OF

A MECHANICAL ESSAY,

_To derive Power from expanding Metals_.

It is not supposed that this Essay can lead, immediately, to any result

of magnitude; but it is thought to be a subject capable of further

extension, and thus, finally, of future usefulness. Were this process

only sufficient to supply a single house with water, at a small expence,

the labour bestowed on it would not be altogether in vain.

By General Roy’s experiments, cast iron (and steel) expanded by 180° of

heat (or, by passing from the freezing to the boiling point of

FAHRENHEIT) 0.013 of an inch per foot.

Supposing, then (Plate 34, fig. 1), the tubes _A B C_ to be 20 feet

long, their whole expansion will be 0.26 hundredths of an inch. But, as

the tubes are placed in the figure, the _half_ tubes _A D B D_ act

together on the sphere _D_, and, both together, drive it in the

direction _E D_, _more_ than as the above expansion, in the proportion

of the line _E D_ to that _A D_. Taking, then, one half only of the

above expansion = 0.13 hundredths of an inch, _that_ must be augmented

in the ratio of the sine of 60 degrees to radius, or in that of _A D_ to

_E D_. I, therefore, multiply this decimal 0.13 by the fraction

1000/866, which gives 1300 to be divided by 866, or very nearly 0.15

for the expansion, in the direction _E D_, occasioned by the two half

bars _A D B D_: and the same is true at the other angles _F_ and _G_.

Again, to find the expansion (and _contraction_) of the bars _a b c_, we

must compute their length as compared with the half tubes

above-mentioned; and that length is to 10 feet (the half tube _A D_ or

_B D_) as 866 is to 1000 = 11.54 nearly: the expansion of which is thus

found:--if 10 feet expand 0.13, what will 11.54?--Answer, 0.15. Now, as

the machine acts by the _heating_ of the pipes _A B C_ simultaneously

with the _cooling_ of the bars _a b c_, we must add the former expansion

to this _contraction_, which gives us 0.30, or _three tenths_ of an inch

for this combined effect at the three angles of the Machine. And,

_supposing_, now, any pair of bars to act directly against each other,

as at _H I K_; and that, further, the bars be stretched until the angle

with the horizon be only 2 degrees, then the vertical motion at _I_ will

be to the horizontal (arising from the expansion aforesaid) as 1000 to

35, the sine of 2; that will be, in round numbers, 28 times as great, or

28 _times three tenths of an inch_ = 8.4 inches, which is the _stroke_

of this Machine in these dimensions.

In this calculation, I have not forgotten that the vertical and

horizontal motions are _nearer alike_, when the bars are not drawn so

tight at _K H_; that is, when the joint _I_ is lowered. But it is

equally true that, when the joint _I_ rises still more, the difference

between these motions is _still greater_; so that, as a medium effect, I

think we may reckon on an _eight-inch stroke_ in the present case.

The question now recurs, of what _strength_ are these strokes? Are they

sufficiently powerful to produce a useful effect with so _short_ a

motion? This I cannot say from experience; but, from the known strength

of iron and steel, their power, in these dimensions, must be _very

great_. A few more observations may occur in the course of the enlarged

description we shall give of the Machine itself.

_A B C_ are three pipes of cast iron, well turned at the end, and having

conical points of iron, well steeled, let into them, so as to have no

tendency to _bend_. _a b c_ are three steel bars, placed in troughs, so

as to be heated or cooled by water poured into the latter. Or, these

troughs _may_ be exchanged for tubes, to admit heated or cooled air,

according to the means used to cause these mutations. In a word,

although I have represented these bars as contained in troughs, I intend

to finish my description, on the supposition that they are _tubes_,

because I intend to suppose the Machine worked by _air_ instead of

water.

To proceed: at _d_ is an opening _under_ the tube _B_, into which air

enters, and _C_ is an opening _on_ the top of the tube which emits the

same air, the three pipes being made to communicate by means of a short

junction-pipe at each of the angles _D_ and _G_. Here, then, the

fire-place _f g_, fig. 2, must be noticed: the use of which is both to

heat and cool the Machine; and the following are the means:--This little

instrument contains fire in it’s middle compartment, and that fire draws

_air_ into the part _f_, and drives it out of the part _g_. It also

_turns_ on a centre-pin, seen in the figure. This chaffing-dish, then,

is placed at _i d_, and there serves a double purpose. When it’s pipe

_g_ conveys heated air into the pipes _B A C_ (and _out_ at _C_), it

heats those pipes and expands them; but, at the same time, the pipe _f_

of this instrument draws cold air through the three tubes _a b c_, in

which are the steel bars that require to be _contracted_: both which

operations conduce alike to the above-described effect. By these means,

the weight _w_ is raised, and (for example) water sucked into the pump

_X_. But, turning the fire-place half round, we reverse this effect. The

_hot_ air is now drawn, out of the pipes _A B C_, and _cold_ air drawn

through them, by which they are _cooled_; while the hot air, from the

fire, is thrown through the pipe _g_ into the tubes _a b c_, and passing

through the chimneys _k l_, there heat the bars and expand them,--both

which operations concur in _letting down_ the weight _E_, and thus, in

forcing the water of the pump to whatever destination was previously

assigned it.

