–
April 22, 2026
Guided Hike
with Professor Robert (Thor) Thorson
Space is limited & registration is required.
Hike Handout
Joshua's Trust's Annual Earth Day Walk will take place at two sites near each other in Lebanon, Connecticut. First, we will briefly commemorate the 250th anniversary of the American Revolution at the War Office near the southwest corner of the Town Green. Then we will take a short drive to Joshua's Trust's Pigeon Swamp Preserve. There we will enjoy a trail walk to an overlook at Big Pond. At an old mill-dam and sluiceway, we will reflect on the energy transition from hydropower to fossil fuels. At an overlook, we will commemorate the wanton extinction of the passenger pigeon as an exemplar for the ongoing Sixth Extinction. As always, segments of the walk will alternate with brief readings followed by sharing and discussion. As always, we will honor the birth of Earth System Science with a reading from Sir James Hutton's Theory of the Earth, published in 1795. This great intellectual revolution coincided with the Presidency of George Washington.
- War Office, Lebanon, Town Green. Parking is on the road right in front. Half an hour at most. Reading will be the text of the sign out front, followed by sharing and discussion. The key message is that armies don't march on an empty stomach, and that CT was critical to the war effort.
- Pigeon Swamp Preserve. We will caravan to the parking on Pigeon Swamp Road.
Readings:
JAMES HUTTON: 1795 - Theory of the Earth with Proofs and Illustrations: In Four Parts, James Hutton, M.D. & F.R.SE, Royal Society of Edinburg. Volume 1. Translation from turgid prose: 1802 - Playfair, John, Illus. of the Huttonian Theory of the Earth (NY, Dover, 1964)
"We have been long accustomed to admire that beautiful contrivance in nature, by which the water of the ocean, drawn up in vapour by the atmosphere, imparts, in its descent, fertility to the earth, and becomes the great cause of vegetation and of life; but now we find that this vapour not only fertilizes, but creates the soil ; prepares it from the solid rock, and, after employing it in the great operations of the surface, carries it back into the regions where all its mineral characters are renewed. Thus, the circulation of moisture through the air, is a prime mover, not only in the annual succession of the seasons, but in the great geological cycle, by which the waste and reproduction of entire continents is circumscribed."
"How often these vicissitudes of decay and renovation have been repeated, is not for us to determine : they constitute a series, of which, as the author of this theory has remarked, we neither see the beginning nor the end .... The Author of nature has not given laws to the universe, which, like the institutions of men, carry in themselves the elements of their own destruction"
ROBERT THORSON, 2026, in press at Princeton University Press, The Walden Experiments.
The passenger pigeon (Ectopistes migratorius) enriching the text of Walden went extinct a half-century later. They were iridescently beautiful, like gray-blue doves, but much larger, up to a pound in weight and over a foot long. Reliable 19th century reports describe enormous flocks flying sixty miles per hour casting shadows for hundreds of miles and creating a roar like a storm. John James Audubon reported one flock traveling like a wide river lasting three days straight. Dan Flores, in Wild New World, describes "the largest nesting site ever reported, near Sparta, Wisconsin in 1871, spread across 850 square miles" and many trees "contained 400 nests per tree." A single flock was estimated to contain 3.7 billion birds.[i] Such populations were likely a consequence of ecological release from land clearing and pioneering succession of a previously stable Holocene landscape.
ROBERT THORSON AND ROBERT GROSS, November 2025, "Why Concord?" in a special, book-like issue of The Atlantic titled: The Unfinished Revolution,
Before steam power and the internal combustion engine, the main source of mechanical power in Concord derived from flowing water. Harnessing hydropower required the construction of a dam, behind which a reservoir filled up with streamflow. For much of its history, Concord village was defined by a man-made pond, the filling of which was the counterpart to our putting fuel in a tank or recharging a battery.
[i] Flores, Wild New World, 33 and 266.
There is no fee for this program but donations support future programs at Joshua's Trust.
Questions about this program can be directed to Melica Stinnett, Development & Communications Coordinator at melica.stinnett@joshuastrust.org