a central card, such as _A B_, fig. 2; and the horizontal lines between
_x_ and _y_, shew the height of the card teeth. Of these, I take out a
portion in several perpendicular lines round the card--say, at an inch
distance from each other: the intervals thus stripped, being about 1/16
of an inch in width: and in all these upright slits, I introduce a blade
_x y_, (whose transverse section is like that of a card wire) and whose
edge is undulated as at _a b_. Finally, to these blades is given, (by a
proper Machine) a slow up-and-down motion, which makes them push off
the filament from the card wires at the highest points of the waves, and
suffer the wires to retain these filaments at the lowest points; whence
it follows, from the motion just mentioned, that these points of
reception and exclusion of filament, are constantly changing on the
surface of the whole card, and that, therefore, the card will never be
totally clogged with wool--as it is in the common process. It will be
seen that the use of this System need not interrupt _that_ of the common
_flyer_, (or stripping card) whose use is to keep the teeth in working
order, and to discharge a part of the obtruding filament.
In terminating this article, I cannot resist the desire of recommending
this whole subject to any opulent English Manufacturer, whose zeal and
public spirit, are commensurate with the scope which these hints
embrace, and to which they tend, if duly appreciated.
OF
MY PARALLEL MOTION,
_As applied to_ HEAVY _Steam Engines._
While this Invention, as described in page 30 of the first Part, is
allowed to possess curious properties, and to be a _pretty_ thing,
opinions do not all concur in declaring it, essentially and generally, a
_good_ thing. Nor could I be unjust enough to insist that it is so, in
every kind and magnitude of application. I have, however, convinced
myself that it is susceptible of practical excellence, as a _first
motion_ to steam engines, whatever be their dimensions; and have,
therefore, presumed to re-produce it, with those modifications which are
required to make it so. In thus acting, I have again preferred the
_useful_ to the _agreeable_, and in some measure inverted the order of
my subjects. But I trust this deviation will be excused, in favour of
the motive and the result; on both which I feel a good degree of
confidence.
To obviate the point of mechanical _weakness_ in this Parallel Motion,
(see Plate 41, fig. 3,) I have _doubled_ it’s parts; and brought the
piston rod _a b_, to act, at once, on _two_ of the circulating wheels _c
d_, placed exactly opposite each other, and rolling, as before, on the
inside of the fixed wheels _f e_, so as to produce the rectilinear
motion, by the action of the piston rod _on them both_. And to make
their respective motions one, (as connected with the fly _B A_) this
latter is fixed to a shaft common to the two wheels _g h_, and by which,
therefore, the two other wheels _i k_, fixed to the crank shafts _m n_,
are kept in due position. Thus, then, is all winding or twisting motion
done away: and, therefore, can this System be employed in engines of
every required power. Nor need I add, (what will be generally allowed)
that much of the expence, and of the retardation, which a given engine
suffers from the beam, the connecting rod, &c. will thus be completely
obviated.
I must, however, stop every gainsaying mouth, on the circumstance of
using _geering_ between the engine and the fly--a system which I
acknowledge to have been hitherto an evil; though, perhaps, a
_necessary_ evil--as giving (by a simple method) a _double_ speed to the
fly from a _single_ motion of the piston. At all events, in this shape,
I submit only to a very common difficulty--and might there rest my
apology.
But I should have hesitated to go thus far, had I not foreseen that
_all_ the evil arising from _this_ use of wheels, can easily be avoided
by my geering:--by means of which I am bold to say, every vestige of
shake or _backlash_ may be destroyed; and this method of working a steam
engine be made as _silent_ as when a beam is used: in which case,
considerable advantages must accrue from this method.
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.
PART FIFTH.
A NEW CENTURY OF
Inventions.
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 _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.