Students and professionals alike have long felt the need of a modern source of practical advice on the use of optical tools in scientific research. Walter T. Welford's Useful Optics meets this need. Welford offers a succinct review of principles basic to the construction and use of optics in physics. His lucid explanations and clear illustrations will particularly help those whose interests lie in other areas but who nevertheless must understand enough about optics to create the experimental apparatus necessary to their research. Consistently emphasizing applications and practical points of design, Welford covers a host of topics: mirrors and prisms, optical materials, aberration, the limits of image formation and resolution, illumination for image-forming systems, laser beams, interference and interferometry, detectors and light sources, holography, and more. The final chapter deals with putting together an experimental optics system. Many areas of the physical sciences and engineering increasingly demand an appreciation of optics. Welford's Useful Optics will prove indispensable to any researcher trying to develop and use effective optical apparatus. Walter T. Welford (1916-1990) was professor of physics at Imperial College of Science, Technology and Medicine from 1951 until his death. He was a Fellow of the Royal Society and of the Optical Society of America.