the reflection of the
gardens and villages that were on the river Nile, thrown up into the
air, like the ships the sailors saw, only in the clear atmosphere of
Egypt these images are projected to a long distance. And demons had
nothing whatever to do with it.

People used to believe in a fairy called Fata Morgana. Wonderful
things were said of her, and her dominions were in the air, where she
had large cities which she sometimes amused herself by turning into a
variety of shapes. The cities were often seen by dwellers on the
Mediterranean sea-coast. Sometimes one of them would be like an
earthly city, with houses and churches, and nearly always with a
background of mountains. In a moment it would change into a confused
mass of long colonnades, lofty towers, and battlements waving with
flags, and then the mountains reeling and falling, a long row of
windows would appear glowing with rainbow colors, and perhaps, in
another instant, all this would be swept away, and nothing be seen but
gloomy cypress trees.

[Illustration]

These things can be seen now occasionally, as of old, but they are no
longer in Fairyland. Now we know that they are the images of cities
and mountains on the coast, and the reason they assume these
fantastic forms is that the layers of air through which the rays of
light pass are curved and irregular.

[Illustration]

A gigantic figure haunts the Vosges Mountains, known by the name of
"The Spectre of the Brocken." The ignorant peasants were, in former
times, in great fear of it, thinking it a supernatural being, and
fancying that it brought upon them all manner of evil. And it must be
confessed it was a fearful sight to behold suddenly upon the summit of
a lofty mountain an immense giant, sometimes pointing in a threatening
attitude to a village below, as if dooming it to destruction;
sometimes with arms upraised, as if invoking ruin upon all the
country; and sometimes stalking along with such tremendous strides as
to make but one step from peak to peak; often dwarfing himself to
nothingness, and again stretching up until his head is in the clouds,
then disappearing entirely for a moment, only to reappear more
formidable than before.

But now the Spectre of the Brocken is no longer an object of fear.
Why? Because men have found him out, and he is nothing in the world
but a shadow. When the sun is in the right position, an ordinary-sized
man on a lower mountain will see a gigantic shadow of him