Archive for April, 2009


Thoreau was a frequent visitor to Brister’s Spring during his travels between Walden Pond and Concord.

He described the spring as the source of the Mill Brook and speculated about Walden Pond potential inflows and outflows but he never seems to have considered that Walden Pond was seeping into the Mill Brook or into Brister’s Spring.

In 2000 the USGS reported that Walden Pond probably seeps into the Mill Brook but did not suggest a Brister’s Spring connection, although that seems quite likely given the seven foot water level difference between Walden Pond and Brister’s Spring 670 meters to its north, the direction of ground water flow.    See figure 1



“Commonly I rested an hour or two in the shade at noon, after planting, and ate my lunch, and read a little by a spring which was the source of a swamp and of a brook, oozing from under Brister’s Hill, half a mile from my field.”

“The approach to this was through a succession of descending grassy hollows, full of young pitch pines, into a larger wood about the swamp. There, in a very secluded and shaded spot, under a spreading white pine, there was yet a clean, firm sward to sit on.”

“I had dug out the spring and made a well of clear gray water, where I could dip up a pailful without roiling it, and thither I went for this purpose almost every day in midsummer, when the pond was warmest.”

Henry David Thoreau

Brister’s Spring by Gleason B&W 7”x9.5”. N.d. Written in pencil on verso: “commonly I rested an hour or two in the shade at noon.”

  Thoreau measured, drew plans and recorded Walden Pond’s X-Y and Z dimensions by surveying the Walden’s boundaries and depth in winter 1846.

“In the early 1850s, Thoreau’s facility as a land surveyor became widely known and he supported himself by surveying through the 1850s. Thoreau published two books in his lifetime and often gave lectures, but these were never profitable enough for him to give up his surveying. He saw surveying as an opportunity to pursue his real interest: observing the natural world around him.” “Surveying,” he writes in the Journal, “seems a noble employment which brings you within hearing of [the birds]” (29 April 1856).

In 1847, Thoreau described his life for the members of his Harvard class this way: “I am a School master–a Private Tutor, a Surveyor–a Gardener, a Farmer–a Painter, I mean a House Painter, a Carpenter, a Mason, a Day-Laborer, a Pencil-Maker, a Glass-paper Maker, a Writer, and sometimes a Poetaster.”


(165 surveys and plans created by Thoreau are on file in the Concord Library and available on-line)


Thoreau expressed a curiosity about Walden Pond’s in-flows and out-flows. :

“[14] As for the inlet or outlet of Walden, I have not discovered any but rain and snow and evaporation, though perhaps, with a thermometer and a line, such places may be found, for where the water flows into the pond it will probably be coldest in summer and warmest in winter. When the ice-men were at work here in ’46-7, the cakes sent to the shore were one day rejected by those who were stacking them up there, not being thick enough to lie side by side with the rest; and the cutters thus discovered that the ice over a small space was two or three inches thinner than elsewhere, which made them think that there was an inlet there. They also showed me in another place what they thought was a “leach-hole,” through which the pond leaked out under a hill into a neighboring meadow, pushing me out on a cake of ice to see it. It was a small cavity under ten feet of water; but I think that I can warrant the pond not to need soldering till they find a worse leak than that. One has suggested, that if such a “leach-hole” should be found, its connection with the meadow, if any existed, might be proved by conveying some, colored powder or sawdust to the mouth of the hole, and then putting a strainer over the spring in the meadow, which would catch some of the particles carried through by the current.”

16. The Pond in Winter Walden

However, Thoreau’s writings never recorded a suspicion that Brister’s Spring may be fed by groundwater seepage from Walden Pond, just over the hill that separates them.

This is likely due to the fact that glaciation theory in geology was just evolving and being proposed by Louis Agassiz after his appointment as Professor of Zoology and Geology at Harvard in 1847.

In a 2000 study the USGS has reported that “Northeast of Walden Pond, the Concord municipal landfill and the trailer park are located on the north side of a ground-water divide; ground water north of the divide flows generally northward away from Walden Pond toward Fairyland Pond and Mill Brook, a tributary to the Concord River” …

“Lake-derived ground water flows towards and discharges into the Sudbury and Concord Rivers or to wetlands and streams draining into these rivers.

Southwest of Walden Pond, between the bedrock high of Fairhaven Hill and Emerson’s Cliff, ground water discharges to Heywood’s Meadow and the Andromeda Ponds, which drain into the Sudbury River by way of Fairhaven Bay. The steep water-table gradient southwest of Walden Pond is caused by large water level differences (14 ft) between Walden Pond and discharging areas.

Northwest of Walden Pond, ground water discharges into an unnamed stream and wetlands draining into the Sudbury River or into the Mill Brook watershed that drains into the Concord River.”

Page 10

Geohydrology and Limnology of Walden Pond, Concord, Massachusetts


John A. Colman and  Paul J. Friesz

Published 2000


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