The original period covered by the convention, which brought the Union into existence, terminated on December 31, 1931. An extraordinary meeting of the General Assembly was held in London on September 19,1931, at which a set of new Statutes was approved for the period ending on December 31,1943. An account of this meeting and of the preliminary steps preceding it will be given later in this report.

At the meeting held at Leiden on July 13, 1928, the Union approved the recommendation of Commission 3 to adopt new boundaries for the constellations north of 12°·5 south declination, these boundaries being, in each case, hour circles or parallels of declination. The Union also approved of a grant to cover the cost of publishing an atlas showing these new boundaries. The boundaries were defined by Mr Delporte of the Uccle Observatory from whom this proposal originally came. Mr Delporte’s boundaries were carefully examined at Yale Observatory in order to make sure that no variable stars would have their designations changed, and that a minimum of stars having Baeyer or Flamsteed designations would be moved to other constellations. After making a few minor alterations on these accounts, Mr Delporte sent his manuscript to the General Secretary, under whose supervision the Cambridge University Press published, in 1930, a volume entitled, Délimitation Scientifique des Constellations. At the suggestion of the present writer this volume extends not merely to 12°·5 south declination, but from pole to pole. Gould had, for the most part, defined the southern constellations by hour circles and parallels; in the few cases where this had not been done, Mr Delporte revised the boundaries accordingly.

On July 31, 1930, Commission 3 reported that the names of two stars to which two names are commonly given had been settled. These two stars are:

They have been fixed as in Libra and Andromeda respectively. In accordance with the suggestion of the Secretary of the Union, this report was communicated to the Directors of the Nautical Almanacs, no objection being raised by the members of the Commission.

Dans la note qu’il a rédigée en vue de ce rapport, M. J. Mascart rappelle les résolutions prises à la réunion de Leyde en 1928 (Trans, of the I.A.U. 3, 1928, p. 300). Il signale qu’il a mis au point toutes les abréviations; pour les sources allemandes il est d’accord avec MM. Kopff et Neugebauer, ce résultat est d’autant plus important qu’en Allemagne il existe, pour les abréviations, une entente entre astronomes et physiciens. Mais il faudrait publier les abréviations et ensuite que les auteurs s’y conforment. En ce qui concerne les résolutions de Leyde, M. Mascart rappelle que (résolution 3) l’Union a conseillé aux auteurs de fournir eux-mêmes un bref résumé de leur travail, cet usage s’est développé mais n’est pas encore assez général.

From June 8, 1928 (date of the last report) up to the present date the Bureau has distributed 813 telegrams and published 175 circulars (Nos. 207-381). In two periods the number of telegrams and circulars has been particularly great: the Pluto- and comet-period in the spring of 1930 and the asteroid- and comet-period in the spring of 1932.

Again the Bureau has been supported by a great many colleagues and institutions.

As heretofore the leading principle in our work has been as far as possible to procure provisional data for the continuous observation of new objects. Following this line the telegraphic service has been used when necessary to secure new discoveries, while in all cases possible the circulars have been depended on. Thus, as before, in dubious cases we have to begin with sending a telegram to a few correspondents only, asking for control. In cases of rediscovery of periodic comets and in other cases, when there was no risk of losing the object, we have distributed the announcement through the circulars.

There do not appear to be at the present moment any problems in dynamical astronomy of which the solutions call for combined action and international organisation rather than private efforts of mathematicians. The only possible contents of a report of the commission under these circumstances would be a historical survey of the work done in the subject since the last meeting. I do not think that a review of this nature is the proper function of such a report. My conviction that the subject of dynamical astronomy does not at the present moment stand in need of international co-operation, has been strengthened by the fact that a circular letter sent to all members of the commission has elicited only two replies, one of which expressed doubt regarding the usefulness of international co-ordination of the subject, whilst the other intimated that the writer had no remarks to offer.

Since the last meeting of the International Astronomical Union, much attention has been given both in Germany and America to the systematic errors of the fundamental catalogues of Boss and Auwers. This is of special importance if the proper motions of any of the stars are to be used in the verification of the rotation in the plane of the Milky Way. The periodic errors in the proper motions, both in right ascension and declination, are of significance in this connection, while the motion of the equinox is required for the determination of precession, and the systematic correction to the proper motions of declination affects the position of the Solar Apex and the Vertices of the Star Streams.

Matériaux. La fabrication de grands disques de quartz a été poursuivie aux États-Unis; mais aucun résultat n’a encore été communiqué à la Commission.

Mlle Clavier, de l’Observatoire de Paris, a étudié des miroirs en acier inoxydable, taillés, polis optiquement et argentés. Deux points d’ordre chimique restaient à élucider pour rendre pratique l’emploi de cette matière: (a) l’argenture, qui ne donnait jamais de couches bien régulières et adhérentes; (b) l’enlèvement de l’argent terni, en vue d’une argenture nouvelle.

The president calls attention to the large and increasing membership of Commission 12 and the policy of concentrating in it all matters relating to the sun. The result makes it comparable in breadth of field and in membership to the former Union for Co-operation in Solar Research. The main point in favour of this policy is the increased interest in the meetings of the Commission and the larger number of individuals reached compared with the meetings of small committees. One recalls the general sessions of the Solar Union in which each one present felt himself a part of the Union and in real touch with the work of different sections and after the discussions went away with fuller knowledge of what it was all about. This was a valuable result not attained to the same degree from the general sessions of the present Union, but in a measure it does follow from the meetings of the Solar Physics Committee. On the other hand the question may be raised whether or not the merging of independent commissions into subdivisions of a large commission lessens their interest to an extent not balanced by the advantages. If the present policy holds, it seems to the president that a re-organisation of Commission 12 is advisable by which more responsibility is laid upon the directors of centres. The basis of membership in the Commission may well be considered and recommendations formulated for transmission to the Executive Committee.

