John Phin.

The seven follies of science; a popular account of the most famous scientific impossibilities and the attempts which have been made to solve them. To which is added a small budget of interesting paradoxes, illusions, and marvels online

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Online LibraryJohn PhinThe seven follies of science; a popular account of the most famous scientific impossibilities and the attempts which have been made to solve them. To which is added a small budget of interesting paradoxes, illusions, and marvels → online text (page 4 of 12)
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so that in one direction they can rest upon the circumfer-
ence, while on the opposite side, being carried away by the
weight at the extremity, they are obliged to arrange them-
selves in the direction of the radius continued. This being
supposed, it is evident that when the wheel turns in the
direction ABC, the weights A, B, and C will recede from the
center; consequently, as they act with more force, they
will carry the wheel towards that side ; and as a new lever





Fig. 5. Fig. 6.

will be thrown out, in proportion as the wheel revolves, it
thence follows, say they, that the wheel will continue to
move in the same direction. But notwithstanding the
specious appearance of this reasoning, experience has
proved that the machine will not go ; and it may indeed be
demonstrated that there is a certain position in which the
center of gravity of all these weights is in the vertical
plane passing through the point of suspension, and that
therefore it must stop."

Another invention of a similar kind is thus described by
the same author :

" In a cylindric drum, in perfect equilibrium on its axis,
are formed channels as seen in Fig. 6, which contain balls
of lead or a certain quantity of quicksilver. In consequence
of this disposition, the balls or quicksilver must, on the one
side, ascend by approaching the center, and on the other



44



THE SEVEN FOLLIES OF SCIENCE



must roll towards the circumference. The machine ought,
therefore, to turn incessantly towards that side."

In his "Course of Lectures on Natural Philosophy,"
Dr. Thomas Young speaks of these contrivances as fol-
lows :

" One of the most common fallacies, by which the super-
ficial projectors of machines for obtaining perpetual motion
have been deluded, has arisen from imagining that any




Fig. 7.

number of weights ascending by a certain path, on one
side of the center of motion and descending on the other
at a greater distance, must cause a constant preponderance
on the side of the descent: for this purpose the weights
have either been fixed on hinges, which allow them to fall
over at a certain point, so as to become more distant from
the center, or made to slide or roll along grooves or planes
which lead them to a more remote part of the wheel, from
whence they return as they ascend; but it will appear on
the inspection of such a machine, that although some of
the weights are more distant from the center than others,



PERPETUAL MOTION 45

yet there is always a proportionately smaller number of
them on that side on which they have the greatest power,
so that these circumstances precisely counterbalance each
other."

He then gives the illustration (Fig. 7), shown on the
preceding page, of "a wheel supposed to be capable of pro-
ducing a perpetual motion; the descending balls acting at a
greater distance from the center, but being fewer in number
than the ascending. In the model, the balls may be kept
in their places by a plate of glass covering the wheel."




A more elaborate arrangement embodying the same idea
is figured and described by Ozanam. The machine, which
is shown in Fig. 8, consists of "a kind of wheel formed of
six or eight arms, proceeding from a center where the axis
of motion is placed. Each of these arms is furnished with
a receptacle in the form of a pair of bellows : but those on
the opposite arms stand in contrary directions, as seen in



46 THE SEVEN FOLLIES OF SCIENCE

the figure. The movable top of each receptacle has
affixed to it a weight, which shuts it in one situation and
opens it in the other. In the last place, the bellows of the
opposite arms have a communication by means of a canal,
and one of them is filled with quicksilver.

" These things being supposed, it is visible that the bel-
lows on the one side must open, and those on the other
must shut ; consequently, the mercury will pass from the
latter into the former, while the contrary will be the case
on the opposite side."

Ozanam naively adds : " It might be difficult to point
out the deficiency of this reasoning ; but those acquainted
with the true principles of mechanics will not hesitate to
bet a hundred to one, that the machine, when constructed,
will not answer the intended purpose."

That this bet would have been a perfectly safe one must
be quite evident to any person who has the slightest knowl-
edge of practical mechanics, and yet the fundamental idea
which is embodied in this and the other examples which we
have just given, forms the basis of almost all the attempts
which have been made to produce a perpetual motion by
purely mechanical means.

