Données numeriques de photographie: Redigeés par Dr. W. Clark, Eastman Kodak Company, Rochester, et L. P. Clerc, Faculté des Sciences, Paris. Extract from Volume VIII, 1927–1928, of the annual tables of constants and numerical data on chemistry, physics, biology and technology, published under the patronage of the International Council on Research and the International Union on Chemistry, pure and applied. xxi-32 pages, 22 × 28 cms., boards. Paris, Gauthier-Villars, and New York, McGraw-Hill Book Company. Inc.. 1012. Price $1.56