Monday, June 29, 2015

Fill-In... Saturday? .. and Sunday!

Apologies, dear readers, for the long break in posts. Today is my first day off in more than a week and its been incredibly intense finishing up Oven Site and then starting - and finishing - the other three sites. Plus, the crew inevitably hits a physical wall in week five as the hotter and more humid  Bermuda days take their toll. I am happy to report that all the students survived their ordeals (and, for some, self-inflicted wounds) and half of them are now safely home. The excavations are not finished - Cave Site and the new Cistern Site at Oven House are still open and active - but Smallpox Bay, Kiln, and the main Oven Site are now filled in - about which more later.

The Tragic Tale of the Iron Plate

The last week started with our valiant attempt to raise intact the iron plate we discovered at the end of last season in unit N5 E5, which waited patiently for us to remove the four feet of stratigraphy lying atop it in N4 E5. On Monday the final layer of char and rubble related to the expansion of Oven Site in circa 1630s came off and the full extent of the plate was exposed. I was hoping for something resembling a breastplate or other piece of armour, which would have fit the c. 1630s period (brought in with the first settlers, but cast off by that date as superfluous now that forts protected against a Spanish invastion) and have been consistent with the home of the commander of Smiths Fort, but alas the actual shape was much more ambiguous...
Since we determined that the plate has no actual intact iron left in it and is more a rust stain where once a plate had been, we had to develop a field conservation plan that consolidated and strengthened what was left but at the same time was reversible. Returning Field School veteran Kristina brought in some microcrystalline wax with which to impregnate the surface and act as a binder, which we first used to treat the exposed northern half of the plate.

Online research and consultancy with other conservators suggested that applying the wax in a molten or melted form could yield better results with deeper penetration, so we melted and applied the wax in a way that might be confused with meth lab production... But it worked quite well as we channeled the melted wax along a brush to evenly coat the exposed plate surface.

Attempt 1 with hair

 When the rest of the plate was exposed, we shifted strategies. The first approach left a thick layer of wax on the plate surface but did not produce sufficient penetration to bind the entirety of the plate. Applying heat would solve this problem. First, we borrowed a 12 volt boat battery and hooked it up to a power inverter I brought with me to convert to AC power, and plugged in a hair dryer to melt the wax on the surface. I quickly learned that hair dryers draw too many amps and kept tripping the inverter. So we upper our game and borrowed a portable generator (thanks Faith and Neil!!!) and a heat gun. Equipped thus, we could apply the microcrystalline wax as a paste on the plate surface and then melt it into the plate.
Applying the wax slurry

Mid-treatment, with wax in the northern half of the plate melted and absorbed 

And then came the tricky part: removal. The plate/rust smear was pressed into the uneven Bermuda bedrock limestone floor of the original Period I house, left there on the day workmen began robbing out the house's original oven and building up the floor to be level with the expanded western portion. My original idea was to use a thin wire to undercut the plate, running it along the bedrock surface in order to free up the entire plate intact. We quickly found that the wire (a guitar string) caught on high spots of the floor and wouldn't work, so we shifted to plan B: steak knives, which are thinner and more flexible than trowel blades. Sadly, and despite our best efforts, the plate fragmented as it was removed. We set up a board next to it and repositioned the pieces (for possible future cross-mending), but the end result was a much shattered recovery. In the broad scheme of things, the plate itself was an ambiguous shape, with no diagnostic elements or even original iron to help identify what it once was, but it would have been nice to have recovered it whole all the same.
Cam and Sam working on the Plate

Oven Site's New Revelations

With the iron plate removed, we could progress to the full removal of the last layer overlying the Period I floor and reveal what features were cut into it at the dawn of the house's creation. And there were many! Consistent with other parts of the house, there was no posthole in the NW corner, but we did find a very large centrally situated posthole along the middle of the west wall that matched the one we found on the east wall in 2014. Accordingly, the original house was supported by two enormous posts running up to a roof ridge, with a modified semi-subterranean A-frame structure resembling one that James Deetz conjectures for a very early site at Flowerdew Hundred in Virginia. A single deep posthole just outside the center of the north floor cut anchored the front wall of the house.
On Father's Day, I had a further great revelation as I removed several courses of what appeared to be flagstones stacked up against the northern wall cut. After puzzling over what could be the function of all these consistently flat slabs for a while (since they didn't seem to form a floor), I finally noticed that many of them had linear impressions on their surfaces, or smooth plastered faces. Others were very porous and more resembled concrete than quarried stone. It then clicked: these stones weren't cut, but rather were reconstituted limestone rubble infill for the original walls.
 Where Virginians used wattle and clay daub, Bermudian settlers at Oven Site used a limestone mixture for the infill between their wooden vertical posts - probably obtained from the quarrying out of the original floor in the 1610s. When the first-period house was dismantled prior to expansion, the builders used the discarded former wall slabs to raise up the deeper period-one floor cut as a step up to the outside surface at the time, and used other bits to bring the deeper floor up to the new Period II level.

More Later, after I catch up on some data backup, and have dinner! 

1 comment:

Jonathan Zeleznik said...

Despite the lack of blog posts this year, the iron plate post was a fun and interesting read. This weeks primetime "feature". This may serve as a sherd of hope for more frequent updates moving forward.

Can I offer up a student for slaughter, perhaps a couple for the remaining day, giving us guest blogger updates from the students' perspective??