Buddles?
The Champion Mill, like any mill on the Keweenaw, works to separate copper from the rock that entombs it. First, copper rock is broken down into very small particles using stamps, then a series of machines work to separate the heavier copper from the much lighter rock. The copper is collected for shipping to the smelter, while the rock is deposited as waste into the lake. During out Mohawk Mill exploration, we took a detailed look at the process including the use of jigs and wifely tables. (as seen by the photo to the right, taken inside the mill during operation) By the ruins we found at Champion, it became apparent that a few more machines were in use here that were absent at Mohawk.
From the vantage point of the panoramic photo taken yesterday, we found ourselves in the middle of the wash floor of the mill. This is where the wifely tables of the mill would be located; stretched in long lines across the concrete floor we currently were standing on. Wifley tables were small and light machines, requiring very little in terms of concrete foundations or supports. That is why the large concrete foundations we found along this floor seemed a little out of place. Specially since we never found them at Mohawk.
These were conical shaped concrete basins, about three feet in height. The basin tapered into a circular hole in its center under which a short tunnel made it way out the side of the base. Around the outer edge was a defined lip, looking as if it may have supported something at one time. While there appeared to be only two of them here, we had seen similar structures in greater numbers at the C&H mill.
There were two possible identities for these basins. First was a grinder. As mills matured, companies supplemented their stamps with grinders to help break the copper rock down into even finer particles. Sand grinders would mix the slime (copper rock/water mixture) with ball bearings and sand in a conical drum. The drum would rotate, grinding the copper rock against the sand and bearings. These basins could have supported a rotating drum, especially one conically shaped. While probable, this solution does hot seem likely. The location of these basins at the end of the building would indicate that they were involved in the last step in the milling process before the stamp sand was dumped into the lake. Grinders would be used early on, before the slimes were worked over by the jigs and wifely tables. This make the second identity the more likely: buddles.
Buddles were yet another way to separate the heavier copper from the lighter rock particles through the differences in their specific gravities. Theses machines consisted of a spinning disc, slightly convex in shape. The slime would be poured over this disc on which the heavier copper would settle while the lighter rocks and water would simply pour off. Workers would then brush off the copper from the disc and the process would be repeated. The similarities between a buddle and these structures are compelling. Consider a rotating disc placed over the basin, much like a lid. Water that falls off its edge would fall into the basin, and naturally drain into the center hole. From there the mixture would flow out of the structure and into a waiting launder for removal from the building. The current structure would support all those claims, making a buddle the most logical answer. Satisfied with our deductions, we moved further up the ruins, towards the terraced levels ahead of us.
To get a better idea of what a buddle would look like, check out this model of a buddle from the Powerhouse Museum at Sydney Australia. Comparing this model to the diagram of the ruin we found, the similarities become even more clear.
explorer | December 4, 2006