OF

A MACHINE,

_For Making Laces, Covering Whips, &c._

Many people, in these parts, have seen a certain machine, said to have

been invented by an inmate of that laudable institution the Liverpool

Asylum for Blind People; for the purpose of making laces, covering

whips, &c. I hope the similarity of name will not induce any reader to

suppose that I have had that machine in view, and am endeavouring to

cast it into the shade, or purposely to supersede it. If any person

should thus think, I have a _safe_ reply at hand. My own invention

(somewhat less perfect than it now is) was made, many years ago, on

purpose to serve _an Asylum for the Blind in Paris!_--a reflection with

which I shall, at once, close this, perhaps, unnecessary apology.

This Machine is represented in Plate 34, at figs. 3 and 4. It consists

of a frame of wood or metal _A B_, on which are _mounted_ the following

objects:--1st, on the traverse _B_, a fixed tube, having for it’s base

the horizontal plate _a b_, and rising perpendicularly to _near_ _c d_;

where it unites with a conical or trumpet-like vessel _c d_, _f e_; the

left side of which is shewn in perspective, and the right side in a

section only. To this _fixture_ is adjusted the spherical portion _g h_,

_h_, prepared to receive several cuts or slits 1 2 3 for the

bobbin-slides hereafter-mentioned, to slide up and down in. This leads

us to observe the upper fixture _C_, which is a cylinder, terminated

downward by a spherical _dome_ _i k_, _k_; also receiving the several

cuts 4, 5, 6, into which the aforesaid bobbin-slides pass from the

former slits 1, 2, 3, &c. Now it will be seen that the two spherical

parts thus fixed, are separated from each other by the circular and

horizontal slit _l m_, whose use is to permit the _pipes_ shewn in the

section at _n o_, to circulate _all round the machine_, while the

bobbin-slides and bobbins _k p_ are sometimes _above_ and sometimes

_under_ the said slit _l m_.

Now, then, it becomes necessary to speak of the _cause_ of this passage

of the bobbin-slides from the under to the upper parts of the slits 1,

4, 2, 5, and _vice versa_. That cause is in the second dome _q r_, which

covers, as far as it rises, the inner dome _f i_, _k h_; and it consists

in a serpentine canal, of which a section is given to the left of _q_,

and at _s_, _in the section of the principal figure_.

But to make this important piece of the Machine better known, I have

drawn it apart, in figure 4, on the _supposition_--that it is a portion

of _a cone instead of a sphere_: I say a cone drawn with the radii _t

q_, _t r_, according to the dotted line _t r_. The surface then of this

cone, is supposed straightened in the lateral figure; and the aforesaid

serpentine canal is shewn at _a b c d e_, having the rollers of the

bobbin-slides placed in that canal, at the same points _a b c_, &c.

Here also, certain dotted lines _f g_, _h i_, &c. shew the _relative_

positions of the slits 1 4, 2 5, &c. of the principal figure, and also

of the horizontal slit _l m_: whence it appears, that the revolution of

the bent canal, _a b c_, &c. must some times drive the rollers towards

_g i_, &c. and sometimes towards _f h_, &c. while the _pipes_ _n o_ pass

undisturbedly round the Machine, in the horizontal slit _l m_ of both

figures.

The question now arises, _how_ is the circular motion given to the outer

dome _q r_ of the principal figure? that dome is _screwed_ to the cone

_r v w r_, being itself of one piece with the hollow tube _v w_, on

which the wheel _x y_ is fixed. Now, this wheel _x y_, is driven by a

vertical wheel _z_, of _twice_ the diameter, for a reason we shall soon

disclose.

It remains now, principally, to speak of the drawing-system of this

Machine, shewn, in small, at _c_, and of a natural size in fig. 5 of

this Plate. That Machine has also it’s own tube _c x′_, working inside

of the fixed tube _a b_, &c. and terminated, at bottom, by the wheel

_x′_, which turns it by means of the second vertical wheel _x′ z_, fixed

on the same axis as the wheel _z_ before-mentioned, and of half it’s

diameter.

