Chapter XV: Introduction (8)

We shall now turn to figs. 3 and 4 of Plate 43, which give another representation of the carrying-mechanism, adapted especially to the anomalous _carriages_ of 4, 12, and 20, in reference to farthings, pence, shillings, and pounds, and _then_ following the decuple ratio.

In fig. 3, _k l_ represent the two acting wheels of the shaft _B G_, fig. 2; the latter _dotted_, as being placed _behind_ the former; these wheels, however, are not our present object, but rather the carrying system before alluded to; and described separately, in fig. 3 of Plate 42. _A_, in figures 3 and 4 (of Plate 43) is the first wheel of this series. It has 12 teeth with _three_ carriage-pins (or plates) _a_, which jog the carrying-pinion _B_, at every passage of 4 teeth; thus shewing every _penny_ that is accumulated by the _farthings_. This is so, because the farthings are marked on the teeth of this first wheel in this order--1, 2, 3, 0; 1, 2, 3, &c. and it is in passing from 3 to 0, that this wheel, by the carriage-pinion _B_, jogs forward the _pence wheel_ _C_ one tooth: But this pence wheel is divided into 12 numbers, from 0 to 11; and has on it only _one_ carrying-pin (or plate) _b_; so that, here, there is no effect produced on the third wheel _D_, until 12 pence have been brought to this second wheel _C_, by the first, or farthing wheel _A_. Now, this third wheel _D_, is marked, on it’s _twenty_ teeth, with the figures 0 to 19, and makes, therefore, one revolution, then only, when there have been twenty shillings impressed upon it by twenty jogs of the carriage-pin _b_, in the second wheel _C_. But when this wheel _D_ has made one whole revolution, it’s single _carriage-pin_ _c_, acting on the small _carriage-pinion_, like that _c d_, (but not shewn) jogs forward, by one tooth, the wheel _E_, which expresses _pounds_; and having _two_ carriage-pins _e f_, turns the wheel called _tens of pounds_, one tooth for every half turn of this wheel _E_: and as, on all the succeeding wheels, to the left from _E_--(see fig. 2, Plate 42) there are two sets of digits up to 10, and two carriage-pins; the decuple ratio now continues without any change: and thus can we cast up sums consisting of pounds, shillings, pence, and farthings, expressing the results, in a row of figures, exactly as they would be written by an accountant. The opening, through which they would appear, being shewn in fig. 1, at the point _w_, corresponding with the line _x y_ of fig. 2 in the same Plate.

I shall only remark, further, that the figures 3 and 4 in Plate 43, are of the natural size, founded, indeed, on the use of a chain that I think _too large_; being, in a word, the real chain _de Vaucanson_, mentioned in a former article: and that the figures of Plate 42 are made to half these dimensions, in order to bring them into a convenient compass on the Plate.

I would just repeat, that I have not attempted here an arithmetical machine in general; but a Machine fit for the daily operations of the counting-house; by which to favour the thinking faculty, by easing it of this ungrateful and uncertain labour. Had I been thus minded, I could have gone further, in a road which has been already _travelled_ by my noble friend the late Earl Stanhope, (then Lord Mahon) but I took a lower aim; intending in the words of Bacon--“to come home to men’s business and bosoms.”

OF
A ROTATORY PUNCH MACHINE
_Adapted to my own Engraving Machine_.

