So some of the continuity has been lost in this process due to situations out of my control, but picking up where I left off with this element of the work. I now have clays to work with for testing along with the elements of organic material. I need to fire the clay to two temperatures to see what happens. some at a low temperature firing or bisque earthenware as this may be the type of clay that I have prepared or it may be stoneware clay at maturity. One at 1000'c the others at 1230'c. this doesn't sound like a big difference but it is enough to melt an earthenware clay out of recognition and I currently don't know what these clays are.
Here are the clays with organic materials in.
These are the clays used either as a slip or a body clay showing marks for measuring proportional shrinkage after firing.
1) the Swardeston clay is really sandy so i mixed it 50/50 with stoneware clay as this can be underfired. I have added a slip of Derbyshire clay over the top 2) this is Swardeston clay and stoneware 3) this is pure un-sieved Derbyshire clay