What various kinds of ice there are!

January 31. 

P. M. —— Up river across Cyanean Meadow. 

Now we have quite another kind of ice. It has rained hard, converting into a very thin liquid the snow which had fallen on the old ice, and this, having frozen, has made a perfectly smooth but white snow ice. It is white like polished marble (I call it marble ice), and the trees and hill are reflected in it, as not in the other. It is far less varied than the other, but still is very peculiar and interesting. You notice the polished surface much more, as if it were the marble floor of some stupendous hall. Yet such is its composition it is not quite so hard and metallic, I think. The skater probably makes more of a scratch. The other was hard and crystalline.

As I look south just before sunset, over this fresh and shining ice, I notice that its surface is divided, as it were, into a great many contiguous tables in different planes, somewhat like so many different facets of a polyhedron as large as the earth itself. These tables or planes are bounded by cracks, though without any appreciable opening, and the different levels are betrayed by the reflections of the light or sky being interrupted at the cracks. 

The ice formed last night is a day old, and these cracks, as I find, run generally from northeast to southwest across the entire meadow, some twenty-five or thirty rods, nearly at right angles with the river, and are from five to fifteen feet apart, while there are comparatively few cracks crossing them in the other direction. You notice this phenomenon looking over the ice some rods before you; otherwise might not observe the cracks when upon them. 

It is as if the very globe itself were a crystal with a certain number of facets. 

When I look westward now to the flat snow-crusted shore, it reflects a strong violet color. 

Also the pink light reflected from the low, flat snowy surfaces amid the ice on the meadows, just before sunset, is a constant phenomenon these clear winter days. Whole fields and sides of hills are often the same, but it is more distinct on these flat islands of snow scattered here and there over the meadow ice. I also see this pink in the dust made by the skaters.

Perhaps the green seen at the same time in ice and water is produced by the general yellow or amber light of this hour, mingled with the blue of the reflected sky? ? 

Surely the ice is a great and absorbing phenomenon. Consider how much of the surface of the town it occupies, how much attention it monopolizes! We do not commonly distinguish more than one kind of water in the river, but what various kinds of ice there are! 

Young Heywood told me that the trout which he caught in Walden was twenty-seven inches long and weighed five pounds, but was thin, not in good condition. (He saw another.) It was in the little cove between the deep one and the railroad.

H. D. Thoreau, Journal, January 31, 1859

Pink light reflected from the low, flat snowy surfaces amid the ice on the meadows, just before sunset, is a constant phenomenon these clear winter days. See  December 20, 1854 ("in some places, where the sun falls on it, the snow has a pinkish tinge");  December 21, 1854 ("The last rays of the sun falling on the Baker Farm reflect a clear pink color. "); January 1, 1855 ("We see the pink light on the snow within a rod of us"); January 10, 1859 ("This is one of the phenomena of the winter sunset, this distinct pink light reflected from the brows of snow-clad hills on one side of you as you are facing the sun."); January 19, 1859 ("I see a rosy tinge like dust on the snow when I look directly toward the setting sun, but very little on the hills. Methinks this pink on snow (as well as blue shadows) requires a clear, cold evening."); January 23, 1859 ("I notice on the ice where it slopes up eastward a little, a distinct rosy light (or pink) reflected from it generally, half an hour before sunset. This is a colder evening than of late, and there is so much the more of it.")

Perhaps the green seen at the same time in ice and water is produced by the general yellow or amber light of this hour, mingled with the blue of the reflected sky. See Janusry 20, 1859 ("The green of the ice and water begins to be visible about half an hour before sunset. Is it produced by the reflected blue of the sky mingling with the yellow or pink of the setting sun?"); December 29, 1859 ("To-night I notice the rose-color in the snow and the green in the ice at the same time, having been looking out for them. ")

But what various kinds of ice there are! See January 26, 1859 ("What various kinds of ice there are!