It is highly desirable, (not to say indispensable) in the use of my engraving Machine, to have punches not only of the true cylindrical form, but exactly of the proper length. (See the remarks on this subject, in the description of that Machine). It is, therefore, a matter of consequence, to be assured that both these circumstances unite; and to unite them _without_ depending on personal skill, whenever the work can be accomplished without such dependence: and this is the object of the present rotatory Punch Machine. Adverting first to the length of the punch: _that_ is insured by having a kind of slide on the Punch Machine, formed like the _frog_ spoken of in the above article--Engraving Machine. In the 5th. figure of Plate 43, this slide is shewn at _a_, and it is at exactly the same distance from the centre of motion _A_, as the bottom of the frog-plate fig. 3 Plate 39 is from _it’s_ centre of motion. Thus, the bottom of the punch is filed straight, once for all, and being fixed in proper clams, as in the figures, the shaft _A_ is set a-turning, by power--from which motion two uses are derived: first, the cylindrical form is given to the punch by presenting to it, in it’s revolution, a _file_ duly wedged on the (now fixed) slide of the Machine _B B_; against which it is kept turning, till, by a due depression of the centre _A_, the radius is brought to the length required, and the surface perfectly formed and smoothed. This being achieved, the cams _c d_, are fixed to the slide _B B_, and to the turning body _A d_, so that when the die _f_ is moved toward the left hand by the said cams, the prepared punch gently presses on it, and begins to receive it’s impressions; which are gradually deepened by the set screws _g h_, fig. 6; till, at once, the proper radius is given, and the engraving sufficiently transferred from the die to the punch--an operation which this process is calculated to perform, rather by means of frequent and gentle contacts, than by slow and heavy pressure. It need not be added, that the motion of the slide _B B_ is reciprocated by the spring _C_, against that _D_, after each forward motion given to it--as _begun_ by the _cams_ _c d_, and continued by the contact of the die and punch, all which a mere inspection of the figures will sufficiently explain. It is likewise evident, that the figs. 5 and 6, shew, both, the same objects, namely:--the regulating wedges _i k_, the upper set screws _g h_, and the rollers _E_, on which the slide vibrates during the operation of the Machine.

OF
A PORTABLE PUMP,
_To be worked by the Feet_.

It is not solely because, to work with the feet is a good method of employing the strength of men, that this device is presented to the mechanical public; but it is with the view of _so_ employing the feet and hands, that they may occasion a constant and _equable_ flow of water. The means, (see Plate 44, fig. 1) are, to provide the man with two supports _a b_ for his hands, and two pedals _c d_ for his feet, by which the two rods _e f_ are worked; and by them, through the cords or chains _g h_, the piston rods _i_ and _k_. Of the latter, the one which answers to the lower pump _l_, goes through the upper piston, whose rod is _i_: and the pistons are both constructed in the manner shewn in fig. 2; that is to say, the piston has no _body_, fitting the pump barrel: but a triangular bar _x_, going diagonally across the pump barrel, (which is square) and carrying two wings or valves _y z_; which, both together, fill the barrel _when down_, and leave it as empty as possible when up, by which motion the chains _a e_ are slackened. Further, these pistons, with their rods, are heavy enough to raise the pedals, the instant the man raises his feet in any degree: so that, by a proper combination of the motions of his hands and feet, he can let down a given piston, and begin again it’s ascending motion before his effort has wholly ceased on the other pedal. A mean this, of producing a constant and equable rising motion in the column of water through the pumps _k l_; and a mean also, of doing more work with a given fatigue, than would be _possible_ in a pump whose motions were merely reciprocal, and the water of which, in rising, would be subject to any unequable or convulsive motions.

In general, this portable pump was made (many years ago) with a view to being easily carried to any field or garden, bordering on a river, and worked on it’s bank; the flexible suction pipe _p_ being thrown into the river, or a well, as occasion might require. To this end, the whole frame (as is evident from the figure) can be folded up into a kind of _faggot_: and thus it’s transport from place to place, be made perfectly commodious.

OF
THE BISECTING COMPASSES.

It _often_ happens, that from a central line, (in drawing for example) we want to set off, quickly, many equal distances on each side; or between two given lines we want a central line; to perform either of which operations, is the use of the Instrument just mentioned.

It is represented in Plate 44. figs. 3 and 4, where _A B_ is the central _point_, being cylindrical in the greatest part of it’s length, and conical at _E B_. It slides correctly in two _cannons_ or swivels _E_ & _A_, which also have two short axes or trunnions, on which _first_, the double compass joints _C D_ turn; and second, the _two_ pairs of arms _F G_. I have called these cannons, _swivels_, that I may shew their construction, by referring to figure 1 in Plate 30--which describes the swivel of the _forcing Machine_; and which will give a complete idea of what is here intended. From this construction it will appear evident, that the point _A B_, (Plate 44) will be always found in the middle, between the two points, of the outer legs of the compasses; and _that_ whether the question is to take two equal distances from a central point, or to _bisect_ a given line or distance at one operation. The point or style now _slides_ in the two swivels _A_ and _E_; but the Instrument might be so constructed, as for it to follow the rising motion of the middle joint (_E_), and thus to keep the three joints in the same horizontal line: but I think a small perpendicular motion of the said _style_, would be always desirable in the Machine, as a drawing Instrument.

