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 b