Experimenting with Dorset Palaeoeskimo Tools

Scraping the spurs on a harpoon head

I got some exciting news today - a project and paper that I was involved with was just published.  It's based on some experiments that I did with Patty Wells for her PhD research into organic tools from Dorset Palaeoeskimo contexts at Port au Choix.  The paper was published in the Canadian Journal of Archaeology and is called:

Dorset Culture Bone and Antler Tool Reproductions Using Replica Lithics: Report on the Identification of Some Possible Manufacture Traces on Osseous Tools from Phillip’s Garden, Newfoundland  – Patricia J. Wells, M. A. P. Renouf, and Tim Rast

The finished antler harpoon head

Ahead of the work, I made reproductions of a range of Dorset scrapers, burins, knives, and hafted microblades and then tried to experimentally reproduce four different organic tools using the kit.  I worked antler, bird bone, caribou bone, and whale bone.  Patty documented the work and compared the results to the archaeologically recovered artifacts.  In some cases the tool marks from the reproductions matched the originals and in other cases they differed, indicating that the Dorset craftspeople used different tools or techniques that the ones I chose.  Both instances were informative.

This is a whalebone tool.  Maybe a foreshaft, maybe something else.   After a very tedious, long time of working the bone, we finally tried soaking it in water and it started to carve like butter.

A bird bone needle

I think the bird bone needle was the first tool that I worked on in the set.  It was one of the simpler tools to get started on.

A barbed point made on caribou bone.  

  

A lot of people think its really hard to make tiny holes like those found on Dorset tools, but its actually not that hard.  The Dorset didn't use drills, so the holes have to be gouged out.  Before a hole gets big, it starts out as a tiny hole.  It's the big holes that take time to make.

 Photo Credits: Patricia Wells

Red Ochre Acts As A Hardener in Spruce Resin Pitch

The reddish brown glue under the
sinew, where the stone meets the
wood, is red ochre and spruce pitch

While I was in Alberta for the Archaeological Society of Alberta flintknapping workshops in Calgary and Edmonton, I experimented with spruce resin and red ochre glue.  I've used spruce resin and charcoal as pitch in the past, but I wanted to try mixing it with ochre because that seems to have been the glue of choice on the emaculately preserved darts and arrows that have been found in the Yukon ice patches.  My previous experiments with red ochre pitch made use of commercially prepared pine pitch, not spruce resin that I collected myself.

Sap oozes out of spruce
trees  wherever they've
been cut or damaged

I collected the spruce resin from a walking trail between St. John's and Cape Spear.  Spruce trees will bleed sap if they are wounded.  This can happen naturally from storms tearing off branches or even lightening strikes.  Groomed hiking trails or parks are good places to look for spruce resin, because the trunks will ooze sap wherever a branch has been cut off.  Collecting the resin while its cold out makes the work a little less sticky.  I use a sharp knife to cut the bigger globs off the tree and scrape the thinner layers of sap into a plastic bag.  I'm not exactly sure, but I think that the biggest clumps of resin were on the cuts that were a year or two old.

If you collect it on a cold day, its not very sticky and you can use a sharp knife to chip the gobs of resin into a bag.

Mixing the ochre.  The
 bits of bark that we
picked out of the melted
resin dot the paper beside
 the hot plate.

There is a lot of bark and lichen attached to the resin, but I don't worry about sorting that out until I melt the sap.  In the woods, you can melt the resin on a flat rock over a fire.  Be careful, its flammable.  In fact, you can use the spruce resin to help get a fire going while camping.  In the workshops, we melted the resin in a small frying pan on a hotplate.  You definitely want to use a dedicated frying pan, because it will be nearly impossible to clean it up afterwards.  The same is true for the hotplate - you can melt this stuff on your stove at home, but be prepared for some intense cleaning afterwards.

