time to raise the smallest weight as the largest; unless the man who
works them turn or walk with such velocity as must soon tire him. In
other Cranes, perhaps, two or three powers may be procured; to obtain
which, some pinion must be shifted, or fresh handle applied or resorted
to. In this Crane on the contrary, if the labourer find his load so
heavy as to permit him to ascend the wheel without turning it, let him
only move a step or two towards the circumference, and he will be fully
equal to the task. Again, if the load be so light as scarcely to resist
the action of his feet, and thus to oblige him to _run_ through so much
space as to tire him beyond necessity, let him move laterally towards
the centre, and he will soon feel the place where his strength will
suffer the least fatigue by raising the load in question. One man’s
weight applied to the extremity of the wheel would raise upwards of a
ton: and it need not be added that a single sheaved block (at the jib)
would double that power. Suffice it to say that the size of the machine
may be varied in any required degree, and that this wheel will give as
great advantage at any point of its plane as a common walking wheel of
equal diameter; as the inclination can be varied at pleasure, as far as
expediency may require. It may be well to observe that what in this
figure is the frame and seems to form a part of the Crane, must be
considered as part of the house in which it is placed; since it would be
mostly unnecessary should such cranes be erected in houses already
built: and with respect to the horizontal part, by walking on which, the
man who attends the jib, occasionally assists in raising the load, it is
not an essential part of this invention, when the crane and jib are not
contiguous: although, when they are, it would certainly be convenient
and economical.’”
The Doctor continues: “Notwithstanding, however, the advantages which
have been enumerated, Mr. Whyte’s (White’s) Crane is subject to the
theoretical objection, that it derives less use than might be wished
from the weight of the man or men: for a great part of that weight
(_half_ of it if the inclination be 30 degrees,) lies directly upon the
plane, and has no tendency to produce motion. Besides, when this Crane
is of small dimensions, the effective power of the men is very unequal;
and the barrel too small for winding a thick rope: when large, the
weight of the materials, added to that of the men, put it out of shape
and give it the appearance of an unwieldy moving floor.”
The Doctor continues: “We know one large Crane of this construction,
which has an upright post near the rim on each side, to support it, and
keep it in shape; and as much as possible to prevent friction, each post
had a vertical wheel at it’s top.” (N. B. _I_ never saw, or heard,
before, of this monster.)--“We were informed this Crane was seldom used;
and that it was soon put out of order. Nor, moreover, is it every
situation that will allow the Crane-rope to form a right angle with the
barrel on which it winds; and when this angle is oblique, the friction
must be much increased. The friction arising from the wheels at the top
of the vertical _crutches_ might indeed be _got shut off_, by making the
inclined wheel very strong; but this would add _greatly_ to the friction
of the lower gudgeon of the oblique shaft, and _considerably_ increase
the expence of the Machine.”
“There remains then (says Dr. Gregory) another stage of improvement with
regard to the construction of Cranes, in which the weight of the
labourers shall operate without diminution, at the end of an horizontal
lever; and in which the impulsive force thus arising, may be
occasionally augmented by the action of the hands, either in pulling or
lifting”--and then follows the conclusion. “This step in the progress
has been lately effected by Mr. David Hardie, of the East India
Company’s Bengal warehouse!”
I cannot follow the author (whoever he be) of the glowing picture next
given of Mr. Hardie’s Invention, (to which the obloquy thrown on my poor
abortion is clearly _the foil_) as my readers must already be anxious to
“get shut” of such unmitigated Bathos, bestowed on so trivial a theme.
With respect to my Crane, I shall only say that it fulfilled the
conditions required by the Society, _and obtained the Premium_: and if
on the one hand, the language in which, thirty years ago, I described
it, exhibits the impetuosity of youth, untempered with the moderation of
age, I will say on the other, that if impartial criticism, mechanical
acumen, or comprehensive _science_ are essential components of a
mechanical work _of high pretensions_,--these qualities were seldom more
wantonly abandoned or abused, than in the paragraphs above quoted:
except, perhaps, in the attack of the same work, on the labours and
character of the justly celebrated Watt, whose merits had this author
known how to appreciate, he _could not_ thus have attempted to lessen in
the public esteem.
