Some Final Images of Excavations

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Here are some elevated wide shots of our excavations at the close of the field season. We were really unlucky this year to have very few days of clouds, and therefore many of our photos were taken under less than ideal circumstances. You want an even light so clouds are best, but I guess you […]

Defining the Beam

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One of the last tasks tackled during excavations at the mill was trying to better understand the purpose and size of the large beam that seems to divide the stamp room and wash house. We’d uncovered this piece of architecture weeks ago but we never fully cleaned it off of all the sediment in order […]

June 11th: Another New Trench Opened… and Stuff!

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June 11th was a pretty busy day. Not only were we busy drawing and finishing up 100.U1 and 100.U2, we also cut out a large wood plank in 101.T7 and then decided to start another trench unit. This trench unit, 101.T4, was located just south and abutting 101.T3 (makes sense, right?). We knew wood features […]

Soil Peel You Tube Video

Here is a video created by crew member Mark Dice and starring our very own Dr. Scarlett. In in, Dr. Scarlett attempts to remove a latex soil peel from an excavation profile from 101.T7 in order to preserve its soil stratigraphy.

Where Does the Water Come From and More Importantly….

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…where does it go? That was the question we asked ourselves at the beginning of June 10th. Just how was water used at the Cliff mill and what was their source? Did they use seasonal runoff from up above the bluff behind them? Did they run a water race from a dammed pond a 1/4 […]

Back from a Long Break, Continued

101.T8 after closing the first level of excavation and opening another. For the most part, this unit is already mostly completed due to the amount of wood surface exposed. Note the green-stained wood at center.

Back in the wash house, excavations continued east of the current open trenches. The new unit trench, 101.T8, was another 4×2 meter area with a north-south sloping topography. This unit was connected to 101.T3 on the west but off set 1 meter to the south. We assumed we’d find much the same thing in it during excavation, a wood working surface in the north end and a tangle of wood launders and a hard to reach bottom in the south end.

The students took to 101.T8 with shovels at first, but quickly found that trowels were required once they came upon some wood in the north half closer to the surface than the wood found in 101.T3. This was a long beam that began just within the western sidewall and continued east through the east side wall. The beam was 30 cm wide and at least that tall. It was split right down the middle of its length and had 2 large iron bolts sticking up out of it. To the north of this beam was a floor, but the beam was so close to the northern side wall that only 20 cm of this floor could be exposed. It continued south of the beam as well for another 40+ cm.

In the middle of the unit (at the end of the floor)  a green-stained surface of planks was discovered at the same level as the floor just mentioned. The green stain was copper residue and the planks were likely part of some sort of separation technology we’re not able to identify as of yet. Beyond that to the south there was a void filled with stamp sand. We decided to call it a day on 101.T3, take photos and draw what we had uncovered so far.

The Answer to Yesterday’s Question

The iron straps are attached to the stamp batteries. Therefore, the end-grained wood mounts we've discovered were located between two batteries.

So there you have it. What we discovered in 100.U1 and 100.U2 were the remains of the “gap” between two stamp batteries. Each iron strap was attached to the front uprights of an individual battery. The “gap” consisted of a slab of end-grained wood with iron braces and more slabs of wood underneath it. All of this points to the idea that the weight of the stamps and stamp batteries themselves were not distributed directly underneath them, but instead off the sides. This makes sense since the areas directly under the batteries were found to be hollow.

May 27th: Just Where is the Floor in this Place, Anyway?

Eric (lying down) and myself trying to find the bottom of the wash house in 101.T3 I'm sitting in there by the way, not standing.

The wood working surface uncovered in 101.T3 a few days prior was soon found to end about 1 meter short of the 4 meter long trench. We’re not sure if the floor was ripped out or if it was designed to end at that point. It may even have continued as removable planking, and just happened to have been removed long ago. What is for certain is that the last 1 meter or so occupying the south end of 101.T3 is a complicated mess.

At upper right, the box. The trough/launder moves overflow material SW from the box and then jogs west, out of the trench. If you look closely you can see groves worn into the trough at bottom left corner.

First, protruding out of the east profile was a box, 75 cm square in size. Its depth was about 50 cm and at its bottom was found a thin layer of copper residue (or fines). Jutting out from (but not directly connected to) this box was a sluice/launder slightly angled downward. Its orientation was NE to SW and after about 1.25 meters, it jogged west and continued out the west profile of the trench. Defining these features with a trowel was pretty easy, but the areas surrounding them were getting tighter and tighter to work in, and they appeared to have no end to them. As you can see in the photo above, Nick had to reach into the unit to remove material and I had to climb inside. I was sitting on a small wood platform but there were areas below me that continued down probably a meter from the surface. At this point, we have no idea how far down this building goes.

