An abundance of excellent skating, the freshet that covered the meadows being frozen. Many boys and girls are skating on Mantatuket Meadow and on Merrick’s. Looking from this shore, they appear decidedly elevated,—not by their skates merely. What is the cause? Do we take the ice to be air?
I see an abundance of caterpillars of various kinds on the ice of the meadows, many of those large, dark, hairy, with longitudinal light stripes, somewhat like the common apple one. Many of them are frozen in yet, some for two thirds their length, yet all are alive.
Yet it has been so cold since the rise that you can now cross the channel almost anywhere.
I also see a great many of those little brown grasshoppers and one perfectly green one, some of them frozen in, but generally on the surface, showing no signs of life; yet when I brought them home to experiment on, I found them all alive and kicking in my pocket.
There were also a small kind of reddish wasp, quite lively, on the ice, and other insects; those naked, or smooth, worms or caterpillars.
This shows what insects have their winter quarters in the meadow-grass. This ice is a good field for an entomologist.
I experimented on the large bubbles under the ice. Some, the oldest and nearest the surface, were white; others, the newest and against the present under surface, were of a bluish or slate color, more transparent. I found that the whiteness of the first was owing to the great quantity of little bubbles above and below the great one produced by the heat of this “burning-glass,” while those of recent formation have not had time to accomplish this.
When I cut through with my knife an inch or two to one of the latter kind, making a very slight opening, the confined air, pressed by the water, burst up with a considerable hissing sound, sometimes spurting a little water with it, and thus the bubble was contracted, almost annihilated; but frequently, when I cut into one of the old or white ones, there was no sound, the air did not rush out because there was no pressure, there being ice below as well as above it; but when I also pierced the lower ice it did rush out with a sound like the others.
My object at first was to ascertain if both kinds of bubbles contained air. But that was plain enough, for when the water rushed in the bluish, or new, ones wholly beneath the ice wholly or nearly disappeared, while the white ones, giving place to water, were no longer white. It would seem, then, that a considerable pressure, such as the water exerts on an air-bubble under the ice, does not force it through the ice, certainly not for a considerable time.
How, then, can the musquash draw air through the ice as is asserted? He might, however, come to breathe in such a bubble as this already existing.
The larger spiders generally rest on the ice with all their legs spread, but on being touched they gather them up.
H. D. Thoreau, Journal, January 24, 1859
This ice is a good field for an entomologist. See January 22, 1859 ("Perhaps the caterpillars, etc., crawl forth in sunny and warm days in midwinter when the earth is bare, and so supply the birds, and are ready to be washed away by a flow of water! I find thus a great variety of living insects now washed out. ")
I found that the whiteness of the first was owing to the great quantity of little bubbles above and below the great one produced by the heat of this “burning-glass,” See January 9, 1859 ("I inferred, therefore, that all those infinite minute bubbles I had seen first on the under side of the ice were now frozen in with it, and that each, in its proportion or degree, like the large ones, had operated like a burning-glass on the ice beneath it")
No comments:
Post a Comment