Measure for measure - Sally Dugan

From the sub-atomic to the inter-galactic, we measure to bring order to a disorderly world, and this book offers the reader a longer, wider and deeper understanding of how and why things are measured.;The human body was once used as measuring tool - for example, as a guide to foot-lengths around the world. It was only after the original yardstick went up in flames with the Houses of Parliament in 1834 that the British could set about finding a standard set of lengths that everyone would agree on - apart from the French, who wanted to use the circumference of the earth to derive a unit of measurement, instead of the irregular human body.;The chapter on the metre explains how a platinum bar led to the electronic metre measured in wavelengths of radioactive krypton. A look at weights shows how the custodians of the original kilogramme called in the 40 copies and found that they were slightly heavier than the original. (Now nobody knows what the weight of a kilogramme should be, since there is nothing to check it against.) The confusing array of measurements includes the bushel of corn, which is different from a bushel of grain, and the teaspoon for recipes, which can be heaped or level.;Anders Celsius may have got the scale right, but he got it the wrong way round - he had water boiling at zero and freezing at 100. The section on the measurement of time tells of the huge prize offered by kings and queens in the 16th century, for the first accurate timepiece. Galileo, Newton and Halley failed, but a 21-year-old self-taught carpenter succeeded.