You don't want to boil the resin, so keep a careful eye on the pan.  Boiling the sap for too long will change it and it will become crystalized, rather than consistent and gooey.  While the resin was soft and runny, we picked out the bigger bits of bark and debris that were stuck in it.  Unlike a lot of the stuff that I boil, spruce resin smells great.  It smells like Christmas.

We ground the ochre into a fine powder with a mortar and pestle.

spooning in the red ochre

We ground the red ochre up with a mortar and pestle to make a fine powder.  When it was ground and the resin was melted and picked clean of debris, we slowly added the ochre to the glue and stirred it in.  We didn't measure exactly how much ochre, but I estimate that the ochre:resin ratio was somewhere between 1:2 and 1:1.  I don't think you'd want to mix in more ochre than resin, but that's just me.  Equal parts resin and ochre, or a little more resin than ochre seemed to work well.

Adding sinew and hide glue
over the pitch.

The ochre acts as a hardener in the glue.  Spruce resin at room temperature is soft and gooey.  Its very sticky, but it will stay pliable.  By adding charcoal, or in this case red ochre, the resin will be pliable at high temperatures but solidifies quickly as it cools.  The spruce resin and red ochre glue sets extremely quickly.  You have less than a minute to work with it before it sets and becomes solid.  Most of that time the glue is burning hot to the touch, but as soon as it becomes bearable to handle you can shape it and smooth it like putty with your fingers.  Again, its very hot and will stick to your fingers, so be careful.

Ice Patch artifact,
 the pink stain is
ochre and spruce
glue outlining the
shaft that it was
once hafted to.

Its best to plan your job carefully, because you have very little time to work with the glue before it sets.  I usually dab the glue into the wood socket and then jam the point into place so that the glue squishes out around the edges.  I pinch and tap down the excess pitch that oozes out to smooth the transition between the wood shaft and the stone point, to create a more aerodynamic shape that would penetrate the target more easily.  There are a couple good examples from the Yukon ice patches where you can see exactly this pattern; the ghostly silhouette of the wood shaft is visible and the glue was spread around the edges of the wood, over the surface of the stone point.

The pitch alone will do a pretty good job of securing the point in place, but its still a good idea to do a sinew wrap over the join and down the wood shaft.  The sinew will protect the pitch from chipping and will help prevent splitting in the wood shaft.  The sinew wrap also contributes to smoothing out the transition between the stone and the wood, which again, improves the aerodynamics of the projectile and helps the point penetrate deeper into the target.

Willow shaft, chert projectile point, red ochre and spruce pitch, sinew and hide glue hafting.  This is the foreshaft that I made in the workshops, using a little  Hoko Knife to work the wood 

Hafted point from
Calgary workshop.

We didn't experiment with the strength of the glue.  I recall from hearing Andrew Zipkin talk about his experiments with adding ochre to plant resin that in the best case scenario the ochre glue was just as strong as the ochre-free plant resin.  In most experiments it actually weakened the glue.  Which makes me think that ochre wasn't used to make a tighter bond, but it does change the properties of the pitch by acting as a hardener.  Spruce resin on its own is gooey and soft at room temperature, but once a bit of ochre is mixed in it changes.  For a few seconds, while it is cooling, it can be shaped like putty and it rapidly solidifies into a hard, water resistant glue that creates a very strong bond between stone and wood.


Photo Credits:
1-7, 9, 10: Tim Rast
8: Screen capture from The Frozen Past: The Yukon Ice Patches.

Plains Atlatl

Northern Plains Atlatl Reproduction

This is a reproduction of a Northern Plains atlatl for Mount Royal University in Calgary.  This atlatl and a Dorset Palaeoeskimo harpoon will be used as examples of artifacts by anthropology professors in the classroom.  The atlatl didn't have to be functional, but a functional reproduction is a more accurate reproduction, so I chose to make something robust enough to stand up to years of wear and tear.  Besides, I had a bit of steam to blow off this week, so I spent a couple hours flinging darts around a nearby park to make sure everything worked properly.