Back to the trough/launder, its top end was severely damaged due to charring, and its overall state was extremely fragile. It was so bad that originally we thought it was rubble, and not lying in situ. We decided to cut it out and only after we started cutting with a saw did we realize it was in place. Due to its fragility, we decided to leave the material inside the trough as it was what was holding it all together. We did remove the material inside at the point where the trough/launder turned west, and found that the water and material that flowed through it historically was traveling at a strong enough rate to actually cut rivulets of grooves throughout its length. Also, there were pockets of copper fines scattered on its surface.

So what did we find? Well, I’m not exactly sure if its related to the washing process or simply waste removal. The material collected in the box must have overflowed into the trough, since it is not connected via a valve or hole in the side of the box. If this is the case, only the lighter material would have run down the launder, meaning it is for waste product. But, there were fines found in the trough as well, so I could be wrong. We’ll just have to open up the trench to the west to see where this trough/launder goes.

May 27th: A Very Busy Day (and Stairs!!!)

May 27th was a busy day indeed. 101.T3 was basically finished, 100.T2 almost as well, and another new trench was opened to the west of these two, 101.T7. This post is concerned with 100.T2 and the fact that this trench sits on the border between two buildings, the stamp room and wash house.

At left can be seen the stamp mill as it sat in ruins towards the end of the 19th century. The long white roofline is the stamp room, the wood remains lying in front are what's left of the wash house. Note the gabled roofline where the two perpendicularly aligned buildings met (click on the photo for a larger view).

The photo above shows the distinction between these two buildings rather well. Of course we can’t see inside the stamp room (that would be too easy, right?). 100.T2′s is a 4 meter long trench, and the first 3 meters of it are in the stamp room. The last meter overlies the “step” between the higher sitting stamp room and wash house that sits a few feet below.

Dr. Sam Sweitz helps Nick take down the "step" of fill material in 100.T2.

Excavating 100.T2 for the first 3 meters required very little work. For the most part the features in this area of the trench are only 20-30 cm below the surface. The “step” however had a lot of sloping fill that needed to be removed. At the top of the step was a 30 cm wide board that ran across the entire east-west  axis of the trench. This was in pretty bad shape and likely spent a fair amount of time exposed at the surface years ago. Under this board, an extremely large beam also ran east-west through the trench. Some of this board showed signs of char, but for the most part was a solid piece of wood. Cut into the top of this beam were a few small notches, likely post holes/mortises for the stamp room’s south facade. Supporting this large beam were granite blocks of stone. This was very interesting since you’d expect to find mine waste rock (its free building material), but knowing something about the geology of the area the Cliff’s trap rock was very soft, and maybe it was felt a sturdier rock was needed for this part of the construction.

Meghan, Kim, and volunteer Brandon contemplate and record the stairs and granite stones marking the division between the stamp room and wash house.

These granite stones eventually met the working surface uncovered in 101.T3 days earlier. Now with most of that fill gone, the joining of the stamp room and wash house could be easily seen. How they worked in concert was still a puzzle though. We hoped to find a trough or launder starting in the stamp room and running into the was house. This would have helped explain how the stamping/washing process transitioned from one building to the other. There was no launder or trough however, we would have to wait a bit longer to find the clues we were looking for.

One big surprise discovered while digging out the fill in 100.T2 was the remains of stairs! The three-step stair case leads up from the wash house over the granite and wood beams into the stamp room. We may not have been able to see how material moved from one building to the other, but we were able to see how workers did it. The students (and myself) were really excited about this discovery. This is without a doubt the best feature available to us for interpreting the site to visitors. It’s hard to imagine large steam equipment and washing machinery when all there is are the mounts left. People can actually see a set of steps and know exactly what is going on. When you start with the easily identifiable, you can open up a visitor’s mind to the less tangible, ephemeral remains all around them.

LiDAR at Cliff

This is just a quick post to inform the blog followers that we were visited by the guys from Clearwater Surveying out of South Range and Steve Curelli from Michigan Tech’s School of Technology. The crew brought out a Light Detection and Ranging (LiDAR) scanning instrument. This is a remote sensing technology that uses lasers to record millions-yes millions-of individual points of data of any surface the scanner is pointed at.

As the scanner rotates on the tripod, its recorded data is displayed on the laptop-a laptop that required some quick thinking to keep it from dying on us.

We spent the entire day (our day off mind you) running 7 scans of the excavated mill, and although there was one major hiccup (we had to jerry-rig jumper cables to charge the laptop that stores the scan data), the raw data looks great. This raw data will require a lot of processing but I hope to have some images created out of the scan (what is called a point cloud) up in the near future.

This technology is being used by historic building recorders like the Historic American Engineering Record to assist in making measured drawings of features. The data’s also useful for creating 3-D digital models. This way, even though the excavations will be backfilled in a week, we may be able to access a 3-D representation of the works for further analysis without having to return to the site. Our hope is to use the data for both of these reasons as well as test its sensitivity to different materials on site. Historic wood, stamp sand, and even the copper residue found on the wood may respond differently to the laser. By understanding these responses, or intensities, we may be able to refine the technology for future scans of historic structures in the Upper Peninsula.

So stay tuned for a more detailed post on the days work and results. Tomorrow, back to the excavations.