Tech Report: Hammerstones, Harpoon Heads and Lasers

Checking the reference photos

Yesterday was a bit of a running around day, but hopefully I can spend today in the workshop or at least part of it.  The harpoon heads are coming along nicely.  I try not to move too fast when I'm working on designs that are new to me.  I find it takes a while to wrap my head around the new shapes and if I try to finish them too quickly there are always details that I miss.  I'll make a few cuts in the workshop, then bring the pieces back inside and compare them with the reference photos or artifacts, if I'm lucky enough to be working directly from an artifact.  In the evenings, I'll fidget with them and make new notes and marks on them while watching TV or working on the computer.

The Elfshot wall at the PAO

I had a quick visit up at the Provincial Archaeology Office yesterday to collect some rock samples that need some smaller flakes knocked off them.  The cores don't know it yet, but they are on their way to get laser ablated in the Department of Earth Sciences at Memorial University of Newfoundland.  But before they can be ablated, they need to be cracked and walloped into manageable size pieces that will fit inside the machine.  The analysis gives a detailed picture of the elements that make up the rock.  The purpose of the testing is to attempt to match stone tools made from an un-sourced material with rock samples from known quarries, to try to determine where the ancient knapper got their stone.

Prepare to be ablated.

I like the idea that the same technology used to prepare tools to butcher an antelope 2.5 million years ago in Africa can be used to prepare rock samples in 2010 for something called Laser Ablation Microprobe Inductively Coupled Plasma Mass Spectrometry.

Photo Credits: Tim Rast

Thinking Out Loud about Sinew and Workshops

This week has been kind of all over the place, while I've been slowly getting back to work and organizing myself and my workspace for the coming year. I managed to braid a 60 foot line of sinew before I ran out of material. I still have short pieces of sinew that I can use on small hafting projects, but I need a little bit more before I can get to my 70 foot goal. I'm not really sure where all 70 feet will be used, but if that's what people say to use, then that's what I'll use. I don't want to be the guy who backs his bow with 60 feet of sinew when everyone else uses 70 feet. Nobody wants to be that guy.

So, I've ordered some more materials. I need to restock my sinew. For the most part I use 3RiversArchery.Com, a traditional archery supplier for sinew and similar resources. I put in an order for rock and fibre optic glass with Neolithics as well. I'm still planning to offer some flintknapping workshops in St. John's in the coming weeks - a basic "beer bottle to arrowheads" pressure flaking class and also an "introduction to percussion" workshop, where people will work with hammerstones and antler billets. I'll need the Obsidian and English Flint that I have on order for the percussion workshop, so I can't really set the dates until it arrives. But hopefully things will work out for the 2nd or 3rd week of February.

I do have one demonstration date that I can share - February 21st at The Rooms, 2-4 PM. I'll be working Ramah Chert and demonstrating how stone tools were made - bring the kids!

Things are also in the plans for a workshop in Calgary at the beginning of March. I'll post more details on that when, and if, things get firmed up.

Photo Credits:
Top, Middle: Tim Rast
Bottom: Patty Wells

Photo Captions:
Top: 60 Feet of braided sinew.
Middle: Ramah Chert Flake Scatter
Bottom: Scraping with a stone scraper

How To Get A Round Rock

My aunt Marlene left this morning on a 5 am flight bound for Regina via Toronto. Uncle Gary booked later and couldn't get the same flights, so he's with us until Tuesday evening. They rented a car over the weekend and toured around the Irish Loop and some of the Baccalieu Trail.

Lori and I had a pretty quiet weekend at home. I worked a little on two stone ball reproductions from the collection of artifacts from Ivvavik National Park. The original artifact is pretty close to a perfect sphere and is about 3.5 cm in diameter. It was found in a historic site alongside other toys. Without scratching it or cutting into it its pretty hard to identify the material. It could be clay or stone. I've shown the object to archaeologists and potters and opinions are split. Parks Canada showed this object and the others from Ivvavik National Park to Inuvialuit elders and the majority identified it as a round stone similar to others that they had seen within the area. I'm more comfortable working with stone, so I've chosen to make the reproductions from limestone that I picked up on the west coast of Newfoundland. The weathered surface of the stone is very similar to the weathered surface of the Ivvavik artifact.