Supposing then, for the moment, that the mechanism _c_ derives from it’s

circular motion, the property of drawing downward the threads from the

pipe _n o_, and the bobbin _p_; (being one of the _twelve pair_

distributed round the Machine) we shall now set the Machine at work, for

the purpose of viewing it’s operation a little more narrowly. Looking at

the two kinds of texture, indicated in the figure below the traverse

_B_, we see that on the left composed (in weavers’ language) of a

straight _warp_, crossed by an oblique _weft_; and this I believe, is

the common texture of _round, small ware_, as usually woven: the slope

of the weft being less and less as the number of shuttles diminishes,

insomuch that with one shuttle that slope, _might_ become almost

invisible. But in the work made on this Machine, where, virtually, there

are as many shuttles as threads in the chain, the slope would become

very perceptible, too much so, perhaps, to give a desirable appearance

to the work; although the rapidity of execution, from the multitude of

crossings, would compensate for some imperfection of that kind. But, in

fact, this Machine is intended to make a diagonal or diamond texture, as

in the specimen to the right hand: and _that_ is the object of the _two_

pair of wheels _x y_, with _z_; and _x′_ with _x′ z_ before mentioned.

Their effect is this: when the large vertical wheel _z_, has turned the

outer dome and the pins _n o_, once round the common centre, the smaller

vertical wheel _x′ z_, has turned the drawing-system _c_, just one half

as much round that centre, and thus sloped the threads coming from the

fixed slits in which the bobbins move, as much, in one direction, as the

_whole_ turn given to the pins _n o_, has sloped the other half of the

threads in the other direction, and the result has been the aforesaid

diagonal texture.

There are a few other things to be observed by way of closing this

article. As the Lace, or Cord is made on the Machine by a turning

motion, it must be received below into a turning vessel, or it will be

twisted, and thus injured. The vessel _D_, is provided for that purpose;

and is turned by a cord from a pulley on the axis of the wheel _z_,

coming under two vertical pullies, and acting on an horizontal pulley _F

E_, connected with the said vessel; and if preferred, the draught itself

might be placed in, or above, the vessel _D_, but it would not, I think,

produce so perfect an article.

With respect to the drawing Machinery _in_ the Machine at _c_, there is

shewn, a flat surface just under that Machinery. It’s purpose is to

serve as a _mover_ for that System: To shew which, in a clearer manner,

is the use of the fifth figure. In this figure, the drawing rollers turn

in a frame _a b b_, and carry on one of their shafts a cog-wheel _c_

_or_ _d_, by which they receive this motion from the pinion _e_; this

pinion being connected with the rowel _f g_, and running with it on a

stud _h_, more or less removed from the centre, as circumstances may

require. This rowel then, (for it’s edge, formed as in the figure, is

_indented_ with sharp teeth across it’s face) runs on the _flat surface_

before indicated, at or near _e_, (fig. 3) and by the rotatory motion

received from the wheel _x′_, gives a drawing motion to the rollers, the

use of which has already been explained; namely, to draw down the

_goods_ as they are formed. It need hardly be observed further, that

_any kind of filling_ may be brought down twisted from _C_, to the

entrance of these rollers at _c_, and thus be included in the plaited

texture; and in fact, the rollers in fig. 5, are shewn (by the dotted

lines) as formed to receive an object of considerable diameter, as a

whip, &c. that it may be wished to cover. Where I remark, that this

lozenge form of the grooves _O_, is not given without a motive: the

grooves are thus formed (the cylinders being supposed capable of opening

by a springy movement) in order that, if desired, they may draw the body

downward, so much the faster, as it’s diameter increases--and thus keep

the covering threads at the same angle in every case. I shall only add,

that these movements can be permanently determined by wheels, when the

rowel _f g_, acting on the horizontal surface _c_, has fixed the real

velocities of draught required for a given purpose.

This Machine then, is capable of excellent results, and of a speed

almost inconceivable: since at every turn, if there are _twelve_ bobbins

_p_, and twelve pipes _n o_, it makes twenty-four passages of the

threads among each other, answering, in some cases, to an _inch_ in

length of the fabricated texture; so that, counting 120 turns per

minute, (which is moderate) we have 2880 passages, and 120 inches of

work in a minute; equal to 200 yards per hour--a quantity which does not

yet limit the produce of this Machine.

OF

A BATTING MACHINE,

_For Cotton, or_ FINE _Filaments in general_.