The hydrostatic paradox by which a few ounces of liquid
may apparently balance many pounds, or even tons, has
frequently suggested a form of apparatus designed to secure
a perpetual motion. Dr. Arnott, in his " Elements of Phy-
sics," relates the following anecdote : " A projector thought
that the vessel of his contrivance, represented here (Fig. 9),
was to solve the renowned problem of the perpetual mo-
tion. It was goblet-shaped, lessening gradually towards
the bottom until it became a tube, bent upwards at c and
pointing with an open extremity into the goblet again. He



PERPETUAL MOTION



47



reasoned thus : A pint of water in the goblet a must more
than counterbalance an ounce which the tube b will con-
tain, and must, therefore, be constantly pushing the ounce
forward into the vessel again at a, and keeping up a stream
or circulation, which will cease only when the water dries




Fig. 9.



up. He was confounded when a trial showed him the
same level in a and in b"

This suggestion has been adopted over and over again by
sanguine inventors. Dircks, in his " Perpetuum Mobile,"
tells us that a contrivance, on precisely the same principle,
was proposed by the Abbe de la Roque, in " Le Journal
des Sc^avans," Paris, 1686. The instrument was a U tube,
one leg longer than the other and bent over, so that any
liquid might drop into the top end of the short leg, which
he proposed to be made of wax, and the long one of iron.
Presuming the liquid to be more condensed in the metal
than the wax tube, it would flow from the end into the wax
tube and so continue.



48 THE SEVEN FOLLIES OF SCIENCE

This is a typical case. A man of learning and of high
position is so confident that his theory is right that he does
not think it worth while to test it experimentally, but
rushes into print and immortalizes himself as the author
of a blunder. It is safe to say that this absurd invention
will do more to perpetuate his name than all his learning
and real achievements. And there are others in the same
predicament circle-squarers who, a quarter of a century
hence, will be remembered for their errors when all else
connected with them will be forgotten.

To every miller whose mill ceased working for want of
water, the idea has no doubt occurred that if he could only
pump the water back again and use it a second or a third
time he might be independent of dry or wet seasons. Of
course no practical miller was ever so far deluded as to
attempt to put such a suggestion into practice, but innu-
merable machines of this kind, and of the most crude
arrangement, have been sketched and described in maga-
zines and papers. Figures of wheels driving an ordinary
pump, which returns to an elevated reservoir the water
which has driven the wheel, are so common that it is not
worth while to reproduce any of them. In the following
attempt, however, which is copied from Bishop Wilkins'
famous book, "Mathematical Magic" (1648), the well-
known Archimedean screw is employed instead of a pump,
and the naivete of the good bishop's description and con-
clusion are well worth the space they will occupy.

After an elaborate description of the screw, he says :
"These things, considered together, it will hence appear
how a perpetual motion may seem easily contrivable.
For, if there were but such a waterwheel made on this
instrument, upon which the stream that is carried up



PERPETUAL MOTION 49

may fall in its descent, it would turn the screw round,
and by that means convey as much water up as is required
to move it; so that the motion must needs be continual
since the same weight which in its fall does turn the wheel,
is, by the turning of the wheel, carried up again. Or, if
the water, falling upon one wheel, would not be forcible
enough for this effect, why then there might be two, or
three, or more, according as the length and elevation of the
instrument will admit ; by which means the weight of it
may be so multiplied in the fall that it shall be equivalent
to twice or thrice that quantity of water which ascends ;
as may be more plainly discerned by the following diagram
(Fig. 10):

"Where the figure LM at the bottom does represent a
wooden cylinder with helical cavities cut in it, which at AB
is supposed to be covered over with tin plates, and three
waterwheels, upon it, HIK; the lower cistern, which
contains the water, being CD. Now, this cylinder being
turned round, all the water which from the cistern ascends
through it, will fall into the vessel at E, and from that
vessel being conveyed upon the waterwheel H, shall conse-
quently give a circular motion to the whole screw. Or, if
this alone should be too weak for the turning of it, then
the same water which falls from the wheel H, being re-
ceived into the other vessel F, may from thence again
descend on the wheel I, by which means the force of it
will be doubled. And if this be yet insufficient, then "may
the water, which falls on the second wheel T, be received
into the other vessel G, and from thence again descend on
the third wheel at K ; and so for as many other wheels as
the instrument is capable of. So that besides the greater
distance of these three streams from the center or axis by



50 THE SEVEN FOLLIES OF SCIENCE

which they are made so much heavier; and besides that
the fall of this outward water is forcible and violent,
whereas the ascent of that within is natural besides all
this, there is twice as much water to turn the screw as is
carried up by it.




