Myths and Marvels of Astronomy
reasoning men in our time have abandoned the idea that comets are sent
to warn the inhabitants of this small earth. Obeying in their movements
the same law of gravitation which guides the planets in their courses,
the comets are tracked by the skilful mathematician along those remote
parts of their course where even the telescope fails to keep them in
view. Not only are they no longer regarded as presaging the fortunes of
men on this earth, but men on this earth are able to predict the
fortunes of comets. Not only is it seen that they cannot influence the
fates of the earth or other planets, but we perceive that the earth and
planets by their attractive energies influence, and in no unimportant
degree, the fates of these visitants from outer space. Encouraging,
truly, is the lesson taught us by the success of earnest study and
careful inquiry in determining some at least among the laws which govern
bodies once thought the wildest and most erratic creatures in the whole
of God's universe.
IX.
_THE LUNAR HOAX._
Then he gave them an account of the famous moon hoax, which came
out in 1835. It was full of the most barefaced absurdities, yet
people swallowed it all; and even Arago is said to have treated it
seriously as a thing that could not well be true, for Mr. Herschel
would have certainly notified him of these marvellous discoveries.
The writer of it had not troubled himself to invent probabilities,
but had borrowed his scenery from the 'Arabian Nights' and his
lunar inhabitants from 'Peter Wilkins.'--OLIVER WENDELL HOLMES (in
_The Poet at the Breakfast-Table_).
In one of the earliest numbers of 'Macmillan's Magazine, the late
Professor De Morgan, in an article on Scientific Hoaxing, gave a brief
account of the so-called 'lunar hoax'--an instance of scientific
trickery frequently mentioned, though probably few are familiar with the
real facts. De Morgan himself possessed a copy of the second English
edition of the pamphlet, published in London in 1836. But the original
pamphlet edition, published in America in September 1835, is not easily
to be obtained. The proprietors of the New York 'Sun,' in which the
fictitious narrative first appeared, published an edition of 60,000
copies, and every copy was sold in less than a month. Lately a single
copy of that edition was sold for three dollars seventy-five cents.[45]
The pamphlet is interesting in many respects, and I propose to give
here a brief account of it. But first it may be well to describe briefly
the origin of the hoax.
It is said that after the French revolution of 1830 Nicollet, a French
astronomer of some repute, especially for certain lunar observations of
a very delicate and difficult kind, left France in debt and also in bad
odour with the republican party. According to this story, Arago the
astronomer was especially obnoxious to Nicollet, and it was as much with
the view of revenging himself on his foe as from a wish to raise a
little money that Nicollet wrote the moon-fable. It is said further that
Arago was entrapped, as Nicollet desired, and circulated all over Paris
the wonders related in the pamphlet, until Nicollet wrote to his friend
Bouvard explaining the trick. So runs the story, but the story cannot be
altogether true. Nicollet may have prepared the narrative and partly
written it, but there are passages in the pamphlet as published in
America which no astronomer could have written. Possibly there is some
truth in De Morgan's supposition that the original work was French. This
may have been Nicollet's: and the American edition was probably enlarged
by the translator, who, according to this account, was Richard Alton
Locke,[46] to whom in America the whole credit, or discredit, of the
hoax is commonly attributed. There can be no doubt that either the
French version was much more carefully designed than the American, or
there was no truth in the story that Arago was deceived by the
narrative; for in its present form the story, though clever, could not
for an instant have deceived any one acquainted with the most elementary
laws of optics. The whole story turns on optical rather than on
astronomical considerations; but every astronomer of the least skill is
acquainted with the principles on which the construction of optical
instruments depends. Though the success of the deception recently
practised on M. Chasles by the forger of the Pascal papers has been
regarded as showing how easily mathematicians may be entrapped, yet even
M. Chasles would not have been deceived by bad mathematics; and Arago, a
master of the science of optics, could not but have detected optical
blunders which would be glaring to the average Cambridge undergraduate.
But let us turn to the story itself.
The account opens with a passage unmistakably from an American hand,
though purporting, be it remembered, to be quoted from the 'Supplement
to the Edinburgh Journal of Science.' 'In this unusual addition to our
journal, we have the happiness of making known to the British public,
and thence to the whole civilised world, recent discoveries in astronomy
which will build an imperishable monument to the age in which we live,
and confer upon the present generation of the human race a proud
distinction through all future time. It has been poetically said' [where
and by whom?] 'that the stars of heaven are the hereditary regalia of
man, as the intellectual sovereign of the animal creation. He may now
fold the zodiac around him with a loftier consciousness of his mental
supremacy.' To the American mind enwrapment in the star-jewelled zodiac
may appear as natural as their ordinary oratorical references to the
star-spangled banner; but the idea is essentially transatlantic, and not
even the most poetical European astronomer could have risen to such a
height of imagery.