This Machine is represented in figs. 1 2 3 of Plate 35. It is composed

of a frame _A B_, on which are placed two sets of rollers _a b_, _c d_,

round which is stretched an endless feeding cloth, on the upper surface

of which the Cotton is laid by the attendant. Across this frame _A B_,

is fixed a strong board _C D_, having a ledge or _bridge_ at each end,

over which are tightened the cat-gut strings 1 2, 3 4, &c. Moreover,

across this board, is fixed on proper bearings, (placed either straight

or diagonally) the axis _e f_, furnished with any proper number of _iron

fingers_ 7 8, &c. which _spring_ the cords 1 2, 3 4, &c. every time they

pass by them: where it may be observed, that by the varied _forms_ of

the ends of those fingers, the vibrations are made to be vertical,

horizontal, or oblique, at pleasure. In fig. 2, these fingers are seen

from one end of their axis _e f_--and in figs. 1 and 3, they are shewn

sideways: and in the latter figure, the strings are shewn as small

circles between _e_ and _f_, with the feeding cloth _a c_, stretched

under them.

The following then, describes the effect of this Machine: The Cotton

being laid on this feeding cloth near _B_, is gently drawn under the

vibrating cords at _g h_: for while _this_ takes place by the action of

the handle at _e_, the pulley _f_ by the cord _i_, gives a slow motion

to the cylinder _B_, and by it to the feeding cloth _B A g h_. The

Cotton then passes under the strings toward _B A_, and is greatly

agitated in the passage; and when arrived at _A_, it falls into any

proper receptacle--whence it is taken to undergo the succeeding

operations of the factory. I would just mention, finally, that the axis

_e f_, though here supposed to be turned by the handle _e_, would, _of

course_, receive it’s motion from a proper _power_; set on, or stopped

by the usual methods.

OF

A HORIZONTAL WIND MACHINE,

_For raising Water in large quantities_.

This Invention has for it’s object, to make a more abundant use of the

wind’s agency, _at a given expence_, than is usually done: and the

means, generally, are to avoid a part of the expence lavished on the

foundations or fixtures of wind-mills, and _yet_ to carry _more sail_

than that system admits of. Machines of this nature, are chiefly used in

low marshy countries, where there is much water to be raised, and little

solid ground to build on. My idea here, is to found the whole on the

water, and to make that element the medium, and as it were the _centre_

of every motion.

Let us then suppose already constructed, the _long_ and narrow boat _A

B_, figs. 4 and 5 of Plate 35:--and that there is contained in the

middle of it’s width, a cylindrical _pipe_ of iron, (or a square wooden

box) of equal length, serving as a pump, by means of a spherical or

square piston _a_ or _b_, drawn from end to end by the means soon to be

described. The cost of such a pump-barrel would not be _great_, though

it should be of considerable length--(even 300 feet would not cost so

many pounds). Now, at each end of this vessel _A B_, there would be

raised a vertical part of equal size _C D_, surmounted by a caster, (_E

F_) turning, horizontally, on a hollow centre, _through_ which a rope

would pass from the aforesaid piston, (_a_ or _b_) to the boat or ship

_S_, which is the _primum mobile_ of the System. This boat would further

be made to carry as much sail as possible, and to encounter as little

resistance as possible from the water. It’s properties of carrying sail,

might even be enlarged, by the use of one or more _out-riggers_, as is

done in various eastern countries.

It would be proper, likewise, to give the vessel a rudder at each end,

and to reverse her motion by changing the sails, _without tacking_. This

is also represented in the two figures 4 and 5: and, in the present

case, the vessel is rigged with three masts, and three large sails

nearly square, yet somewhat _deeper_ on the lee side than to windward,

to make the sails the more governable, though as large as possible.

Supposing now, all these things arranged, and the rope _N O_ fastened to

or near the middle of the vessel, and to the aforesaid piston over the

pullies of the casters _E F_; _then_, if the vessel sails in the _long

ellipsis_ 1, 2, 3, 4, the _sum_ of the two portions of rope _N, O_, will

be always the same; and, the wind coming from _a_, in the direction of

the arrow, she will sail advantageously from 1 to 4, or the contrary,

carrying the piston from end to end of the pump; and thus exhausting it

at every passage; and filling it again from the _lower_ water.