But to return, this _Diatribe_ begins by comparing my Crane to a foot
mill: and kindly supposes I did not know that its principle existed in
Germany 150 years ago. But the fact is, my object was nothing like that
of the author of the mill in question: the very figure of which, proves
that _he_ had no view to the variation of power by change of place on
the wheel: whereas _that_ is the principal use I make of this “unwieldy
moving floor,” as the Doctor _heavily_ terms it. Again, this author
asserts that by making men walk on an _inclined_ plane, I derive less
use than might be wished from their weight; and yet! a page before he
told us that “the mechanists on the Continent had long since insured the
advantage of availing themselves of that addition to the moving power
which the weight of the men may furnish;” so that poor _I_ have the
merit of imitating them without knowing it, and yet of _not_ drawing the
same advantages as they from the self same principle!
But again, “a great part of the weight of the man (_half_ of it, if the
inclination be 30 degrees) lies directly on the plane, and has no
tendency to produce motion,” which _one sided truism_ is placed there to
give relief to the portentous _dictum_, which follows:--that “there
remains then another stage of improvement with regard to the
construction of Cranes, in which the weight of the labourers shall
operate without diminution at the end of an horizontal lever: and that
stage has been effected by Mr. D. H. of the East India Company’s Bengal
warehouse.”
But is this conclusion definitive? are there no countervailing evils?
Will Dr. Gregory presume to say there is no _disadvantage_ attending
this advantage? Did the Doctor ever ascend an upright ladder? and did he
_prefer_ that, to going up an easy flight of stairs? was he ever in the
geometrical stairs of St. Paul’s? or in any large _winding_ stair-case?
and if so did he prefer ascending close to the nucleus? or did he
quickly seek a point where the step was _wider than high?_ most
certainly the latter; and why then did he not perceive that if the
weight of my man is diminished one half on the plane, for the very same
reason, a given _elevation_ of his feet (on which his _fatigue_ depends)
will cause a circular motion twice as extensive; yet this is quite as
clear as the Doctor’s _ex-parte_ proposition.
But I must wade on a little further, trusting that my readers will exert
a little more patience to follow me: for this same dictum of the
Doctor’s accuses indirectly, the Society of Arts of being a set of
blockheads, for remunerating an Invention with only _supposed_
properties. I really wish these self-constituted judges of other
people’s labours would utter their oracles with more regard to truth and
propriety! and above all, not mix up their passions (which alas! are not
always purified by science) with their judgement on the merits of other
men’s inventions. Had the author of this article been wise enough to
proceed thus, he would not have _supposed_ me capable of offering
_suppositions_ for realities; nor the Society of Arts of rewarding as
genuine, _suppositious_ merit; and still less would he have emblazoned
the very properties he calls _supposed_, with _reality_ written in
glaring characters on every one of them! These properties are in fact
only the transcript of what the society required of the candidates: and
I therefore said my Crane is simple: Can this author say it is not? I
said it has little friction? will he say it has _much?_ I said it is
durable: Is it now possible to contradict this? I said it is safe: and
will Dr. G. say it is not, when it is moveable, _only during the wish of
the workman_: since _whatever_ suspends this wish, (whether accident or
design) the Crane becomes of itself _immoveable_. In fine, I observed,
that this Crane admits of an indefinite number of _powers_, without any
modification of it’s parts; and can any one say these are _supposed_
properties? If the Doctor or his coadjutors persist in saying so, I must
_suppose_ them actuated by improper motives; for truth will never bear
them out in these allegations. I take leave to add, that but for the
interests of truth, these strictures had never appeared. Even
self-defence would not have provoked one line of them: But I felt it
incumbent on me to deter, if possible, inadvertency as well as
malevolence, from infesting with the thorns of misrepresentation, the
paths which genius explores, in search of useful knowledge.
OF
A DIRECT AND DIFFERENTIAL PRESS,
_With two Powers: of which_ ONE _immense_.
