THE report of the Laboratory for the year 1934 is a well-illustrated and indexed quarto volume of 260 pages. Each of the eight departments of the Laboratory gives a short account of its principal activities in an interesting and thoroughly readable form. The increase in activity in industry has produced a corresponding increase in the work carried out by the Laboratory, particularly in that relating to shipbuilding, and it has been necessary to call for overtime and to increase the staff. The movement for the abatement of noise has resulted in demands on the Sound Department from the Ministries of Health and of Transport. The deaths of Sir Arthur Schuster, Sir Horace Lamb, Sir Alfred Ewing and Dr. W. Rosenhain have deprived the Laboratory of four of its friends and supporters, but the changes of staff have been slight. The lectures on the work of the Laboratory given at a number of provincial centres have been much appreciated, and are to be continued. The new buildings for photometry will probably be brought into use this year, new high-speed wind tunnels are already in operation and the Lithgow installation for testing propeller blades will be available next year. The comparison of standards of measurement of all kinds with those of other countries has been continued with satisfactory results. The sound-isolating properties of walls and partitions of many types have been investigated and field tests of actual buildings can now be carried out. The work on refrigeration and preservation of food of all kinds has been continued for the Food Investigation Board, and that on protection from and dosage of X-rays and radium, for the Medical Research Council. The lubricating value of the oils derived from the distillation of coal is being investigated, and the production and working of the extremely light alloys of magnesium are being tested. Rapid advances are being made in our knowledge of the structure of the ionosphere, on which so many of the phenomena of wireless communication depend.