When my Duluth colleagues Ava and Dan (proprietor of substreet.org) came to visit me during one of my autumn Copper Country vacations, Point Mills was one of the places we decided to check out. Though we were unable to get to the Franklin Mill, we did scope out the Arcadian. When we came across the remnants of the rock bins, we knew we had found it.
As always, the metal portions of the mill (namely its walls and roof!) had been removed long ago for scrap.
Standing on top of the pile, we also had a good view of the mill floor as it sloped down toward the lake, which is partially in view through the trees:
There was a time when the rumor going around was that any hole that was dug anywhere in the Keweenaw Peninsula would lead to copper riches, and apparently the Arcadian's investors still believed that.
The Arcadian Mine faded into history after just a few years, and everything was sold off. Luckily a much more profitable company, the Centennial Mine, was in the market just then for a stamp mill of their own, so they snatched this one up and renamed it the Centennial Mill after themselves. I wrote of the Centennial Mine's #2, #3, and #6 shafts in the following older posts:
The Abandoned Mine Down the Street
Arriving in Centennial
The End of an Era
I have also explored and written about other stamp mills in the Copper Country in these posts: Of Stamps, & Smelters (Part 1), Of Stamps & Smelters (Part 2), Mining in the Clouds, and "Hunting on the King’s Lands".
The ruins of the old concrete railroad grade-separation piers at Point Mills Junction are a familiar Copper Country landmark seen from highway M-26 as one passes through the area, thanks to the old advertisement for the Arcadian Copper Mine tour. I never did bother to get a photo of my own, so here is one of Mike's:The Abandoned Mine Down the Street
Arriving in Centennial
The End of an Era
I have also explored and written about other stamp mills in the Copper Country in these posts: Of Stamps, & Smelters (Part 1), Of Stamps & Smelters (Part 2), Mining in the Clouds, and "Hunting on the King’s Lands".
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| Photo from CopperCountryExplorer.com |
The Centennial modernized and expanded the old Arcadian Mill significantly in 1910, adding three more stamp heads for a total of six, which effectively doubled its output capacity. They also added an electric generating station to the boiler house, to power its many wash tables and jigs.
The leaf-covered incline in the foreground is actually the stack's flue.
The mill's carpenter shop, and office building were once located here behind the smokestack foundation:
A view inside of the basement, which is basically all that's left:
Beginning our trip down the mill floor, I came across some sandstone specimens, some with iron studs sticking up out of them. These pieces of course were to the original Arcadian Mill, and predated the concrete foundations that were added by Centennial later:
When the massive Calumet & Hecla (C&H) mining conglomerate bought up the Centennial, they acquired this mill as well as the Osceola Mills, the Dollar Bay smelter, the Ahmeek Mill, and two of the Tamarack stamp mills. With all these acquisitions in their back pocket, C&H had way more milling capacity than they needed, so they used the Arcadian / Centennial Mill to contract milling services to other independent mines in the Copper Country. Of course they also planned more upgrades and expansion at this mill to handle this increase in work, and make it more efficient.
A stamp mill, Mike explains, is typically a huge terraced concrete foundation built near a large body of water, whose stepped levels provide places for the mill’s bins, stamps, jigs, and wash tables to handle copper ore in successive stages as it is moved on its way through the refining process. This layout allows for the optimal use of gravity in the transportation of the "slime" throughout the facility and its subsequent ejection from the launders. The material is referred to as slime because that's what it looks like when copper-bearing rock is ground down to super-fine consistency and mixed with water, so as to compel it to flow more easily through the machines and their processes.
The ore starts out in large rock form in bins at the top of the mill, and goes into the stamps which break it down into smaller size so that it can be handled by the jigs on the next level down, and so on. At the bottom of the mill, waste tailings are deposited in piles and the final product is loaded up on a train again to go to a smelter so that it can become actual copper.
This stamp floor would have originally been home to three Nordberg stamps, with another three located at the opposite end of the building. These were huge steam-powered juggernauts that lifted and dropped massive steel hammerheads down onto the rock. The six stamps at this mill had a daily capacity to handle 4,000 tons of rock, Mike wrote.
Here at the Arcadian / Centennial Mill, the stepped layout of the classical stamp mill formula was altered slightly to utilize only a couple of terraced levels for the stamps, rock bins, and roughing jigs, while the rest of the mill floor beyond that was simply a concrete slope, upon which angled foundations for the jigs and wash tables sat.
