Rupert Birkin, in D.H. Lawrence's novel, Women in Love, took a jaundiced view of the piano in the parlour, and its significance for members of the working class. "It takes him to amazing heights of upright grandeur," he proclaimed. "It makes him so much higher in his neighbouring collier's eyes. He sees himself reflected in the neighbouring opinion, like in a Brocken mist, several feet taller on the strength of the pianoforte, and he is satisfied. He lives for the sake of that Brocken spectre, the reflection of himself in the human opinion."
Lawrence's metaphor is a phenomenon that takes its name from a German mountain on which, apparently, it was very frequently observed. The Harz Mountains straddle the former Kingdom of Hanover and the equally former Grand Duchy of Brunswig, and lie close to the former border between East and West. Their highest peak, just slightly taller than Carrauntouhill, is the Brocken.
The spectre of the Brocken is a giant shadowy figure looming from the mist, usually seen in the very early morning, or occasionally in the evening, just before the sun has set.
As one walks, the spectre appears to walk at the same pace, a distant, silent and very spooky partner. But despite its eerie aspect, it is very easily explained; it is simply the observer's own shadow, cast by a low sun on a bank of cloud or mist.
It is often seen on mountain tops, because low clouds frequently provide the "screen" onto which the shadow is projected. Now and then it can be seen at ground level if one happens to be in the right position, standing upright, say, between the early morning sun and a nearby bank of fog.
The shadow has a very evocative and strange triangular shape because, unlike most shadows, it is not localised on a particular surface, but is projected through the mist to extend over a depth of perhaps 80 or 100 feet. The rays of light just grazing your body, and forming the edge of the shadow, are subject to the same perspective effect as railway lines which appear to converge as they disappear into the distance.
Another noticeable characteristic of the Brocken spectre is the appearance of a number of brilliantly coloured rings or halos around its head, which is, of course, the shadow of the head of the observer. The coloured rings are produced by a process called diffraction, a bending of the light-waves by water droplets of a certain size which also breaks up the white sunlight into its constituent spectral colours.