well, even if as cleverly devised and as well executed. The facts of
popular astronomy and of general popular science have been more widely
disseminated. America, too, more than any other great nation, has
advanced in the interval. It was about two years after this pamphlet had
appeared, that J. Quincy Adams used the following significant language
in advocating the erection of an astronomical observatory at Washington:
'It is with no feeling of pride as an American that the remark may be
made, that on the comparatively small territorial surface of Europe
there are existing more than 130 of these lighthouses of the skies;
while throughout the whole American hemisphere there is but one.' At
present, some of the finest observatories in the world belong to
American cities, or are attached to American colleges; and much of the
most interesting astronomical work of this country has been achieved by
American observers.
Yet we still hear from time to time of the attempted publication of
hoaxes of greater or less ingenuity. It is singular (and I think
significant) how often these relate to the moon. There would seem to be
some charm about our satellite for the minds of paradoxists and hoaxers
generally. Nor are these tricks invariably detected at once by the
general public, or even by persons of some culture. I remember being
gravely asked (in January 1874) whether an account given in the 'New
York World,' purporting to describe how the moon's frame was gradually
cracking, threatening eventually to fall into several separate
fragments, was in reality based on fact. In the far West, at Lincoln,
Nebraska, a lawyer asked me, not long since, why I had not described the
great discoveries recently made by means of a powerful reflector erected
near Paris. According to the 'Chicago Times,' this powerful instrument
had shown buildings in the moon, and bands of workers could be seen with
it who manifestly were undergoing some kind of penal servitude, for they
were chained together. It was clear, from the presence of these and the
absence of other inhabitants, that the side of the moon turned
earthwards is a dreary and unpleasant place of abode, the real 'happy
hunting grounds' of the moon lying on her remote and unseen hemisphere.
As gauges of general knowledge, scientific hoaxes have their uses, just
as paradoxical works have. No one, certainly no student of science, can
thoroughly understand how little some persons know about science, until
he has observed how much will be believed, if only published with the
apparent authority of a few known names, and announced with a sufficient
parade of technical verbiage; nor is it so easy as might be thought,
even for those who are acquainted with the facts, to disprove either a
hoax or a paradox. Nothing, indeed, can much more thoroughly perplex and
confound a student of science than to be asked to prove, for example,
that the earth is not flat, or the moon not inhabited by creatures like
ourselves; for the circumstance that such a question is asked implies
ignorance so thorough of the very facts on which the proof must be
based, as to render argument all but hopeless from the outset. I have
had a somewhat wide experience of paradoxists, and have noted the
experience of De Morgan and others who, like him, have tried to convince
them of their folly. The conclusion at which I have arrived is, that to
make a rope of sand were an easy task compared with the attempt to
instil the simpler facts of science into paradoxical heads.
I would make some remarks, in conclusion, upon scientific or
quasi-scientific papers not intended to deceive, but yet presenting
imaginary scenes, events, and so forth, described more or less in
accordance with scientific facts. Imaginary journeys to the sun, moon,
planets, and stars; travels over regions on the earth as yet unexplored;
voyages under the sea, through the bowels of the earth, and other such
narratives, may, perhaps, be sometimes usefully written and read, so
long as certain conditions are fulfilled by the narrator. In the first
place, while adopting, to preserve the unities, the tone of one relating
facts which actually occurred, he should not suffer even the simplest
among his readers to lie under the least misapprehension as to the true
nature of the narrative. Again, since of necessity established facts
must in such a narrative appear in company with the results of more or
less probable surmise, the reader should have some means of
distinguishing where fact ends and surmise begins. For example, in a
paper I once wrote, entitled 'A Journey to Saturn,' I was not
sufficiently careful to note that while the appearances described in the
approach towards the planet were in reality based on the observed
appearances as higher and higher telescopic powers are applied to the
planet, others supposed to have been seen by the visitors to Saturn when
actually within his system, were only such as might possibly or probably