Fig. 10.



"But, on the other side, if all the water falling upon one
wheel would be able to turn it round, then half of it would
serve with two wheels, and the rest may be so disposed of
in the fall as to serve unto some other useful, delightful
ends.



PERPETUAL MOTION 5!

"When I first thought of this invention, I could scarce
forbear, with Archimedes, to cry out 'Eureka! Eureka!'
it seeming so infallible a way for the effecting of a per-
petual motion that nothing could be so much as probably
objected against it; but, upon trial and experience, I find it
altogether insufficient for any such purpose, and that for
these two reasons :

1 . The water that ascends will not make any considera-
ble stream in the fall.

2. This stream, though multiplied, will not be of force
enough to turn about the screw."

How well it would have been for many of those inven-
tors, who supposed that they had discovered a successful
perpetual motion, if they had only given their contrivances
a fair and unprejudiced test as did the good old bishop!

A modification of this device, in which mercury is used
instead of water, is thus described by a correspondent of
"The Mechanic's Magazine." (London.)

"In Fig. n, A is the screw turning on its two pivots
GG; B is a cistern to be filled above the level of the lower
aperture of the screw with mercury, which I conceive to be
preferable to water on many accounts, and principally be-
cause it does not adhere or evaporate like water; c is a
reservoir, which, when the screw is turned round, receives
the mercury which falls from the top ; there is a pipe, which,
by the force of gravity, conveys the mercury from the
reservoir c on to (what for want of a better term may be
called) the float-board E, fixed at right angles to the center
[axis] of the screw, and furnished at its circumference with
ridges or floats to intercept the mercury, the moment and
weight of which will cause the float-board and screw to re-
volve, until, by the proper inclination of the floats, the
mercury falls into the receiver F, from whence it again falls
by its spout into the cistern G, where the constant revolu-
tion of the screw takes it up again as before."



52 THE SEVEN FOLLIES OF SCIENCE

He then suggests some difficulties which the ball, seen
just under the letter E, is intended to overcome, but he
confesses that he has never tried it, and to any practical
mechanic it is very obvious that the machine will not work.




Fig. ii.



But we give the description in the language of the inventor,
as a fair type of this class of perpetual-motion machines.

In the year 1790 a Doctor Schweirs took out a patent
for a machine in which small metal balls were used instead
of a liquid, and they were raised by a sort of chain pump
which delivered them upon the circumference of a large
wheel, which was thus caused to revolve. It was claimed
for this invention that it kept going for some months, but
any mechanic who will examine the Doctor's drawing must
see that it could not have continued in motion after the
initial impulse had been expended.



PERPETUAL MOTION 53

That property of liquids known as capillary attraction
has been frequently called to the aid of perpetual-motion
seekers, and the fact that although water will, in capillary
tubes and sponges, rise several inches above the general
level, it will not overflow, has been a startling surprise to
the would-be inventors. Perhaps the most notable instance
of a mistake of this kind occurred in the case of the famous
Sir William Congreve, the inventor of the military rockets
that bore his name, and the author of certain improvements
in matches which were called after him. It was thus de-
scribed and figured in an article which appeared in the
" Atlas " (London) and was copied into " The Mechanic's
Magazine" (London) for 1827:

" The celebrated Boyle entertained an idea that perpetual
motion might be obtained by means of capillary attraction;
and, indeed, there seems but little doubt that nature has
employed this force in many instances to produce this effect.

" There are many situations in which there is every
reason to believe that the sources of springs on the tops
and sides of mountains depend on the accumulation of
water created at certain elevations by the operation of
capillary attraction, acting in large masses of porous ma-
terial, or through laminated substances. These masses
being saturated, in process of time become the sources of
springs and the heads of rivers; and thus by an endless
round of ascending and descending waters, form, on the
great scale of nature, an incessant cause of perpetual
motion, in the purest acceptance of the term, and precisely
on the principle that was contemplated by Boyle. It is
probable, however, that any imitation of this process on
the limited scale practicable by human art would not be
of sufficient magnitude to be effective. Nature, by the
immensity of her operations, is able to allow for a slowness
of process which would baffle the attempts of man in any
direct and simple imitation of her works. Working, there-
fore, upon the same causes, he finds himself obliged to
take a more complicated mode to produce the same effect.



