Yesterday evening Nick Overton and myself had ourselves a marathon 4 hour knapping session. I was interested in making two more points from the remaining Camp Coffee preforms and whilst doing so we had some stimulating conversation about the nature of retouch. It has been a theme in this blog that I seem to struggle to replicate the character of the retouch seen on the museum pieces. By the time I got to my last point I think I recognised why. I produced my four points and as can be seen from the photographs below it has made a really nice narrative sequence. Finding the period material; using a stone to make the preforms; using the preforms to make the points.
Nick is using a different Bombay Sapphire bottle glass and is focusing upon getting a series of fully invasive removals on his first sweep. To achieve this he is taking very ‘flat’ removals off the surface of the glass by placing his pressure flaker close to the top of the platform and pushing straight in. He then uses his knee to provide the transverse force necessary to remove the flake, like this. Although my pressure flaking method is different I am doing something similar, in that we are ending up with similar results. On my last point I started to place my pressure flaker lower on the platform and changed the angle of pressure. This allowed me to work in a more systematic and aggressive manner punching off the removals. I started to get concavity on both ventral and dorsal surfaces and the final point is more similar in character to the museum examples. I am chasing a characteristic method of applying retouch, which in turn produces a characteristic feel to the finished piece. I think the thicker glass allows this kind of work. I am pleased with my nest of points all from the one half bottle. I am really pleased with this punchy approach to flake removal. The next one I think will be an experiment in platforms and pressure flaker angles.
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.
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.
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.
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 🙂
After quartering the Camp Coffee bottle yesterday I roughed out the first Kimberley Point. This morning I finished it (I think).
The ASGO are useful landmarks for recognising how much material has been lost.
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.
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.
This gave me confidence and I continued working along the remaining longitudinal edges. Voila, bottle quartered into four usable blanks using a small hammerstone.
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.