Thanks for the loggy bonfire tips.
After finding the space I planned for the bonfire to be smaller than I remembered and with shrubs closer than I would have liked I decided against the big flames Guy Fawkes teepee stylee approach and went for a modified version of Mark S's triangular slow burn. Three logs arranged as a triangle with one end on the ground and one end resting on the tail of the next in the triangle. I kept it small, kept feeding it and eventually the logs reduced. I've left it tonight with the tails of the logs turned around and all should be well so thanks to all who replied.
As an aside, I thought I would take a chainsaw in case it was needed so phoned up my normally excellent hire shop to ask how much. After asking him to repeat himself 3 times I said, "75quid, no hire for the day, not buy". This was blamed on them having to 'give' me all the gear and they also said I had to buy the chain, wot, nobody sharpens the chains anymore?
If anyone's looking for me I'm off to freecycle to find a chainsaw.
Btw: it was a 14" petrol if anyone's interested.