: and it is evident, by the relative diameters of the wheel and pinion A B and D, (as well as by the small diameter of the wheel) that a considerable velocity will be obtained at the source of power,--whence, of course, the subsequent _geering_ to obtain the swifter motions, will be proportionately diminished.

OF
A DIFFERENTIAL COMBINATION OF WHEELS,
_To count very high numbers, or gain immense power_.

In fig. 2, of Plate 9, (which offers an horizontal section of the Machine), A B is an axis, to the cylindrical part of which the wheels C D are fitted, so as to turn with ease in either direction. Each of these wheels, C and D, has two rims of teeth, _a b_, and _c d_; and between those _b d_ are placed an intermediate pinion W, connected by it’s centre with the arm _x_, which forms a part of the axis A B. There is likewise a fourth wheel or pinion Z, working in the outer rims _a c_ of the wheels C and D. It appears from the figure itself, that the action of this Machine depends on the greater or lesser _difference_ between the motion _forward_ of the wheel C, and the motion _backward_ of the wheel D; for if these opposite motions were exactly alike, the wheels would indeed all turn, but produce no effect on the arm _x_, or the axis A B: whereas _this_ motion is the very thing required. Since then the motion of the bar _x_, and finger _g_ depends on the difference of action of the wheels C and D on the intermediate pinion W, we now observe, that in the present state of things, the rims _a_, _b_, _c_, _d_, have respectively 99, 100, 100, and 101 teeth: and that when _one revolution_ has been given to the wheel C, the rim _b_ of this wheel has acted, by 100 of its teeth, on those of the intermediate pinion W; insomuch that if the opposite wheel D had been immoveable, the arm _x_ would have been carried round the common centre a portion equal to 50 teeth, or one half of it’s circumference (which effect takes place because the pinion W _rolls_ against the wheels C and D, it’s centre progressing only half as fast as it’s circumference.) But instead of the wheel D standing still, it has moved in a direction opposite to the former, a space equal to 99/100 of a revolution, and brought into the teeth of the pinion W, 99/100 of 101 teeth; that is, 99 teeth, and 99 hundredths of one tooth: so that the _account_ between the two motions stands thus:

The forward motion by the wheel C, is equal to 100,00 teeth.
And the backward motion by the wheel D, is 99,99 „
------
And the difference in favour of the forward motion is 00,01 of 1
tooth.

Or, dividing the whole circumference into 101 parts (each one equal to a tooth of the rim _d_,) this difference becomes 1/100 part of 1/101 = 1/10100 of a revolution of the axis A B, for each revolution of the wheel C. But we have observed, that the arm _x_ progresses only _half_ as much, on account of the _rolling_ motion: whence it appears that the wheel C, must make 20200 turns to produce _one_ turn of this axis A B. And if, with 20 teeth in the pinion Z, we suppose the movement to be given by the handle _y_, this handle must make _more_ than 20200 revolutions, in the proportion of 99 (the teeth in the wheel) to 20, the teeth in the pinion Z. Thus the said 20200 turns must be multiplied by the fraction 99/20 which gives 99990 turns of the handle, for one of the axis A B. And finally, if instead of turning this Machine by the handle and pinion _y_ Z, we turned it by an endless screw, taking into the rim _c_, of 100 teeth; the handle of such screw must revolve 2020000 times to produce one single revolution of the axis A B; or to carry the finger _g_, once round the common centre.

The above calculations are founded on the very numbers of a Machine of this kind I made in Paris: and of which I handed a model to a public man nearly thirty years ago. I need not add that this kind of movement admits of an almost endless variety: since it depends both on the numbers of the wheels and their differences; nay, on the differences of their differences. I might have gone to some length in these calculations had I not conceived it more important to bring other objects into view, than to touch at present the extensive discussions _this subject_ invites and will doubtless suggest to many. Suffice it now to say, that here is a simple Machine which gains power (or occasions slowness), in the ratio of two millions and twenty thousand to one; giving, (if executed in proper dimensions) to a man of ordinary strength, the power _of raising, singly, from three to four hundred millions of pounds_. It may be useful to observe that using this Machine for an opposite purpose, that of _gaining speed_, _extreme rapidity_ may be caused by a power acting very slowly on the axis A B; only in that case, the _difference_ must be enlarged, and the diameters and numbers of the wheels be calculated _on the principles of perfect geering_--which is as easy in this Machine as in any other.