be seen, but for which we have no real evidence. In consequence of this
omission, I received several inquiries about these matters. 'Is it
true,' some wrote, 'that the small satellite Hyperion' (scarce
discernible in powerful telescopes, while Titan and Japetus on either
side are large) 'is only one of a ring of small satellites travelling
between the orbits of the larger moons?'--as the same planets travel
between the paths of Mars and Jupiter. Others asked on what grounds it
was said that the voyagers found small moons circling about Titan, the
giant moon of the Saturnian system, as the moons of Jupiter and Saturn
circle around those giant members of the solar system. In each case, I
was reduced to the abject necessity of explaining that there was no
evidence for the alleged state of things, which, however, might
nevertheless exist. Scientific fiction which has to be interpreted in
that way is as bad as a joke that has to be explained. In my 'Journey to
the Sun' I was more successful (it was the earlier essay, however);
insomuch that Professor Young, of Dartmouth College (Hanover, N.H.), one
of the most skilful solar observers living, assured me that, with
scarcely a single exception, the various phenomena described
corresponded exactly with the ideas he had formed respecting the
probable condition of our luminary.[50]
But I must confess that my own experience has not been, on the whole,
favourable to that kind of popular science writing. It appears to me
that the more thoroughly the writer of such an essay has studied any
particular scientific subject, the less able must he be to write a
fictitious narrative respecting it. Just as those ignorant of any
subject are often the readiest to theorise about it, because least
hampered by exact knowledge, so I think that the careful avoidance of
any exact study of the details of a scientific subject must greatly
facilitate the writing of a fictitious narrative respecting it. But
unfortunately a narrative written under such conditions, however
interesting to the general reader, can scarcely forward the propagation
of scientific knowledge, one of the qualities claimed for fables of the
kind. As an instance in point, I may cite Jules Verne's 'Voyage to the
Moon,' where (apart, of course, from the inherent and intentional
absurdity of the scheme itself), the circumstances which are described
are calculated to give entirely erroneous ideas about the laws of
motion. Nothing could be more amusing, but at the same time nothing more
scientifically absurd, than the story of the dead dog Satellite, which,
flung out of the travelling projectile, becomes a veritable satellite,
moving always beside the voyagers; for, with whatever velocity the dog
had been expelled by them, with that same velocity would he have
retreated continually from their projectile abode, whose own attraction
on the dog would have had no appreciable effect in checking his
departure. Again, the scene when the projectile reaches the neutral
point between the earth and moon, so that there is no longer any gravity
to keep the travellers on the floor of their travelling car, is well
conceived (though, in part, somewhat profane); but in reality the state
of things described as occurring there would have prevailed throughout
the journey. The travellers would no more be drawn earthwards (as
compared with the projectile itself) than we travellers on the earth are
drawn sunwards with reference to the earth. The earth's attracting force
on the projectile and on the travellers would be equal all through the
journey, not solely when the projectile reached the neutral point; and
being equal on both, would not draw them together. It may be argued that
the attractions were equal before the projectile set out on its journey,
and therefore, if the reasoning just given were correct, the travellers
ought not to have had any weight keeping them on the floor of the
projectile before it started, 'which is absurd.' But the pressure upon
the floor of the projectile at rest is caused by the floor being kept
from moving; let it be free to obey gravity, and there will no longer be
any pressure: and throughout the journey to the moon, the projectile,
like the travellers it contains, is obeying the action of gravity.
Unfortunately, those who are able to follow the correct reasoning in
such matters are not those to whom Jules Verne's account would suggest
wrong ideas about matters dynamical; the young learner who _is_ misled
by such narratives is neither able to reason out the matter for himself,
nor to understand the true reasoning respecting it. He is, therefore,
apt to be set quite at sea by stories of the kind, and especially by the
specious reasoning introduced to explain the events described. In fine,
it would seem that such narratives must be valued for their intrinsic
interest, just like other novels or romances, not for the quality
sometimes claimed for them of combining instruction with amusement.
X.
