Like for its three predecessors, the purpose of this fourth edition is chiefly to help physicists, physical chemists, materials scientists, metallurgists, engineers, and biologists to carry out investigations at low temperatures. This new edition takes into account the major changes in cryogenic technology over the past twenty years. These changes include areas of temperature measurement and control, superconducting magnets, cryocoolers, ultra-low temperatures, technical data on materials, commercially available cryostats for optical, x-ray, thermal and electrical measurements. Less emphasis is now placed on methods of constructing cryostats in the laboratory and more emphasis on commercially available cryostats, temperature controllers, and closed circuit cryocoolers. The book contains comprehensive, up-to-date tables of physical property data on metals, polymers, and ceramics. It will be of value to graduate students as well as to engineers and biologists facing cryogenic\nproblems.