OF
A MUSICIAN’S PITCH-FORK,
_With variable Tones_.

This device is shewn, in two positions, at figs. 1 and 2 of Plate 45. In it’s present application, it is intended to produce a whole octave on the diatonic scale: and therefore, the unsupported ends of the fork are just half as long as they would become if the sliding handle _A_, were drawn to the bottom end of the branches _c d_. For, again, the fixing screw _C_, and it’s box _D_ are fastened to this sliding handle by one or two screws, (_s_) so as to be always ready to press the branches against the enclosed slide _A B_, at whatever place the intended tone may be found. Now, the branches _a c_, _b d_, spring out of a common trunk _c d_, which is pierced with a square hole, exactly fitting this sliding handle _A B_; and the latter is marked, at proper distances, with lines across it, each of which (placed opposite the mark _c d_) gives such a length to the remaining branches _a b_, as to make them sound the note desired. Thus, the line l, brought to _c d_, lengthens the branches _a b_, to (nearly) 53 parts, from 50 at which they are _now_ fixed; the whole length _a c_, being 100. This, and the following divisions would, of course, follow any desired _temperament_, according to the will of the tuner: but I have supposed them founded on the equi-harmonic scale; and thus will the successive intervals to be set off on the slide _B A_, be as follows: (while the corresponding notes will be those expressed in the table.)

In the state represented by the figures 1 and 2, the line a _B_, is 5000; being one half of the whole length _a b_, _c d_.

To form the Sharp 7th. it becomes 5297 the distance _c d_ 1, being 297.
„ greater 6th. „ 5946 „ 1-2, „ 649.
„ „ 5th. „ 6674 „ 2-3, „ 728.
„ „ 4th. „ 7491 „ 3-4, „ 817.
„ „ 3rd. „ 7937 „ 4-5, „ 446.
„ „ 2nd. „ 8909 „ 5-6, „ 972.
„ the fundamental note 10000 „ 6-7, „ 1091.

The above lengths 1 2, 2 3, &c. have been measured off on the slide _A B_, as nearly as possible, or at least with precision enough to give the idea: and the rest I must leave the detail of, to those musical readers who may feel interested in the subject.

OF
AN ESSAY,
_To obtain a Level at Sea_.

I have done right in calling these attempts “essays”: and if I had said “immature attempts,” they would have been better designated. Yet, having promised them to my readers, I cannot now withhold them, although, from want of opportunity of trial, I can do little more than _talk_ of their supposed properties.

The first essay, as shewn in fig. 3 of Plate 45, is a _mental deduction_ from a device which I executed in 1801, and brought before the public at the exhibition then given, by the French government, of the produce of national _industrie_. It was, nothing more than a _pendulum_, made with a view to lengthen, considerably, the going of a given clock, without altering the wheels. To that end, the weight or bob, was a heavy bar _C D_, suspended diagonally on two points _A B_, placed at a distance from each other, exactly equal to the length of the said bar: and _that_ by the double cross-bars _B C_ and _A D_, of a length sufficient to make the whole assume a form exactly square: where it may be noted--that were this figure _longer_ than high, the curve of vibration would have two points of inflexion, and the bar _would not_ place itself horizontally at last; and that were it narrower and _higher_, that curve would assume a form more like, though still distant from, the arc of a circle. In the present case, such was the effect of this disposition of things, that the centre of gravity of the bar described, in vibrating, a curve _E C D F_, the lower form of which, was so near to a _horizontal line_, that the _times_ of vibration were immensely prolonged; so much indeed, as to represent a common pendulum of several thousand feet in height; and to give a proportionate slowness to any mechanism with which it should have been connected. In fact, this line is so minutely different from such horizontal line, that it is wholly included in the thickness of the _drawn-line_ _C D_: nor becomes visible but near it’s two ends _C D_, when it begins to rise, and _then_ rises faster than that described by a _short_ common pendulum.

