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.
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 himself thrown upon a cloud beyond the Brocken, though it appears to be on the mountain itself, and it is so perfect a representation that it is difficult to believe it is only a shadow. But it can be easily proved. If the man stoops to pick up anything, down goes the spectre; if he raises his hand, so does the spectre; if he takes a step of two feet, the spectre takes one of miles; if he raises his hat, the spectre politely returns his salute.
When you behold anything marvellous, and your eyes tell you that you have seen some ghostly thing, don't believe them, but investigate the matter closely, and you will find it no more a phantom than the mirage or the Spectre of the Brocken.