Mike drew up a nice diagram of this:
The material is moved down through the levels of the mill by gravity, utilizing a series of chutes...
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| Photo from CopperCountryExplorer.com |
This was all that was left of one of the chutes, nowadays funneling more golden leaves than copper ores.
After the stamps, the copper ore is sent through a series of classifiers, which sort the rubble according to size.
This sorted rock then goes down to the mill’s jig floor, first to the larger roughing jigs, and then the finishing jigs, being ground down to a finer and finer consistency.
The final refining stage of the mill is a line of wash tables, which turn the now finely-ground copper ore into a slime by mixing it with water and separating out the heavier copper particles from the waste material.
This flat open area of the mill floor, Mike says, was once home to the finishing jigs and wash tables. Originally there were 110 washing jigs and nine tables, but when Centennial upgraded the mill later those numbers were doubled.
The concrete troughs in the floor were the launders, which carried waste material away like a sluice, and deposited it at the bottom of the hill. The autumn leaves collecting in them makes it look like rivers of gold...
Originally the launders would have probably been lined with wood.
There were also a few rails set into the floor of the mill, along which tram carts would have moved.
Toward the bottom of the mill was another series of stubby pedestals stretching across the floor, where the mill’s battery of wilfley tables was once located.
Mike says that when the Arcadian Mill was built, there were only a handful of wilfley tables in use. By the time Centennial took over this mill they were an industry standard. But like jigs, the wilfley tables were built of wood and would have rotted away long ago. More likely they were removed, and reinstalled in some other mill.
I had reached the very bottom end of the mill floor, and there was a very large trench running horizontally along it, as well as a few other curious structures.
In Bulfinch's Mythology, Arcadia is a region of Greece, meaning "the place of Arcas," though it was also the favorite realm of the woodland god Pan. In Greek mythology, Arcas was a hunter as well as one of Zeus's innumerable illegitimate sons. Arcas and his mother Callisto were placed in the heavens by Zeus after being turned into bears by the goddess Hera, the jealous and vengeful wife of Zeus.
Callisto became the constellation Ursa Major and Arcas became her twin constellation, Ursa Minor–the Big and Little Dippers–both of which circle around Polaris, the North Star, which shines at the tip of Arcas's tail. Thus it was referred to as the "Star of Arcady" by Milton in his poem Comus, in 1634. And now you have one more bit of trivial knowledge taking up space in your brain.
Anyway, this trench was once covered over with a roof of some sort, and was called the mineral house:
Waste mineral was washed away through launders and dumped into the lake (shhh, don't tell the EPA), while the good copper ore was deposited here via the tram carts I mentioned earlier, for delivery to the smelter by train.
This was a small cubby that had a valve shutoff or something utilitarian in it, if I recall correctly:
Down in the trench...where railroad cars were loaded up from above, before their trip around the lake to the smelter.
A small opening looking down into the trench, perhaps it was once a chute that would have delivered payload into the mineral house:
This view from the top of the other side of the trench shows just how high off the ground the rest of the mill floor is:
Climbing all the way back up to the top corner of the mill again, I found a weird area that was recessed like a pit, down below the level of the rest of the mill floor. Inside there were a couple pyramid-shaped pedestals, of no discernible purpose. Some were concrete, but at least one was sandstone.
Mike Forgrave puzzled over this same feature, and found out that it was actually part of an unfinished addition to the mill that was started in 1928.
Soon after this expansion started however, the mill was shut down forever and the new phase was never completed.
The sandstone parts, again, all date to the original construction by Arcadian. I believe this sandstone footing once supported the railway trestle that brought loaded trains from the mines to dump in the rock bin at the top of the mill:
He said that it could have supported a small steam engine, most likely to power the movement of the stamps themselves.
Some early Sanborn maps denoted the existence of a 150-horsepower engine in this general area he said, so that's most likely the case.
There were more picture-worthy ruins to see down by the lake shore where the mill's pump house and docks were located, but we did not make it that far.
References:
http://www.coppercountryexplorer.com/explorations/mills/centennial-mill/
A Guide to Michigan's Historic Keweenaw Copper District, by Lawrence J. Molloy, p. 19
http://www.coppercountryexplorer.com/2008/09/anatomy-of-a-mill-stamps/
Bulfinch's Mythology, by Thomas Bulfinch, p. 31-34, 885