OF
A CRANE,
_Which combines_ VARIABLE POWERS _with speed and safety_.

Doctor Gregory (in his Mechanics 2d. volume page 157,) thus introduces the description of this Crane, and the observations with which he tags that description.

“The several Cranes described in this article, as preferable to the common walking Crane, while they are free from the dangers attending that Machine, lose at the same time one of it’s advantages, that is, they do not avail themselves of that addition to the moving power which the weight of the men employed may furnish: yet this advantage has been long since insured by the mechanists on the continent: who cause the labourers to walk upon an inclined plane, turning upon an axis, after the manner shewn in the figure referred to under the article _foot-mill_,--where we have described a contrivance of that kind, well known in Germany nearly 150 years ago. The same principle has been lately brought into notice (probably without knowing it had been adopted before) by Mr. Whyte, (White) of Chevening in Kent: His Crane is exhibited,--fig. 2 and 4, Plate 10, _as it was described in the Transactions of the Society for the Encouragement of Arts_.”

“A, Plate 9, fig. 4, (of this Work) is a circular inclined plane, moving on a pivot under it, and carrying round with it the axis E. A person walking on this plane at A, and pressing against a lever, throws off a gripe or brake, and thus permits the plane to move freely, and raise the weight G by the coiling of the rope F, round the axis E. To shew more clearly the construction and action of the lever and gripe, _a plan_ of the plane connected with them, is added in fig. 5, where B represents the lever, and D the gripe: where it is seen that when the lever B is in the situation in which it now appears, the brake or gripe D, _presses against the periphery of the plane_; but when the lever B is driven out to the dotted line H, the gripe D is detached, and the whole Machine left at liberty to move: a rope or cord of a proper length, being fastened to B, and to one of the uprights in the frame, to prevent this lever from being pushed too far towards H, by the man working at the Crane.”

“The _supposed properties_ of this Crane, (says Dr. Gregory) for which the premium of forty guineas was adjudged by the society to the Inventor, are as follows:”

“‘1. It is simple, consisting merely of a wheel and axle:

“‘2. It has comparatively little friction, as is obvious from the bare inspection of the figure:

“‘3. It is durable from the two properties above mentioned:

“‘4. It is safe: for it cannot move but during the pleasure of the man, and while he is actually pressing on the gripe lever:

“‘5. This Crane admits of an almost infinite variety of different powers; and this variation is obtained without the least alteration of any part of the Machine. If in unloading a vessel, there should be found goods of every weight, from a few hundreds to a ton and upwards, the workman will be able so to adapt his strength to each, as to raise it in a space of time, (inversely) proportionate to it’s weight, he walking always with the same velocity as nature and his greatest ease may teach him.’”

“‘It is a great disadvantage in some Cranes, that they take as long a time to raise the smallest weight as the largest; unless the man who works them turn or walk with such velocity as must soon tire him. In other Cranes, perhaps, two or three powers may be procured; to obtain which, some pinion must be shifted, or fresh handle applied or resorted to. In this Crane on the contrary, if the labourer find his load so heavy as to permit him to ascend the wheel without turning it, let him only move a step or two towards the circumference, and he will be fully equal to the task. Again, if the load be so light as scarcely to resist the action of his feet, and thus to oblige him to _run_ through so much space as to tire him beyond necessity, let him move laterally towards the centre, and he will soon feel the place where his strength will suffer the least fatigue by raising the load in question. One man’s weight applied to the extremity of the wheel would raise upwards of a ton: and it need not be added that a single sheaved block (at the jib) would double that power. Suffice it to say that the size of the machine may be varied in any required degree, and that this wheel will give as great advantage at any point of its plane as a common walking wheel of equal diameter; as the inclination can be varied at pleasure, as far as expediency may require. It may be well to observe that what in this figure is the frame and seems to form a part of the Crane, must be considered as part of the house in which it is placed; since it would be mostly unnecessary should such cranes be erected in houses already built: and with respect to the horizontal part, by walking on which, the man who attends the jib, occasionally assists in raising the load, it is not an essential part of this invention, when the crane and jib are not contiguous: although, when they are, it would certainly be convenient and economical.’”

