The following work embodying researches coming within the scope of this commission has been published since the last meeting of the Union: La Planète Mercure et la Rotation des Satellites, by E. M. Antoniadi; Gauthier-Villars, Paris.

In addition to references to the work of other astronomers the author gives a summary of his own observations with the 0.83 m. refractor at Meudon and his conclusions.

The following Memoirs or papers not specifically referred to in the body of the Report have also been published since the last meeting of the Union: Cometa Halley. Vol. xxv of Resultados del Observatorio Nacional Argentino. This is a monograph on the Comet at its 1910 return. By C. D. Perrine. Les Comètes en 1930,1931 et 1932. By F. Baldet. (L’ Astronomie 46,497 et 48,175.) I Fondamenti Psicologici dell’ Indagine Visuale. By M. Maggini. (Memorie dellaSoc. Astron. Italiana, Vol. VIII, 2.) Théorie Photométrique des Eclipses de Lune. By F. M. Link. (Bulletin Astronomique,

8 fase. 11.) Relative Lunar Heights and Topography by means of the Motion Picture Negative.