Astronomy is experiencing a golden age, with a new generation of innovative telescopes yielding a flood of information on the Universe. This book traces the development of telescopes from Galileo to the present day, and explains the basic principles of telescopes that operate in different parts of electromagnetic spectrum. Nobody could have done a better job than Graham Smith in presenting such a balanced and clear survey of telescopes in all wavebands, and setting them in a historical context. His book will be appreciated by all astronomers.