To come to the point:—the small figure 4, in Plate 41, relates to this subject. My geering is there seen in three forms or applications—each one intended to bring the above property into play. The part n o, represents the manner in which two wheels with singly-inclined teeth, work together when one of them is furnished with a cheek, as directed in fig. 3 of Plate 14. But here, in addition to that, the teeth of both wheels are sloped more on one side than on the other, so as to assume a wedge-like form: insomuch, that in beginning to work, (if not perfectly formed) the wheels would not occupy the same plane. For, in fact, the cheek screws press home the cheek o against a number of thin washers all round the wheel, and thus only draw the wedge-formed teeth into each other as they become bedded, and successive washers are taken away. Hence, a good degree of precision is obtained—accompanied with little friction, and thus with great durability.

But we stop not here. The part p q of this figure, shews a pair of wheels doubly inclined—one of them only, being made in two halves, which are connected together by screws and washers, like that just described. Here then, another degree of friction is got rid of—namely, that of the cheek o: but still, a small degree remains, (dependent on the double versed sine of the angle formed on the wheel’s circumference, by the thickness of a tooth). This quantity, is indeed, very minute; and brings, perhaps, the whole near enough to perfection. To do, however, completely away with all friction, (see my preceding statement)—as well in the wheel acting backward, as in that acting forward, we must do what is shewn in the parts r or s of fig. 4: we must have a pair of V wheels on the same shaft, with the power of turning one of them in reference to the other; and then connecting them by proper screws, &c. to preserve the position thus given: by which means, in a word, all shake or backlash will be completely annulled.

OF
AN ADDING MACHINE,
Or Machine to Cast up large Columns of Figures.

This Machine is not, generally, an arithmetical Machine. It points lower: and therefore promises more general utility. Though less comprehensive than machines which perform all the rules of arithmetic, it is thought capable of taking a prominent place in the counting-house, and there of effecting two useful purposes—to secure correctness; and thus, in many cases, to banish contention. It is represented in figs. 1, 2, 3, and 4 of Plate 42, and in figs. 3 and 4 of Plate 43.

There are two distinct classes of operations which may be noticed in this Machine: the one that does the addition, properly speaking; and the other that records it by figures, in the very terms of common arithmetic. The first operation is the adding: which is performed by means of an endless geering chain, stretched round the wheels A B C D, (fig. 1) and over the two rows of smaller pulleys a b c d e f g h i; where, observe, that the chain is bent round the pulley A, merely to shorten the Machine, as otherwise the keys 1 2 3, &c. to 9, might have been placed in a straight line, and thus the bending of the chain have been avoided.

The chain, as before observed, geers in the wheels B and D, which both have ratchets to make them turn one way only. Now, the keys 1 2, &c. have pulleys at their lower ends, which press on the aforesaid chain more or less according to the number it is to produce, and the depth to which it is suffered to go by the bed on which the keys rest, when pressed down with the fingers. Thus, if the key 1 be pressed, as low as it can go, it will bend the chain enough to draw the wheel B round one tooth—which the catch E will secure, and which the wheel C will permit it to do by the spring F giving way. But when the key 1 is suffered to rise again, this spring F will tighten the chain by drawing it round the pulleys A and D, thus giving it a circulating motion, more or less rapid, according to the number of the key pressed. Thus, the key 5 would carry five teeth of the wheel B to the left; and the catch E would fix the wheel B in this new position: after which the spring T would tighten the chain in the same direction and manner as before. It is thus evident, that which-ever key is pressed down, a given number of teeth in the wheel B, will be taken and secured by the catch E; and, afterwards, the chain be again stretched by the spring F. It may be remarked, that, in the figure, all the keys are supposed pressed down: so as to turn the wheel B, a number of teeth equal to the sum of the digits 1, 2, 3—to 9. But this is merely supposed to shew the increasing deflexion of the chain, as the digits increase: for the fact can hardly ever occur. We draw from it, however, one piece of knowledge—which is, that should the eye, in computing, catch several numbers at once on the page, the fingers may impress them at once on the keys and chain; when the result will be the same as though performed in due succession.

Thus then, the process of adding, is reduced to that of touching (and pressing as low as possible) a series of keys, which are marked with the names of the several digits, and each of which is sure to affect the result according to it’s real value: And this seems all that need be observed in the description of this process. It remains, however, to describe the 5th. figure, which is an elevation of the edge of the keyboard, intended to shew the manner in which the two rows of keys are combined and brought to a convenient distance, for the purpose of being easily fingered.

We now come to the other part of the subject—that of recording the several effects before-mentioned. The principle feature in this part, is the System of carrying, or transferring to a new place of figures, the results obtained at any given one. This operation depends on the effect we can produce by one wheel on another, placed near it, on the same pin; and on the possibility of affecting the second, much less than the first is affected: Thus, in fig. 3 and 4, (Plate 42,) if A be any tooth of one such wheel, placed out of the plane of the pinion B, it will, in turning, produce no effect upon that pinion: but if we drive a pin (a) into the tooth A, that pin will move the pinion B one tooth (and no more) every time this pin passes from a to b. And if we now place a second wheel (F) similar to A, at a small distance from it, so as to geer in all the teeth of the pinion B, this latter wheel will be turned a space equal to one tooth, every time the pin a passes the line of the centres of the wheel and pinion A B, (say from a to b.) It may be added, likewise, that this motion, of one tooth, is assured by the instrument shewn at E D, which is called in French a tout ou rien, (signifying all or nothing) and which, as soon as the given motion is half performed, is sure to effect the rest: and thus does this part of the process acquire, likewise, a great degree of certainty—if indeed, certainty admits of comparison.

It is then, easy to perceive, how this effect on the different places of figures is produced: and it is clear, that with the chain motion just described, it forms the basis of the whole Machine. There is, however, one other process to be mentioned, and as the 2d. figure is before us, we shall now advert to it. In adding up large sums, we have sometimes to work on the tens, sometimes on the hundreds; which mutations are thus performed: The wheel B, (fig. 2) is the same as that B, fig. 1; and it turns the square shaft B G, on which the wheels k l slide. The wheel l is to our present purpose. It is now opposite the place of shillings; but by the slide m, it can be successively placed opposite pounds, tens, hundreds, &c. at pleasure: on either of which columns, therefore, we can operate by the chain first described—the wheel B being the common mover.

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 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.

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.

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.

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.