The Doctor continues: “Notwithstanding, however, the advantages which have been enumerated, Mr. Whyte’s (White’s) Crane is subject to the theoretical objection, that it derives less use than might be wished from the weight of the man or men: for a great part of that weight (_half_ of it if the inclination be 30 degrees,) lies directly upon the plane, and has no tendency to produce motion. Besides, when this Crane is of small dimensions, the effective power of the men is very unequal; and the barrel too small for winding a thick rope: when large, the weight of the materials, added to that of the men, put it out of shape and give it the appearance of an unwieldy moving floor.”

The Doctor continues: “We know one large Crane of this construction, which has an upright post near the rim on each side, to support it, and keep it in shape; and as much as possible to prevent friction, each post had a vertical wheel at it’s top.” (N. B. _I_ never saw, or heard, before, of this monster.)--“We were informed this Crane was seldom used; and that it was soon put out of order. Nor, moreover, is it every situation that will allow the Crane-rope to form a right angle with the barrel on which it winds; and when this angle is oblique, the friction must be much increased. The friction arising from the wheels at the top of the vertical _crutches_ might indeed be _got shut off_, by making the inclined wheel very strong; but this would add _greatly_ to the friction of the lower gudgeon of the oblique shaft, and _considerably_ increase the expence of the Machine.”

“There remains then (says Dr. Gregory) another stage of improvement with regard to the construction of Cranes, in which the weight of the labourers shall operate without diminution, at the end of an horizontal lever; and in which the impulsive force thus arising, may be occasionally augmented by the action of the hands, either in pulling or lifting”--and then follows the conclusion. “This step in the progress has been lately effected by Mr. David Hardie, of the East India Company’s Bengal warehouse!”

I cannot follow the author (whoever he be) of the glowing picture next given of Mr. Hardie’s Invention, (to which the obloquy thrown on my poor abortion is clearly _the foil_) as my readers must already be anxious to “get shut” of such unmitigated Bathos, bestowed on so trivial a theme. With respect to my Crane, I shall only say that it fulfilled the conditions required by the Society, _and obtained the Premium_: and if on the one hand, the language in which, thirty years ago, I described it, exhibits the impetuosity of youth, untempered with the moderation of age, I will say on the other, that if impartial criticism, mechanical acumen, or comprehensive _science_ are essential components of a mechanical work _of high pretensions_,--these qualities were seldom more wantonly abandoned or abused, than in the paragraphs above quoted: except, perhaps, in the attack of the same work, on the labours and character of the justly celebrated Watt, whose merits had this author known how to appreciate, he _could not_ thus have attempted to lessen in the public esteem.

But to return, this _Diatribe_ begins by comparing my Crane to a foot mill: and kindly supposes I did not know that its principle existed in Germany 150 years ago. But the fact is, my object was nothing like that of the author of the mill in question: the very figure of which, proves that _he_ had no view to the variation of power by change of place on the wheel: whereas _that_ is the principal use I make of this “unwieldy moving floor,” as the Doctor _heavily_ terms it. Again, this author asserts that by making men walk on an _inclined_ plane, I derive less use than might be wished from their weight; and yet! a page before he told us that “the mechanists on the Continent had long since insured the advantage of availing themselves of that addition to the moving power which the weight of the men may furnish;” so that poor _I_ have the merit of imitating them without knowing it, and yet of _not_ drawing the same advantages as they from the self same principle!

But again, “a great part of the weight of the man (_half_ of it, if the inclination be 30 degrees) lies directly on the plane, and has no tendency to produce motion,” which _one sided truism_ is placed there to give relief to the portentous _dictum_, which follows:--that “there remains then another stage of improvement with regard to the construction of Cranes, in which the weight of the labourers shall operate without diminution at the end of an horizontal lever: and that stage has been effected by Mr. D. H. of the East India Company’s Bengal warehouse.”

