All the navigators who have penetrated into the arctic seas speak with enthusiasm of the splendour of floating ice-masses. They take the most curious and fantastic shapes; sometimes appearing like great cities of white marble, with domes and towers and spires in profusion; sometimes looming huge and grand like fortresses, and many of them with their summits overhanging so much as to suggest the idea that they are about to fall. This indeed, they often do, adding to the grandeur of the scene, and not a little to the danger, should ships chance to be in the neighbourhood. The atmospheric illusions, before mentioned, are the result of different temperatures existing within a few miles of each other, and which are caused by the presence of large bodies of ice. The effect of this is to cause the ice-masses on the horizon to appear as if floating in the air, and to distort them into all sorts of shapes, even turning them upside down, and thus affording to an innovative mind a most ample and attractive field wherein to expatiate. To ascertain the causes of facts and effects so curious must be interesting to all who have inquiring minds. We will, therefore, attempt to describe and account for arctic phenomena in the following chapters as simply as may be. CHAPTER NINE. FORMATION OF ICE--DANGERS OF DISRUPTING ICE--ANECDOTE--DRIFTING ICE-- DRIFT OF THE "FOX"--"NIPPING" ANECDOTE--LOSS OF THE "BREADALBANE." It is well known that when fresh water becomes so cold that its temperature is 32 degrees of Fahrenheit's scale, it loses its liquid form and becomes ice. A somewhat lower temperature than this is necessary to freeze salt water; the reason being, that greater force is required to expel the salt which the sea holds in solution,--which salt is always more or less expelled in the process of freezing. Ice commences to form in the shape of needles, which shoot out at angles from each other. In smooth water, under the influence of intense cold, the process is rapid, and a thin cake soon covers the water, and increases in thickness hour by hour. But when the sea is agitated the process is retarded, and the fine needles are broken up into what arctic navigators call _sludge_. This, however, soon begins to cake, and is broken by the swell into small cakes; which, as they thicken, again unite, and are again broken up into larger masses. These masses, by rubbing against each other, have their edges slightly rounded up, and in this form receive the name of _pancake_ ice. When a quantity of ice covers the ocean in a wide level sheet of considerable extent, it is called an _ice-field_. Fields of this kind are often seen by navigators hundreds of miles in extent, and nearly thirty feet thick. Ice of such thickness, however, only shows five or six feet above water. When fields are broken by heavy ocean-swells, the edges are violently forced up, and fall in debris on the surface; thus _hummocks_ or mounds are formed.