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.
To do this, a frame _A_ (Plate 50, fig. 2) holds the Mirror; and this
frame has a horizontal motion round the _post_ _B_, something like a
common windmill. In this frame and on two horizontal trunnions, turns
the Mirror _C D_: and one or both these trunnions are hollow, to admit
of a process we shall shortly mention. This Mirror itself is composed of
an air-tight ring _C D_, of a width proportionate to the diameter
adopted; and on which are fixed two _heads_, much like those of a
_tambourine_, (or the _under_ head might be made of some metallic
substance). The head _a b c_, is made of a fine texture, duly prepared
and varnished till it becomes air tight, and then there are stuck to it,
a number of small _hexagonal_ looking-glasses or mirrors of any kind,
(see fig. 7) which thus fill up the whole space, and prepare the Mirror
for the intended change of form. The method of giving this form,
consists in exhausting, more or less, this _tambourine_ of air, when, by
the pressure of the atmosphere, the heads will take the form _a b c_,
that is a _spherically concave form_--fit to reflect the sun’s rays _as
correctly_ as this our object requires; and thus may some thousand small
images of the sun be brought to fall on the same spot, and an immense
heat be occasioned. The accounts we have of the destruction of the Roman
fleet by the _united_ mirrors of Archimedes, make this process appear
the more feasible--as whatever were the methods of uniting the _foci_ of
his mirrors, a similar effect _may be expected_ from this simple
process.
My readers will perceive that this Machine has the advantages of the
universal joint, by which it can be directed to the sun in every
position; and even made to fix his ardours on any immoveable spot for a
good length of time. The persons to whom I particularly address these
ideas, will require no further details to conceive the less obvious
circumstances of this Invention. In general, we want no effect that
requires _optical precision_: but if we did, it could be obtained to a
good degree, by methods similar to these.
I shall only add here, that this fig. 2 is given _as a section_--because
intended to represent a parallelogram, as well as a solid of revolution:
and thus (with proper mirrors) to make what now appears a spherical
focus, _a linear one_--fit to heat a cylindrical vessel with it’s
contents; and thereby draw _power_ from the sun’s heat, _without_
running expense. I am serious when I say, that we can thus, practically,
collect the solar rays which fall on many hundred square feet of
surface; and produce by them, at any desired distance, effects to which
those obtained from _modern_ burning mirrors, are but as sparks to a
blaze.
OF
AN ENGRAVING MACHINE,
_For large Patterns_.
This Machine supposes at once a _new kind_ of engraving, and admits of
patterns of _very large_ dimensions. This kind of engraving will be best
understood by persons acquainted with figure-weaving; and especially
with the manner of _mounting_ the looms for that purpose. In that
System, (see Plate 50, fig. 8) the patterns are drawn on ruled paper
divided into squares; and each of these squares represents a point in
the texture, composed of one or more threads each way; insomuch that
whenever that _square_ has any desired colour in it on the pattern, it’s
threads are _taken_ by the person who prepares the loom; and they are
_missed_ in every case where nothing appears in that square, or a colour
not then wanted. Now, whatever be the dimensions of these elementary
points on the loom, they may be represented by squares of any convenient
size on the pattern: only remembering that the smaller they are, in
reality, the better will be the delineation. Thus in carpeting, for
example, an element of this kind may be a square of one tenth of an inch
and more; while one on a ribbon or a piece of silk, is often not the
hundredth part. And therefore, the perfection of this engraving depends
on the fineness of the points of which the figures are composed. For, in
a word, this System proceeds on the same principle. When any part of a
line requires a dot or mark to be made, the Machine strikes a blow
_there_; and when no impression is to be made, the Machine (by means
that will be shewn) suffers the cylinder to pass that place without
striking. The means of regulating this is committed to workmen who
merely know how to _read_ off the pattern _in it’s length_, as it is now
read off _in it’s width_ by the weaver. To describe the construction of
the Machine, (as exhibited in figs. 3 and 4 of Plate 50) _A_ is the
cylinder to be engraved; and _B_ is a worm-wheel _fixed_ to it’s
mandril, and destined to turn it. This it does, slowly, by the endless
screw _a_, as turned by proper straps on the fast and loose pullies _b
c_, (figs. 3 and 4). _C_ shews a second wheel, concentric with that _B_,
but running loose on it’s axis, which is a pin fitted into the end of
the mandril. This wheel, when the threads of the screw _a_ are _fine_,
requires a motion more rapid than the wheel _B_--to give which motion by
means of the latter, we use a pair of multiplying wheels _d_, which
geer, one in the larger bevil wheel cut near the edge of the wheel _B_;
and the other in a smaller bevil wheel cut or fixed on the inner face of
the wheel _C_--and whence this latter wheel receives a velocity of about
ten times the speed of _B_. The use of this wheel _C_, is to carry,
across the Machine, certain bars, of wood or metal, shewn in figs. 5 and
6, whose function is to carry short pins or studs 1, 2, 3, 4, &c. for
the purpose of determining the places _where_ the punch is to act, and
where it is not. To this end, _g h_ is a frame, which is raised by a
_cam_ or tappet _i_, fixed in the endless screw _a_, once every turn;
and _that_ through the medium of the little tumbler _i e f_, by which is
finally determined whether the stroke shall take place or not--for _m_
being a section of the stud bar of figs. 5 and 6, it’s pins, _when they
occur_, raise the end _f_ of the bent lever _f e i_; and when there is
no pin or stud in _m_, this lever is not raised, and the point _i_, does
_not_ come near enough to the cam to be laid hold of, in which case no
stroke is given. This then, is so whenever the studs fail in the bar
_m_; and these fail whenever the _pattern-reader_ has said to the
stud-setter, _miss_: and they occur whenever he has said _take_--both
which cases happen more or less often according to the state of the
squares in the pattern.