To recapitulate--and bring the several parts again to view; _S_, in

both figures, is the vessel, supposed of the best form for carrying

_much_ sail: _E F_ are two casters with their pullies; _p q_ are two

pullies at the bottom of the vertical barrels _C D_, _under_ which the

rope passes to the piston at _a_ or _b_, &c. In fine, _q r s_ are the

three sails, and _t v_ the two rudders, by which the vessel is steered

in either direction, so as to keep it’s wind without causing _too much

stress_ on the rope _N O_. This consideration involves another, which

must now be cleared up: namely, _how_ can this mechanism be made to

produce the same effect in every direction of the wind? I answer, the

whole System must be _moored_ at one end _A_, in the strongest manner;

while the opposite extremity _B_, shall have liberty to veer round that

point, as a centre, through 90 degrees of a circle; _some one position_,

between which extremes, will suit every wind, _on this condition_, that

the vessel by it’s rudders, keel, &c. be able to keep her ground,

although the wind should come from the _convex_ side of the ellipsis; a

thing by no means impossible, though less desirable than the state first

represented.

Thus it appears, that I expect the favourable result of this System from

two sources: the first, (but _least_) from the length of this pump,

which permits much water to be raised without much agitation; and

second, from the _quantity of sail_ it is possible to carry by this

method, compared with the sails of a wind-mill. My idea is, indeed, that

since the power of the wind is so boundless, we ought to use it more

liberally than we do: and I am persuaded, that _ten times_ as much work

might be done _at a given expense_, by such means as these, as can be

done by the usual methods.

Before I quit this subject, I would just observe, that there are _many_

situations in which this powerful agent might be made useful, in

conjunction with water power, as applied, perhaps, to encreasing works,

and being itself incapable of proportionate extension. Thus, there are

_many_ water mills (used for various purposes) that are obliged to

_wait_ the re-filling of the mill pond; and which, therefore, lose much

time, although the _wheel_ would be capable of doing even more work than

is actually wanted. In fact, it _often_ happens, that the worse the

supply of water, the better is the wheel: for _this_ has been sometimes

thought a mean of making up the deficiency. In such a case then, a cheap

wind apparatus might double or triple the effect of the wheel, and the

produce of a given establishment. But it will be objected, that the wind

is an uncertain helper! and thus less fit to be resorted to. This I

acknowledge; but still say, that could it be used when only a _breeze or

a zephyr_, it’s utility would be much extended; and _this_ is another

consequence of a system founded on the application of _much sail_ to a

given purpose. Still however, as nothing absolutely conclusive can be

said on so _variable_ a subject, I shall not now lengthen this

discussion.

OF

A FLAX-BREAKING MACHINE.

It is important, in _most_ machines, to avoid oscillatory

motions:--which uniformly protract _the time_ of an operation, or

require a greater _power_ to perform it. This consideration has given

rise to the form and properties of the Machine I am about to describe.

In Plate 36, figs. 1, 2 and 3, represent this production. The first is

an elevation; and the second is a plan, serving to shew the manner of

_feeding_ the Machine. To speak first of the second figure--_A B_ is a

pulley, (shewn at large in fig. 1, and marked with the same letters;)

it’s use is to receive the endless cord _C D E_, which is composed of

three strands, like the apparatus of a peruke-maker; these strands being

divided at _F_, and passing there over three pullies placed at a proper

distance on the same shaft _F_. These pullies are gently turned by that

shaft, and carry with them the afore-mentioned triple cord, _to_ which,

in the passage _toward_ the Machine, have been _woven_ small handfuls of

flax, by the same process as the barber uses to fasten the hair of a

wig; one difference however obtains: the flax is knit to the cords at

it’s _small_ end, and within a few inches of it, so that the root-ends

hang pendent, and when that part of the cord enters beyond the pulley

_E_, those ends hang round the large pulley _A B_, against the grooved

surface of the outer rim: The method of grooving this drum is better

shewn in fig. 3: and it should be noted, that the smaller drums _C D_,

are grooved in a similar form, their diameters being such as to divide

exactly, in _some_ ratio, the outer cylinder _E F_. In fig. 1, two

_portions_ of these handfulls of flax are represented by the waved lines

_m n_, drawn between the cylinders _C D_, and the section _E F_ of the

said outer cylinder; where it is evident, that if these cylinders had,

in that place, teeth like those of fig. 3, these handfulls of flax would

appear _bent_--which is indeed the process by which the wood is broken,

and the filament divested of it. It appears also by the figure 1, that

the cylinders _C D_, run on centres, fastened _only_ to the pins of the

cross piece _o p_, (shewn by dotted lines in fig. 2.) These cylinders I

say, are thus mounted, that there may be _no centres below_, to gather

up the flax or wood, and thus embarrass the motion of the Machine.