Neolithic Milk of Magnesia interlude.

I had the opportunity to have a wander around Chorlton Ees one morning last week and came home with quite a few pieces of old glass recovered from the roots of fallen trees.

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This lovely blue piece in particular caught my eye and I like to think it is the base of an old Milk of Magnesia bottle.

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As you can see it is chunky and I wasn’t quite sure how well I could reduce it. This is because it is both narrow and thick and I was worried that I may run out of width before it was adequately thinned. Anyway, today has been a beautiful day here in Manchester and I got to spend a couple of hours outside playing with it.

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I am pleased with the result. It has become a Neolithic leaf shaped arrowhead, similar in proportion to some of the stone examples I have seen. The edges are sharp, the tip is good and it is fairly symmetrical.  What really makes it stand out though is the lovely blue colour. When Nick Overton sees this photograph he will immediately focus upon the very, very small section of original surface left in the middle. All I can say Nick, is: “when a pickpocket meets a saint, all he sees is pockets!”.

 

A test run for the Ishi Stick, and a ‘tough break’

Since getting together with John, Rob and a few others for our regular knapping sessions, pressure flaking has become a bit of an obsession for me-in particular, working pre-cut glass slabs into points of various sizes.  Key to this is taking a good first set of pressure flakes, to remove all of the original surface-an end result that is ‘fully invasive’ has become somewhat of a holy grail for me over the last few weeks. To that end, I decided to make an Ishi stick out of a chair leg John donated-a number of the knappers on youtube, including palaeomanjim, seem to use them for their larger pressure flake removals, and the general idea is the longer handle allows more power to be applied, thus removing longer flakes.

The construction of the Ishi stick is very similar to the Ishi style pressure flakers John discussed a few posts ago-I split the lower part of the chair leg, cut a groove for the nail, and carved a collar to locate the copper cap, and another recessed section, which I bound with string to secure the whole thing. Initial attempts to use the Ishi stick were a little shaky, and overall it felt a little odd, as the long handle runs up the forearm and braces the wrist.  However, once used to it, it allowed a more controlled application of power, and resulted in some excellent long pressure flakes.

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Detail of the Ishi stick at the business end

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The Ishi stick (top) and the Ishi style pressure flaker

However, as the often uttered phrase goes, with great power, comes great responsibility.  In this case, a responsibility to pick the correct platforms, and a responsibility to control the removal process and avoid unnecessary force.  On this first outing of the Ishi stick, it was a lesson I learnt the hard way, breaking every piece I started. But, there is a lesson to learn in every mistake-on reflection, all of the breakages occurred at the same point in the point-making process. I had successfully removed the plate glass surface with the first pass of pressure flaking using the Ishi stick, and I had returned to take a second set off, using the high spots left in between the pressure flake scars taken in the first pass as platforms. I used both the Ishi stick, and the Ishi style pressure flaker for this stage on different pieces, but both resulted in the piece ending in two bits.

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Good invasive removals from the blank, but both broke in the middle

At this moment in time, I have yet to decide whether this is because I am putting too much force into this second set of removals, because my technique is exerting too much ‘bending’ force on the piece (exerting a force along the axis of its thickness, as opposed to across its width), or whether the pad I am using for pressure flaking, with a groove to allow a free pressure flake removal, is not offering enough support.

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My pressure flaking pad and one of the broken pieces. Is the groove in the pad too big to support a piece this size?

So our next knapping session on Thursday will see a new three-fold approach: 1) Removal of the first set of flakes using the Ishi stick and pressure flaker pad. 2) Good platform preparation (or re-preparation). 3) Removal of second set of pressure flakes using the Ishi style pressure flaker, and a new pressure flaking pad with a smaller groove, so as to offer extra support.

As John said at the end of his last post, I am sure we will be making a few more of these-for me, it’s fully invasive or bust!

First Ishi point.

I am very interested in the story of Ishi, not just from a lithic technology perspective, but also the tragedy of it. For anyone else interested there is a documentary on Youtube, Ishi, The Last Yahi. In our knapping session tonight we had an Ishi focus, Nick has made an Ishi stick, which he tested out (I will get him to post about this), I used my Ishi style flaker to make a point. For the later part of his life Ishi lived and worked (as a ‘Stone Age remnant’) within the University of California, Berkeley, Museum of Anthropology demonstrating his Stone Age skills to the public. He adapted to new materials and used a glass cutter to produce blanks, and nails within his pressure flaker. This is my first attempt at this kind of point. It is made on a flat slab of fishtank glass supplied by Rob Howarth. The size, and retouch has worked well, but I ran into problems with the notching. I am thinking that another nail, filed to a very thin point might work better. If I do this I can fit it onto the other end of my flaker.

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I think I will be making a few more of these.

 

The R&D department has been working overtime.

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Innovation update. This morning I popped into Hillcourt Street Cycles and they kindly gave me two old inner-tubes from a racing bike. I suspected they would fit and I was correct. This section of inner tube serves to hold the two sections of bean pole together thus making the second copper end piece redundant. As the bike shop has to pay to dispose of the inner tubes they are free. This means that material production costs have been slashed by 70p, a phenomenal 28% (I think?). Unfortunately, these savings cannot be passed on to the consumer due to the overtime costs incurred by the Research and Development department 🙂

Making an ‘Ishi’ type pressure flaker.

Ishi was a Native American from who much of our understanding of the practicalities of pressure flaking has been gleaned. Within our twice weekly knapping sessions Nick Overton has raised the bar by introducing the use of soft iron nail pressure flakers, similar to those used by Ishi. This is a version of the same with a replaceable point. It is easy to make with total material costs of less than £2.50. Tools needed are a saw, chisel, hammer, large nail and a gimlet. Time wise it takes about half as hour. Materials needed are a bean pole (22mm wide, 75p), two copper end pieces (internal width 22mm, £1.40), one cut flooring nail (60mm long, can’t remember how much, they come in bags of about 20).

1. Use the saw to cut a section of the bean pole to a length that will be comfortable in your hand (perhaps 140mm). Then use the hammer and chisel to split it in half.

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2. Use the cut flooring nail to gouge out a groove on both pieces to fit the nail, and then use the gimlet to bore a small hole on one side to accommodate the head of the nail. Then insert the nail.

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3. Put both pieces together and modify to make a tight fit.

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4. Use the hammer and large nail to punch a hole in one of the copper end pieces and insert it over the nail to hold the pieces of bean pole together.

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5. Stick the second end piece on the other end. These two pieces need to be tight and so some trimming or padding may be needed. When finished the nail needs to be filed to a point and when used, kept sharp. The main benefit of this design is that as the nail gets filed down it can be replaced easily with a new one. When you make one of these, by default you have to then start making Ishi Points. Perhaps that will be the next post!

A second point from the second preform.

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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

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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.

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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.