Much progress has been made since the last meeting of the Union in the measurement and reduction of photographic plates and in the reduction of micrometric observations obtained near the opposition of Eros, 1930-31. The reduction of photographs and measures which are dependent upon positions of secondary comparison stars have had necessarily to be postponed until the positions of these ‘stars are available. In this report, the present position of the investigations is summarized.

1. Reference Stars, (a) Primary. The positions of these stars, based on meridian observations at several observatories, were published by A. Kopff, H. Nowacki and F. Gondolatsch in Ast. Nach. 241, Nos. 5781-2 and 244, Nos. 5852-3. The reduction of series of path plates, taken for the purpose of providing positions of secondary reference stars, and of series of Eros plates obtained with telescopes of astrographic focal length have shown that the positions of some of these stars are considerably in error. As is to be expected in view of their smaller average weight, the largest discordances are in the positions of some of the southern stars.