54



THE SEVEN FOLLIES OF SCIENCE



" To amuse the hours of a long confinement from illness,
Sir William Congreve has recently contrived a scheme of
perpetual motion, founded on this principle of capillary at-
traction, which, it is apprehended, will not be subject to
the general refutation applicable to those plans in which
the power is supposed to be derived from gravity only.
Sir William's perpetual motion is as follows:

" Let ABC, Fig. 12, be three horizontal rollers fixed in
a frame; aaa, etc., is an endless band of sponge, running
round these rollers; and bbb, etc., is an endless chain of
weights, surrounding the band of sponge, and attached




to it, so that they must move together; every part of this
band and chain being so accurately uniform in weight that
the perpendicular side AB will, in all positions of the band
and chain, be in equilibrium with the hypothenuse AC, on
the principle of the inclined plane. Now, if the frame in
which these rollers are fixed be placed in a cistern of water,
having its lower part immersed therein, so that the water's
edge cuts the upper part of the rollers BC, then, if the
weight and quantity of the endless chain be duly propor-
tioned to the thickness and breadth of the band of sponge,
the band and chain will, on the water in the cistern being
brought to the proper level, begin to move round the rollers
in the direction AB, by the force of capillary attraction,
and will continue so to move. The process is as follows :



PERPETUAL MOTION 55

" On the side AB of the triangle, the weights bbb, etc.,
hanging perpendicularly alongside the band of sponge, the
band is not compressed by them, and its pores being left
open, the water at the point x, at which the band meets its
surface, will rise to a certain height y, above its level, and
thereby create a load, which load will not exist on the as-
cending side CA, because on this side the chain of weights
compresses the band at the water's edge, and squeezes out
any water that may have previously accumulated in it; so
that the band rises in a dry state, the weight of the chain
having been so proportioned to the breadth and thickness
of the band as to be sufficient to produce this effect. The
load, therefore, on the descending side AB, not being op-
posed by any similar load on the ascending side, and the
equilibrium of the other parts not being disturbed by the
alternate expansion and compression of the sponge, the
band will begin to move in the direction AB; and as it
moves downwards, the accumulation of water will continue
to rise, and thereby carry on a constant motion, provided
the load at xy be sufficient to overcome the friction on the
rollers ABC.

" Now to ascertain the quantity of this load in any par-
ticular machine, it must be stated that it is found by ex-
periment that the water will rise in a fine sponge about an
inch above its level; if, therefore, the band and sponge be
one foot thick and six feet broad, the area of its horizontal
section in contact with the water would be 864 square
inches, and the weight of the accumulation of water raised
by the capillary attraction being one inch rise upon 864
square inches, would be 30 lb., which, it is conceived, would
be much more than equivalent to the friction of the rollers."

The article, inspired no doubt by Sir William, then goes
on to give elaborate reasons for the success of the device,
but all these are met by the damning fact that the machine
never worked. Some time afterwards Sir William, at
considerable expense, published a pamphlet in which he
explained and defended his views. If he had only had a
working model made and the thing had continued in motion



56 THE SEVEN FOLLIES OF SCIENCE

for a few hours, he would have silenced all objectors far
more quickly and forcibly than he ever could have done
by any amount of argument.

And in his case there could have been no excuse for
his not making a small machine after the plans that he
published and even patented. He was wealthy and could
have commanded the services of the best mechanics in
London, but no working model was ever made. Many in-
ventors of perpetual-motion machines offer their poverty
as an excuse for not making a model or working machine.
Thus Dircks, in his " Perpetuum Mobile " gives an account
of " a mechanic, a model maker, who had a neat brass
model of a time-piece, in which were two steel balls A and
B ; B to fall into a semicircular gallery C, and be car-
ried to the end D of a straight trough DE ; while A in its
turn rolls to E, and so on continuously ; only the gallery C
not being screwed in its place, we are desired to take the
will for the deed, until twenty shillings be raised to com-
plete this part of the work ! "

And Mr. Dircks also quotes from the " Builder" of
June, 1847 : " This vain delusion, if not still in force, is at
least as standing a fallacy as ever. Joseph Hutt, a frame-
work knitter, in the neighborhood of the enlightened town
of Hinckley, professes to have discovered it [perpetual
motion] and only wants twenty pounds, as usual, to set it
agoing."