But is this conclusion definitive? are there no countervailing evils? Will Dr. Gregory presume to say there is no _disadvantage_ attending this advantage? Did the Doctor ever ascend an upright ladder? and did he _prefer_ that, to going up an easy flight of stairs? was he ever in the geometrical stairs of St. Paul’s? or in any large _winding_ stair-case? and if so did he prefer ascending close to the nucleus? or did he quickly seek a point where the step was _wider than high?_ most certainly the latter; and why then did he not perceive that if the weight of my man is diminished one half on the plane, for the very same reason, a given _elevation_ of his feet (on which his _fatigue_ depends) will cause a circular motion twice as extensive; yet this is quite as clear as the Doctor’s _ex-parte_ proposition.

But I must wade on a little further, trusting that my readers will exert a little more patience to follow me: for this same dictum of the Doctor’s accuses indirectly, the Society of Arts of being a set of blockheads, for remunerating an Invention with only _supposed_ properties. I really wish these self-constituted judges of other people’s labours would utter their oracles with more regard to truth and propriety! and above all, not mix up their passions (which alas! are not always purified by science) with their judgement on the merits of other men’s inventions. Had the author of this article been wise enough to proceed thus, he would not have _supposed_ me capable of offering _suppositions_ for realities; nor the Society of Arts of rewarding as genuine, _suppositious_ merit; and still less would he have emblazoned the very properties he calls _supposed_, with _reality_ written in glaring characters on every one of them! These properties are in fact only the transcript of what the society required of the candidates: and I therefore said my Crane is simple: Can this author say it is not? I said it has little friction? will he say it has _much?_ I said it is durable: Is it now possible to contradict this? I said it is safe: and will Dr. G. say it is not, when it is moveable, _only during the wish of the workman_: since _whatever_ suspends this wish, (whether accident or design) the Crane becomes of itself _immoveable_. In fine, I observed, that this Crane admits of an indefinite number of _powers_, without any modification of it’s parts; and can any one say these are _supposed_ properties? If the Doctor or his coadjutors persist in saying so, I must _suppose_ them actuated by improper motives; for truth will never bear them out in these allegations. I take leave to add, that but for the interests of truth, these strictures had never appeared. Even self-defence would not have provoked one line of them: But I felt it incumbent on me to deter, if possible, inadvertency as well as malevolence, from infesting with the thorns of misrepresentation, the paths which genius explores, in search of useful knowledge.

OF
A DIRECT AND DIFFERENTIAL PRESS,
_With two Powers: of which_ ONE _immense_.

The effects intended to be obtained from this Press, are to introduce two distinct powers; the one to raise and lower the pressing cap with convenient speed; the other to _press_ with _very_ great force. In Plate 10, A B is a frame, the under part of which contains the goods to be pressed. The toothed wheel C D turns the screw S, and that E F turns the nut G H, _both the same way_. The long pinions I K, turn both these wheels C D, and E F; and occasionally one only, as will be seen presently. L M are two bevil wheels on the axes of the long pinions I K; and N O, are two similar ones, on the power shaft P Q. This latter shaft runs in two boxes R T, the _stems_ of which fit and turn in the gudgeons of the long pinions, or rather suffer these to revolve round _them_: being pinned on through a circular groove which connects them in the perpendicular direction only. Finally, the rope and pulleys _indicated_ at X Y Z, serve to raise both shaft and pinions; thus disengaging the latter from the wheel E F, when the nut G H, is _not_ to be turned. We may remark, that the parts M T O are _doubled_ in this machinery, at L R N; merely to take away the side tendency from the screw S: as otherwise _one half_ of this mechanism would produce the very same effect, and leave the Machine the more simple. Supposing now, this Press charged with goods in it’s present position,

The wheel C D, having 69 teeth; } with proportionate
that E F, „ 70 „ } diameters.
The pinions I & K, each 10 „
The wheels L N & M O equal;

The thread of the screw S, 1 inch; and in fine, the crank V Q, having a radius of 18 inches.