In the 1928 report of this Commission, reference was made to differences in the specifications for the production of the red cadmium line adopted by the International Conference of Weights and Measures in 1927 and by the International Astronomical Union in 1925. The difference appears to have arisen mainly from the inadvertent adherence of the International Conference to the text of the provisional recommendation of the Commission on Wave-lengths (Tr. I.A.U. 2, 47) instead of to that finally adopted (p. 232).

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.

A sub-committee, consisting of Miss M. A. Blagg and Dr K. Müller, has been at work during the past twelve months on the preparation of a list of names and designations for the lunar formations. This work is practically complete but as it was received by the chairman as late as August 22 it has not been possible for him to do more than glance over it. This brief report by him is therefore merely a summary of their work and of the material which is ready for action by the Commission.

Les premiers mots de ce Rapport seront un souvenir ému à la mémoire de notre regretté Président, le Général Ferrie, brutalement arraché, en pleine activité physique et intellectuelle, au respect et à l’affection de tous, le 16 février 1932. Il fut l’instigateur et l’animateur des travaux auxquels se consacre notre Commission. Nous ne saurions lui rendre de plus bel hommage—celui-là même qu’il eut souhaité sans doute—qu’en nous attachant à poursuivre, dans la voie qu’il avait tracée en 1926 et qu’il avait commencé de prolonger en vue des opérations de 1933, la mise au point d’une entreprise de haute portée scientifique et qui était au tout premier plan de ses préoccupations.

The values given below are those published in every annual report of the international latitude work. Those for the first three years were calculated from the observed results in three stations, namely, Mizusawa, Carloforte and Ukiah, while that for the last year was from the results of four stations with one additional station, Kitab.

In accordance with suggestions made by members of the Commission further consideration of the following topics is proposed:

1. (1) Improvement of the present plan for distribution of observations and computations relating to minor planets and comets, with special reference to those which depart considerably from their ephemerides.

2. (2) Designation of a central bureau to supervise any accepted plan for coordination of observations and computations. It is suggested that separate bureaus be established for Minor Planets and for Comets.

3. (3) Systematic investigations of the orbits of the recently discovered objects designated as minor planets: Reinmuth 1932 HA, and Delporte 1932 EA1( and other objects of similar interest.

4. (4) Financing of proposals (2) and (3).

5. (5) Standard equinoxes as proposed by Comrie (1950.0) and by Bower (1900.0).

6. (6) Designation of published residuals as observed residuals rather than referring to the epoch of the comparison star.

7. (7) Greater adherence to the convention “That the dates used in giving the osculation epochs of elements for comets and minor planets shall be the midnight following an integral Julian date which is exactly divisible by 40, and for ephemerides, divisible by 8 (or 4, etc.),” to facilitate intercomparison of ephemerides and elements.

8. (8) Inauguration of complete residuals of comets, similar to those of minor planets with provision for their continuation.

9. (9) Inclusion in astronomical telegrams of some information of a descriptive nature to indicate the accuracy of the measured position, in confirmation of previous action.

10. (10) Greater emphasis on accurate rather than on approximate positions, particularly in (9), or preliminary orbits.

During the past four years the most important events in meteoric astronomy have been the good showers of the Leonids in 1930 and 1931. When these observations are added to the predictions based on computations of the perturbations, there is good reason to hope for an even better shower in 1932, perhaps rivalling that of 1866. As to the study of meteors in general, there has been an increasing revival of interest. Meteor Notes are now regular features of many scientific journals. Never before have so many people been working in this branch of science. A very brief outline of such activities follows.

Depuis le dernier Rapport, la Commission de la Carte du Ciel a été durement et douloureusement éprouvée par la mort imprévue de son eminent Président H. H. Turner. Il laisse parmi ses collègues de profonds et unanimes regrets.

Il s’était ardemment dévoué à ses fonctions de Président et, plus particulièrement, à l’achèvement du Catalogue photographique, auquel, sous sa direction, l’Observatoire de l’Université d’Oxford avait déjà pris une grande part. Sous son impulsion, et souvent avec le concours de son Observatoire, des Zones en retard avaient accompli d’importants progrès. Sa fin prématurée ne lui aura pas permis de voir le Catalogue terminé. Après comme avant la mort de Turner, la poursuite de ce but, qui lui était cher, demeure la tâche la plus urgente.

In November 1931 the President circulated a letter to the members of the Commission which in part was as follows:

In view of the fact that it is now over a quarter of a century since Schlesinger by photography began to determine trigonometric parallaxes by a long focus telescope, and fifteen years since Adams and Kohlschütter derived the first spectroscopic parallaxes, it would seem appropriate to take stock of our present position and to make plans for future development.

Will you be good enough, therefore, to furnish such statements concerning the following topics as are appropriate to the work of your observatory?

Much material extending our knowledge of stellar magnitudes has accumulated during the last four years. In the appendix to this report will be found a list of recent catalogues, a summary of the discussion made at Mt Wilson by Seares and the formulae that he finds for the reduction of these catalogues to a fundamental system, until such time as a more extended discussion shall have furnished definitive corrections.