In fine, this curve itself is formed by continually bisecting the line or bar _C D_, and drawing lines from it’s centre of gravity, thus found in one of it’s positions, to the same in another position, till the curve _E C D_, &c. arises from this process.

It follows, then, from the nature of this curve, (or pair of curves) that the time of vibration of this pendulum is the _longer_, the _shorter_ the arcs are, in which it vibrates; and that, when the vibrations have attained a certain _length_, compared with the height to which the centre of gravity rises, the _time_ becomes considerably shorter. I shall not now pursue this idea, because it is at once an abstruse question, and at the same time one of uncertain utility--I mean that it’s use is problematical as a pendulum: since the _time_ of a vibration depends on it’s _length_, which cannot _easily_ be determined by any invariable method. I shall, however, add two things on this subject, by way of land mark; the one, that the balance-wheel of a watch has power enough to drive this pendulum, heavy as it is;--and the other, that I have _seen_ it make (for many hours together) vibrations of _half a minute’s duration!_ In a word, this is one of the subjects, which untoward circumstances have prevented me from bringing to maturity--but which I owe to my subscribers, and the public, in any, or every state, to which I have brought them.

I therefore, say nothing more of this Instrument as a pendulum: but an inspection of the figure will shew, that it will not be useless as an ELIPSOGRAPH--which it clearly is, since the intersection of the bars _A D_ & _B C_; describes a true Ellipsis. It may be further shewn, that the ends of the moveable bar _C D_, are the vibrating _foci_ of a second ellipsis, like the first, which rolls under the other, so that the curve itself is _that_ which the centre of one ellipsis _a b c_ would describe, by rolling on the surface of another _e b d_. But, into these considerations I cannot now enter, as my “Century of Inventions” is fast becoming due, and time commands dispatch; I beg leave, therefore, to pass to the relation this subject seems to bear to a “Marine Level.”

It must, however, be premised, that I scarcely expect either of these methods to be correct enough for astronomical observations; as among other things, they have the _nautical top_ to contend with: but if I am fortunate enough to have suggested useful methods of procuring _relative_ stability on board a rolling ship, so as to suspend the better, a _nice_ instrument of astronomy; or so to counteract the restless ocean, as to assist the victims of sea-sickness, I shall not entirely have lost my labour.

My first idea on this subject, is the following: If we had on ship-board, a simple pendulum of several thousand feet high, it appears _certain_ that the oscillations of the ship would be begun and ended, before any single vibration could have been given to such a length of pendulum--which therefore, would scarcely vibrate at all: and if the natural _time_ of this compound pendulum (for we are not confined to these small dimensions) were made to be much longer than those of the ship _on it’s meta-centre_, this pendulum would scarcely vibrate at all: because it’s several tendencies to take motion from the ship, would extinguish each other before they had had time to produce any common effect.

Further, this result would probably be assisted by another property belonging to this mechanism: see fig. 4. This diagonal suspension, as repeated at _a b c d_, fig. 4, is of such a nature, that when it’s centres _a b_, are placed in any oblique position _e f_, (say by the rolling of a ship) the suspended bar _c d_, immediately takes a position of opposite obliquity _g h_, pointing _upward_ towards _i_, just as much as the line _e b_ points _downward_; while the middle line _k l_ remains level--whether caused by the slides _k l_, or the single slide _m_.

I dare not assert any thing respecting the form this principle should assume, in order to produce the most useful effects; but it appears that the principal _weight_ of the apparatus should be placed in the centre of gravity of the under bar _c d_. It would occur, of course, to every mechanician applying this System to real use, that in this fig. 4, we have only provided for one motion of the ship, the _rolling_ motion: and that, in consequence, this System should be suspended _in_ another similar one, acting longitudinally, so as to provide for the _pitching_ motions of the vessel. In a word, I confess, with regret, that I leave much _to do_, by way of bringing this idea to maturity--it being at this late hour, more than doubtful, whether I shall myself ever be able to resume the subject _at sea_, where alone it can be duly tried.

OF
A SECOND ESSAY,
_To procure a Marine Level_.

This would seem to be a simpler process than the former: but how far it may go beyond it in effect, I cannot say--having never had it in my power to _try_ either of these ideas on ship-board. I therefore merely present them to my readers, as themes for future thought and experiment.