In this state of things, the motion of the pressing cap W, is to the motion of the handle V, as 1 to 52164; and, the power gained bears the same proportion to the strength exerted: for when the handle has made one revolution, the wheel C D has made 10/69 of a revolution, and the screw _would have_ gone down 10/69 of a thread, or 10/69 of an inch: but in the same time the wheel E F has turned the _nut_ 10/70 of a revolution _in the same direction_; so that the latter has only gone down 10/69 less 10/70 of an inch; that is, (reducing to a common denominator) 700/4830 - 690/4830 = 10/4830 = 1/483 of an inch: Now to do this, the handle Q V has described a circle of three feet in diameter, or in round numbers 9 feet, or 108 inches; and to complete a descent of the screw of one thread, (or one inch) the handle must move through a space 483 times as great; that is, a space of 108 inches multiplied by 483 = 52164 inches: whence we see that the power gained is, as 52164 to 1: and reckoning a man’s strength at 150lbs. (exclusive of friction) that strength exhibits a pressure of _five millions two hundred and sixteen thousand four hundred pounds_; or upwards of _two thousand three hundred tons_: a result not unworthy to be mentioned with those of the hydraulic press; to which it might be still further assimilated by other proportions in the screw and nut wheels C D, E F. Adverting now, to the second property of this Machine: namely the simple power intended to act when the press is to be laden or discharged, the handle V should first be turned _backward_, until the cap W has slackened upon the goods; and the long pinions I K be raised by the mechanism X Y Z, which pinions, then geering only in the wheel C D, will raise the cap 1 inch for every turn of that wheel; or for every 69/10 turns of the handle V, say in round numbers for every seven turns: here then is a power of 756 to 1; very different from the former; yet produced by only a few inches motion of the long pinions I K.

We remark further, that the figure shews at G H _two_ of a system of friction rollers, destined to lessen the resistance which the turning-nut would otherwise oppose to the motion of the Machine. As to the friction between the screw itself and the nut--see a future article, in this _part_, tending to lessen or take away the friction of screws in general.

OF
A PERISTALTIC MACHINE,
_For raising much Water to small heights_.

Physicians will soonest understand the nature of this Machine, from the name I have given it. It is perhaps the most simple of Water-Machines; and certainly not the least efficient where it applies. It’s name is taken from the similarity of its action to the creeping of a worm, and to some of the functions of animal life. Yet it might be explained to the most unlettered housewife, when in the act of converting certain long vessels into _chitterlings_; or making room for the materials of a sausage or black pudding. To be serious: this Machine, in it’s simplest form, (see Plate 11) consists of a flexible tube C D, fig. 2, nailed to the ground, and connected with a short tube of metal containing two valves, A B, itself affixed to a box D, filled with water, or into which water flows. This water runs through the valve A, and distends the tube C D, on which rolls the body F, similar in form to a land roller. The Machine acts in the following manner: When the roller is drawn to the end D of the tube, the water fills the latter through the valve A; and on the roller’s return, this water is forced into the rising tube through the valve B.

The above is the simplest form of this mechanical trifle: But it has the disadvantage of an inconstant vibratory motion, not only of the water but the roller: which latter being heavy, would absorb considerable power. To remedy this evil, I have given the principle a rotatory form in fig. 1; where A B C is a spiral tube, duly fastened to the bottom of a shallow tub D E. At B is seen a conical roller, having the middle of the bottom of the tub for its summit and centre of gyration. The tube A B C, occupies rather more than one circumference; so that the cone presses during a small part of it’s revolution on both spires at once: by which means the Machine _would act_ without even one valve; though it is better to place one, _under_ the opening A. Now, observe the operation: as the cone rolls over the tube and round the common centre, in the direction of the arrow R the water enters behind it, through the opening A, (for the tub is plunged a few inches into the water) and is forced by it’s pressure into the ascending tube, which is a continuation of that, A B C. It would be superfluous to add, that these tubes are shewn in the figures _as cut open_, and presenting their inside to view; which representation is adopted in order to shew more completely the valves A and B of the 2d. figure.

An objection may occur to some, at sight of this Machine: namely, that the roller or cone B, would soon destroy the flexible tubes, by pressing too hard on their _puckered texture_. But to obviate this difficulty I have added, in fig. 3, a form of the tube (supposed of leather) which insures a proper _position_ of the leather under these rollers; accompanied by ledges A B, on which their surplus weight would bear, so as to annul every excess of pressure on the tube.

