Mancunian exotica

As is usual here in Manchester, the weather has been absolutely fantastic. Consequently I have been outdoors a lot and the dog and myself spent an hour or so having a root around Chorlton Ees. I am still amazed at the amount of treasure there is to find just lying on the surface.

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Some material has been unearthed by burrowing animals, and some has just been lying around for many decades. I was particularly pleased coming home with a carrier bag full of 1900s thick broken bottle bases. This glut of material reminded me that I am indebted to three people and I have not made any effort yet to repay their kindness. It would seem that now is the time.

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This Kimberley point, or more accurately Mancunian point is made from the flat piece of glass on the left. A scratch on the surface caused a little step fracturing but ultimately it was no problem.

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I am really loving flint knapping at the moment and I have lots of material to play with. The sun coming out is just the icing on the cake and if it stays like this I can look forward to getting the other two done in the next day or so. In the meantime I will enjoy posting this one off tomorrow morning.

 

 

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Kim Akerman makes a Kimberley point

I have mentioned a few times that Kim Akerman is the preeminent scholar when it comes to these points, and that he has been very helpful in my research. He has kept in touch and answered some of my questions on the production process that have been sticking points for me. This post is his response to a couple of my general questions, about the correct order of work, and invasive flaking without losing too much width. To illustrate he produced a point and recorded the process. This post will be lengthy, but informative if this is a subject of interest. This body text is my interpretation, the photos with text are his explanations.

 

 

This is the piece of water worn period glass that Kim started with. We had discussed the differing ways of establishing a platform and this was the issue he dealt with first of all.

 

 

He used the margin of the convex outer surface as a natural platform and a small hard hammer along one edge, and a pressure flaker along the second to begin invasive flaking. As can be seen both methods achieved similar results.

 

 

He then continued to take more invasive flakes and establish in his mind the shape of the point he was aiming for. All this flaking was aimed at flattening the inner concave surface of the glass.

 

 

Here we can see that whilst the inner concave face is now heavily worked and being flattened, the outer convex face is as yet un-flaked. Shaping in plan has also begun.

 

 

5c. Lateral edge showing unifacial pressure flaking on interior concave faceSame story in that the concave inner surface is now almost completely flaked apart from an intermittent central ridge of original surface. Kim has a problem with this later. The curved outer surface still remains un-flaked and you can see the edge of the original outer glass surface curving up at the forefront of the photo.

 

 

And at this point flaking of the easier convex outer surface begins. What follows is a process of flaking and shaping to achieve the approximate form required.

 

 

At the above stage the easier to flake curved outer surface is used only to create platforms so that invasive flakes can be removed from (what was) the curved inner surface. The aim here was to remove the intermittent central ridge of original surface that remained on the inner face.

9b. Removal of margin by overshot flake

The aim was to get flakes to penetrate across the centre in order to remove the problematic ridge and it is at this stage that a flake overshoots and takes off too much material.

 

 

the central ridge has been removed and the task now is to bring the reduced piece back into shape, and this is done by working both faces.

11a. Final form. Concave face

11b. Final form Convex face.

This is the end result, what Kim calls a rose-leaf shaped point. I commented in the previous post how my points need to be called ‘Manchester’ points. I think this is not the case for Kim’s. He was trained by aboriginals, uses the same bodily methods, materials, tools and reduction sequences. When aboriginal tool making lapsed, Kim carried the process on, and I believe this is why he has gone to the trouble of sharing the process here. He cares about sharing this knowledge with other people who value it. Perhaps the process of sharing a valued knowledge was one part of what Kimberley points were about.

& Chicory Kimberley Point

And the process continues. I still do not like the Glasgow point, and all I can say really is that it doesn’t feel right. As so after playing with it for a while I decided to opt for an overtly plano-convex approach with my next attempt. The rationale behind this was to make the process simple. Rough out the shape by attacking one surface only. This would also create a platform all around the preform. I could then use this platform to punch out large flakes making the plano-convex cross section and giving the piece the characteristic look.

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For this second point I selected another blank from the Camp Coffee bottle, this one from the ‘& Chicory’ section. In theory the plano-convex approach would leave on the lettering.

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In practice, it didn’t. I like this point, although it is difficult to explain exactly why it looks and feels more correct. It is approximating a lens shaped profile, and I was able to be more confident in how I worked this piece. It may simply be that in plan this piece looks similar to the museum examples I have seen. All I can say is that I am pleased with it. The ‘&’ is a useful landmark to show how much material has been removed.

