CHAPTER XLIX.
PHYSICAL GEOGRAPHY. METEOROLOGY (continued).
ATMOSPHERIC PHENOMENA—THUNDER AND LIGHTNING—AURORA BOREALIS—THE RAINBOW—MOCK SUNS AND MOCK-MOONS—HALOS—FATA MORGANA—REFLECTION AND REFRACTION—MIRAGE—SPECTRE OF THE BROCKEN.
There are a great number of interesting, and to inhabitants of these islands uncommon,—perhaps we might say fortunately uncommon,—phenomena, which overtake the traveller in other countries. We have referred to whirlwinds and tornados, and will now mention two phenomena connected with these storms. There is the water-spout, for instance, and sand-pillars in the desert, which are whirled up by these winds in spiral columns of water and sand respectively. The tiny whirlwind at cross-roads, which picks up straws and leaves, is the common appearance of whirling or crossing currents of air.
Fig. 724.—The Waterspout.
Waterspouts, when they are permitted to come near a ship at sea, or when they break upon land, which is seldom, are very destructive. The waterspout is begun generally by the agitation of the sea, and the cloud above drops to meet the water, which at last unites with it, and then the column of whirling liquid, tremendously disturbed at the base, advances with the prevailing wind. Its course is frequently changed, and ships within its influence would be speedily wrecked. The only way to save the vessel is to fire a cannon ball through the column and break it.