In many of the subjects I shall have to lay before my readers, the _forms_ are so numerous as to leave some difficulty in judging where the actual descriptions ought to end. This article itself, small as it is, offers an example of this: for I could draw several corollaries from the foregoing, that would offer new degrees of interest: but I am withheld by the apprehended want of room in the plates. I must at least defer my first intention, of _multiplying_ examples and shewing the influence of FORM on mechanical results in general. It will, however, always be open to me, to resume this subject when the principal object has been achieved--that of making known the principles of these inventions, with their most useful forms and properties. I observe, however, what has just occurred to me, that this Machine would be somewhat more _durable_, if the water-tube was pressed _between two rollers_, instead of being contracted from one side, by the action of a single one.

OF
A DRAYMAN’S CANTER,
_Or inclined Plane with increased Power_.

This Machine presents a simple method of increasing the power of the inclined plane, as used by carters or draymen for loading their carts; and called by them (in some counties) CANTERS. It admits of a gentle declivity in those planes: and thus considerably increases their power. The means consist in the transfer of the declivity from one end of the Machine to the other. Thus (plate 11, fig. 4) when the cask is rolled up from A to B, it is _wedged_ in that position by the wedge F; when _so much_ of its weight is supported by the feet C, (for all the feet are in pairs) that the end D of the Canter can be raised _with ease_ to E, so as to _re_-form the plane, in the direction of C E; at which time the feet D G drop into an upright position, and secure this new state of the plane. The cask is now rolled back from B to E, where it is found twice as _high_ as it was at B; and this manœuvre may be repeated several times according to the number of feet provided, and their length respectively. The _power_ of an inclined plane, is as its length to its height: and that power is doubled when the force is applied at the circumference of a cask or other rolling body. So that, here, the power being as 16 to 1, if a man can exert an energy of 200_lb._ the cask may weigh 3200_lb._ and still be raised with ease on this _Canter_, which therefore is three times as powerful as though the weight was raised directly from A to F in the usual method.

Should it be suggested, or thought, that this Machine applies only to _rolling_ bodies, I would just say that it might apply, cæteris paribus, as well to bodies sliding up the plane; or (using a small truck on the Machine) it might serve in a cotton warehouse, for piling the bags, &c. This System is doubtless susceptible of _discussion_, and may require to be modified for different purposes: but it is by no means devoid of practical capabilities.

OF
A PERPETUAL WEDGE MACHINE,
_Being a simple Method of gaining Power._

In Plate 12, fig. 5, let A B represent a wheel and axle, of which the wheel A is divided into 100 teeth; (more or less) and let C represent a second wheel with one tooth (or several) less than those of the first wheel A. These two wheels are concentric, for the axis of the wheel A, turns in the hollow centre of the wheel C; which latter wheel is fixed to the frame of the Machine, not here represented. D is a pinion that circulates round the wheel A and C in and along with the frame E as impelled by the hand acting on the handle F. Thus the circulating pinion is constantly occupied by means of its wedge formed teeth (of which one is shewn at D), in bringing the unequal teeth _a b_ of the wheels A and C _abreast of each other_: whence arises a _slow_ revolution of the wheel A, and of the axis B round the common centre. For if the number of the teeth on these wheels (A and C) differ only by unity or _one_, then must the handle D revolve one turn about that common centre to occasion 1/100 part of a revolution of the wheel A, and of course 100 turns to move the axis B once round that centre. And if further the wheel A be three times the diameter of the axis B, the power gained _there_ would be as 300 to 1, that is a power of 1_lb._ at a distance from the centre, _only_ equal to the radius of the wheel A, would countervail a weight of 300_lb._ suspended on the axis B: and supposing a man’s strength to be 100_lb._ he would raise (exclusive of friction) 30000_lb._ by this simple machine.

To shew more fully the essential properties of this Machine, I have represented only three teeth in all: one _b_ in the fixed wheel C; one a little smaller _a_, in the wheel A, (since this wheel has _more_ teeth than the former) and one D in the circulating pinion, whose form and manner of acting justifies in my apprehension, the name I have given to the Machine--a perpetual wedge Machine. I shall only add that there would equally be motion if the teeth of the wheel A instead of being more numerous than those of the wheel C were less numerous: but the manner of action would be different and I think less perfect.