_ON SOME ASTRONOMICAL PARADOXES._
For many years the late Professor De Morgan contributed to the columns
of the 'Athenaeum' a series of papers in which he dealt with the strange
treatises in which the earth is flattened, the circle squared, the angle
divided into three, the cube doubled (the famous problem which the
Delphic oracle set astronomers), and the whole of modern astronomy shown
to be a delusion and a snare. He treated these works in a quaint
fashion: not unkindly, for his was a kindly nature; not even earnestly,
though he was thoroughly in earnest; yet in such sort as to rouse the
indignation of the unfortunate paradoxists. He was abused roundly for
what he said, but much more roundly when he declined further
controversy. Paradoxists of the ignorant sort (for it must be remembered
that not all are ignorant) are, indeed, well practised in abuse, and
have long learned to call mathematicians and astronomers cheats and
charlatans. They freely used their vocabulary for the benefit of De
Morgan, whom they denounced as a scurrilous scribbler, a defamatory,
dishonest, abusive, ungentlemanly, and libellous trickster.
He bore this shower of abuse with exceeding patience and good nature. He
had not been wholly unprepared for it, in fact; and, as he had a purpose
in dealing with the paradoxists, he was satisfied to continue that quiet
analysis of their work which so roused their indignation. He found in
them a curious subject of study; and he found an equally curious subject
of study in their disciples. The simpler--not to say more
foolish--paradoxists, whose wonderful discoveries are merely amazing
misapprehensions, were even more interesting to De Morgan than the
craftier sort who make a living, or try to make a living, out of their
pretended theories. Indeed, these last he treated, as they deserved,
with a scathing satire quite different from his humorous and not
ungenial comments on the wonderful theories of the honest paradoxists.
There is one special use to which the study of paradox-literature may be
applied, which--so far as I know--has not hitherto been much attended
to. It may be questioned whether half the strange notions into which
paradoxists fall must not be ascribed to the vagueness of too many of
our scientific treatises. A half-understood explanation, or a carelessly
worded account of some natural phenomenon, leads the paradoxist, whose
nature is compounded of conceit and simplicity, to originate a theory of
his own on the subject. Once such a theory has been devised, it takes
complete possession of the paradoxist's mind. All the facts of which he
thenceforward hears, which bear in the least on his favourite craze,
appear to give evidence in its favour, even though in reality they are
most obviously opposed to it. He learns to look upon himself as an
unappreciated Newton, and to see the bitterest malevolence in those who
venture to question his preposterous notions. He is fortunate if he do
not suffer his theories to withdraw him from his means of earning a
livelihood, or if he do not waste his substance in propounding and
defending them.
One of the favourite subjects for paradox-forming is the accepted theory
of the solar system. Our books on astronomy too often present this
theory in such sort that it seems only a _successor_ of Ptolemy's; and
the impression is conveyed that, like Ptolemy's, it may be one day
superseded by some other theory. This is quite enough for the
paradoxist. If a new theory is to replace the one now accepted, why
should not _he_ be the new Copernicus? He starts upon the road without a
tithe of the knowledge that old Ptolemy possessed, unaware of the
difficulties which Ptolemy met and dealt with--free, therefore, because
of his perfect ignorance, to form theories at which Ptolemy would have
smiled. He has probably heard of the
centrics and eccentrics scribbled o'er
Cycle and epicycle, orb in orb,
which disfigured the theories of the ancients; but he is quite
unconscious that every one of those scribblings had a real meaning, each
being intended to account for some observed peculiarity of planetary
motion, which _must_ be accounted for by any theory which is to claim
acceptance. In this happy unconsciousness that there are any
peculiarities requiring explanation, knowing nothing of the strange
paths which the planets are seen to follow on the heavenly vault,
Their wand'ring course now high, now low, then hid,
Progressive, retrograde, or standing still,
he placidly puts forward--and presently very vehemently urges--a theory
which accounts for none of these things.
