A unique compendium of information from the world of measures and conversions, now reissued in a new flexibinding This Collins Gem is being reissued in flexibinding, providing the durability of a hardback with the flexibility of a paperback. The stylish new cover design will enliven this and 70 other bestselling Gems. Measurements are used to help establish the size of something, to answer such questions as 'How heavy?', 'How long?' or 'How far away?' Many standards of measurements have been developed, and to these the Collins Gem Ready Reference provides a useful guide. We use many measures to help define length, area, volume, weight, energy, temperature, time and speed: all these subjects are covered. * Over 120 conversion tables are included, along with guidance both on quick and accurate conversions between different measurement systems. * A wide range of practical measures are also included, such as clothing sizes, paper sizes and time zones. * Key information on numbers, geometry, astronomy and the Earth are provided. Whether you wish to know about a joule or a chain, an elephant or a grain, this Gem should measure up to your needs.