It extends the throwers arm

In the above video, I had all of the parts duct taped in place to check that the spur and weight were properly fit.  It should give you some idea of how an atlatl works to fire a dart.  The atlatl extends a persons arm, greatly increasing the force and distance that they can put behind launching a projectile.  This was a major technological innovation over throwing a spear by hand.  The technology was phased out with the introduction of the bow and arrow in most places, although it never really disappeared.  In was used into historic times in the arctic because it could be operated from a sitting position with one hand, which made it perfect for use in a kayak to launch bird darts or harpoons.  Similarly, it was used in Mesoamerica for hunting birds on the water and pinning Spaniards into their armour, when the need arose.

Moving my body weight forward onto my right foot

The throw is fast and overhand

Shoulder, elbow, and wrist all snap forward to launch the dart

The dart should detach smoothly from the spur

Follow-through.  On this particular day I was throwing darts about 45-50 metres., which is at least 2 or 3 times farther than I can throw the same darts without the atlatl.

Wedge-shaped antler spur

There are a few perfectly preserved atlatls from arid regions south and west of the Great Plains and from frozen areas to the north, but I'm not aware of any complete preserved atlatls from the Plains themselves.  Atlatls are usually composite tools and occasionally the bone or antler spur or the stone weights will be recovered from archaeological sites.  I used a fairly simple wedge shaped antler tine for the spur, slightly countersunk into the wood and lashed in place with gut.  I used gut for all the lashings because it has a slightly more robust look than sinew and I feel that it works well for archaic reproductions and darts.  I didn't have to make any darts for this particular piece, but an atlatl dart is often built like an oversized arrow and since gut has the look of oversized sinew when it dries, I though it would be an appropriate material to use.

The spur fits into a shallow socket or dimple on the base of the dart, which would often be fletched, just like a big arrow.

A stone weight tied to the shaft

The atlatl weight that I used is made from argillite and is an elongated "boat-shaped" form based on weights found in the central and northern plains, as illustrated in Neuman's 1967 American Antiquity article; Atlatl Weights from Certain Sites on the Northern and Central Great Plains.  These weights would be tied in place along the body of the atlatl and for a while their function perplexed archaeologists.  Some people thought that they might help create momentum, but they didn't seem to improve the range or power of the darts propelled by atlatls.  Now, it seems likely that they are there to help balance the system.  When the dart is loaded into the atlatl and the hunter holds the atlatl in the ready position, the added weight can help balance the atlatl and dart together.  Without a weight, a heavy dart will pull the front of the system down and it becomes very uncomfortable to hold in a short time.  Like trying to balance a tray of drinks over your shoulder with all the glasses on one side of the tray.  Add a  glass or two to the other side and it becomes much easier to hold.  There's a really good paper on the subject by Larry Kinsella here.  Check out the graphs at the bottom of the page to see the difference in muscle strain that adding a weight to an atlatl makes.

The added stone weight will help balance the system.  I'm holding a relatively short dart in this photo, but atlatl darts could be much longer and heavier.  Holding this ready position for several minutes while hunting would be much easier if the atlatl and dart were in balance.

Leather finger loops and gut binding

The rest of this particular reproduction is a little more speculative.  The length is of an atlatl is often described as the distance from your elbow to the tip of your finger.  For the shaft I used tamarack and I wanted a relatively simple stick shape, although I did taper it towards the spur and added slight finger notches.  I didn't want it to be too flat or to have a channel, like many southwestern atlatls.  For the finger loops I used an old leather knapping pad that was worn soft.  The function of the loops is to help grip the atlatl and prevent it from flying away when throwing.  I hope the client likes it.  This is one of those reproductions that I'm kicking myself for not making two and keeping one for myself.

Photo Credits: Tim Rast

Wrapping up the Week

Bird combs, ready to ochre

Today, I'm working on the last of the reproductions bound for teaching kits and a mock dig at Red Bay, Labrador.  Its primarily Groswater Palaeoeskimo and Maritime Archaic Indian reproductions, although there is one Recent Indian arrow in the mix.  The arrow is done and all of the Groswater reproductions are finished, except for the lashings and line on a harpoon.  

