THREE more "Annotated Equilibrium Diagrams" have been published by the Institute of Metals. No. 2 deals with the copper-tin system, No. 3 with the copper-zinc alloys and No. 4 with the copper-aluminium. Prepared by Dr. G. V. Raynor, each sheet contains a large-scale diagram in its latest form, some notes upon it, and an extensive bibliography. At the almost nominal price of 6d. per sheet, they represent what is probably the best value attainable anywhere in metallurgical literature.