No. 345: Merill, P. W. Measurements of wave lengths in the spectra of Krypton and Xenon. No. 349: Gison, K.S. Photoelectric spectrophotometry ba the null method. No. 385: Meggers, W. F. u. P. D. Foote. A new microphotometer for photographic densities. No. 411: Walters, F. M. Walters. Wave-length measurements in arc spectra photographed in the yellow, red, and infra-red. No. 421: Kiess, C.C. Wave lengths longer than 5500 a in the arc spectra of Yttrium, Lanthanum, and Cerium and the preparation of pure rare earth elements. No. 422: Walters, F. M. u. R.Davis. Studies in color sensitive photographic plates and methods of sensitizing by bathing. No. 425: Mohler, F. L. u. P. D. Foote. Characterisitc soft X-rays from arcs in gases and vapors. No. 439: Davis, R. u. F.M. Walters. Sensitometry of photographic emulsions and a survey of the characteristics of plates and films of American manufacture. No. 441: Meggers, W.F. u. K. Burns. Notes on standard wave lengths spectrographs, and spectrum tubes. Np. 444: Meggers, W. F. u.a. Practical spectrographic analysis. No. 454: Davis, R. Action of charred paper on the photographic plate and a method of deciphering charred records. No. 466: Kiess, C. Wave length measurements in the arc spectra of Gadolinium and Dysprosium. – In Englisch.