It has often seemed to me that a large part of the mischief--for let it
be remembered that the published errors of the paradoxist are indicative
of much unpublished misapprehension--arises from the undeserved contempt
with which our books of astronomy too often treat the labours of
Ptolemy, Tycho Brahe, and others who advocated erroneous theories. If
the simple truth were told, that the theory of Ptolemy was a masterpiece
of ingenuity and that it was worked out by his followers in a way which
merits the highest possible praise, while the theory of Tycho Brahe was
placed in reality on a sounder basis than that of Copernicus, and
accounted as well and as simply for observed appearances, the student
would begin to realise the noble nature of the problem which those great
astronomers dealt with. And again, if stress were laid upon the fact
that Tycho Brahe devoted years upon years of his life to secure such
observations of the planets as might settle the questions at issue, the
student would learn something of the spirit in which the true lover of
science proceeds.
It seems to me, also, that far too little is said about the kind of work
by which Kepler and Newton finally established the accepted theories.
There is a strange charm in the history of those twenty years of
Kepler's life during which he was analysing the observations made by
Tycho Brahe. Surrounded with domestic trials and anxieties, which might
well have claimed his whole attention, tried grievously by ill-health
and bodily anguish, he laboured all those years upon erroneous theories.
The very worst of these had infinitely more evidence in its favour than
the best which the paradoxists have brought forth. There was not one of
those theories which nine out of ten of his scientific contemporaries
would not have accepted ungrudgingly. Yet he wrought these theories one
after another to their own disproof. _Nineteen_ of them he tried and
rejected--the twentieth was the true theory of the solar system. Perhaps
nothing in the whole history of astronomy affords a nobler lesson to the
student of science--unless, indeed, it be the calm philosophy with which
Newton for eighteen years suffered the theory of the universe to remain
in abeyance, because faulty measurements of the earth prevented his
calculations from agreeing with observed facts. But, as Professor
Tyndall has well remarked--and the paradoxist should lay the lesson
well to heart--'Newton's action in this matter was the normal action of
the scientific mind. If it were otherwise--if scientific men were not
accustomed to demand verification, if they were satisfied with the
imperfect while the perfect is attainable--their science, instead of
being, as it is, a fortress of adamant, would be a house of clay, ill
fitted to bear the buffetings of the theologic storms to which it has
been from time to time, and is at present, exposed.'
The fame of Newton has proved to many paradoxists an irresistible
attraction; it has been to these unfortunates as the candle to the
fluttering moth. Circle-squaring, as we shall presently see, has had its
attractions, nor have earth-fixing and earth-flattening been neglected;
but attacking the law of gravitation has been the favourite work of
paradoxists. Newton has been praised as surpassing the whole human race
in genius; mathematicians and astronomers have agreed to laud him as
unequalled; why should not Paradoxus displace him and be praised in like
manner? It would be unfair, perhaps, to say that the paradoxist
consciously argues thus. He doubtless in most instances convinces
himself that he has really detected some flaw in the theory of
gravitation. Yet it is impossible not to recognise, as the real motive
of every paradox-monger, the desire to have that said of him which has
been said of Newton: '_Genus humanum ingenio superavit._'
I remember a curious instance of this which occurred soon after the
appearance of the comet of 1858. It chanced that, while that object was
under discussion, reference was made to the action of a repulsive force
exerted by the sun upon the matter of the comet's tail. On this, some
one addressed a long letter to a Glasgow newspaper, announcing that he
had long ago proved that the sun's attraction alone is insufficient to
account for the planetary motions. His reasoning was amazingly simple.
If the sun's attraction is powerful enough to keep the outer planets in
their course, it must be too powerful for Venus and Mercury close by the
sun; if it only just suffices to keep these in their course, it cannot
possibly be powerful enough to restrain the outer planets. The writer of
this letter said that he had been very badly treated by scientific
bodies. He had announced his discovery to the Royal Astronomical
Society, the Royal Society, the Imperial Academy at Paris, and other
scientific bodies; but they had one and all refused to listen to him. He
had forsaken or neglected his trade for several years in order to give
attention to the new and (as he thought) the true theory of the
universe. He complained in a specially bitter manner of the unfavourable
comments which men of science had made upon his views in private letters
addressed to him in reply to his communications.
