Friday, February 22, 2013

Archaeology Test Kitchen's Turkey Surprise!

Hi all,

Click here for the video

Early attempts on left and later attempts on right
Here are the results of the antler inset with blades versus the obsidian Bonito Notched point.  I went to the market to purchase the most meat for the least price, turned out to be a slab of turkey breast that day.  So with target in hand I needed to set up a few more things.  I wanted to start assessing blood loss is some way or another so I rigged up a styrofoam cooler with water and stuck the turkey to that.  It's all still in R&D phase right now.  If you have any suggestions for mimicking blood pressure and hide tension send them my way and I'll make a mock up.

Righto! on to the test...

As usual I shot a cane arrow shaft (from last time) fletched with turkey feathers from a 45 lb recurve bow.  I used one Bonito point hafted to a foreshaft with pine pitch and deer sinew and one composite antler and blade point.

This is going to be awesome
A little about setting blades into antler.  It's not as easy as it looks in the archaeological illustrations.  You'll find that a lot of archaeological illustrations that intend to describe production chains are over simplified to such a degree that they are almost incorrect.  Perhaps this comes about as authors adapt images for their own papers and mess up the nuances.  In this case I needed a lot more pine pitch and the grooves needed to be way deeper than I originally imagined.

Isolated platforms over dorsal ridges
Additionally, those tiny little blades put up a fight and don't like to stay in the pitch.  I ended up roughing up the basal edge of the flakes to give more surface area for the pitch to adhere to.  Set them deep and use a healthy dose of pitch.  I found it helped to heat the pitch, set the blade, then reheat the blade to get it in further.

Regarding the microblades, uniformity is nice but by no means essential.  Now when I imply that a little variability is ok, we're still talking in millimeters.  I find that the most critical measure to control is flake thickness, as in the amount of space the blade needs between the edges of the slot you've cut.  I used an antler punch with indirect percussion at first but found the technique to make thicker blades than I needed.  I'll need to get better at that technique as I imagine it is totally possible to mass produce fantastically uniform flakes with this method.  Pressure flaking actually produced the thinnest, most uniform flakes in this test.  Platform preparation is key.  set high-angle, isolated platforms directly over your ridges.  Remember, the further back you place your pressure flaker the thicker the flake will be so keep things close to the edge of the core.  I also found it helpful to score a little notch on either side of the isolated platform with a chert flake.  A little cut on either side makes it easier to initiate flake detachment.  Another trick I've seen is to grind the entire top of the core on sandstone to break up the surface tension.  Doing this kept a uniform platform angle and actually made flake removal much easier. 

So how did it all work?
Composite left, Bonito right

Well...the Bonito point flew great and made lenticular holes in the meat.  I was able to make upwards of six successful hits before the point snapped.  The blades had to be replaced after every shot, some of which I dug out and refitted.  The Bonito point penetrated further than the composite tip, most likely due to lower friction as opposed to the massive surface area and resultant drag of composite weapons.  The composite point had issues with blades popping out but created massive tissue damage when things worked well.  The composite point created wound paths around 3x larger than the bifacial Bonito point, yet lost speed quicker once in the tissue.  So it's a trade off, massive tissue damage for shallower or a longer wound path with less trauma.  Anyone know of any studies that formulate some sort of tissue damage index? like surface area cut/distance traveled?

Sinew held but something had to give.

All in all an informative preliminary test of wound depth versus surface area damaged between composite and bifacial projectiles.  Hopefully we can do a test with actual numbers soon.  This will all be used to make a much larger composite projectile for use in an atlatl dart thrower, just imagine what that thing is going to do!


-Research Spotlight with Joshua Lynch - Composite antler/microblade atlatl points

-Archaeology Test Kitchen's Witches Brew

  Thanks for stopping by!


Thursday, February 21, 2013

Gearing up for the Turkey Test!

Hi all,

We're back with a quick post about replicating a Bonito Side Notched Point for the next meat test (check for that in tomorrow).  I've decided to lump all of the tests where I demolish meats under the heading "Archaeology Test Kitchen", tell ya friends.  I'll post the newest ATK video, pictures and text tomorrow evening.  These things take a little bit of preparation so let's see a few things that went into tomorrow's Archaeology Test Kitchen bonanza.  I will be starting a new string of post under the heading "Research Spotlight" where I get with friends and colleagues to test the nuances of the technology that they research.

I'll be making composite antler/microblade atlatl projectiles for a test coming up soon and figured I should get a little practice in.  I also wanted to test the damage created by microblade points against that of a normal old biface so we could see some of the trade offs/benefits/weaknesses attached to each.  This gave us a test to see tissue damage and breakage rates between the two very different approaches to finding dinner.

For a bit of fun I decided to copy the morphology and flaking pattern of a Bonito Notched point (ca. A.D. 950-1150).  These are simple little leaf-shaped points that were made by folks in and around Chaco Canyon, NM.  The point type is named after Pueblo Bonito where around 80 composite arrows armed with this shape were recovered in the early years of excavation.  I'm excited to go back there this coming summer.
Up above Pueblo Bonito

I selected a simple flake that I made while thinning another point a while back.  Pueblo type points were made on biface thinning flakes all the time and it's quite common to see a little of the original flake scar on finished points.  A quick brushing along the margins with sandstone strengthens the working edge and supplies the first rough outline.  Here you're just getting an angle so you can start your first little flake pass.  Next I took a few small overpass flakes across the bulb of percussion left from the original flake removal.  It wasn't a big task, antler tools typically leave relatively diffuse bulb under the platform.  So you don't get a curved point you need to tailor the distal end of the flake back to keep things nice and flat.  A curved point will snap in a heartbeat and works about as well as a flying spork.