Grinding the ochre

The Maritime Archaic pieces are all finished, except for the ochre.  I think I'll ochre all the archaic artifacts reproductions this time. I still don't know if things like adzes or projectile points would have been covered in ochre when they were in day-to-day use, but it does help make the reproductions look cool.  It also creates a talking point for interpreters.  My pet theory is that ochre and grease on tools in this damp part of the world was a waterproofing agent that would help prolong the life of the objects that they coated.

Patty and Bjarne and whalebone

It would be simple enough to test a theory like that, I just need to get organized enough to come up with an experiment and do it.  Perhaps what I need to do is plan some purely experimental time into my yearly workshop schedule, rather than try to tack the experiments on to regular Elfshot work.  I alluded in Wednesday's post that I wanted to get a little more organized about the experimental archaeology side of the job. While Bjarne Grønnow was in town earlier this week for Patty Well's Ph.D. defense (passed with distinction - congratulations!) I had a chance to hang out while the two of them and Priscilla Renouf went through some of the organic Dorset artifacts from Port au Choix. There's a place for making reproductions and playing around with them to see how they work and what their limits are, but Bjarne encouraged a little more systematic and rigourous approach to experimenting with reproductions.  Hopefully, more on that later.

Groswater harpoon assembly

Anyhow, for now, I'm wrapping up one order in the workshop and moving full time into the Cape Krusenstern reproductions next week. I'll probably post a few more shots of the reproductions bound for Red Bay once everything is assembled, stained, and dried.  There are one or two pieces in there that I have never made before, so it was fun for me.

Burning blubber inside a Choris pot for Cape Krusenstern.  I want to stain the inside of the pot  with grease as much as possible before breaking it apart into sherds.  A big hole blew out in the side above the flame not long after this photo. Oh well, it has to come apart somehow.

 Photo Credits: Tim Rast

Firing the Thule Pots

Whole and exploded pots

I fired the Thule and Choris/Norton pots yesterday, with generally positive results.   Laurie let me use one of the fire pits on The Compound for this phase of the project.  Of the six pots that started the firing, one was reduced to a ziploc bag full of barely recognizable pottery sherds by the end of the day.  The remaining five stayed in more-or-less one piece, although two had sizeable heat spalls pop off in the second hour of the firing.

Looking good on the outside

I fired them for just under three hours, turning them every 10-15 minutes.  I'm not sure exactly what the firing accomplished.  I wouldn't say that the pots are fired like ceramics in a kiln.  I don't think there was a significant change in the chemistry of the clay, but it got hot and dry and hopefully a little harder and more durable.  They should be a little more stable now, although I didn't get all of the colour change that I was hoping for.  A couple of the pots have a good colour on the outside, but the clay inside is still very light coloured.  I need them to be almost black in cross-section so I'll have to antique them a bit more once I crack the sherds into shape.

The  six pots before the firing. 

The five survivors at the end.

This one lasted about a minute

I had originally planned to put two pots directly in the fire and heat the remaining four around the edge.  These are pretty fresh pots, with a lot of moisture in them.  I made half of them five days before the firing and the other half four days before the firing.  In pottery terms, I'm sure I would have had much safer results if I had waited another week or two for the pots to dry.  But, even stretching the drying time to four or five days was pretty generous for this style of pottery which would traditionally go from raw clay to firing all in one day.  The plan to put two pots in the fire ended pretty abruptly when the first pot that I put in started exploding almost immediately.  It kept popping like popcorn until it was rubble.  The two video clips below show the pot popping.  Based on that, I didn't bother putting a second pot into the fire.

At the end of the firing, I fished these and a dozen other fragements from the exploded pot out of the coals.

