Jena Glass. By Hovestadt, translated by J. D. and A. Everett. Contains a full account of the scientific work on glass and its practical application, done in connection with the Jena Works of Schott. Particularly interesting in connection with the subjects of Chapters I., II., XII., and XIII. As the title indicates, the book is written from the Jena point of view, and scarcely does justice to work done elsewhere. The book has gained considerably at the hands of the translators. Some Properties of Glass. By W. Rosenhain. (Transactions of the Optical Society of London, 1903.) Gives a brief account of the properties of glass as affecting its optical uses. Possible Directions of Progress in Optical Glass. By W. Rosenhain. (Proceedings of the Optical Convention, London, 1905.) Has been referred to in the text of this book (Chapter XII.). Catalogue of the Optical Convention Exhibition, London, 1905. Contains historical and general notices of optical and lighthouse glass, glass-working machinery, etc. Glass for Optical Instruments. By R. T. Glazebrook. (Cantor Lectures to the Society of Arts.) Gives an account of modern optical glass manufacture. Old English Glasses. By Albert Hartshorne. Gives an account of the history of glass-making in England. The Methods of Glass Blowing. By W. Shenstone. Describes the manipulation of glass-blowing for experimental purposes, _i.e._, lamp work. _French Books on Glass Manufacture._ Guide du Verrier. By G. Bontemps. A classical work by one of the greatest experts of his day. Much of the contents of the book is, however, entirely out of date at the present time. The book is interesting as being the work of the man who introduced optical glass manufacture into England. Verres et Emaux. By L. Coffignal. Chiefly of interest in connection with the subjects of Chapter VIII. Le Verre et le Crystal. By J. Henrivaux. (P. Vicq Dunod et Cie., Paris.) A lengthy book profusely illustrated and giving a great wealth of detailed information. The writer was for some time the general manager of one of the largest plate-glass manufactories in Europe; his account of plate-glass manufacture is, therefore, especially valuable. Much space in this book is devoted to historical and æsthetical matter. La Verrerie au XX^{ieme} Siècle. By J. Henrivaux. (Paris, R. Bernard et Cie., 1903.) Practically a supplement to the preceding; some of the processes and products described are, however, not of a practical nature. Chiefly valuable for recent developments in plate-glass and bottle-glass manufacture. _German Books on Glass Manufacture._ Die Glasfabrikation. By R. Gerner. (A. Hartleben’s Verlag, Vienna and Leipzig, 1897.) A concise and clear account of most of the more important processes of glass manufacture. Very practical in character. The information given appears to be reliable, although far from complete.