Forging a Propeller Shaft.--How large steamer shafts are forged, with example of the operation as exhibited to the Shah of Persia at Brown & Co.'s works, Sheffield, England.--1 illustration. 11447 The Naval Forges and Steel Works at St. Chamond.--The forging of a piece of ordnance from a 90 ton ingot of steel, an artistic presentation of the subject.--1 illustration. 11447 VI. PHOTOGRAPHY.--The Pyro Developer with Metabisulphite of Potash.--By Dr. J. M. EDER.--A new addition to the pyro developer, with formulae and results. 11462 VII. PHYSICS.--Quartz Fibers.--A lecture by Mr. C. V. BOYS on his famous experiments of the production of microscopic fibers, with enlarged illustrations of the same, and a graphic account of the entire subject.--7 illustrations. 11452 The Modern Theory of Light.--By Prof. OLIVER LODGE.--An abstract of a lecture by the eminent investigator and expositor of Prof. Hertz's experiments, giving a brief review of the present aspect of this absorbing question. 11459 VIII. PHYSIOLOGY.--Heat in Man.--Experiments recently made by Dr. Loewy on the heat of the human system.--Described and commented on by Prof. ZUNTZ. 11461 IX. SANITATION.--On Purification of Air by Ozone--with an Account of a New Method.--By Dr. B. W. RICHARDSON.--A very important subject treated in full, giving the past attempts in the utilization of ozone and a method now available. 11460 X. TECHNOLOGY.--Alkali Manufactories.--Present aspect of the Leblanc process and the new process for the recovery of sulphur from its waste. 11457 Dried Wine Grapes.--The preparation of the above wine on a large scale in California, with full details of the process adopted. 11461 The Production of Ammonia from Coal.--By LUDWIG MOND.--A valuable review of this important industry, with actual working results obtained in carrying out a retort process.--2 illustrations. 11454 Nature, Composition, and Treatment of Animal and Vegetable Fabrics.--The history of fabrics and fibers in the vegetable and animal world, their sources, applications, and treatments. 11453 Walnut Oil.--By Thomas T. P. BRUCE WARREN.--An excellent oil for painters' use, with description of a simple method for preparing it on a small scale. 11462 * * * * * THE NAVAL FORGES AND STEEL WORKS AT ST. CHAMOND.