Plate 45, fig. 5 represents this System--which is founded on the idea of deadening oscillatory motions at sea, by connecting the bodies to be thus _guarded_, with _a stream of flowing liquid_, the horizontal motions of which _must be_ subject to laws very different from those which rule vibrating bodies merely suspended.

The fluid used in this Machine (as oil, water, mercury, &c.) is to be pumped up by appropriate mechanism, from the vessel into which it flows at _x_, into a vessel placed a little above _z_; and to be let out by the cock _y_, through a kind of strainer _s_, of sufficient collective area to supply, with ease, the descending column _C_. The vessel and tube _C D_ are made as thin and light as possible: and the upper part, which is spherical, is inclosed in and suspended by the universal joint _a b c_, like those used to suspend other bodies, as a compass, &c. Moreover, the areas, at different heights, of the tube _C D_, are made in the inverse ratio of the velocities of the spouting fluid, at each given depth--so as to leave it but little tendency to press either outward or inward, while thus obeying the law of gravity. By these means, then, I think no vibrating motion will be excited in the falling column: but that the liquid will continue to flow perpendicularly, so as to preserve (nearly) the quietude of the vessel _C D_, and of any mirror or instrument it may be wished to keep in a given position, by connecting it with the perpendicular line thus obtained.

I repeat, however, that I know not how far these methods may go towards obtaining an artificial horizon, for astronomical uses. Indeed, I fear they will fall short in this respect--but I think them still worth trying, even for these--but especially for the purposes to which I have already alluded. And, if success crowns _this publication_, to the degree I am led to anticipate, I will not always leave so rich a question, in this doubtful predicament.

OF
A FIRE-ESCAPE,
_On a retarding Principle_.

This is a recollection from the specification of a Patent which I took out above thirty years ago, and in which I huddled together as many objects as a child would like to see in a box of play things. I perhaps acted, then, according to the _words_ of a French proverb--“abondance de bien ne nuit pas;” but in so doing, I fell into the charybdis of _another_ French proverb--“qui trop embrasse, mal étreint,” (a wide embrace cannot be a strong one) and in so doing, paved the way to much litigation--which happily did not occur.

The intention of this Machine, as represented in Plate 46, fig. 2, was to retard the fall of any _body_, or person, suspended to it, so as to prevent any concussion on reaching the ground. The means are brought to view in the perspective sketch given of the Machine. It is a kind of _jack_, inclosed in a case, and supposed to be laid carefully aside in the house represented in fig. 1 of this Plate. The Machine has a barrel, much like that of the jacks used for roasting; round which a rope is coiled, of sufficient length to reach the ground: and a wheel, connected with this barrel, works in an endless screw, which turns a shaft also like that of a common jack, but somewhat stronger; and finally, to this shaft is fixed a small cross piece, carrying, on pins, two weights _y z_, inclosed in the _fixed_ barrel _x_; by the centrifugal force of which enough friction is created, to prevent the acceleration of the falling body--whether a person or weight of any kind.

There is, moreover, a jib _a_, fig. 1, fixed between some, or all, the windows of the house whose inhabitants it is wished to guard from the danger of fire; this jib having the property, from the form of it’s foot, of taking by the suspension of any weight to it, a position perpendicular to the wall: Insomuch, that by the act of suspending the Machine to the jib--engaging the wrist in the noose _n_, and perhaps the foot in another loop of the same cord; a person may safely flee those dangers from fire, of which so many persons become the unhappy victims.

Since the 46th. Plate was engraved, it has occurred to me, that a method should have been shewn for raising the cord _n_, (fig. 2) after each descent. This operation might be performed by a handle put on the axis of the Machine, accompanied by a ratchet on the wheel, just like the similar parts of a jack for roasting. But, lest the inmates of a house on fire, should not have presence of mind enough to perform this operation, it might be better to have a spiral spring _in_ the Machine, to be _wound up_ by the descending body, and of force sufficient to raise again the cord after such descent.

OF
A SECOND FIRE-ESCAPE,
_By breaking the Fall_.