I carve the stones into a sphere using my angle grinder with a diamond cutting blade and then tumble them in a rock tumbler for a couple days to erase the tool marks and wear down the facets. The secret to grinding a sphere out of rock is to look for the sharpest angles and grind them down blunt. Keep turning the rock looking for the sharpest angles. Unfortunately the natural weathered surface of the stone is worn off almost immediately and I need to antique the surface to recreate that worn cortex. To add the cortex I use a combination of red ochre, soapstone and limestone dust, diluted carpenters glue and a blow torch. I'm working towards a dusty texture and a warm yellowish-buff-brown colour. I made one of these for Parks last year and I know that I can get a pretty good match to the artifact if I keep adding lots and lots of very thin layers. I'll compare the progress so far to the artifact during my Rooms visit on Tuesday.

The limestone spheres immedietly after carving with the angle grinder and diamond blade.

The same rocks after 36 hours in the rock tumbler.

After the first pass of antiquing. The ball in the foreground is getting close, but I think I may need to tone down the ochre colour in the one in the back.

Photo Credits: Tim Rast

Photo Captions:
Top: The Ivvavik stone ball artifact
Second: My rock tumbler - purchased a couple years back at Toys R Us
Third-Fifth: Stages of stone ball manufacture.

How long have rocks been around?

I got some really tough questions from the Beavers and Cubs on Monday night. First we had to establish that a flintknapper wasn't a kidnapper who takes flint. Most of the kids were Beavers, so they were between 5 and 7 and they needed some help understanding that things used to be different in the past. Usually I start a demo explaining what makes a good rock for making stone tools, but for this age they needed a little more background and had questions like "why did people make tools out of stone?" or "why didn't they just buy them with money?". The next time I work with kids this age, I'll need to remember to start at the beginning.

One of the tough questions I got at the end was "How long have rocks been around?". I think the question was asking what people made their tools from before rocks were around, so the answer was that rocks were always here. They were here before people came to Newfoundland and they were even around before the dinosaurs - which is about as old as you can imagine. I was grasping for a better answer - something that would acknowledge that rocks are as old as the earth or some kind of absolute number. Eventually I remembered that I had seen the oldest rock in the world recently. It was in the airport in Yellowknife and it was at least 3.9 Billion years old. I couldn't recall the name - "Acasta Gneiss" - but it came from the Northwest Territories and it dates between 3.9 and 4.1 Billion years old.

Unfortunately for the Yellowknife airport display (and the Smithsonian who hauled a 4 tonne boulder of this stuff down to Washington in 2003) researchers in Northern Quebec have apparently trumped the Acasta Gneiss with some 4.28Billion year old rock from the Quebec shore of Hudson's Bay.

I still like the Yellowknife airport though - they saved my darts for me while Canadian North lost the rest of my luggage.

Last summer, Lori and I were working in Nunavut and during our week off we flew to Calgary instead of St. John's. We didn't go through security at the start of our flight in Iqaluit, because the plane made a couple stops in the north. Before we could fly into an airport in the south we had to deplane and go through security in Yellowknife. I wasn't thinking and so I had my darts in my pocket. The security guard did everything he could to keep from taking them away from me, but he couldn't let me get back on the plane with them and I didn't know anyone in Yellowknife to hold them for me. I'd be flying back through Yellowknife in a week and he offered to hang onto them for me, so he gave me his info and put my darts in an envelope and put them in his pocket.

A week later we were flying back through Yellowknife and I tried to find the guard, but he wasn't working that shift, so I lost my darts. By that point, the darts weren't a big deal, because Canadian North had lost my checked luggage which had all my field gear and Lori's camera in it. I had to repurchase all my gear on my week off so that I could go back to work, so losing a set of darts on top of that was a pretty minor loss. It turned out that we couldn't fly into Iqaluit that day because of fog, so our Calgary-Edmonton-Yellowknife-Rankin Inlet-Iqaluit flight paused at Rankin Inlet and took us back to Yellowknife, for the night. Which meant I had another shot at getting my darts back - this time the guard was in the airport and he still had my darts in his glove box. So he ran out to his car and got them for me. The irony is that if I would have packed them correctly on the trip south they would have been lost with all my other gear, so my minor loss turned into a major victory!

The rest of the trip was a blur - we wound up going back to Edmonton and Calgary and then flying to Ottawa, overnight there, and then back to Iqaluit the next day.

Photo Credits:
Top, Bottom: Lori White
Middle: Tim Rast

Photo Captions:
Scenes from the Yellowknife airport, summer 2008.