The following rather curious arrangement was described
in "The Mechanic's Magazine" for 1825.

" I beg leave to offer the prefixed device. The point at
which, like all the rest, it fails, I confess I did not (as I
do now) plainly perceive at once, although it is certainly
very obvious. The original idea was this to enable a



PERPETUAL MOTION 57

body which would float in a heavy medium and sink in a
lighter one, to pass successively through the one to the
other, the continuation of which would be the end in view.
To say that valves cannot be made to act as proposed will
not be to show the rationale (if I may so say) upon which
the idea is fallacious."

The figure is supposed to be tubular, and made of glass,
for the purpose of seeing the action of the balls inside,
which float or fall as they travel from air through water
and from water through air. The foot is supposed to be
placed in water, but it would answer the same purpose if
the bottom were closed.

DESCRIPTION OF THE ENGRAVING, FIG. 13. No. i, the
left leg, filled with water from B to A. 2 and 3, valves,
having in their centers very small projecting valves ; they
all open upwards. 4, the right leg, containing air from
A to F. 5 and 6, valves, having very small ones in their
centers ; they all open downwards. The whole apparatus
is supposed to be air and water-tight. The round figures
represent hollow balls, which will sink one-fourth of their
bulk in water (of course will fall in air) ; the weight there-
fore of three balls resting upon one ball in water, as at E,
will just bring its top even with the water's edge ; the
weight of four balls will sink it under the surface until the
ball immediately over it is one-fourth its bulk in water,
when the under ball will escape round the corner at C,
and begin to ascend.

"The machine is supposed (in the figure) to be in
action, and No. 8 (one of the balls) to have just escaped
round the corner at C, and to be, by its buoyancy, rising
up to valve No. 3, striking first the small projecting valve
in the center, which when opened, the large one will be



THE SEVEN FOLLIES OF SCIENCE



raised by the buoyancy of the ball ; because the moment
the small valve in the center is opened (although only the
size of a pin's head), No. 2 valve will have taken upon it-
self to sustain the whole column of water from A to B.
The said ball (No. 8) having passed through the valve



M




No. 3, will, by appropriate weights or spripgs, close ; the
ball will proceed upwards to the next valve (No. 2), and
perform the same operation there. Having arrived at A,
it will float upon the surface three-fourths of its bulk out
of water. Upon another ball in due course arriving under
it, it will be lifted quite out of the water, and fall over the



PERPETUAL MOTION 59

point D, pass into the right leg (containing air), and fall to
valve No. 5, strike and open the small valve in its center,
then open the large one, and pass through ; this valve will
then, by appropriate weights or springs, close ; the ball will
roll on through the bent tube (which is made in that form
to gain time as well as to exhibit motion) to the next valve
(No. 6), where it will perform the same operation, and
then, falling upon the four balls at E, force the bottom one
round the corner at C. This ball will proceed as did No.
8, and the rest in the same manner successively."

That an ordinary amateur mechanic should be misled by
such arguments is perhaps not so surprising, when we re-
member that the famous John Bernoulli claimed to have
invented a perpetual motion based on the difference be-
tween the specific gravities of two liquids. A translation
of the original Latin may be found in the Encyclopaedia
Britannica, Vol. XVIII, page 555. Some of the premises
on which he depends are, however, impossibilities, and
Professor Chrystal concludes his notice of the invention
' thus : " One really is at a loss with Bernoulli's wonderful
theory, whether to admire most the conscientious state-
ment of the hypothesis, the prim logic of the demonstra-
tion so carefully cut according to the pattern of the
ancients or the weighty superstructure built on so frail


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Online LibraryJohn PhinThe seven follies of science; a popular account of the most famous scientific impossibilities and the attempts which have been made to solve them. To which is added a small budget of interesting paradoxes, illusions, and marvels → online text (page 4 of 12)