Monday, October 18, 2010

Making Ötzi's Pressure Flaker

Ötzi's pressure flaker, reproduction
The 5300 year old mummified remains of a man nicknamed Ötzi, (or Oetzi) were found in 1991, melting out of a glacier in the Ötztal Alps. Many of the tools that he used in his day-to-day life were found scattered around his body.  Ötzi's mummified remains have provide a wealth of information on his health and diet and cause of death, but I've always been more fascinated by the tools that he was found with.  As a flintknapper, his antler and lime wood pressure flaker is probably my favourite of all his possessions.

Copper and antler pressure flakers
A pressure flaker (sometimes referred to as a retoucher in the iceman literature) is a tool used to finish or resharpen a chipped stone tool.  Antler is probably the most common pressure flaking material, because its soft enough to grip the edge of a stone tool without crushing it, strong enough that a large force can be applied to it without deforming, and durable enough to last through repeated use.  The simplest way to make an antler pressure flaker is to cut a single pointed tine from an antler, that fits comfortably in your hand.  The tip of an antler tine from any species of deer is a perfect natural pressure flaker.  In this century, antler isn't always the easiest material to get a hold of, so many knappers use copper tipped pressure flakers as a substitute.  Copper has the right combination of softness and strength and is even more durable than antler.  Rather than use an entire rod of copper, most copper tipped pressure flakers are made by inserting a heavy gauged copper wire into a wooden handle.

Image of the original artifact from Spindler 1994
The pressure flaker found with Ötzi was a clever combination of the two.  It looks almost identical to the modern copper tipped pressure flakers that many knappers use, but instead of a copper insert, it had a long antler spike driven into its end.  It looks like an oversized pencil.  The overall length of the implement is 11.9cm long and an x-ray of the flaker shows that the antler spike is 5.1cm long, although it only protrudes a few millimetres from the whittled end of the tool.  The end of the tool opposite the antler has a groove cut around it, presumably an attachment place for a cord.  I don't know if the species of the antler has been identified, but the wood was a branch from a lime tree; not a lime tree that grows limes, the other kind of lime tree, from the Tilia genus.

Lime tree destroyed by Hurricane Igor
Bowring Park, St. John's










Lime trees aren't native to Newfoundland, but there was one planted in Bowring Park in 1914 to celebrate the opening of the park.  It was a beautiful old tree and I've been meaning for years to get a couple branches from it when it was pruned to make a proper iceman pressure flaker.  Unfortunately, I was too slow and the tree was blown over a few weeks ago in Hurricane Igor.  By the time I visited the park to check on it, it had been cut up and all the branches were taken away.  I was pretty disappointed, but there were some exposed roots that were the right diameter, so I took some of those.  They're not lime tree branches, but at least they're wood from a lime tree.
I found some pressure flaker diameter roots

Reproduction above an x-ray of the artifact
The moose antler spike that I wound up using in the reproduction was actually the third spike that I attempted.  The first one I used was a scrap of antler.  I'd hoped that the design of the flaker would let me recycled some of the small fragments of antler that I've been saving, but the scrap I picked was too soft.  It was from the flat pan of the antler, and not a tine, so it bent and deformed when I tried to use it.  The second spike that I tried was the dense tip of an antler tine, but midway along its 5 cm length it turned porous and brittle.  I'd hoped that change in density wouldn't matter too much because the tine would be buried so deep in the wood, but it cracked and broke as I tapped the spike into place.  The third tine was the one that worked and its a solid, dense piece of antler along its entire 5 cm length.

Copper, antler, antlet tine
As a reproduction, I'm happy with it.  Its a few millimetres longer than Ötzi's pressure flaker, but I intend to use it and it will get shorter through use.  The wood was still quite green and soft when I worked it, so it was easy to cut and shape using a large chert flake.  The wood did crack as I hammered the spike into place, but Ötzi's pressure flaker had a large crack running its length, so I'm in good company there.  Even with the crack, the very long antler spike is wedged so firmly in place that its a comfortable and sturdy tool to use.  Lori just came in and smelled it and said that it smells nice.  She never says my reproductions smell nice, so that's a huge check mark in the plus column.

A reproduction that will be used
I'm going to use it like this for a while to get a feel for it, but the original artifact has one more detail that will be interesting to experiment with.  The tip of Ötzi's pressure flaker was fire hardened.  I've never tried fire hardening my antler pressure flakers, but its certainly an idea worth experimenting with.

Photo Credits: 
1-2, 4-9: Tim Rast
3,7: Artifact photograph and x-ray from Konrad Spindler's The Man in the Ice, 1994

4 comments:

  1. I'm pretty sure the big trees down the street side of B52 are/were limes (aka linden aka basswood), in case you need more branches. A lot of those big city trees are non-native.

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  2. Thanks - that makes a lot of sense. I should have been out looking around with a tree book after the huricanne. There are still giant mounds of branches left for the city to pick up, but the leaves are starting to get pretty wilty. They'd probably be tough for me to identify, now. But now that I know they are out there, I'll try to find more around the city for next time.

    I'd still really like to make one from a proper branch in case there is something special about lime branches that would make them better suited for this type of tool. Like, do they have an especially spongy or hollow core?

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  3. Youknow, using the Lime root was not all that bad, and I bet if Otzi had a choice, he'd have picked the root too- it's probably many times as tough, hard and durable as the branch wood. When people needed tough wood, root wood was one of the best choices, it's used for pipes, carvings, and other places where structural strengh and hardness are neede, it also does not warp and crack as readily as branch/trunk wood. ( Yeah,I like woods- I took 3 years of Wood Shop in High School to learn all I could about all the different types of wood, etc, etc.!) Otzi may have been trying to improve the hardness of his wood, (or season a green branch quickly for use) Lime wood is notoriously soft, and easy to carve, in fact it has been the favorite of carvers around the world- I wonder why he used it? That is something I would really like to know. Thanks for the great article- I will try to make a replica for my own use.

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