This Machine is also shewn in Plate 46, at fig. 1. It consists of a large truck, _A_, to be drawn rapidly to any _house on fire_, by one or more horses. The carriage or frame part _B B_, is an _open_ square frame _subtended_ by a first sheet of sack cloth, similar to the sacking of a bed: and on this are laid five, or more, _air mattrasses_ made of sack cloth, and varnished on the inside so as to be nearly air-tight; I say _nearly_ so, for it is _not_ intended they should form a spring capable of _returning_ any object thrown on them. On the contrary, each of the mattrasses has, at one or both ends, a valve 1, 2, &c. opening _outwards_, but kept closed by proper springs, so as to determine the pressure at which the air shall escape; that pressure being carefully graduated, so that the upper mattrass shall give way with ease, the second with greater effort, and the successive ones with progressive difficulty, until the under one remains totally closed, and stops the falling body altogether. By these means, if enough mattrasses are used, and they are _duly_ regulated, a person may jump from a house of three or four stories without incurring any danger. As to the length and breadth of this fire-escape, it should be ample enough to give the sufferers confidence to take the leap, and as small as an easy passage in the principal streets would require.

One thing must be described in _words_--as the mechanism to which it relates is fixed under the truck; and could not be seen in this perspective figure. These mattrasses are filled with air by an _horizontal air pump_, worked by a _crank_, which the axle itself of the hind wheels of the truck forms: whence, by pinning this axle to either of the hind wheels, the very motion of the carriage, as drawn by the horses, would distend the mattrasses--which would thus be ready for use the moment they arrived on the spot; and moreover, when there, this air could be replenished, after using, by turning this axle, through the wheels, _by hand cranks slipped on it’s ends_ at the place of the linch-pins. Or, in fine, this operation might be performed by an air pump prepared for it alone, and placed in any convenient part of the Machine.

OF
A ROTATORY CHOCOLATE MILL.

Figures 1 & 2 of Plate 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 instrument _fast_ when pushing it from him, and suffers it to turn _a little_ every 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 in Plate 47. In figs. 1 and 2, _A_ represents a cylinder of stone or metal, used instead of the aforesaid slab; and _B_ a cylinder answering to the roller in question. The latter is placed, by it’s axis, on two forks _a b_, so as to lean, by it’s weight, obliquely against the cylinder _A_, which it does less or more heavily as the forks, or stands _a b_, are placed nearer or farther off from the general centre. Further, the motions of these two rollers _A_ and _B_, are connected by two equal (or nearly equal) wheels _c d_, by which, when _A_ is turned, _B_ turns also; but so as to give the surface of the latter _much less_ velocity than that of _A_, though in the same direction. By these means, all the matter adhering to 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.

OF
A ROTATORY 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. In Plate 47, figs. 3 and 4, is an under cylinder, turned as usual by any convenient _power_. _B_ is a small cylinder not connected with it, nor touching it, being intended merely to receive the weight of the mangle-cylinder _D_, with the _goods_ rolled on it. _C_ is an upper cylinder as heavy as necessary, or loaden through it’s _journals_ or centres, with sufficient weights to make it so. Again, the motions of the two cylinders _A_ and _C_, 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 be _mangled_. This process is so performed, because the cylinders have toothed wheels _a_, _b_, on their axes, but which do _not_ geer together: These wheels being connected by an intermediate wheel _c_, which makes them concur in producing the rolling effect above mentioned. But, one thing remains to be observed: the wheels _a b_, though drawn apparently equal, are not equal. The upper one _a_, has a tooth or two _more_ than the under--so that the motion to the right hand of the under surface of that cylinder, is not equal to the opposite motion of the cylinder _A_. And hence, the cloth roller _D_, progresses from _D_ towards _x_, between the cylinders _A C_, and finally falls out at _x_, after as many turns of the whole, as the wheels _A C_ have been calculated to give; and this, is according to the degree of mangling required.

OF
A MACHINE,
_For driving the_ SHUTTLE _of_ POWER LOOMS.

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 of _forty years_ standing, 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 now _striding_ to 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 fully _prepared_ to act, _before_ it’s action began: and should, then, act independently of every other impulse.

