A second point from the second preform.

9.6.17 1

I was more cautious with this one and it turned out longer. I tried to stick to my method, ventral first, then dorsal, then the point, however the angle of the edge face made me improvise a bit. I am pleased with the needle like point, and am going to arrange to go back into the Manchester Museum to compare and contrast. I think the key difference between mine and the actual points may be thickness and edge angle. Let’s see. 9-6-17-2.jpg

The next post will be about home made pressure flaking tools, as we have been innovating in our twice weekly knapping get-togethers.

Period bottle glass number two

4.6.17.2

This is one half of a piece of period bottle glass recovered from Chorlton Ees. My aim this time was to make a larger point and maintain some of the lettering on the dorsal surface (see Foraging for early 20th Century glass and ceramics).  I used a glass cutter to score the inner concave ventral surface of the larger piece of glass, and then tapped the dorsal convex surace with a hard hammer. The large piece split cleanly into two useful preforms, one of which you see here. I then started to work on the ventral surface of the margins to produce a steep edge angle. This would allow me to flip it over and start using the newly created steep edge as a platform for penetrative flakes. The aim of this penetrative flaking was to flatten the convex curvature on the ventral face. I was able to straigten and steepen the margins but was not as systematic as I could have been. Working around a thick area semi-disaster struck! break.png

I called it a day in the lab and took both pieces home, and the following day finished it off. The ‘A’ is a useful landmark on all three photos and gives an insight into the degree of reduction. I am getting a feel for this thicker and uneven material and was able to avoid a large internal bubble, which is why the base has remained relatively unworked. The end result isapproximately 76x26x7mm and pretty well flattened on the ventral side.

4.6.17

After the above photograph was taken I serrated the margins. My main learning from this piece is to be systematic in my reduction sequence. If my edge steepening had been more consistent I would have achieved a longer point. I am making some points for Eleanor Casella’s teaching collection and I think this can be one of them as it has an interesting provenance and biography, as well as being an aestheically pleasing example.

Something far less useful

Microwave 1

On Thursday evening I had a knapping session with Nick Overton and Rob Howarth. The ‘dish of the day’ was a toughened glass microwave turntable found in Nick’s garden. It took me a couple of hours to be able to get beyond the raised edge that was the outer lip of the turntable. As such it has been a masterclass in working angles and really got me thinking. Following the published methods is very interesting and the previous post focused upon managing the curve on bottle glass. However, this toughened and lipped turntable presented a different set of problems. It has made me think about the difference between aboriginal examples with plano-convex, and those with lens like cross sections. I wonder if plate glass examples like this lead to lens like cross sections because both faces are worked in a similar manner? I finished the above preform off this morning.

Microwave 3

As can be seen, it has reduced in size considerably, and this is a reflection of working to get increasingly shallow angles and therefore longer removals.

Microwave 2

This image shows better the degree of removals from the surface, and I can now report that the really long removals are in fact a combination of well prepared platforms that allow pressure to travel along a shallow surface angle. These shallow angles come from transforming a perpendicular edge into a steep angle, and then using this steep angle as a platform to take another removal that creates a longer shallow angle one. None of this discussion is new, however I am beginning to be able to apply these aspects systematically within a meta-approach to either plate glass or bottle glass. I am making practical sense of the textual descriptions that do not really separate out how these processes change (or remain the same) depending upon the materials used. It would be useful now to revisit the Manchester Museum examples to see if I can recognise if the source material was either plate or bottle glass, and if this actually does reflect a plano-convex or lens like cross section. Anyway, to para-phrase Nick, it has been immensely satisfying transforming this microwave turntable into something far less useful!