The effects intended to be obtained from this Press, are to introduce
two distinct powers; the one to raise and lower the pressing cap with
convenient speed; the other to _press_ with _very_ great force. In Plate
10, A B is a frame, the under part of which contains the goods to be
pressed. The toothed wheel C D turns the screw S, and that E F turns the
nut G H, _both the same way_. The long pinions I K, turn both these
wheels C D, and E F; and occasionally one only, as will be seen
presently. L M are two bevil wheels on the axes of the long pinions I K;
and N O, are two similar ones, on the power shaft P Q. This latter shaft
runs in two boxes R T, the _stems_ of which fit and turn in the gudgeons
of the long pinions, or rather suffer these to revolve round _them_:
being pinned on through a circular groove which connects them in the
perpendicular direction only. Finally, the rope and pulleys _indicated_
at X Y Z, serve to raise both shaft and pinions; thus disengaging the
latter from the wheel E F, when the nut G H, is _not_ to be turned. We
may remark, that the parts M T O are _doubled_ in this machinery, at L R
N; merely to take away the side tendency from the screw S: as otherwise
_one half_ of this mechanism would produce the very same effect, and
leave the Machine the more simple. Supposing now, this Press charged
with goods in it’s present position,
The wheel C D, having 69 teeth; } with proportionate
that E F, „ 70 „ } diameters.
The pinions I & K, each 10 „
The wheels L N & M O equal;
The thread of the screw S, 1 inch; and in fine, the crank V Q, having a
radius of 18 inches.
In this state of things, the motion of the pressing cap W, is to the
motion of the handle V, as 1 to 52164; and, the power gained bears the
same proportion to the strength exerted: for when the handle has made
one revolution, the wheel C D has made 10/69 of a revolution, and the
screw _would have_ gone down 10/69 of a thread, or 10/69 of an inch: but
in the same time the wheel E F has turned the _nut_ 10/70 of a
revolution _in the same direction_; so that the latter has only gone
down 10/69 less 10/70 of an inch; that is, (reducing to a common
denominator) 700/4830 - 690/4830 = 10/4830 = 1/483 of an inch: Now to do
this, the handle Q V has described a circle of three feet in diameter,
or in round numbers 9 feet, or 108 inches; and to complete a descent of
the screw of one thread, (or one inch) the handle must move through a
space 483 times as great; that is, a space of 108 inches multiplied by
483 = 52164 inches: whence we see that the power gained is, as 52164 to
1: and reckoning a man’s strength at 150lbs. (exclusive of friction)
that strength exhibits a pressure of _five millions two hundred and
sixteen thousand four hundred pounds_; or upwards of _two thousand three
hundred tons_: a result not unworthy to be mentioned with those of the
hydraulic press; to which it might be still further assimilated by other
proportions in the screw and nut wheels C D, E F. Adverting now, to the
second property of this Machine: namely the simple power intended to act
when the press is to be laden or discharged, the handle V should first
be turned _backward_, until the cap W has slackened upon the goods; and
the long pinions I K be raised by the mechanism X Y Z, which pinions,
then geering only in the wheel C D, will raise the cap 1 inch for every
turn of that wheel; or for every 69/10 turns of the handle V, say in
round numbers for every seven turns: here then is a power of 756 to 1;
very different from the former; yet produced by only a few inches motion
of the long pinions I K.
We remark further, that the figure shews at G H _two_ of a system of
friction rollers, destined to lessen the resistance which the
turning-nut would otherwise oppose to the motion of the Machine. As to
the friction between the screw itself and the nut--see a future article,
in this _part_, tending to lessen or take away the friction of screws in
general.
OF
A PERISTALTIC MACHINE,
_For raising much Water to small heights_.
Physicians will soonest understand the nature of this Machine, from the
name I have given it. It is perhaps the most simple of Water-Machines;
and certainly not the least efficient where it applies. It’s name is
taken from the similarity of its action to the creeping of a worm, and
to some of the functions of animal life. Yet it might be explained to
the most unlettered housewife, when in the act of converting certain
long vessels into _chitterlings_; or making room for the materials of a
sausage or black pudding. To be serious: this Machine, in it’s simplest
form, (see Plate 11) consists of a flexible tube C D, fig. 2, nailed to
the ground, and connected with a short tube of metal containing two
valves, A B, itself affixed to a box D, filled with water, or into which
water flows. This water runs through the valve A, and distends the tube
C D, on which rolls the body F, similar in form to a land roller. The
Machine acts in the following manner: When the roller is drawn to the
end D of the tube, the water fills the latter through the valve A; and
on the roller’s return, this water is forced into the rising tube
through the valve B.