To be a little more particular: in fig. 5 we see a part of the wheel _C_
of fig. 3, and also a part of the stud bars _m m_, which _geer_ in the
wheel _C_, and which being conducted by the guides _n_, follow the
motion of that wheel, presenting at _f_, (fig. 3) a stud to raise the
lever _f e_, whenever the pattern requires it. It may be mentioned, that
these studs act _obliquely_ on the wing _f_ of this lever, and thus
_raise_ it as they pass under it. And further, these stud bars are made
and fitted to each other in the manner shewn at fig. 6. There is a
geering tooth under every stud hole, and the last stud hole of a given
bar has, fixed in it, a thin tube _a_, into which the stud enters the
same way as in any other place: but this tube whether studded or not
serves to lay hold of the succeeding bar _b_, by it’s first hole--so, in
fine, as to make the bars endless; the attendant having nothing else to
do than to hook them to each other as the wheel _C_ draws them in.
Thus then, are the strokes of the _hammer frame_, _g h_, conformed to
the pattern: for these bars have been studded before hand by one or more
readers and setters; and it is a merely mechanical process to put them
in while the Machine moves: from which, by the bye, they _fall out_
after the passage into a proper box, and the studs out of them, to be
_composed_ again from the succeeding figures of the pattern. A dozen or
two of these bars might be prepared at _any_ time and place, and to
_any_ pattern, which they will thus transfer to a cylinder at _any_
desired moment, without the further preparation of dies, punches, mills,
&c.--as used in other Machines. N. B. The strength of the blows thus
given by the hammer frame _g h_, is lessened or augmented by the
position of the point _i_ fixed to the bent lever _i e f_, and which
makes that lift higher or lower as required--which is a mean of
_shading_ offered by this Machine. But to mention it’s other properties,
the endless screw _a_, (figs. 3 and 4) carries another endless screw
_o_, _more or less fine_, which turns at the same time the wheel _p_,
and, by that, the long screw _s s_, whose office it is to shift, slowly,
the punch carriers _k l_, along the Machine, from _k_ by _l_, towards
_s_. And here an observation occurs: this can only be so, when the
pattern permits the action of the punches _k_ or _l_, to take place
_spirally_ on the cylinder; that is, when the _sketches_ are distinct
enough _not_ to shew the anomaly that would occur were a _straight_
pattern thus transferred to a set of spiral lines. But should it be
desirable to engrave patterns so correct as to require an exact parallel
motion round the cylinder, _then_ the motion of this screw must _not_ be
continual--but must intermit and be resumed, at every beginning of a new
line round the cylinder. I hope, I make myself understood: a pattern
drawn on _squares_, produces lines all parallel to the first; while the
spiral motion of the punch causes a slight deviation--which, in a word,
can either be suffered or avoided. At all events, this deviation is so
much the smaller as the punch motion is slower in both directions; and,
in _fine_ patterns, must be _very small_. One remark will close this
part of the subject: although a fine pattern, requires a great number of
blows, and thus a certain expence of time, each blow can be so much the
lighter and more frequent; so as to compensate, in some degree, for this
cause of delay. I add, that the levers shewn above and around fig. 6,
are intended to lift the hammer frame _g h_, equally at both ends: while
the screw _Z_ regulates the _depth_ to which it is permitted to fall.
I observe, finally, that, according to the size of the intended pattern,
there are more or fewer of the punch bearers _k l_, connected, by their
nuts, with the screw _s s_; each of which thus engraves it’s sketch,
similar to the collateral ones; and that were it wished to make _one_
pattern of the whole length and circumference of the cylinder, a single
punch bearer would be required--since nothing else limits the extent of
a pattern engraved by this Machine.
* * * * *
Thus have I gone through my proposed “Century of Inventions,” for every
imperfection in which I beg the indulgence of my numerous readers. And
here I can truly say I have _neglected_ nothing--although the precarious
state of my health may have sometimes veiled the evidence of my
descriptions. On the other hand, I did not even attempt many of the
lesser details of execution; as I wrote for those to whom they would
have been superfluous: but as to the objects themselves, I believe there
is not one that is without the pale of practical utility. In a word,
many of the subjects have been frequently executed, and _are in daily
use_: and as to those which remain to be tried, I engage, if called on,
to give them useful existence. And the better to convince candid minds
of the serious attention I have paid to these subjects, I shall add _the
scales_ on which they have been executed, or to which they are
drawn--those scales expressed by a fraction, shewing what proportion the
figures bear to the reality. Thus the scale of one inch to a foot will
be expressed by the fraction 1/12; that of two inches to a foot, by 1/6,
&c. that is, the figures, in these cases, will be (nearly) 1/12 or 1/6
of the size of the Machines. This premised--and also that we shall
observe the alphabetical order, the following is the
TABLE OF CONTENTS.
No. Scale Page.