Anyone who has ever been flummoxed by measuring systems will take pleasure in About the Size of it.

Author Warwick Cairns explains why humans stick stubbornly to ways of measuring and weighing even as the world around them changes. His book sums up 10 years of research, which included polls conducted in Britain to gauge public opinion on the subject. That led to his being an 'expert witness' called to explain why traders taken to court for selling bananas by the pound should be allowed to continue doing so. One reason for this unit's popularity, he says, is that 'a pound is about as much as you can comfortably hold in one hand'. For liquids the pound became a pint - about four full mouths full, or what you can fit in your bladder. Readers will have to take Cairns' word for certain things, although much in this entertaining book can be verified by observation. We have the foot because 75 per cent of men take a size 8, 9 or 10 shoe (in the west anyway), the sole of which is about a foot long. An inch, he adds, is about the width of a thumb - which perhaps explains why pipes in many countries are about an inch in diameter: you can use your thumb to stop the water.