A more detailed reduction sequence.

mm ventral

I am currently revisiting the literature before we start on our collection of antique bottle fragments. In particular a 2002 paper called “Weapons and wunan: production and exchange of Kimberley points” (Akerman, Fullager and van Gijn) as on page 22 it outlines a very detailed but concise reduction sequence. Essentially, for bottle fragments the most energy is spent flattening the curved inner surface. Consequently this inner face is flaked from either side, in turn, until flat. The above photo is of a point within the Manchester Museum collection and illustrates this description excellently. This process ‘sets up’ the upper or dorsal surface for the next phase of removals. This involves a single series of flakes being taken from each edge.

mm dorsal

This is what we see on the dorsal face above, and I think this is one facet that gives these points their characteristic look. Only then is the edge serrated or notched and the tip worked. This example doesn’t have the needle like tip and is what gave me the notion that larger ones may have been used as knives. Returning again to the ventral surface, what we can see in the photo is an almost plano-convex cross section as opposed to lens shaped. Finally, it would take an aboriginal knapper about 45 minutes to make a 200mm long point. This would be a very large point indeed. The overall approach outlined above is the one I am going to take with our period materials, although it may take me a little longer than 45 minutes 🙂

Akerman, K., Fullagar, R. and van Gijn, A., 2002. Weapons and wunan: production, function and exchange of Kimberley points. Australian Aboriginal Studies, (1), pp.13-42

Glass Kimberley Point by Karl Lee

karl point

Today we had Karl Lee for the day, demonstrating and producing various pieces for three different research projects including my own. I tasked him with producing a Kimberley Point from the second piece of modern 6mm plate glass found at Chorlton Water Park. He did a pretty good job as can be seen above. Because the glass had a hole and a bevel Karl thought it was toughened table glass which would explain why it was difficult to get the removals to travel. He did however do a better job than me, and I think shape wise his is more characteristic of what would be described as a Kimberley Point. The day was pretty successful, however for me disappointing. For various reasons I wasn’t able to capture the video footage I wanted, and I had to miss the end of Karl finishing my point and so didn’t see first hand how he serrated the edges (although I did leave the camera running and so have got it). We didn’t go through the platform preparation either and so I think a trip to see Karl is in order. We can spend a bit of time playing with stuff, rather than cramming it all into one long day.

The point of today

first pass

This is the first series of removals from a 7mm fragment of plate glass from Chorlton Ees. After doing the same on the other side I used a hard hammer to get it into shape, my large pressure flaker to thin it and then the small flaker to finish it. The no.8 wire was used to put in the notches. It is 81mm long, 30mm wide and (still) 7mm thick.

finished-point.jpg

Karl Lee is coming to Manchester tomorrow. I showed him a photograph of this tonight and he is going to show me how to prepare my platforms so that I can get flakes that travel right across. Watch this space.

I think I have just passed my Kimberley Points ‘A’ Level

Kimberley Point A level

I can’t seem to stop myself at the moment. This was a large piece of 6mm plate glass found at Chorlton Water Park yesterday. It was from near a blown down tree but I think the glass is modern. I divided it into two halves (using a glass cutter) so as to have two goes. This is the result from the first half. I followed the ‘one side, one face’ rule, with a little bit of hard hammer shaping for the base to get rid of big bits. Mainly though it was the large copper pressure flaker and the abraiding stone that has been used to get it into shape. This involves getting a series of really nice invasive removals, and a good edge, and then abraiding heavily in the areas that need reduction. Repeat until required shape is achieved. When close I shifted to my smaller copper flaker.

Materials

This Kimberley Point is large, something like 153mm long, 29mm wide and 6mm thick, and not disimilar to some of the Manchester Museum larger examples. What I discovered is that it is quite stressful when you get to the later stages, as mistakes can have big consequences. ‘Koalaboi ‘ on Bushcraftoz.com told me that he found making “the very fine point at the tip is excruciatingly difficult!”. Up until now I have found that process relatively OK, until working this large point. A lot of time and effort is invested and then it becomes quite stressful because the tip is so thin. In relation to these needle type tips, not all examples have them and I suspect larger examples like this do not because they were used as knives. I have put one on this example but need to check the literature again. Anyway, right shape, method, retouch pretty invasive and similar to museum examples. This evening I am feeling pretty pleased with myself!

pleased-with-myself.jpg