It is one hundred years since Wilhelm Rontgen first discovered x-rays in Wurzburg on 8 November 1895. Rontgen's discovery revolutionised many areas of 20th century science, not just medicine. While everybody knows of the uses of x-rays in medicine and dentistry, and in security checks at airports, and while the space age will have drawn the attention of many to x-ray astronomy, most people are still unaware of the wide ranging applications of x-rays. The centenary of their discovery presents an opportunity for this to be redressed. The book has been written by eminent scientists connected with the production and use of x-rays. Their contributions give an historical flavour as well as discussing modern, up-to-date, techniques and applications. All the important areas of x-ray science and technology are described, ranging from medical applications, through various types of x-ray analysis such as diffraction, spectroscopy and microscopy, to x-ray lithography and astronomy, including the development of modern x-ray sources. The book concludes with a look ahead to the next hundred years.