I've learn't a couple of things over the past few days.
1) My tools all need sharpening.

2) An interesting piece of wood does not necessarily make an interesting sculpture, be it a lamp or not.
Let me explain. Looking at the piece of wood before I put any major work into it one might think there is a fabulous sculpture to be eked out of it. There are lots of interesting nooks and crannies and some fabulous colours. The problem is, the sculpture is already made by nature and this limits to an extreme what one can do with it without destroying what attracted one to the piece in the first place. I've seen lots of 'interesting' pieces of wood like this called driftwood art on the net and in various arty type shops usually by the seaside somewhere. What is usually done is the piece of wood is dipped in acid to clean it and then sprayed with varnish. I would find it difficult to take much in the way of artistic credit or craftsmanship from doing this.
The fact is I've just got an interesting piece of wood and what I can do to it is pretty much what I've done so far. I could scrape out every section of the grey wood and fill with slate paste; I would still have an interesting piece of wood filled in with slate paste though.
This is how it started out.
This is how it is now.
Most of the section on the right was so badly cracked it had to be removed. Basically I've got the same piece of wood but less of it and maybe not as interesting after quite a lot of work. I will finish the back and sides and put it on a plinth but it is what it is and it isn't really a sculpture done by me.
To better appreciate the point I'm trying to make, the first picture is the piece of wood I started out with when I made Bob lamp. The second picture is the finished lamp. That is quite some transformation. Every surface was been worked and one would not recognise the original piece of wood as the lamp when completed.