"O'er many a frozen, many a fiery Alp";
and one may sup full of horrors on the exceedingly cold collation provided for the next world by the Norse Edda.
But, after all, there are few such terrific periods in our Massachusetts winters, and the appointed exit from their frigidity is usually through a snow-storm. After a day of this severe sunshine there comes commonly a darker day of cloud, still hard and forbidding, though milder in promise, with a sky of lead, deepening near the horizon into darker films of iron. Then, while all the nerves of the universe seem rigid and tense, the first reluctant flake steals slowly down, like a tear. In a few hours the whole atmosphere begins to relax once more, and in our astonishing climate very possibly the snow changes to rain in twenty-four hours, and a thaw sets in. It is not strange, therefore, that snow, which to Southern races is typical of cold and terror, brings associations of warmth and shelter to the children of the North.
Snow, indeed, actually nourishes animal life. It holds in its bosom numerous animalcules: you may have a glass of water, perfectly free from infusoria, which yet, after your dissolving in it a handful of snow, will show itself full of microscopic creatures, shrimp-like and swift; and the famous red snow of the Arctic regions is only an exhibition of the same property. It has sometimes been fancied that persons buried under the snow have received sustenance through the pores of the skin, like reptiles imbedded in rock. Elizabeth Woodcock lived eight days beneath a snow-drift, in 1799, without eating a morsel; and a Swiss family were buried beneath an avalanche, in a manger, for five months, in 1755, with no food but a trifling store of chestnuts and a small daily supply of milk from a goat which was buried with them. In neither case was there extreme suffering from cold, and it is unquestionable that the interior of a drift is far warmer than the surface. On the 23d of December, 1860, at 9 P.M., I was surprised to observe drops falling from the under side of a heavy bank of snow at the eaves, at a distance from any chimney, while the mercury on the same side was only fifteen degrees above zero, not having indeed risen above the point of freezing during the whole day.
Dr. Kane pays ample tribute to these kindly properties. "Few of us at home can recognize the protecting value of this warm coverlet of snow. No eider-down in the cradle of an infant is tucked in more kindly than the sleeping-dress of winter about this feeble flower-life. The first warm snows of August and September, falling on a thickly pleached carpet of grasses, heaths, and willows, enshrine the flowery growths which nestle round them in a non-conducting air-chamber; and as each successive snow increases the thickness of the cover, we have, before the intense cold of winter sets in, a light cellular bed covered by drift, six, eight, or ten feet deep, in which the plant retains its vitality. … I have found in midwinter, in this high latitude of 78° 50', the surface so nearly moist as to be friable to the touch; and upon the ice-floes, commencing with a surface-temperature of-30°, I found at two feet deep a temperature of-8°, at four feet + 2°, and at eight feet + 26°. … The glacier which we became so familiar with afterwards at Etah yields an uninterrupted stream throughout the year." And he afterwards shows that even the varying texture and quality of the snow deposited during the earlier and later portions of the Arctic winter have their special adaptations to the welfare of the vegetation they protect.
The process of crystallization seems a microcosm of the universe. Radiata, mollusca, feathers, flowers, ferns, mosses, palms, pines, grain-fields, leaves of cedar, chestnut, elm, acanthus: these and multitudes of other objects are figured on your frosty window; on sixteen different panes I have counted sixteen patterns strikingly distinct, and it appeared like a show-case for the globe. What can seem remoter relatives than the star, the starfish, the star-flower, and the starry snow-flake which clings this moment to your sleeve?—yet some philosophers hold that one day their law of existence will be found precisely the same. The connection with the primeval star, especially, seems far and fanciful enough, but there are yet unexplored affinities between light and crystallization: some crystals have a tendency to grow toward the light, and others develop electricity and give out flashes of light during their formation. Slight foundations for scientific fancies, indeed, but slight is all our knowledge.