This Machine is among the first inventions I carried into real practice on coming to manhood. It must be about 40 years ago, and was first constructed as a Crane at the request of the late Doctor Bliss, of Paddington. It _may_ offer some difficulty as a _Power_ Engine from the small diameters and the friction thence resulting: but for any Machine where great _slowness_ is desirable, whether to express slow motion, or to count high numbers, &c., it still appears to me a very good Machine.

OF
A DROPPING-WEIGHT-MOVER;
_Or Machine for lengthening the Time of going of a Clock, Jack, or
other Weight-Machine_.

Suppose A B (plate 12, fig. 4) to be the first wheel of a Clock or other Machine required to _go_ a long time without winding up. This wheel works into the two pinions _c d_, both of which are connected by ratchets with the axis E F of the wheel G H, _in one direction only_; insomuch that whether the wheel A B turn forward or backward, the wheel G H will always turn the same way. This process is well known in the mechanical world; and I have merely adapted it to my present invention. F and G are two tubes, or square vessels, of equal size, containing a number of balls--the tubes so balanced against each other, that _one_ of them is always heaviest by the weight of _half a ball_. Suppose for example that the tube F contains six balls and the tube G five; and that the tube G is so much heavier than F as only to be outweighed by half a ball: _That_ half will then be the moving power; and the vessel F will turn the wheel A B backward, raising the tube G at the same time. But arriving at the bottom the mechanism m will let go the lowest ball in F, and then the tube G which is at the top will preponderate and turn the clock till it also gets to the bottom; when a similar mechanism at _n_, will disengage one ball from it, by which subtraction the tube F will resume the ascendency and perpetuate the motion. Thus may the _going_ of any clock, jack, &c. be protracted to a period almost indefinite. Nor need it, strictly speaking, be wound up at all. It is only taking care to drop at proper intervals, an _equal number_ of balls into each tube, and this reciprocation of movement will become perpetual. The figure of this little Machine is unfortunately small: and the scapement is but imperfectly shewn; It has however, only _one_ property that it is essential to notice; which is that the detent _o_, shall suffer the cross _m_ to turn only one quarter round at each discharge: and _this_ is insured by the spiral ledge of the four ratchet teeth _m_, which by a pin fixed to the side of the detent, draw the latter down into the succeeding tooth as soon as the tube F begins to rise, so that there is only one ball discharged at each descent of that tube.

OF
A MACHINE,
_To promote Evaporation, with or without Heat_.

The vessel containing the liquid to be evaporated, (see Plate 12, fig. 6,) is long and shallow, and the liquid rises nearly to it’s brim. In this vessel is placed a _long_ hollow drum A B, covered with open wire-work, or any kind of cloth of a very loose texture. This drum turns slowly, on the hollow centre C, to which is fitted a stuffing box and tube, connecting the drum A B, with the pump P; the latter worked by any convenient power. The pump then, drives air, either hot or cold into the drum, and thence through the interstices of it’s texture; where it comes in contact with the liquid at _an indefinite number of points_, breaks the films formed by the liquid, and, saturated thereby, passes into the open air; thus occasioning a rapid evaporation, which might be increased either by heating the liquid or the injected air, or both, _ad libitum_. The whole idea consists in the multitude of points of contact between the liquid and the drying medium.

OF
A CUTTING OR GRATING MACHINE,
_For Green Roots, Tobacco, &c._

This Machine is composed of a perpendicular axis A B, fig. 7, driven with considerable velocity by any proper _geering_. C D is a vessel formed something like a shoe with the toe cut off: its entrance D is concentric with the shaft A B, and a weight _m_, fastened to it’s side, _equilibrizes_ the weight of the eccentric part C. Around this vessel, and concentrically with it, is placed a cylindrical _rasp_ or _grater_ E F, consisting, here, of a number of _blades_ so grooved on one surface as that by grinding them obliquely on the edge, each one shall form a line of sharp teeth, which, combined with those of the other blades, constitute a rasp similar to that used for powdering dye-woods; with this difference however, that these blades have interstices between them, through which the pulp escapes outwards, and thus the rasp is kept clean at all times. When this Machine is used the roots are merely thrown into the vessel D as into the hopper of a mill, and they are pressed against the rasp _by their own centrifugal force_; which is made as strong or weak as desired, by the greater or less velocity of the Machine.