A few flake passes later and we have our finished preform.  Notching on these points wasn't too fancy, just simple shallow notched coming in from the side.  Oh! and one last thing, you'll find that a lot of folks oriented the preform so that the base of the point would be along the distal end of the original flake.  This means that they used the thinnest part of the original flake for the hafting element, why make a job harder!

The point worked out well and I matched the original illustration in a decent manner.  The weapon flew great too...more on that coming soon!

Also, here's a quick look at how the microblade stuff turned out.  I did a few things right, a few things wrong and learned a ton.  The point in the image has been inset with "microliths", tiny little triangular-shaped blades.  The actual microblades are to the side of the point and ended up being absolutely brutal. 


Archaeology Test Kitchen's Turkey Surprise!

Monday, February 11, 2013

Battle of the Barbs: Foreshafts of Doom

Hello all,

Prelims took up some time, it's good to be back behind the bow.  Check out the video HERE!

I've been wanting to make an arrow from a stand of cane in the back yard for a while now.  It turns out to be a little challenging but well worth the time.  I'll do a post about making those later on.  Since it's hollow, cane allows for the use of foreshafts, meaning the arrow has two parts, a mainshaft and a foreshaft.  This composite weapon has a few distinct advantages over one-piece or "self arrows".
Bruiser of a Snaketown point

Here's how it rolls:  One can reduce the amount of transported weight by carrying a only a couple of arrow shafts and a whole clutch of foreshafts.  The foreshafts can be quickly replaced when you break a point or after the main shaft falls out of a hit animal.  This idea of interchangeable parts is great! instead of carrying a ton of arrows around you just carry the tips and change them out as needed.  And you know what? A little secret...foreshafts work great as knives too.  This type of technology has all the traits of an item you want with you: light weight, replaceable, multipurpose, deadly.

  On to the test!

I had some raccoon meat left in the freezer from a hunt with my brother (congrats!) a while back.  While really good in stew, no kidding, the meat had freezer burn and was put to use as a test target.  I like to use meat with bones in it as it presents a realistic test of projectile/animal interaction.  I harp on this all the time, but it remains true, prehistoric weapon systems were constructed to kill stuff, not to be found by archaeologists and drooled over. As such they were tailored to break bone, lacerate, and kill through blood loss. Awesome...I know...I know.  Shooting through bone and sinew gives a realistic idea of breakage ratios and projectile performance.

I made two cane arrows that ran the spectrum of size and technology.  The larger shaft was fitted with interchangeable foreshafts and the smaller arrow had a single point lashed with sinew and pitch.  This would give me an idea of how the two types stack up.
Cane arrow with wooden nock and sinew to prevent splitting

Dacite Snaketown

I made two versions of Snaketown points, specifically a Salt River Indented Base and a Snaketown Trangular that I took a little liberty with and gave a stem to.  These point types come from the Santa Cruze phase of the Hohokam and date to ca. A.D.850-1000 in Central Arizona.  Some authors have proposed that these ornate points were the work of specialists engaged in competition for prestige through a display of skill.  I can get on board with that to some degree.  Read up on Hohokam culture, their ball courts are pretty cool.
Sobaipuri no sinew
Buck Taylor serrated with sinew

I also made another Pueblo Side Notch of the Buck Taylor variety (ca. A.D. 1400-1800 Central AZ) and a Sobaipuri point (A.D. 1500-1800 Central AZ).  All points were secured with pine pitch and one of each point type was fastened with deer sinew.  The raccoon meat was shot with the composite cane arrow from a distance of 15 yards with a 45lb recurve bow.  I used a new type of fletching call flu-flu fletching (odd, yes) that makes a cool zip sound as it flies.  The big fletches are actually super stable in flight.


Just look at that! Buck Taylor = meatsplosion
All but the larger Snaketown point broke.
The Sobaipuri point was only attached with pine pitch and as such failed miserably.  I had high hopes but it just didn't do the trick for me.  The Buck Taylor serrated did its job and gets a gold star.  These have become my go-to point for hunting along with the Walnut Creek.  The Snaketown points stood up well and made some unique damage .

 the Snaketown makes a combo slice/round hole as it rotates, epic!

Oh, the arrow with a the single hafted point broke on the first shot and was benched.  The composite arrow was used for another 30 shots or so and tips were easily exchanged. Composite wins, hands down. 

A Final Word 

As opposed to the slice-like cuts that your run of the mill lenticular points make, the Snaketowns powered through bone and made star-shaped holes.  I was surprised at the tenacity these points have.  As the barbs rotate they cut a big rounded hole, somewhat like a bullet wound.  The Buck Taylor made cleaner cuts until it exploded on a bone and caused some rather brutal trauma, check the end of the video for that, yikes!

All in all a fun test that gave some interesting results.  The diamond cross-section with barbs cut star-shaped holes and punched through bone.  The lenticular cross-sectioned Buck Taylor made knife-like wounds and then caused the most damage of them all in the end.  I'm not sure what to make of that little Buck Taylor, it gets the gold medal for overall tissue damage while the Snaketowns get the prize for big bone-crunching holes.

And I didn't even hit a deck chair!

I'm taking suggestions from ya'll...what should we do next?  

 I'm thinking composite points, yeah, two points notched and stuck together to make a broadhead