By Deane Rykerson
TMI President

Tide mills had all the functions that stream mills did, from cutting lumber to milling flour. But did you ever wonder why gristmills are so much more vertical than sawmills? There is often a roof monitor or cupola in a gristmill. Well, form follows function and gravity is an important part of the function of grinding grain. If we follow a kernel of wheat from harvesting to being ready for bread, we can see how important height can be to aid the milling process. What goes up must come down.

At the top of the mill there is storage for the grain, fed by a hopper. The grain then descends to a screening process that shakes and sifts to remove gravel and sticks from the food product. At the next lower level the clean kernels are fed between the grinding stones, gradually working outward on the grooves of the bedstone. A rotating screened tube, called a bolter, can then be used to separate the coarser meal from the finer flour.

Continue reading “Grist Mills and Gravity” →

Even if you haven’t visited southern Maine, you’re still sure to enjoy The Tide Mills of Kittery, a new 34-minute video about tide mill technology and history, exploring several abandoned tide mill sites between Kennebunkport, Maine, and Hampton, N.H. By themselves, the superb aerial video segments by Jim White are enough to make viewing well worth your time.

This video premiered at the annual conference of the Tide Mill Institute, held on line in mid-November, and all are now invited to watch it by clicking the link at the end of this announcement. The drone’s eye views of tide mill sites gives us a new way to examine these somewhat hidden landscapes.  After decades of tide mill enthusiasts dealing with muddy boots or looking down from satellites with Google Earth, we now have a fantastic tool to see this history in our own backyards and in great detail.

The tour starts with a welcome by Bud Warren, a Tide Mill Institute founder and former president. Bud explains the role of tide mills in American Colonial history and describes how ingenious millers trapped seawater from the incoming tide and then released it through a channel to power water wheels or turbines. This mechanical power was then harnessed to grind grain, saw timber and perform other tasks formerly requiring human or animal muscle power.

Continue reading “New Tide Mill Video – Not Just for Locals” →

by Robert Gordon

A recent article on a rehabilitated tide-power installation describes it as a “newly revived link to lunar energy.” It isn’t. Tide power comes from the earth, not the moon. Think of a toy gyroscope. Spin the wheel and it gradually slows because of friction in its bearings and the air drag on its disc. The friction of tidal currents flowing over the sea floor is doing this for the earth. How do we know it is happening? Because the speed of the earth’s rotation about its axis is slowing. That means our day is getting longer, and the number of days in a month is decreasing. Not by much, but enough to be seen in the time kept by modern precise atomic clocks. But we already knew this before those precise clocks were invented, from the sex life of clams. Here’s how.

Some species of bivalves add to their shells day-by-day. Section a shell and you can see growth rings, like those on the end of a log or tree stump. Clams have to reproduce themselves, fairly frequently since they don’t have long lives. For some species the sex act is triggered by the full moon. Reproduction takes a lot of energy. This leaves less for growing a shell. Every month the spacing of the growth rings in the clam’s shell gets smaller for a few days. Count the number of large rings in the shell between the bands of narrow ones and you have the number of days in the month, about 30 in a modern shell.

Continue reading “Where Does Tide Power Come From?” →

By Deane Rykerson
TMI Acting President

Fall is definitely here and I can now reflect on the interesting summer we have had filming The Tide Mills of Kittery Maine.

This idea got its start last year when Fred Perry suggested we compile all of the presentations about Kittery tide mills from our annual 2019 conference. I thought it was a great idea but how much greater could this be if we included drone footage of our tide mill remnants. I thought about my friend and neighbor Jim White who is an excellent documentary filmmaker and FAA-licensed drone pilot. Then I realized that this was going to be a PROJECT (which usually involves MONEY). Luckily the Maine Humanities Council was offering bicentennial grants (Maine 200), so I thought, “let’s try.” After a commitment from the board of TMI and other sponsors, I got letters of support and completed the application by early January.

Continue reading “Filming a Tide Mill Documentary” →

Yesterday, Verdant Power, Inc., announced it installed an array of three 35-kilowatt, 5-meter-diameter turbines in the East River of New York City. These turbines, powered by tidal currents in the river, will provide a small amount of electricity to Roosevelt Island, which lies between Manhattan and Queens.

If the project is successful, it could lead to deployment of similar but larger (10-meter) turbines off the coast of Wales sometime in 2023, according to a news article in GTM (Greentech Media) published on October 20.

Read more about this project in GTM.
Project details on Verdant Power, Inc., website.

Tide Mill Institute is confronting the COVID-19 crisis by hosting its 17th annual conference on line Saturday, November 14, at 10 a.m.

This year, the online “mini-conference” via Zoom video conferencing requires us to be brief, but you shouldn’t miss it. TMI will feature the world premier of a video about historic tide mills in southern Maine. Other features of this Zoom event include presentations about an unusual tide mill swindle in Lubec, Maine, and a sensitively shared story about a Virginia tide mill that still has its original machinery and other molinological tidbits.

Some details:

Tide Mills of Kittery. The idea for this film emerged after speakers at last year’s conference and a local film-maker realized the value of joining forces to retell their story in a more effective, visual way, with striking drone photography of actual sites and interviews with tide mill historians. TMI obtained funding for the project from the Maine Humanities Council. Watch the film’s promotional trailer.

Continue reading “2020 Tide Mill Conference: Nov 14 Online” →