In fig. 1 of Plate 48, _A_ is a wheel or pulley of about six inches in diameter, from which two cords proceed in opposite directions (_B C_) to the _pickers_, which drive the shuttles _D E_ in the usual method. This pulley runs on an axis going through the bottom of the lathe, (or beater) and it _might_ have a crank, behind, of a radius equal to _a b_: but to shew the whole in one figure, I suppose the following mechanism to be placed in the front of the lathe, and just _before_ the face of this wheel or pulley _A_. _c d_ is a bar turning on the centre _c_, and receiving at it’s other end the pressure of a spring _e d_, which in it’s turn, is susceptible of different degrees of springiness, as regulated by the screw _f_. On a stud _i_ in the wheel _A_, is put the small bar _i d_, which forms also a turning joint in the bar _c d_: and thus communicates the effort of the spring to the stud _i_, and thence to the wheel _A_. 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 the _breast beam_ of the loom, round the pullies _x_ and _y_, to this wheel _a b i_, according to the dotted lines. Supposing then, _one_ of these cords to be tightened by the backward motion of the lathe, it will draw the wheel _A_ about half round: when the stud _i_ will rise to the point _b_, straining the spring to get over the centre: and as soon as it _is_ over, the spring will _act_, and drive the picker and the shuttle with the desired speed, independently of any other _mover_. And it is evident, that now the opposite cord _x_ or _y_, 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 centre _a_, and re-produce another impulse in a contrary direction.

OF
AN AIR PUMP,
_Or_ ESSAY _towards completing the Vacuum_.

The rapidity with which a vacuum is formed by an Air Pump, depends on the _ratio_ between 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 a _very_ large proportion) the exhaustion will follow this series:--there will _remain_ in 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 contains _twice_ the volume of the receiver--then the remaining air, after the strokes, will be 1/3, 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, _much_ larger 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.

Thus, in fig. 2 of Plate 48, _A_ is a receiver, _B_ is a large vessel that can be filled with water from the tub _C_ below; and _D_ is the pump, worked by the handle _E_. It is a common water pump, (so much the readier adopted, as requiring _little_ care in the execution.) The question was to make this pump alternately _fill_ and _empty_ the vessel _B_. Adverting first to the _filling_, _a c_ are two cocks, having each a side-passage for the water; and these passages are _now_ so placed, as by working the pump we suck water out of the tub _C_, and throw it into the vessel _B_, through the valve _b_;--by which means all its air is driven out through the lateral valve _e_. When this is done, the cocks _c d_ (which are so made as to be worked by the same _mover_) are turned into a new position, which opens the pipe _p_ to the pump _D_, and _that_ _q_ to the returning spout _r_; by which means the water is drawn _from_ the vessel _B_, and thrown into the tub _C_: so that the air is again drawn out of the receiver _A_, through the inverted valve _s_, into the vessel _B_, 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 valve _e_ as before, and a new stroke prepared. It is scarcely needful to add, that if the vessel _B_ contained ten times as much volume as the receiver _A_, the exhaustion of the latter at each emptying of the vessel _B_ would 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.

OF
AN INCLINED WATER WHEEL.

The principal mechanical merit I conceive this Machine to possess, lies in the facility it gives of taking a stream of water as _high_, and discharging it as _low_ as 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.

Plate 48 fig. 3, _A B_ is the section of the wheel, and _C D_ a small portion of it’s circumference--which shews the form and position of the floats _a b c_, &c. _E_ is 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 at _d_, whether it there touches the lower water, or not. This wheel is allowed to be incapable of _using_ to advantage a large stream of water--but is doubtless fit to employ a small stream, _in the best manner_.

OF
A VESSEL,
_To assist in taking Medicine, &c._

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, _more_ will approve; and I therefore continue the promised article.

Fig. 4 of Plate 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 funnel _a_, 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.

OF
AN AERO-HYDRAULIC MACHINE,
_For raising Water in large quantities_.

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 think _that 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 my _wind Machines_, in order to give an idea of the means I contemplate for _losing_ the importance of those details in the magnitude of the general effect.