They hold water without reverting to mud

When I got the pots home I wanted to see if they would hold water.  They were still warm from the fire and I didn't want to risk thermal shock so I filled them to the brim with warm water.  They all held water, so I let them sit for about 15 minutes to see if the water would slowly seep through them or if they'd turn back into mud.  When I checked on them again, the two blood coated Thule pots had developed big cracks around the rim.  I'm guessing that they started to reabsorb the water and tried to expand, which led to the cracking.

Cracks formed in the two thicker pots with the best seal blood coating.  There was one thick pot that didn't crack, so I don't think it was thickness alone that caused the problem.

Surface heat spalls

So at the end of the day, I really only have one pot left intact.  Two survived the firing, but are now cracked from the water, two have surfaces pitted with heat spalls, but can hold water, and the sixth pot is in inch sized fragments.  As far as making pots go - this would have to fall into the "learning experience" rather than "howling success" category.  However, for making sherds, I think I'm still on track and can continue to work with these vessels.  Even the surface heat spalls might work out for me.  The sherd that I'm trying to match has a couple areas where the outer rind of the pot has flaked off in a similar size and shape to the heat spalls.

The interesting things that I want to remember for next time:

• Don't put the pots in the fire - heat them around the edge of the flames.
• Pots coated with seal blubber only were the ones to experience surface heat spalls after 2 hours of firing.
• The seal blood adheres to the pots best if it goes on while they are still cool and barely dry.  Blood smeared on the pots on the hot sunny day flaked off in the firing.
• The two thickest pots with seal blood coating were the two that cracked from the added water.  Thinner pots and those smeared with seal blubber only, did not crack.

The three pots in the foreground had seal blood on them at the start of the firing.  The two on the left had the blood applied on a cool day, while the pots were barely dry.  It stayed caked on and was cooked onto the surface - although they are also the two pots that cracked when I filled them with water.  The taller pot on the right had the blood coating applied on a hot sunny day and it never really adhered like the other two.

Photo Credits: Tim Rast

Anthropology, Bushcraft, and Artifact Reproductions

I'm setting up a few scheduled posts for this blog, so that I can get away from the computer for a few days over the holiday.  While Elfshot: Sticks and Stones is on autopilot for a couple weeks, here are some of my new favourite haunts for you to checkout.

Four Stone Hearth:  This is an anthropology blog carnival that has being running bi-weekly since October 2006.  A blog carnival is a collection of blog posts, united by theme, that is hosted by a different blog each issue.  Bloggers who have posted recently on the carnival's theme can submit their link to the upcoming host, who then creates a carnival post that ties together all the separate posts and links back to the submitted articles.  Four Stone Hearth is carnival themed to the big four subdisciplines of Anthropology; Archaeology, Cultural Anthropology, Physical Anthropology, and Linguistics.  The next carnival comes out today, and is hosted by Magnus Reuterdahl, a Swedish archaeologist, osteologist and vinophile who blogs about archaeology at Testimony of the Spade and wine at Aqua vitae – livets vatten.  This week's Four Stone Hearth carnival post, #109, contains my first submission to the carnival.

BushcraftUK: BushcraftUK is a massive forum dedicated to bushcraft.  There's a good deal of overlap between some aspects of experimental archaeology and bushcraft.  These days, people are just as likely to get their first taste of flintknapping from a wilderness survival expert as they are from an archaeologist.  BushcraftUK is populated by a lot of experienced outdoor enthusiasts and the occasional archaeologist.  I'm relatively new to the forum, but it seem like a big friendly group.  Archaeologists might find the site useful for two reasons; first, there's good practical advice in there for helping to understand the lifestyles and tools of the people that we are studying, and secondly, there's a lot of outdoor experience there that would be useful to carry in your head or in your pack while doing fieldwork.

Graham's Potted History: Graham Taylor is a craftsperson and experimental archaeologist from Rothbury, Northumberland who specializes in ceramics; both his own contemporary designs and meticulous artifact reproductions that span thousands of years.  You can see his contemporary work in his Crown Studio Gallery, peruse his artifact reproductions at Potted History, and read about his current projects on his blog; Graham's Potted History.  I've especially enjoyed following his twitterfeed and checking out all his behind the scenes twitpics from inside his studio.  It looks like Northumberland can expect a white Christmas this year!