The above is the simplest form of this mechanical trifle: But it has the
disadvantage of an inconstant vibratory motion, not only of the water
but the roller: which latter being heavy, would absorb considerable
power. To remedy this evil, I have given the principle a rotatory form
in fig. 1; where A B C is a spiral tube, duly fastened to the bottom of
a shallow tub D E. At B is seen a conical roller, having the middle of
the bottom of the tub for its summit and centre of gyration. The tube A
B C, occupies rather more than one circumference; so that the cone
presses during a small part of it’s revolution on both spires at once:
by which means the Machine _would act_ without even one valve; though it
is better to place one, _under_ the opening A. Now, observe the
operation: as the cone rolls over the tube and round the common centre,
in the direction of the arrow R the water enters behind it, through the
opening A, (for the tub is plunged a few inches into the water) and is
forced by it’s pressure into the ascending tube, which is a continuation
of that, A B C. It would be superfluous to add, that these tubes are
shewn in the figures _as cut open_, and presenting their inside to view;
which representation is adopted in order to shew more completely the
valves A and B of the 2d. figure.
An objection may occur to some, at sight of this Machine: namely, that
the roller or cone B, would soon destroy the flexible tubes, by pressing
too hard on their _puckered texture_. But to obviate this difficulty I
have added, in fig. 3, a form of the tube (supposed of leather) which
insures a proper _position_ of the leather under these rollers;
accompanied by ledges A B, on which their surplus weight would bear, so
as to annul every excess of pressure on the tube.
In many of the subjects I shall have to lay before my readers, the
_forms_ are so numerous as to leave some difficulty in judging where the
actual descriptions ought to end. This article itself, small as it is,
offers an example of this: for I could draw several corollaries from the
foregoing, that would offer new degrees of interest: but I am withheld
by the apprehended want of room in the plates. I must at least defer my
first intention, of _multiplying_ examples and shewing the influence of
FORM on mechanical results in general. It will, however, always be open
to me, to resume this subject when the principal object has been
achieved--that of making known the principles of these inventions, with
their most useful forms and properties. I observe, however, what has
just occurred to me, that this Machine would be somewhat more _durable_,
if the water-tube was pressed _between two rollers_, instead of being
contracted from one side, by the action of a single one.
OF
A DRAYMAN’S CANTER,
_Or inclined Plane with increased Power_.
This Machine presents a simple method of increasing the power of the
inclined plane, as used by carters or draymen for loading their carts;
and called by them (in some counties) CANTERS. It admits of a gentle
declivity in those planes: and thus considerably increases their power.
The means consist in the transfer of the declivity from one end of the
Machine to the other. Thus (plate 11, fig. 4) when the cask is rolled up
from A to B, it is _wedged_ in that position by the wedge F; when _so
much_ of its weight is supported by the feet C, (for all the feet are in
pairs) that the end D of the Canter can be raised _with ease_ to E, so
as to _re_-form the plane, in the direction of C E; at which time the
feet D G drop into an upright position, and secure this new state of the
plane. The cask is now rolled back from B to E, where it is found twice
as _high_ as it was at B; and this manœuvre may be repeated several
times according to the number of feet provided, and their length
respectively. The _power_ of an inclined plane, is as its length to its
height: and that power is doubled when the force is applied at the
circumference of a cask or other rolling body. So that, here, the power
being as 16 to 1, if a man can exert an energy of 200_lb._ the cask may
weigh 3200_lb._ and still be raised with ease on this _Canter_, which
therefore is three times as powerful as though the weight was raised
directly from A to F in the usual method.
Should it be suggested, or thought, that this Machine applies only to
_rolling_ bodies, I would just say that it might apply, cæteris paribus,
as well to bodies sliding up the plane; or (using a small truck on the
Machine) it might serve in a cotton warehouse, for piling the bags, &c.
This System is doubtless susceptible of _discussion_, and may require to
be modified for different purposes: but it is by no means devoid of
practical capabilities.