Passing over several pages of introductory matter, we come to the
description of the method by which a telescope of sufficient magnifying
power to show living creatures in the moon was constructed by Sir John
Herschel. It had occurred, it would seem, to the elder Herschel to
construct an improved series of parabolic and spherical reflectors
'uniting all the meritorious points in the Gregorian and Newtonian
instruments, with the highly interesting achromatic discovery of
Dolland'(_sic_). [This is much as though one should say that a clever
engineer had conceived the idea of constructing an improved series of
railway engines, combining all the meritorious points in stationary and
locomotive engines, with _Isaac_ Watts' highly ingenious discovery of
screw propulsion. For the Gregorian and Newtonian instruments simply
differ in sending the rays received from the great mirror in different
directions, and Dolland's discovery relates to the ordinary forms of
telescopes with large lens, not with large mirror.] However,
accumulating infirmities and eventually death prevented Sir William
Herschel from applying his plan, which 'evinced the most profound
research in optical science, and the most dexterous ingenuity in
mechanical contrivance. But his son, Sir John Herschel, nursed and
cradled in the observatory, and a practical astronomer from his boyhood,
determined upon testing it at whatever cost. Within two years of his
father's death he completed his new apparatus, and adapted it to the old
telescope with nearly perfect success.' A short account of the
observations made with this instrument, now magnifying six thousand
times, follows, in which most of the astronomical statements are very
correctly and justly worded, being, in fact, borrowed from a paper by
Sir W. Herschel on observation of the moon with precisely that power.
But this great improvement upon all former telescopes still left the
observer at a distance of forty miles from the moon; and at that
distance no object less than about twenty yards in diameter could be
distinguished, and even objects of that size 'would appear only as
feeble, shapeless points.' Sir John 'had the satisfaction to know that
if he could leap astride a cannon-ball, and travel upon its wings of
fury for the respectable period of several millions of years, he would
not obtain a more enlarged view of the more distant stars than he could
now possess in a few minutes of time; and that it would require an
ultra-railroad speed of fifty miles an hour for nearly the livelong
year, to secure him a more favourable inspection of the gentle luminary
of the night;' but 'the exciting question whether this "observed" of all
the sons of men, from the days of Eden to those of Edinburgh, be
inhabited by beings, like ourselves, of consciousness and curiosity, was
left to the benevolent index of natural analogy, or to the severe
tradition that the moon is tenanted only by the hoary _solitaire_, whom
the criminal code of the nursery had banished thither for collecting
fuel on the Sabbath-day.'[47] But the time had arrived when the great
discovery was to be made, by which at length the moon could be brought
near enough, by telescopic power, for living creatures on her surface to
be seen if any exist.
The account of the sudden discovery of the new method, during a
conversation between Sir John Herschel and Sir David Brewster, is one of
the most cleverly conceived (though also one of the absurdest) passages
in the pamphlet. 'About three years ago, in the course of a
conversational discussion with Sir David Brewster upon the merits of
some ingenious suggestions by the latter, in his article on Optics in
the "Edinburgh Encyclopaedia," p. 644, for improvements in Newtonian
reflectors, Sir John Herschel adverted to the convenient simplicity of
the old astronomical telescopes that were without tubes, and the
object-glass of which, placed upon a high pole, threw the focal image to
a distance of 150 and even 200 feet. Dr. Brewster readily admitted that
a tube was not necessary, provided the focal image were conveyed into a
dark apartment and there properly received by reflectors.... The
conversation then became directed to that all-invincible enemy, the
paucity of light in powerful magnifiers. After a few moments' silent
thought, Sir John diffidently enquired whether it would not be possible
to effect _a transfusion of artificial light through the focal object of
vision_! Sir David, somewhat startled at the originality of the idea,
paused awhile, and then hesitatingly referred to the refrangibility of
rays, and the angle of incidence. Sir John, grown more confident,
adduced the example of the Newtonian reflector, in which the
refrangibility was corrected by the second speculum, and the angle of
incidence restored by the third.'
All this part of the narrative is simply splendid in absurdity.
Hesitating references to refrangibility and the angle of incidence would
have been sheerly idiotic under the supposed circumstances; and in the
Newtonian reflector (which has only two specula or mirrors) there is no
refrangibility to be corrected; apart from which, 'correcting
refrangibility' has no more meaning than 'restoring the angle of
incidence.'
'"And," continued Sir John, "why cannot the illuminating microscope, say
the hydro-oxygen, be applied to render distinct, and, if necessary, even
to magnify, the focal object?" Sir David sprung from his chair' [and
well he might, though not] 'in an ecstasy of conviction, and, leaping
half-way to the ceiling, exclaimed, "Thou art the man!" Each philosopher
anticipated the other in presenting the prompt illustration that if the
rays of the hydro-oxygen microscope, passed through a drop of water
containing the larvae of a gnat and other objects invisible to the naked
eye, rendered them not only keenly but firmly magnified to dimensions of
many feet; so could the same artificial light, passed through the