We may therefore say of Water that it is believed to be transparently and intrinsically blue; and that its colour, though not actually due to floating specks of dust and other impurities, is a good deal affected by them. Such materials in the Ocean help to modify its colouring, sometimes deepening it, sometimes adding to its brilliance, sometimes deadening its brightness, sometimes turning it green or yellow. Careful observation has also shown that, when water is especially free from dust-specks, it is of a darker and duller hue than when they are present in large quantities to capture and reflect the sunbeams. CHAPTER IX. ICE-NEEDLES TO ICE-MOUNTAINS “In all time, Calm or convulsed,--in breeze or gale or storm, Icing the pole, or in the torrid clime Dark-heaving;--boundless, endless, and sublime-- The image of Eternity,--the throne Of the Invisible.”--BYRON. So far most of our thoughts have been given to Earth’s milder regions; where, indeed, the warm ocean water is at best but a thin slice laid over vast depths of cold water, yet where, so far as man is concerned, heat has the upper hand. In other parts, far to north and south, the Reign of Frost is a dire reality; and that chill monarch “rules the roost” in a masterful fashion, lording it over land and sea for months together, with none to resist his sway. Wherever King Frost waves his sceptre, one result always follows. Water changes from a liquid to a solid. Nor is water the only liquid which so changes. Quicksilver, known to us usually as a liquid, may be frozen, though not without a greater amount of cold than that which freezes water. Then, again, molten iron--that is, iron made soft through great heat--is a liquid which when cold hardens into a solid. Iron as we most often see it is simply in its frozen state; just as much the frozen form of iron as ice is the frozen form of water. And the freezing of the two comes about in the same mode. As molten iron cools and hardens it crystallizes. Minute needles, far too minute to be seen, take shape, crossing and re-crossing at various angles, till the whole becomes a solid mass of interlaced iron needles, held in position by attraction. When water changes into ice, the same thing happens. The water-particles shape themselves into tiny needles, and these ice-needles cross and re-cross, till they are knitted into a compact mass, something like the mass of iron needles. Nor are needles alone found in ice. Exquisite forms resembling ice-flowers are there also, commonly invisible, but composed of ice-needles woven into various shapes, which again are woven into the fabric of the solid ice. So a block of ice may perhaps be said to be formed of ice-flowers, and the ice-flowers to be formed of ice-needles.