OF
A PERPETUAL WEDGE MACHINE,
_Being a simple Method of gaining Power._
In Plate 12, fig. 5, let A B represent a wheel and axle, of which the
wheel A is divided into 100 teeth; (more or less) and let C represent a
second wheel with one tooth (or several) less than those of the first
wheel A. These two wheels are concentric, for the axis of the wheel A,
turns in the hollow centre of the wheel C; which latter wheel is fixed
to the frame of the Machine, not here represented. D is a pinion that
circulates round the wheel A and C in and along with the frame E as
impelled by the hand acting on the handle F. Thus the circulating pinion
is constantly occupied by means of its wedge formed teeth (of which one
is shewn at D), in bringing the unequal teeth _a b_ of the wheels A and
C _abreast of each other_: whence arises a _slow_ revolution of the
wheel A, and of the axis B round the common centre. For if the number of
the teeth on these wheels (A and C) differ only by unity or _one_, then
must the handle D revolve one turn about that common centre to occasion
1/100 part of a revolution of the wheel A, and of course 100 turns to
move the axis B once round that centre. And if further the wheel A be
three times the diameter of the axis B, the power gained _there_ would
be as 300 to 1, that is a power of 1_lb._ at a distance from the
centre, _only_ equal to the radius of the wheel A, would countervail a
weight of 300_lb._ suspended on the axis B: and supposing a man’s
strength to be 100_lb._ he would raise (exclusive of friction)
30000_lb._ by this simple machine.
To shew more fully the essential properties of this Machine, I have
represented only three teeth in all: one _b_ in the fixed wheel C; one a
little smaller _a_, in the wheel A, (since this wheel has _more_ teeth
than the former) and one D in the circulating pinion, whose form and
manner of acting justifies in my apprehension, the name I have given to
the Machine--a perpetual wedge Machine. I shall only add that there
would equally be motion if the teeth of the wheel A instead of being
more numerous than those of the wheel C were less numerous: but the
manner of action would be different and I think less perfect.
This Machine is among the first inventions I carried into real practice
on coming to manhood. It must be about 40 years ago, and was first
constructed as a Crane at the request of the late Doctor Bliss, of
Paddington. It _may_ offer some difficulty as a _Power_ Engine from the
small diameters and the friction thence resulting: but for any Machine
where great _slowness_ is desirable, whether to express slow motion, or
to count high numbers, &c., it still appears to me a very good Machine.
OF
A DROPPING-WEIGHT-MOVER;
_Or Machine for lengthening the Time of going of a Clock, Jack, or
other Weight-Machine_.
Suppose A B (plate 12, fig. 4) to be the first wheel of a Clock or other
Machine required to _go_ a long time without winding up. This wheel
works into the two pinions _c d_, both of which are connected by
ratchets with the axis E F of the wheel G H, _in one direction only_;
insomuch that whether the wheel A B turn forward or backward, the wheel
G H will always turn the same way. This process is well known in the
mechanical world; and I have merely adapted it to my present invention.
F and G are two tubes, or square vessels, of equal size, containing a
number of balls--the tubes so balanced against each other, that _one_ of
them is always heaviest by the weight of _half a ball_. Suppose for
example that the tube F contains six balls and the tube G five; and that
the tube G is so much heavier than F as only to be outweighed by half a
ball: _That_ half will then be the moving power; and the vessel F will
turn the wheel A B backward, raising the tube G at the same time. But
arriving at the bottom the mechanism m will let go the lowest ball in F,
and then the tube G which is at the top will preponderate and turn the
clock till it also gets to the bottom; when a similar mechanism at _n_,
will disengage one ball from it, by which subtraction the tube F will
resume the ascendency and perpetuate the motion. Thus may the _going_ of
any clock, jack, &c. be protracted to a period almost indefinite. Nor
need it, strictly speaking, be wound up at all. It is only taking care
to drop at proper intervals, an _equal number_ of balls into each tube,
and this reciprocation of movement will become perpetual. The figure of
this little Machine is unfortunately small: and the scapement is but
imperfectly shewn; It has however, only _one_ property that it is
essential to notice; which is that the detent _o_, shall suffer the
cross _m_ to turn only one quarter round at each discharge: and _this_
is insured by the spiral ledge of the four ratchet teeth _m_, which by a
pin fixed to the side of the detent, draw the latter down into the
succeeding tooth as soon as the tube F begins to rise, so that there is
only one ball discharged at each descent of that tube.
OF
A MACHINE,
_To promote Evaporation, with or without Heat_.