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Whilst it didn’t work out exactly as expected, I enjoyed the process of working through an idea. The emerging goal seems to be to get four points from the four blanks produced from the Patterson’s Coffee bottle. That would be a satisfying result 🙂

 

Glasgow Kimberley Point

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After quartering the Camp Coffee bottle yesterday I roughed out the first Kimberley Point. This morning I finished it (I think).

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The ASGO are useful landmarks for recognising how much material has been lost.

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However, I am not quite sure if I like it. It is not quite plano-convex, and not quite lens shaped. This is partly an artefact of design as I was aiming to keep on some of the lettering. However it also doesn’t have the consistent deep invasive removals that have characterised the museum points I have seen. It does have some, especially forming the tip, but not enough to give the overall impression that the museum pieces do. Perhaps it is not finished. Perhaps I need to handle and play with it for a while to know. I am pleased with the serrated edges for which I used a flattened end of a number eight wire. I will report the results of my deliberations…soonish.

Quartering a Patterson’s Camp Coffee bottle

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Yesterday we had a knapping session in the department lab. The above is an old Patterson’s Camp Coffee bottle base recovered from Chorlton Ees, and as can be seen, the glass is thick, uneven and with bubbles. Because of its square form I decided to try quartering it following the method described by Stanley Porteus (1931: 111-112) recorded after observing an aboriginal knapper producing blanks for Kimberley Points. The first step is to use a number eight wire to remove the base, and in this I was unsuccessful. The thickness of the base (~9mm) made it too strong, however during the process one of the side panels fractured nicely. I shifted to a small hard hammer and worked along the second longitudinal edge of of the fractured panel and I was able to remove it cleanly. Perhaps the subject of another post, but there were clear sonic signals as to how thick the glass was at each point, and I responded to that iteratively with the amount of ‘umf’ I applied.

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This gave me confidence and I continued working along the remaining longitudinal edges. Voila, bottle quartered into four usable blanks using a small hammerstone.

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I have tried this process before with a modern Bombay Sapphire bottle and it didn’t work. That I believe is because of the thickness of the glass being used. Like most modern glass bottles the Bombay Sapphire is well engineered presumably to optimise strength and minimise materials used, therefore weight. Consequently the Bombay Sapphire fractured unpredictably. The quality of the glass is everything here. Whilst the uneven thickness and bubbles on old glass present their own set of problems, the actual thickness provides some internal cohesion that makes it relatively forgiving to manipulation and modification. This suggests to me that Kimberley Points were ‘of their time’, in that the uneven thickness of early glass gave it qualities akin to a stone flake, and these were recognised as such by aboriginals. This similarity has diminished over time as glass has become more engineered. Aboriginals continued knapping materials such as Pyrex and window glass into the 1980s (Akerman pers. com.), and the methods would seem to have adapted as materials developed. Within this relatively short historical period a really interesting dialogue between human skilled practice and material development has played out. This was in tandem with an aboriginal recognition of the new qualities such as size, colour and transparency that could be marshalled into the traditional production process. In my own modest way I am, following in this tradition, and currently working on a ‘Glasgow’ Kimberley Point, which I am sure will be the subject of a post soon.

Porteus, S.D. 1931. The psychology of a primitive people. London. Butler and Tanner Ltd.

Karl Lee pressure flaking glass

This is a link to a short video of Karl Lee pressure flaking glass . It is of interest to me because it illustrates how he uses his knee “like a vice” to remove the flake. The large piece of glass was modern, and probably a table top. This is the end result.

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Manchester, rain, three Kimberley Points.

Today has been miserable in Manchester, an ideal day for being sat behind a desk, sorting out all those jobs that need doing. I found myself in the backyard, in the rain. I have been inspired since my visit to the museum earlier in the week, and think I am getting it. Consequently, I took three points made previously and reworked them, or refined them to bring them more in line with the museum examples.

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I know you shouldn’t have favourites, but it’s the middle one. Then the one on the right and then the one on the far left. I actually learned the most from working on the one on the far left, and then was able to apply that learning to the other two. Essentially my edge control is getting good. This is allowing me to get flatter points, and in turn serrate the margins more subtly.

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This is one of the museum examples with a broken tip, angled to show the degree of retouch. You can see how the flaking really penetrates up to half way in creating a ridge or spine.

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This is my version. Shape and size and margins are all good. The needle like tip is needle like, the area to improve is fully invasive retouch. It needs to penetrate further in. I therefore need to take a leaf out of Nick Overton’s book and sort that out on my first pass, then bingo!