I might as well add to this thread with some photos from our second trip, where we got to see some less known parts of this well known place.
This time, we made it down under the mill to see the remains of the turbines and some very neat stonework.
28: TailraceTwo levels below the partially-collapsed flooring are the tailraces that carried outflow water from the turbines to the river.
29: Curly PipePipes were made like this in the late 1800s. Most of this part of the mill was built between 1860 and 1890, and continually rebuilt in many ways through the early 20th.
30: Outflow PitTo the right, one of the big outflow pipes plunges down into the mud. The mud here is probably a few feet deep and way too soft to stand on.
31: ArchThere are five of these tailrace tunnels, all linked together and made of really diverse and pretty stonework.
32: Line ShaftThere were four of these big turbines, maybe five, maybe more. This big line shaft passed through them all, with a few clutches and flywheels along its length.
33: Flywheel These flywheels on the line shaft probably once had flat belts running up to the machines above. In the mill's later years they might have run generators instead, but it's obvious that these turbines were slowly abandoned one by one over the years the mill was active.
34: Close/Open20th century tech mixes with 19th in the line-shaft tunnel.
35: BasementIn a different section of the mill, this basement shows a lot of rebuilding and repairing over the years.
36: Nutmeg ClubThis brand of soda from New London CT doesn't exist anymore.
37: OutfallThe other end of the tailrace in 28, on the river bank.
38: Other Outfallthe brickwork here looks identical to a drawing from 1866, so it's probably original.
39: Atmosphereit started raining as we were on our way out.