As many more persons were actually gulled by the “Moon-Hoax” than
      would be willing to acknowledge the fact, it may here afford some
      little amusement to show why no one should have been deceived-to
      point out those particulars of the story which should have been
      sufficient to establish its real character. Indeed, however rich
      the imagination displayed in this ingenious fiction, it wanted
      much of the force which might have been given it by a more
      scrupulous attention to facts and to general analogy. That the
      public were misled, even for an instant, merely proves the gross
      ignorance which is so generally prevalent upon subjects of an
      astronomical nature. The moon’s distance from the earth is, in round numbers, 240,000
      miles. If we desire to ascertain how near, apparently, a lens
      would bring the satellite (or any distant object), we, of course,
      have but to divide the distance by the magnifying or, more
      strictly, by the space-penetrating power of the glass. Mr. L.
      makes his lens have a power of 42,000 times. By this divide
      240,000 (the moon’s real distance), and we have five miles and
      five sevenths, as the apparent distance. No animal at all could
      be seen so far; much less the minute points particularized in the
      story. Mr. L. speaks about Sir John Herschel’s perceiving flowers
      (the Papaver rheas, etc. ), and even detecting the color and the
      shape of the eyes of small birds. Shortly before, too, he has
      himself observed that the lens would not render perceptible
      objects of less than eighteen inches in diameter; but even this,
      as I have said, is giving the glass by far too great power. It
      may be observed, in passing, that this prodigious glass is said
      to have been molded at the glasshouse of Messrs. Hartley and
      Grant, in Dumbarton; but Messrs. H. and G.‘s establishment had
      ceased operations for many years previous to the publication of
      the hoax. On page 13, pamphlet edition, speaking of “a hairy veil” over the
      eyes of a species of bison, the author says: “It immediately
      occurred to the acute mind of Dr. Herschel that this was a
      providential contrivance to protect the eyes of the animal from
      the great extremes of light and darkness to which all the
      inhabitants of our side of the moon are periodically subjected.”
      But this cannot be thought a very “acute” observation of the
      Doctor’s. The inhabitants of our side of the moon have,
      evidently, no darkness at all, so there can be nothing of the
      “extremes” mentioned. In the absence of the sun they have a light
      from the earth equal to that of thirteen full unclouded moons. The topography throughout, even when professing to accord with
      Blunt’s Lunar Chart, is entirely at variance with that or any
      other lunar chart, and even grossly at variance with itself. The
      points of the compass, too, are in inextricable confusion; the
      writer appearing to be ignorant that, on a lunar map, these are
      not in accordance with terrestrial points; the east being to the
      left, etc. Deceived, perhaps, by the vague titles, Mare Nubium, Mare
      Tranquillitatis, Mare Faecunditatis, etc., given to the dark
      spots by former astronomers, Mr. L. has entered into details
      regarding oceans and other large bodies of water in the moon;
      whereas there is no astronomical point more positively
      ascertained than that no such bodies exist there. In examining
      the boundary between light and darkness (in the crescent or
      gibbous moon) where this boundary crosses any of the dark places,
      the line of division is found to be rough and jagged; but, were
      these dark places liquid, it would evidently be even. The description of the wings of the man-bat, on page 21, is but a
      literal copy of Peter Wilkins’ account of the wings of his flying
      islanders. This simple fact should have induced suspicion, at
      least, it might be thought. On page 23, we have the following: “What a prodigious influence
      must our thirteen times larger globe have exercised upon this
      satellite when an embryo in the womb of time, the passive subject
      of chemical affinity!” This is very fine; but it should be
      observed that no astronomer would have made such remark,
      especially to any journal of Science; for the earth, in the sense
      intended, is not only thirteen, but forty-nine times larger than
      the moon. A similar objection applies to the whole of the
      concluding pages, where, by way of introduction to some
      discoveries in Saturn, the philosophical correspondent enters
      into a minute schoolboy account of that planet—this to the
      “Edinburgh Journal of Science!”

      But there is one point, in particular, which should have betrayed
      the fiction. Let us imagine the power actually possessed of
      seeing animals upon the moon’s surface—what would first arrest
      the attention of an observer from the earth? Certainly neither
      their shape, size, nor any other such peculiarity, so soon as
      their remarkable _situation_. They would appear to be walking,
      with heels up and head down, in the manner of flies on a ceiling. The _real_ observer would have uttered an instant ejaculation of
      surprise (however prepared by previous knowledge) at the
      singularity of their position; the _fictitious_ observer has not
      even mentioned the subject, but speaks of seeing the entire
      bodies of such creatures, when it is demonstrable that he could
      have seen only the diameter of their heads! It might as well be remarked, in conclusion, that the size, and
      particularly the powers of the man-bats (for example, their
      ability to fly in so rare an atmosphere—if, indeed, the moon have
      any), with most of the other fancies in regard to animal and
      vegetable existence, are at variance, generally, with all
      analogical reasoning on these themes; and that analogy here will
      often amount to conclusive demonstration. It is, perhaps,
      scarcely necessary to add, that all the suggestions attributed to
      Brewster and Herschel, in the beginning of the article, about “a
      transfusion of artificial light through the focal object of
      vision,” etc., etc., belong to that species of figurative writing
      which comes, most properly, under the denomination of rigmarole. There is a real and very definite limit to optical discovery
      among the stars—a limit whose nature need only be stated to be
      understood. If, indeed, the casting of large lenses were all that
      is required, man’s ingenuity would ultimately prove equal to the
      task, and we might have them of any size demanded.