hills seemed to be surmounted by turrets, battlements, spires, and pinnacles; while others, subjected to one or two reflections, exhibited large masses of rock, apparently suspended in the air, at a considerable elevation above the actual termination of the mountains to which they referred. The whole exhibition was a grand phantasmagoria. Scarcely was any portion sketched before it changed its appearance, and assumed the form of an object totally different. It was, perhaps, alternately a castle, a cathedral, or an obelisk; then expanding horizontally, and coalescing with the adjoining hills, united the intermediate valleys, though some miles in width, by a bridge of a single arch, of the most magnificent appearance and extent. Notwithstanding these repeated changes, the various figures represented in the drawing had all the distinctness of reality; and not only the different strata, but also the veins of the rocks, with the wreaths of snow occupying ravines and fissures, formed sharp and distinct lines, and exhibited every appearance of the most perfect solidity."

On another occasion, on the same coast, Mr. Scoresby saw an inverted image of a ship in the air, and on looking at it, through his telescope, he could distinguish every sail, the general rig of the ship, and its particular character; "insomuch, that I confidently pronounced it to be my father's ship, the Fame, which it afterwards proved to be; though, on comparing notes with my father, I found that our relative position at the time gave a distance

from one another very nearly thirty miles, being about seventeen miles beyond the horizon, and some leagues beyond the limit of direct vision. I was so struck with the peculiarity of the circumstance, that I mentioned it to the officer of the watch, stating my full conviction that the Fame was then cruising in the neighbouring inlet."

In some cases, these aërial reflections are repeated two, three, and even four times; the form of a ship, for example, appearing in the air; then above this the same object inverted; then the third occurs in its right position, and the fourth is inverted.

The surface of the ice in the Arctic regions is by no means so level as we are accustomed to see

it in our own temperate climate. The enormous fields of ice, once set afloat, are driven about by the violence of winds and currents, and sometimes approaching in opposite directions, strike against each other with the force of millions of tons, the effect of which is to squeeze up one piece over another above the common level, and to form what are called hummocks. These hummocks relieve the dull uniformity of the ice, and often present a most fantastic appearance, rising in a variety of shapes to the height of perhaps thirty feet. They are most numerous in the heavy packs, and along the edges of ice-fields. Ships exposed to these moving masses of ice may be either crushed like a thing of nought, or lifted completely out of the water, by the pressure of two opposing masses, and placed high and dry upon the ice. The ships engaged in the northern whale-fishery are accustomed to dangers such as these.

The perpetual circulation of the waters of warm and cold seas, or system of currents and countercurrents, has a marked effect on the course of icebergs. This circulation depends upon the simple fact that, "from whatever part of the ocean a current is found to run, to the same part a current of equal volume is bound to return." An enormous quantity of water is annually carried off from the tropical seas by evaporation: (estimated in the Indian and Pacific oceans alone at more than 139 millions of cubic miles of water!) the equilibrium of the ocean is thus disturbed; but it is again

M

restored, and the waste supplied, by a perpetual flow of cold water from each pole towards the equator. This is the grand source of currents from the north and south poles; and these currents, being comparatively fresh from the melting of the ice, are buoyant, though extremely cold, and form surface currents, on which icebergs mainly drift. Those of the north reach as low as about lat. 40° N., or even 42° N., near the termination of the great bank of Newfoundland: they are also sometimes carried from Baffin's Bay to the Azores.

Now, on reverting to the above simple law of ocean currents, we find that, since there are currents of cold water flowing from each pole to the equator, so there must be currents of comparatively warm water flowing from the equator to each pole. But these warm currents are salt and heavy, and although for a time the direct rays of the sun keep them buoyant and on the surface, yet, after a time, they become cooled, and sink to form undercurrents of great force. It is obvious, therefore, that icebergs of vast proportions, which have the greater part of their bulk submerged, may be carried northwards (as in the case described by Captain Duncan, p. 155) by the power of these under-currents, while ships and smaller icebergs may be carried southwards by surface-currents flowing at the same time.

The appearance of icebergs in warm latitudes, and the phenomena attending their melting and bursting to pieces, have been graphically described

by the Rev. L. L. Noble.* This gentleman pencilled down his impressions of icebergs while his little. vessel was resting under their shadow, and while an artist was engaged in depicting their beauties. His account of the melting of a berg is as follows:

"We appear to be at the edge of a shower, such a sprinkling and pattering of drops. All abroad and all aloft, from every edge and gutter the iceberg spouts, and rains, and drips. Over the entire face of the ice is flowing swiftly down one noiseless river, thin as glass, looking for all the world like the perpetual falling of a transparent veil over the richest satin." In this berg there was "a glistening blue line of ice, threading the whiteness from top to bottom a good 200 feet." This appearance is thus explained: "The glacier, of which this berg is a kind of splinter, is mainly compacted snows, compressed to metallic hardness * As it slides on the long inland valley slope it bends and cracks. The surface water fills the crevice, and is frozen. Thus the glacier is mended, but marked for ever with the splendid scar you see before you."

* *

Of the illustrations of this volume, six in number, two, which we copy in a reduced form, are especially interesting as presenting novel forms of iceberg. The first+ has a regular arch, and a turret

*" After Icebergs with a Painter. A summer voyage to Labrador and around Newfoundland." London and New York. 1862. + See Frontispiece to this chapter.