As I walk over thin ice, settling it down, I see great bubbles under, three or four feet wide, go waddling or wobbling away.

February 14. 

P. M. — On ice up Assabet to railroad. 

The ice-belt which I still see along the steep bank of the Assabet is now some three weeks old, and though it was then six or eight inches thick, it is now only two or three, or much less, in many places nearly wasted away, and those once horizontal tables are often fallen aslant, like shields pierced with many holes. 

That belt, at first consisting of more or less blunt triangles projecting four or five feet from the bank, was at first, of course, perfectly horizontal and level (I see where dogs and foxes have run along on it for half a mile together), but now, such is the flexibility of the ice, it is bent downward by its own weight, or if you stand in front of it, it is a waving or undulating line instead of a level one, i. e. on its edge. 

I see one table, where the ice is a little more than one inch thick, which is curved downward on the sides eighteen inches within a horizontal distance of two and a half feet. There is nothing like a crack at this bend. Some of the belt itself, where three inches thick, has bent downward eighteen inches at four or five feet from the bank.

 I also see on Sunset Interval a large cake a rod square and a foot thick with more than a foot of soil attached beneath, which, by its own weight resting high and dry there, has bent very considerably. 

In one great cake there just like this, I see a fence-post with three holes in it standing upright, and perhaps the whole of it has been brought away in the soil beneath. 

It does not appear where it came from. Looking at the edge of one of these cakes, I notice some bubbles, seen edgewise, in the form of some buttons or of an inverted Moorish dome. 

These are they which when you look down on them appear thus: 

As I walk over thin ice, settling it down, I see great bubbles under, three or four feet wide, go waddling or wobbling away like a seared lady impeded by her train.

I have but little doubt that the musquash gets air from these bubbles, which are probably very conspicuous under the ice. They are its reservoirs.

H. D. Thoreau, Journal, February 14, 1859


The ice-belt which I still see along the steep bank of the Assabet is now some three weeks old. See  January 1, 1857 (" I observe a shelf of ice — what arctic voyagers call the ice-belt or ice-foot (which they see on a very great scale sledging upon it) — adhering to the walls and banks at various heights, the river having fallen nearly two feet since it first froze.""); January 16, 1857("As I pass the Island (Egg Rock), I notice the ice-foot adhering to the rock about two feet above the surface of the ice generally. . . . The same phenomena, no doubt, on a much larger scale occur at the north.”); February 1, 1859 ("Also an ice-belt adheres to the steep shores . . .and you see where this hard and thick ice has bent under its own weight.")


I have but little doubt that the musquash gets air from these bubbles. See January 22, 1859 ("J. Farmer tells me that he once saw a musquash rest three or four minutes under the ice with his nose against the ice in a bubble of air about an inch in diameter, and he thinks that they can draw air through the ice,"); January 24, 1859 ("He might... come to breathe in such a bubble as this already existing.");