How do I measure up?

Arms, feet, local stones and even barleycorn have all played a part in our bid to quantify the world, discovers Ben Lerwill, as he weighs up the stories behind how units of measurement were standardised

- Ben Lerwill

IMAGINE, for a moment, a world without measurements. No miles or kilometres; no grams or ounces; no inches, litres, fathoms or furlongs. A world where height, weight, depth, volume, area and length are essentially incalculable. The thought seems faintly ludicrous. Our current units of measurement have become so ingrained in daily life that they almost seem to have existed since the dawn of time. But not only is each one the product of human invention, each one also has a story behind it.

This is the central premise behind The Curious History of Weights & Measures, a new book by author Claire Cock-Starkey. It tells the tale of how we've used measurements to impose order onto the world around us. Nautical miles, altimeters, measuring jugs, those little increments on old grocers' scales: all of these have helped us to quantify the vague, as have even more obscure units, from wool weights to shoe sizes, from horsepower to light years and from pottles (half a gallon) to oxgangs (an area of land that can be ploughed in a day)-yes, they were new to me, too.

It's a fascinating topic. Over the centuries, people have come up with all sorts of arcane measures, from the barleycorn-the length of a single grain of cultivated barley-to the ell, which was widely used in medieval northern Europe and was based on the length of a man's forearm and outstretched hand. In an era when we can now state with exactness how far away we are from the moon, they seem almost preposterously quaint.

'We now have concepts of these enormous distances,' states Mrs Cock-Starkey. 'Having things such as cars means we can travel so much further, and it's become so much more important that we can measure distance. In times gone by, you would jump on your horse and say "oh, it's a day's ride."