high. But in stating this, we have not given the reader any idea of its vast proportions; for it is well known that all icebergs, or masses of ice, have a much greater proportion of their bulk under than above water—in other words, they sink very deep. The relative proportion that sinks depends on the nature of the ice. Of some kinds, there is usually ten times as much below as there is above water; of other kinds, there may be eight or five parts below. In all cases there is much more below than above; so that a mountain of a hundred feet high—if afloat—may be safely calculated to be a mass of ice not far short of a thousand feet thick.
As these bergs float southward with the currents, they melt very rapidly. The heat of the sun and the action of the waves gradually round off the sharp angles and topple down the spires that characterized them in the land of their birth. The process of dissolution, too, is carried on internally; for rain and melted water on the surface percolates through the mass, rendering it porous. As the waves cut away the base, the centre of gravity is thrown out, and the whole berg turns over with a terrible crash. Sometimes loud reports like cannon-shots are heard, and the huge mountain splits asunder; while, not unfrequently, the whole berg falls into a heap of chaotic ruins, and floats away in a mass of smaller pieces which disappear gradually in their parent sea.
The formation of icebergs has, as we have
