How do we measure time, and where does it come from? How do clocks work - and what happened before they were invented? Find out the fascinating answers inside. * Ruby/Band 14 books give increasing opportunities for children to develop their skills of inference and deduction. * Text type - An information book. * The book is organised into short chapters to help children practise the skills of locating and identifying important information. * The glossary and index on page 44 can be used to develop children's information retrieval skills further. * Curriculum links - Mathematics - measurement; History -chronological understanding