just to mention bricks come out of very very hot ovens,especially engineering bricks! i wouldnt worry about putting them on a flame,its stones that can be dangerous.no pics of the burner,i made one from an extinguisher about the same size as you'd see in a garage,i've also used air tanks off lorries and basically any metal chamber of reasonable thickness that i can put a door on the front and a flue on the top.the burner can be within an inch or so of any woodwork if done right.funniest i saw was a desperately poor guy in a van with no way of buying diesel to escape had hacked a hole in an old electric cooker,put a bit of ventilation duct in for a flue and the oven was the burner.smoky and dangerous but kept him warm!