Photo Credits: Screen grabs from the sites linked in this post.

Shaving the Sealskin with Stone

Shaving the sealskin with a chert flake

On Sunday morning, we started shaving the hooded sealskin thong with stone tools.  Its an incredibly slow and labourious process.  I frequently switched to a metal knife, but Lori and Eliza were much more hardcore, sticking to obsidian and chert for the full two hours that we worked.   In the end, between the three of us, we shaved about 35 feet.  We averaged just under 6 feet per hour per person.  That seems crazy to me.  I know it was slow, but would it really take one person 55 hours of labour to shave the entire 335 foot long thong?

335 feet of sealskin is ridiculously long

It looked like a pile of giant spider legs

The thong had easy patches and hard patches to shave.  They probably correspond to areas of the seal's body.  When we cut the hide into a spiral we noticed that the skin around the neck was especially thick, while it was much thinner towards the sides and belly.  Lori felt that the difficult sections to shave were probably the neck sections of the skin.

Obsidian flakes worked well

We tried Ramah Chert, Bloody Bay Cove Rhyolite, chert from Newfoundland, and obsidian.  When shaving with flakes, we found the obsidian worked the best.  Which makes sense - it creates the sharpest edge.  Unfortunately, its not a local stone, so it wouldn't have been available for any precontact culture in the Province to use.  Of the local stone, microblades of Newfoundland chert hafted in a handle were a close second to the obsidian flakes.  The mechanical advantage of the handle seemed to compensate for the slight difference in sharpness.

Here's a clip of Lori demonstrating shaving the hair with an obsidian flake:

Hafted microblades did the job

After this brief experiment, I really think that even the simplest, expedient flake tools would have been mounted in simple hafts.  Microblades certainly would have been - the difference between using a microblade pinched between your fingers and one firmly hafted in a handle is night and day.  Larger flakes could be held and used with some force and precision, but the small utilized flakes and flake scrapers that we find in sites here would be much more efficient tools with a handle.

Here's a clip of Eliza shaving the sealskin with a hafted microblade:

Scraping with a microblade

Amazingly, the same microblade that we used to cut the thong several weeks ago was still sharp enough to scrape the hair off.  Its the tool that I used most often on Sunday, along with an obsidian blade that was long enough to hold relatively comfortably.  When I'd get stuck, or hit one of those difficult patches, I'd switch to a steel knife blade in my leatherman.  Whatever tool we used, it seemed like holding the blade at close to a 90 degree angle to the skin worked the best.  The usewear builds up on the edge of the stone tools much more quickly while shaving than it did while cutting the skin.  The finer grained the stone, the more quickly the working edge became dotted with tiny chips.  The obsidian started to show signs of wear almost immediately.

Concentration required

Even though it was a slow, tedious process, it still required a good degree of concentration.  When you started shaving a new patch of skin, the middle of the thong was the easiest to shave, which left long hairs on either edge.  When you'd go back to work on the edge, I found it very easy to snag any irregularity along the edge and create small nicks in the edge of the thong.  None of us accidentally cut all the way through, but I know that I created a few weak spots in the section that I was working on.  It made me glad that we initially cut the thong a little wider than I needed it in the first place.  I wanted it wider to allow for shrinkage and to give me the chance to trim down irregularities in the cut, but it will also work to remove some of those nicks and pitting.  I think that if those cuts are left in place they will spread and tear, and I'll need to go back and trim them out.

The shaved sealskin

Despite the labour involved, I'm very happy with the results.  The black, scaled look of the shaved thong is exactly the type of finished leather that I'm looking for.  Its an authentic air-dried sealskin that I haven't been able to get from commercially tanned hides, so its going to look great on the reproductions.

Photo Credits:
1,4: Lori White
2,3,5-7: Tim Rast

Publish Post

Videos: Tim Rast