Depuis la dernière Assemblée générale, notre commission a eu le regret de perdre deux de ses membres les plus éminents: M. Paul Stroobant, directeur de l’Observatoire Royal de Belgique et M. W. H. Pickering, ancien directeur des succursales de l’Observatoire de Harvard à Arequipa (Pérou) et Mandeville (Jamaïque). Les recherches de M. Paul Stroobant se rapportent pour une grande partie aux planètes, notamment Mercure, Vénus, les petites planètes et Saturne dont il étudia pendant des années les anneaux. Il faisait partie de notre Union comme président de la 5e commission et membre de beaucoup d’autres.

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.

The following works embodying researches coming within the scope of this Commission have been published since the last meeting of the Union:

1. “Recherches sur la polarisation de la lumière des planètes et de quelques substances terrestres,” by B. Lyot, Annales de l’Observatoire de Paris, Section de Meudon, 3, Fase. i. Characteristic curves are found representing the fraction of light polarized in the case of the Moon and several of the planets for the angles Sun-Moon or planet-Earth and compared with curves obtained in the laboratory for light reflected by a number of terrestrial substances. Some of the conclusions arrived at are referred to in the notes below.

2. La Planète Mars 1656-1929, by E. M. Antoniadi. This is based mainly on the author’s own telescopic observations with the 0.83 m. Meudon refractor in 1909 and the following years, and contains the author’s conclusions therefrom. The work of numerous earlier and contemporary observers is also summarized and compared with the Meudon observations.

3. The Moon, by W. Goodacre. Contains a description of the lunar surface formations, numerous drawings, charts and photographs, and the author’s revised Map of the Moon in 25 sections.

4. “Ricerche Polarigrafiche sui Pianeti. La Polarizzazione sul Disco di Giove,” by M. Maggini, Mem. della Soc. Astron. Italiana, 4.

5. La Constitution des Comètes, by F. Baldet. Paris, Hermann et Cie. 1930.

6. “ Halley’s Comet in its Apparition of 1909-1911,” by Nicholas T. Bobrovnikoff, Pub. of the Lick Observatory, 17, pt 11, 1931.

7. “Absorptionsspektren und Atmosphären der grossen Planeten,” by R. Wildt, Nach, von der Gesellschaft der Wissenschaften zu Göttingen, Math.-Phys. Klasse, 1932.