Got to source a Log..!?

So over the past few days I have been toying with the idea I had of using the shards of clay as elements of a 'negative shadow' in white on a black floor. I would have some kind of black positive element standing. I did think of a standing log and I have been looking around the local common land to find one since there has been a lot of felling. Nothing has the right diameter. I then realised that they are not all that straight in any given length.

The reasoning behind this is that I thought I could burn the log and get a black 'image' from a material from which the shadow had been created.