There is something melancholy even in what is most ridiculous in cases
of this sort. The simplicity which supposes that considerations so
obvious as those adduced could escape the scrutiny, not of Newton only,
but of all who have followed in the same track during two centuries, is
certainly stupendous; nor can one fail to smile at seeing a difficulty,
such as might naturally suggest itself to a beginner, and such as
half-a-dozen words from an expert would clear up, regarded gravely as a
discovery calculated to make its author famous for all time. Yet, when
one considers the probable consequences of the blunder to the unhappy
enthusiast, and perchance to his family, it is difficult not to feel a
sense of pity, quite apart from that pity allied to contempt which is
excited by his mistake. A few words added to the account of Newton's
theory, which the paradoxist had probably read in some astronomical
treatise, would have prevented all this mischief. Indeed, this
difficulty, which, as we have said, is a natural one, should be dealt
with and removed in any account of the planetary system intended for
beginners. The simple statement that the outer planets move more slowly
than the inner, and so _require_ a smaller force to keep them in their
course, would have sufficed, not, perhaps, altogether to remove the
difficulty, but to show the beginner where the explanation was to be
looked for.
It was in connection with this subject of gravitation that one of the
most well-meaning of the paradoxists--the late Mr. James Reddie--came
under Professor De Morgan's criticism. Mr. Reddie was something more
than well-meaning. He was earnestly desirous of advancing the interests
of science, as well as of defending religion from what he mistakenly
supposed to be the dangerous teachings of the Newtonians. He founded for
these purposes the Victoria Institute, of which society he was the
secretary from the time of its institution until his decease, some years
since; and, probably, many who declined to join that society because of
the Anti-Newtonian proclivities of its secretary, were unaware that to
that secretary the institute owed its existence.
It so chanced that I had myself a good deal of correspondence with Mr.
Reddie (who was, however, personally unknown to me). This correspondence
served to throw quite a new light on the mental habitudes and ways of
thinking of the honest paradoxist. I believe that Professor De Morgan
hardly gave Mr. Reddie credit for the perfect honesty which he really
possessed. It may have been that a clear reasoner like De Morgan could
hardly (despite his wide experience) appreciate the confusion of mind
which is the normal characteristic of the paradoxist. But certainly the
very candid way in which Mr. Reddie admitted, in the correspondence
above named, that he had not known some facts and had misunderstood
others, afforded to my mind the most satisfactory proofs of his
straightforwardness.
It may be instructive to consider a few of those paradoxes of Mr.
Reddie's which Professor De Morgan found chief occasion to pulverise.
In a letter to the Astronomer-Royal Mr. Reddie announced that he was
about to write 'a paper intended to be hereafter published, elaborating
more minutely and discussing more rigidly than before the glaring
fallacies, dating from the time of Newton, relating to the motion of the
moon.' He proceeded to 'indicate the nature of the issues he intended to
raise.' He had discovered that the moon does not, as a matter of fact,
go round the earth at the rate of 2288 miles an hour, as astronomers
say, but follows an undulatory path round the sun at a rate varying
between 65,000 and 70,000 miles an hour; because, while the moon seems
to go round the earth, the latter is travelling onwards at the rate of
67,500 miles an hour round the sun. Of course he was quite right in his
facts, and quite wrong in his inferences; as the Astronomer-Royal
pointed out in a brief letter, closing with the remark that, 'as a very
closely occupied man,' Mr. Airy could 'not enter further into the
matter.' But further Mr. Reddie persisted in going, though he received
no more letters from Greenwich. His reply to Sir G. Airy contained, in
fact, matter enough for a small pamphlet.
Now here was certainly an amazing fact. A well-known astronomical
relation, which astronomers have over and over again described and
explained, is treated as though it were something which had throughout
all ages escaped attention. It is not here the failure to comprehend the
_rationale_ of a simple explanation which is startling, but the notion
that an obvious fact had been wholly overlooked.