The floating surface of Gowing's Swamp

February  1

Measured Gowing's Swamp two and a half rods northeast of the middle of the hole, i. e. in the andromeda and sphagnum near its edge, where I stand in the summer; also five rods northeast of the middle of the open hole, or in the midst of the andromeda. 

In both these places the pole went hard at first, but broke through a crust of roots and sphagnum at about three feet beneath the surface, and I then easily pushed the pole down just twenty feet. This being a small pole, I could not push it any further holding it by the small end; it bent then. With a longer and stiffer pole I could probably have fathomed thirty feet. 

It seems, then, that there is, over this andromeda swamp, a crust about three feet thick, of sphagnum, andromeda (calyculata and Polifolia), and Kalmia glauca, etc., beneath which there is almost clear water, and, under that, an exceedingly thin mud.

There can be no soil above that mud, and yet there were three or four larch trees three feet high or more between these holes, or over exactly the same water, and there were small spruces near by. For aught that appears, the swamp is as deep under the andromeda as in the middle. 

The two andromedas and the Kalmia glauca may be more truly said to grow in water than in soil there. When the surface of a swamp shakes for a rod around you, you may conclude that it is a network of roots two or three feet thick resting on water or a very thin mud. The surface of that swamp, composed in great part of sphagnum, is really floating. 

It evidently begins with sphagnum, which floats on the surface of clear water, and, accumulating, at length affords a basis for that large-seeded sedge (?), andromedas, etc. The filling up of a swamp, then, in this case at least, is not the result of a deposition of vegetable matter washed into it, settling to the bottom and leaving the surface clear, so filling it up from the bottom to the top; but the vegetation first extends itself over it as a film, which gradually thickens till it supports shrubs and completely conceals the water, and the under part of this crust drops to the bottom, so that it is filled up first at the top and the bottom, and the middle part is the last to be reclaimed from the water. 

Perhaps this swamp is in the process of becoming peat. 

This swamp has been partially drained by a ditch. 

I fathomed also two rods within the edge of the blue berry bushes, in the path, but I could not force a pole down more than eight feet five inches; so it is much more solid there, and the blueberry bushes require a firmer soil than the water andromeda. 

This is a regular quag, or shaking surface, and in this way, evidently, floating islands are formed. I am not sure but that meadow, with all its bushes in it, would float a man-of-war.

H. D. Thoreau, Journal, February 1, 1858

With a longer and stiffer pole I could probably have fathomed thirty feet. See January 30, 1858 ("Cut another maple thirty feet long and between four and five inches thick at the butt, sharpened and trimmed and carried it on my shoulder to the spot, and, rough as it was, it went down with very little pressure as much as twenty feet, and with a little more pressure twenty-six feet and one inch.")

There is a crust about three feet thick of sphagnum, andromeda  and Kalmia glauca, beneath which there is almost clear water. See January 30, 1858 ("To my surprise, I found clear water under this crust of sphagnum"); February 3, 1860 ("I accurately pace the swamp in two directions and find it to be shaped thus"): —

August 23, 1854 ("There is . . . an abrupt edge next the water, this on a dense bed of quaking sphagnum, in which I sink eighteen inches in water, upheld by its matted roots, where I fear to break through”).

This swamp has been partially drained by a ditch. See November 23, 1857 ("This swamp appears not to have had any natural outlet, though an artificial one has been dug. The same is perhaps the case with the C. Miles Swamp. And is it so with Beck Stow's These three are the only places where I have found the Andromeda Polifolia. The Kalmia glauca in Gowing's, C. Miles's, and Holden's swamps. The latter has no outlet of any kind.")

The shaking surface

composed in part of sphagnum

is really floating.

A Book of the Seasons, by Henry Thoreau, The floating surface of Gowing's Swamp

A Book of the Seasons, by Henry Thoreau

"A book, each page written in its own season,

out-of-doors, in its own locality."

~edited, assembled and rewritten by zphx © 2009-2025

I can hardly get under the stone bridge without striking my boat.

August 24. 

3 p. m. — Up river to Clamshell. 

Polygonum tenue abundant and in bloom, on side of Money-Diggers' Hill, especially at south base, near apple tree. 

The choke-cherry by fence beyond spring, being dead ripe and a little wilted, is at length tolerable eating, much better than I ever tasted, but the stones are much in the way. 

I was surprised to hear Peter Flood mention it as an objection to a certain peat meadow that he would have to dry the peat on the adjacent upland. But he explained that peat dried thus was apt to crumble, and so was not so good as that dried gradually and all alike on damper ground; so an apparent disadvantage is a real advantage, according to this. 

It rained a little last night, and the river at 3 p. m. is at the same height as last night. It is not remembered when it was so high at this season. 

I have not seen a white lily nor a yellow one in the river for a fortnight. The river meadows probably will not be mown this year. I can hardly get under the stone bridge without striking my boat. Cardinal-flowers, etc., etc., are drowned before they are fairly in bloom. 

River at same height as yesterday.

H. D. Thoreau, Journal, August 24, 1856

I have not seen a white lily nor a yellow one in the river for a fortnight. Compare August 24, 1854 ("The bright crimson-red under sides of the great white lily pads, turned up by the wind in broad fields on the sides of the stream, are a great ornament to the stream. It is not till August, methinks, that they are turned up conspicuously.")

I can hardly get under the stone bridge without striking my boat.  See April 8, 1856 ("River had risen so since yesterday I could not get under the bridge, but was obliged to find a round stick and roll my boat over the road.")