This Machine (see Plate 49, fig. 1,) is capable of great results _merely because it employs, at a small expence, a great mass of air in motion_; whether _ill_ or _well_, is not the question: for as this source of _power_ is almost indefinite, methinks we may draw from it without reserve. The present method of so doing, consists in using _a very large sail_, (_A B_) both to receive the impulse of the wind, and to raise the water. This figure is _a section_ of the Machine _in it’s length_:--and it’s _width_ (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 D_ is the water in it’s lower bed: and _E_, is a canal on a higher level, into which a large quantity is thrown at each _manœuvre_ of the Machine, _a_ is the bank of the upper canal, to which is affixed the _edge_ of the canvass, of which _a B A d_, is a section; and which _might be_ large 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 part _b_ of 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 triangle _b r s_ to 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 tightening _the sail_ towards _A_. At _d_, 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 end _d_, of the sail is connected with a row of posts _C F_, placed more or less closely, as the prevailing strength of the wind and the _size_ of the sail may require. The sail is held to these posts by rolling pulley frames, of which _one_ is seen at _g_, and is drawn up and down by the rope _g h_, acting at one end directly on the rolling pulley-frame _g_, and the other on the sail _d_, after having passed over a pulley (_F_) in the post itself: where note, that this effect can be communicated by proper machinery, from any _one_ of 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-frame _g_ is quickly drawn up to _g_, where the hook _i_ holds it fast. By a necessary consequence the wind fills the sail _d c r_, and stretches it into the figure _d A B a_: in doing which it lifts the water _r s_, and _pours_ it, in all the width of the sail, into the canal _E_; thus raising a thousand cubic feet of water at each stroke. As soon as the water is turned into the canal _E_, the hook _i_ is pulled outward, and the rolling pulley _g_ is forced down, by the wind itself, to the position k, when the wind blowing _over_ the 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 at _b_, 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 number of 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 canal _E_, 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 canal _E_ should be stationary. Made of wood, or metal, it _might_ turn 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.

OF
ANOTHER WIND MACHINE,
_Furnishing immense Powers_.

This is the last of those conceptions I shall now bring forward, for making _more_ than a common use of the WIND as 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 of _a ring_, which thus moves through the water without any other resistance than that arising from the asperities of it’s surface.

In Plate 49, fig. 3, _B B_ is a section of the Vessel, placed in a circular canal _D_, 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 masts _a b_, _c d_; and so placed, that the sails (being a little wider than the interval between the ropes) can _open_ in one direction, but not in the other; and they are shewn open at _c d_, and shut at _a b_, in the figure. 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 water _by the centrifugal force_. As before hinted, the canal _D D_ is circular; and has a bank, sloping outward, with a canal (_E_) on it’s top. When, therefore, the wind blows, the ring boat _B_ (held to the centre by the ropes _f 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 canal _E_, from which it flows in _any_ destined 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 much _sail_, as any other windmill can carry. I add, merely on this occasion, that the sails here mentioned, might be placed _obliquely_, instead of straight across the ring vessel; (see the plan in fig. 2 of this Plate at _E F_) from which disposition, nearly all the advantages of the _vertical_ mill might be transferred to the horizontal; and with this remark I leave the present interesting subject to the studious and candid reader.

OF
A CENTRIFUGAL MIRROR,
_To collect Solar heat_.

My fiftieth and last Plate contains this idea: It is _not_ intended 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 which _better_ mirrors cannot present. It is _intended_ to pave the way for the use of the Sun’s rays in _Engines 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.

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 frame _A 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 vessel _C 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 rays _d c_, _e b_, and, _f a_, collects them into the focus _F_; in, or near which, is placed the vessel where the effect is to become useful, and which of course is _moveable_ so 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 be _moved_ to adapt it to a _fixed_ mirror. I shall only add further, that it is not necessarily an _exact_ movement 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, is _magnitude 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 the _logarithmic curve_ (_a_, _b c_) for it’s section--a curve, which in fact, comes indefinitely near to the parabolic figure which _would be_ required, 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 under _that a b c_) in order to avoid the necessity of using a large quantity of mercury, to form the reflecting surface.

OF
A SECOND MIRROR,
_For collecting the Sun’s rays_.

This Mirror seems superior to the former, as depending on _fixed_ materials. It likewise, produces the desired effect, by offering a _very large surface_ to the sun, and directing the rays to a focus, nearly enough to give the heat required for water, as before mentioned.