More than a hundred different figures of snow-flakes, all regular and kaleidoscopic, have been drawn by Scoresby, Lowe, and Glaisher, and may be found pictured in the encyclopaedias and elsewhere, ranging from the simplest stellar shapes to the most complicated ramifications. Professor Tyndall, in his delightful book on "The Glaciers of the Alps," gives drawings of a few of these snow-blossoms, which he watched falling for hours, the whole air being filled with them, and drifts of several inches being accumulated while he watched. "Let us imagine the eye gifted with microscopic power sufficient to enable it to see the molecules which composed these starry crystals; to observe the solid nucleus formed and floating in the air; to see it drawing towards it its allied atoms, and these arranging themselves as if they moved to music, and ended with rendering that music concrete." Thus do the Alpine winds, like Orpheus, build their walls by harmony.
In some of these frost-flowers the rare and delicate blossom of our wild Mitella diphylla is beautifully figured. Snow-flakes have been also found in the form of regular hexagons and other plane figures, as well as in cylinders and spheres. As a general rule, the intenser the cold the more perfect the formation, and the most perfect specimens are Arctic or Alpine in their locality. In this climate the snow seldom falls when the mercury is much below zero; but the slightest atmospheric changes may alter the whole condition of the deposit, and decide whether it shall sparkle like Italian marble, or be dead-white like the statuary marble of Vermont,—whether it shall be a fine powder which can sift through wherever dust can, or descend in large woolly masses, tossed like mouthfuls to the hungry South.
The most remarkable display of crystallization which I have ever seen was on the 13th of January, 1859. There had been three days of unusual cold, but during the night the weather had moderated, and the mercury in the morning stood at + 14°. About two inches of snow had fallen, and the trees appeared densely coated with it. It proved, on examination, that every twig had on the leeward side a dense row of miniature fronds or fern-leaves executed in snow, with a sharply defined central nerve, or midrib, and perfect ramification, tapering to a point, and varying in length from half an inch to three inches. On every post, every rail, and the corners of every building, the same spectacle was seen; and where the snow had accumulated in deep drifts, it was still made up of the ruins of these fairy structures. The white, enamelled landscape was beautiful, but a close view of the details was far more so. The crystallizations were somewhat uniform in structure, yet suggested a variety of natural objects, as feather-mosses, birds' feathers, and the most delicate lace-corals, but the predominant analogy was with ferns. Yet they seemed to assume a sort of fantastic kindred with the objects to which they adhered: thus, on the leaves of spruce-trees and on delicate lichens they seemed like reduplications of the original growth, and they made the broad, fiat leaves of the arbor-vitae fully twice as wide as before. But this fringe was always on one side only, except when gathered upon dangling fragments of spider's web, or bits of stray thread: these they entirely encircled, probably because these objects had twirled in the light wind while the crystals were forming. Singular disguises were produced: a bit of ragged rope appeared a piece of twisted lace-work; a knot-hole in a board was adorned with a deep antechamber of snowy wreaths; and the frozen body of a hairy caterpillar became its own well-plumed hearse. The most peculiar circumstance was the fact that single flakes never showed any regular crystallization: the magic was in the combination; the under sides of rails and boards exhibited it as unequivocally as the upper sides, indicating that the phenomenon was created in the lower atmosphere, and was more akin to frost than snow; and yet the largest snow-banks were composed of nothing else, and seemed like heaps of blanched iron-filings.
Interesting observations have been made on the relations between ice and snow. The difference seems to lie only in the more or less compacted arrangement of the frozen particles. Water and air, each being transparent when separate, become opaque when intimately mingled; the reason being that the inequalities of refraction break up and scatter every ray of light. Thus, clouds cast a shadow; so does steam; so does foam: and the same elements take a still denser texture when combined as snow. Every snow-flake is permeated with minute airy chambers, among which the light is bewildered and lost; while from perfectly hard and transparent ice every trace of air disappears, and the transmission of light is unbroken. Yet that same ice becomes white and opaque when pulverized, its fragments being then intermingled with air again,—just as colorless glass may be crushed into white powder. On the other hand, Professor Tyndall has converted slabs of snow to ice by regular pressure, and has shown that every Alpine glacier begins as a snow-drift at its summit, and ends in a transparent ice-cavern below. "The blue blocks which span the sources of the Arveiron were once powdery snow upon the slopes of the Col du Géant."